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988f1f576d
linux/fs/btrfs/inode.c
Chris Mason 988f1f576d Merge branch 'for-chris-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.5 
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-11 08:39:28 -08:00

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/mount.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "volumes.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "inode-map.h"
#include "backref.h"
#include "hash.h"
#include "props.h"
#include "qgroup.h"
struct btrfs_iget_args {
struct btrfs_key *location;
struct btrfs_root *root;
};
struct btrfs_dio_data {
u64 outstanding_extents;
u64 reserve;
u64 unsubmitted_oe_range_start;
u64 unsubmitted_oe_range_end;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_dir_ro_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct address_space_operations btrfs_symlink_aops;
static const struct file_operations btrfs_dir_file_operations;
static const struct extent_io_ops btrfs_extent_io_ops;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_path_cachep;
struct kmem_cache *btrfs_free_space_cachep;
#define S_SHIFT 12
static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
[S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
[S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
[S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
[S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
[S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
[S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
};
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct inode *inode);
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock);
static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
u64 len, u64 orig_start,
u64 block_start, u64 block_len,
u64 orig_block_len, u64 ram_bytes,
int type);
static int btrfs_dirty_inode(struct inode *inode);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_inode_set_ops(struct inode *inode)
{
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
#endif
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path, int extent_inserted,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int err = 0;
int ret;
size_t cur_size = size;
unsigned long offset;
if (compressed_size && compressed_pages)
cur_size = compressed_size;
inode_add_bytes(inode, size);
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(inode);
key.offset = start;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (ret) {
err = ret;
goto fail;
}
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_CACHE_SIZE);
kaddr = kmap_atomic(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->i_mapping,
start >> PAGE_CACHE_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page);
offset = start & (PAGE_CACHE_SIZE - 1);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr);
page_cache_release(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
ret = btrfs_update_inode(trans, root, inode);
return ret;
fail:
return err;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct btrfs_root *root,
struct inode *inode, u64 start,
u64 end, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_trans_handle *trans;
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = ALIGN(end, root->sectorsize);
u64 data_len = inline_len;
int ret;
struct btrfs_path *path;
int extent_inserted = 0;
u32 extent_item_size;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end > PAGE_CACHE_SIZE ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
(!compressed_size &&
(actual_end & (root->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > root->fs_info->max_inline) {
return 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
if (compressed_size && compressed_pages)
extent_item_size = btrfs_file_extent_calc_inline_size(
compressed_size);
else
extent_item_size = btrfs_file_extent_calc_inline_size(
inline_len);
ret = __btrfs_drop_extents(trans, root, inode, path,
start, aligned_end, NULL,
1, 1, extent_item_size, &extent_inserted);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, path, extent_inserted,
root, inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, root, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
btrfs_delalloc_release_metadata(inode, end + 1 - start);
btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
return ret;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_cow {
struct inode *inode;
struct btrfs_root *root;
struct page *locked_page;
u64 start;
u64 end;
struct list_head extents;
struct btrfs_work work;
};
static noinline int add_async_extent(struct async_cow *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent); /* -ENOMEM */
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
static inline int inode_need_compress(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
/* force compress */
if (btrfs_test_opt(root, FORCE_COMPRESS))
return 1;
/* bad compression ratios */
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(root, COMPRESS) ||
BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
BTRFS_I(inode)->force_compress)
return 1;
return 0;
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that the flusher thread sent them
* down.
*/
static noinline void compress_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end,
struct async_cow *async_cow,
int *num_added)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 num_bytes;
u64 blocksize = root->sectorsize;
u64 actual_end;
u64 isize = i_size_read(inode);
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long nr_pages_ret = 0;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
unsigned long max_compressed = SZ_128K;
unsigned long max_uncompressed = SZ_128K;
int i;
int will_compress;
int compress_type = root->fs_info->compress_type;
int redirty = 0;
/* if this is a small write inside eof, kick off a defrag */
if ((end - start + 1) < SZ_16K &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
actual_end = min_t(u64, isize, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/*
* skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it dosen't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
goto cleanup_and_bail_uncompressed;
/* we want to make sure that amount of ram required to uncompress
* an extent is reasonable, so we limit the total size in ram
* of a compressed extent to 128k. This is a crucial number
* because it also controls how easily we can spread reads across
* cpus for decompression.
*
* We also want to make sure the amount of IO required to do
* a random read is reasonably small, so we limit the size of
* a compressed extent to 128k.
*/
total_compressed = min(total_compressed, max_uncompressed);
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(inode)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
goto cont;
}
if (BTRFS_I(inode)->force_compress)
compress_type = BTRFS_I(inode)->force_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*/
extent_range_clear_dirty_for_io(inode, start, end);
redirty = 1;
ret = btrfs_compress_pages(compress_type,
inode->i_mapping, start,
total_compressed, pages,
nr_pages, &nr_pages_ret,
&total_in,
&total_compressed,
max_compressed);
if (!ret) {
unsigned long offset = total_compressed &
(PAGE_CACHE_SIZE - 1);
struct page *page = pages[nr_pages_ret - 1];
char *kaddr;
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset) {
kaddr = kmap_atomic(page);
memset(kaddr + offset, 0,
PAGE_CACHE_SIZE - offset);
kunmap_atomic(kaddr);
}
will_compress = 1;
}
}
cont:
if (start == 0) {
/* lets try to make an inline extent */
if (ret || total_in < (actual_end - start)) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(root, inode, start, end,
0, 0, NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(root, inode, start, end,
total_compressed,
compress_type, pages);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DEFRAG;
unsigned long page_error_op;
clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
clear_flags, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
goto free_pages_out;
}
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk
*/
total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
if (total_compressed >= total_in) {
will_compress = 0;
} else {
num_bytes = total_in;
}
}
if (!will_compress && pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
page_cache_release(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages_ret = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->force_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
if (will_compress) {
*num_added += 1;
/* the async work queues will take care of doing actual
* allocation on disk for these compressed pages,
* and will submit them to the elevator.
*/
add_async_extent(async_cow, start, num_bytes,
total_compressed, pages, nr_pages_ret,
compress_type);
if (start + num_bytes < end) {
start += num_bytes;
pages = NULL;
cond_resched();
goto again;
}
} else {
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in
* the file we've been given so far. redirty the locked
* page if it corresponds to our extent and set things up
* for the async work queue to run cow_file_range to do
* the normal delalloc dance
*/
if (page_offset(locked_page) >= start &&
page_offset(locked_page) <= end) {
__set_page_dirty_nobuffers(locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_cow, start, end - start + 1,
0, NULL, 0, BTRFS_COMPRESS_NONE);
*num_added += 1;
}
return;
free_pages_out:
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
page_cache_release(pages[i]);
}
kfree(pages);
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
page_cache_release(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
* queued. We walk all the async extents created by compress_file_range
* and send them down to the disk.
*/
static noinline void submit_compressed_extents(struct inode *inode,
struct async_cow *async_cow)
{
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree;
int ret = 0;
again:
while (!list_empty(&async_cow->extents)) {
async_extent = list_entry(async_cow->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
io_tree = &BTRFS_I(inode)->io_tree;
retry:
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
lock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/* allocate blocks */
ret = cow_file_range(inode, async_cow->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/* JDM XXX */
/*
* if page_started, cow_file_range inserted an
* inline extent and took care of all the unlocking
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
if (!page_started && !ret)
extent_write_locked_range(io_tree,
inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
btrfs_get_extent,
WB_SYNC_ALL);
else if (ret)
unlock_page(async_cow->locked_page);
kfree(async_extent);
cond_resched();
continue;
}
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1);
ret = btrfs_reserve_extent(root,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
if (ret == -ENOSPC) {
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/*
* we need to redirty the pages if we decide to
* fallback to uncompressed IO, otherwise we
* will not submit these pages down to lower
* layers.
*/
extent_range_redirty_for_io(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
goto retry;
}
goto out_free;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out_free_reserve;
}
em->start = async_extent->start;
em->len = async_extent->ram_size;
em->orig_start = em->start;
em->mod_start = em->start;
em->mod_len = em->len;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = async_extent->ram_size;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->compress_type = async_extent->compress_type;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
}
if (ret)
goto out_free_reserve;
ret = btrfs_add_ordered_extent_compress(inode,
async_extent->start,
ins.objectid,
async_extent->ram_size,
ins.offset,
BTRFS_ORDERED_COMPRESSED,
async_extent->compress_type);
if (ret) {
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
goto out_free_reserve;
}
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK);
ret = btrfs_submit_compressed_write(inode,
async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages);
if (ret) {
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
struct page *p = async_extent->pages[0];
const u64 start = async_extent->start;
const u64 end = start + async_extent->ram_size - 1;
p->mapping = inode->i_mapping;
tree->ops->writepage_end_io_hook(p, start, end,
NULL, 0);
p->mapping = NULL;
extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return;
out_free_reserve:
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
kfree(async_extent);
goto again;
}
static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*/
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written,
int unlock)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
u64 disk_num_bytes;
u64 cur_alloc_size;
u64 blocksize = root->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 0;
if (btrfs_is_free_space_inode(inode)) {
WARN_ON_ONCE(1);
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
disk_num_bytes = num_bytes;
/* if this is a small write inside eof, kick off defrag */
if (num_bytes < SZ_64K &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
if (start == 0) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(root, inode, start, end, 0, 0,
NULL);
if (ret == 0) {
extent_clear_unlock_delalloc(inode, start, end, NULL,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
*page_started = 1;
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
BUG_ON(disk_num_bytes >
btrfs_super_total_bytes(root->fs_info->super_copy));
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
while (disk_num_bytes > 0) {
unsigned long op;
cur_alloc_size = disk_num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size,
root->sectorsize, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out_reserve;
}
em->start = start;
em->orig_start = em->start;
ram_size = ins.offset;
em->len = ins.offset;
em->mod_start = em->start;
em->mod_len = em->len;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ram_size;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, start,
start + ram_size - 1, 0);
}
if (ret)
goto out_reserve;
cur_alloc_size = ins.offset;
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size, 0);
if (ret)
goto out_drop_extent_cache;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
if (ret)
goto out_drop_extent_cache;
}
if (disk_num_bytes < cur_alloc_size)
break;
/* we're not doing compressed IO, don't unlock the first
* page (which the caller expects to stay locked), don't
* clear any dirty bits and don't set any writeback bits
*
* Do set the Private2 bit so we know this page was properly
* setup for writepage
*/
op = unlock ? PAGE_UNLOCK : 0;
op |= PAGE_SET_PRIVATE2;
extent_clear_unlock_delalloc(inode, start,
start + ram_size - 1, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
op);
disk_num_bytes -= cur_alloc_size;
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
out_reserve:
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
out_unlock:
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DELALLOC | EXTENT_DEFRAG,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
goto out;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_cow *async_cow;
int num_added = 0;
async_cow = container_of(work, struct async_cow, work);
compress_file_range(async_cow->inode, async_cow->locked_page,
async_cow->start, async_cow->end, async_cow,
&num_added);
if (num_added == 0) {
btrfs_add_delayed_iput(async_cow->inode);
async_cow->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_cow *async_cow;
struct btrfs_root *root;
unsigned long nr_pages;
async_cow = container_of(work, struct async_cow, work);
root = async_cow->root;
nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
PAGE_CACHE_SHIFT;
/*
* atomic_sub_return implies a barrier for waitqueue_active
*/
if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
5 * SZ_1M &&
waitqueue_active(&root->fs_info->async_submit_wait))
wake_up(&root->fs_info->async_submit_wait);
if (async_cow->inode)
submit_compressed_extents(async_cow->inode, async_cow);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_cow *async_cow;
async_cow = container_of(work, struct async_cow, work);
if (async_cow->inode)
btrfs_add_delayed_iput(async_cow->inode);
kfree(async_cow);
}
static int cow_file_range_async(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct async_cow *async_cow;
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long nr_pages;
u64 cur_end;
int limit = 10 * SZ_1M;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1, 0, NULL, GFP_NOFS);
while (start < end) {
async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
BUG_ON(!async_cow); /* -ENOMEM */
async_cow->inode = igrab(inode);
async_cow->root = root;
async_cow->locked_page = locked_page;
async_cow->start = start;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(root, FORCE_COMPRESS))
cur_end = end;
else
cur_end = min(end, start + SZ_512K - 1);
async_cow->end = cur_end;
INIT_LIST_HEAD(&async_cow->extents);
btrfs_init_work(&async_cow->work,
btrfs_delalloc_helper,
async_cow_start, async_cow_submit,
async_cow_free);
nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
PAGE_CACHE_SHIFT;
atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
btrfs_queue_work(root->fs_info->delalloc_workers,
&async_cow->work);
if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) <
limit));
}
while (atomic_read(&root->fs_info->async_submit_draining) &&
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) ==
0));
}
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_root *root,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
bytenr + num_bytes - 1, &list, 0);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
return 1;
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static noinline int run_delalloc_nocow(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started, int force,
unsigned long *nr_written)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_file_extent_item *fi;
struct btrfs_key found_key;
u64 cow_start;
u64 cur_offset;
u64 extent_end;
u64 extent_offset;
u64 disk_bytenr;
u64 num_bytes;
u64 disk_num_bytes;
u64 ram_bytes;
int extent_type;
int ret, err;
int type;
int nocow;
int check_prev = 1;
bool nolock;
u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
nolock = btrfs_is_free_space_inode(inode);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
cow_start = (u64)-1;
cur_offset = start;
while (1) {
ret = btrfs_lookup_file_extent(trans, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = 0;
next_slot:
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto error;
if (ret > 0)
break;
leaf = path->nodes[0];
}
nocow = 0;
disk_bytenr = 0;
num_bytes = 0;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid > ino)
break;
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
if (disk_bytenr == 0)
goto out_check;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
if (btrfs_extent_readonly(root, disk_bytenr))
goto out_check;
if (btrfs_cross_ref_exist(trans, root, ino,
found_key.offset -
extent_offset, disk_bytenr))
goto out_check;
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* if there are pending snapshots for this root,
* we fall into common COW way.
*/
if (!nolock) {
err = btrfs_start_write_no_snapshoting(root);
if (!err)
goto out_check;
}
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
if (csum_exist_in_range(root, disk_bytenr, num_bytes))
goto out_check;
nocow = 1;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset +
btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
extent_end = ALIGN(extent_end, root->sectorsize);
} else {
BUG_ON(1);
}
out_check:
if (extent_end <= start) {
path->slots[0]++;
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto next_slot;
}
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
path->slots[0]++;
goto next_slot;
}
btrfs_release_path(path);
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written, 1);
if (ret) {
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto error;
}
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
struct extent_map *em;
struct extent_map_tree *em_tree;
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
BUG_ON(!em); /* -ENOMEM */
em->start = cur_offset;
em->orig_start = found_key.offset - extent_offset;
em->len = num_bytes;
em->block_len = num_bytes;
em->block_start = disk_bytenr;
em->orig_block_len = disk_num_bytes;
em->ram_bytes = ram_bytes;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->mod_start = em->start;
em->mod_len = em->len;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
set_bit(EXTENT_FLAG_FILLING, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
}
type = BTRFS_ORDERED_PREALLOC;
} else {
type = BTRFS_ORDERED_NOCOW;
}
ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
num_bytes, num_bytes, type);
BUG_ON(ret); /* -ENOMEM */
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
if (ret) {
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto error;
}
}
extent_clear_unlock_delalloc(inode, cur_offset,
cur_offset + num_bytes - 1,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC, PAGE_UNLOCK |
PAGE_SET_PRIVATE2);
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
cur_offset = extent_end;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1) {
cow_start = cur_offset;
cur_offset = end;
}
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page, cow_start, end,
page_started, nr_written, 1);
if (ret)
goto error;
}
error:
err = btrfs_end_transaction(trans, root);
if (!ret)
ret = err;
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
{
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
!(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
return 0;
/*
* @defrag_bytes is a hint value, no spinlock held here,
* if is not zero, it means the file is defragging.
* Force cow if given extent needs to be defragged.
*/
if (BTRFS_I(inode)->defrag_bytes &&
test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
EXTENT_DEFRAG, 0, NULL))
return 1;
return 0;
}
/*
* extent_io.c call back to do delayed allocation processing
*/
static int run_delalloc_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
int ret;
int force_cow = need_force_cow(inode, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
} else if (!inode_need_compress(inode)) {
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags);
ret = cow_file_range_async(inode, locked_page, start, end,
page_started, nr_written);
}
return ret;
}
static void btrfs_split_extent_hook(struct inode *inode,
struct extent_state *orig, u64 split)
{
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > BTRFS_MAX_EXTENT_SIZE) {
u64 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_extent_hook, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
new_size = split - orig->start;
num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE) >= num_extents)
return;
}
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* extent_io.c merge_extent_hook, used to track merged delayed allocation
* extents so we can keep track of new extents that are just merged onto old
* extents, such as when we are doing sequential writes, so we can properly
* account for the metadata space we'll need.
*/
static void btrfs_merge_extent_hook(struct inode *inode,
struct extent_state *new,
struct extent_state *other)
{
u64 new_size, old_size;
u64 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
old_size = new->end - new->start + 1;
num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE) >= num_extents)
return;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct inode *inode)
{
spin_lock(&root->delalloc_lock);
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&root->fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&root->fs_info->delalloc_roots);
spin_unlock(&root->fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct inode *inode)
{
spin_lock(&root->delalloc_lock);
if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_del_init(&BTRFS_I(inode)->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
spin_lock(&root->fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&root->fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
/*
* extent_io.c set_bit_hook, used to track delayed allocation
* bytes in this file, and to maintain the list of inodes that
* have pending delalloc work to be done.
*/
static void btrfs_set_bit_hook(struct inode *inode,
struct extent_state *state, unsigned *bits)
{
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
bool do_list = !btrfs_is_free_space_inode(inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
/* For sanity tests */
if (btrfs_test_is_dummy_root(root))
return;
__percpu_counter_add(&root->fs_info->delalloc_bytes, len,
root->fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
if (*bits & EXTENT_DEFRAG)
BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* extent_io.c clear_bit_hook, see set_bit_hook for why
*/
static void btrfs_clear_bit_hook(struct inode *inode,
struct extent_state *state,
unsigned *bits)
{
u64 len = state->end + 1 - state->start;
u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
BTRFS_MAX_EXTENT_SIZE);
spin_lock(&BTRFS_I(inode)->lock);
if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
BTRFS_I(inode)->defrag_bytes -= len;
spin_unlock(&BTRFS_I(inode)->lock);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
bool do_list = !btrfs_is_free_space_inode(inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents -= num_extents;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call dellalloc_release_metadata if there is an
* error.
*/
if (*bits & EXTENT_DO_ACCOUNTING &&
root != root->fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len);
/* For sanity tests. */
if (btrfs_test_is_dummy_root(root))
return;
if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& do_list && !(state->state & EXTENT_NORESERVE))
btrfs_free_reserved_data_space_noquota(inode,
state->start, len);
__percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
root->fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes -= len;
if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* extent_io.c merge_bio_hook, this must check the chunk tree to make sure
* we don't create bios that span stripes or chunks
*/
int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
size_t size, struct bio *bio,
unsigned long bio_flags)
{
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
length = bio->bi_iter.bi_size;
map_length = length;
ret = btrfs_map_block(root->fs_info, rw, logical,
&map_length, NULL, 0);
/* Will always return 0 with map_multi == NULL */
BUG_ON(ret < 0);
if (map_length < length + size)
return 1;
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static int __btrfs_submit_bio_start(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
if (ret) {
bio->bi_error = ret;
bio_endio(bio);
}
return ret;
}
/*
* extent_io.c submission hook. This does the right thing for csum calculation
* on write, or reading the csums from the tree before a read
*/
static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
int ret = 0;
int skip_sum;
int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (btrfs_is_free_space_inode(inode))
metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
if (!(rw & REQ_WRITE)) {
ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
if (ret)
goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) {
ret = btrfs_submit_compressed_read(inode, bio,
mirror_num,
bio_flags);
goto out;
} else if (!skip_sum) {
ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
if (ret)
goto out;
}
goto mapit;
} else if (async && !skip_sum) {
/* csum items have already been cloned */
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
goto mapit;
/* we're doing a write, do the async checksumming */
ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
inode, rw, bio, mirror_num,
bio_flags, bio_offset,
__btrfs_submit_bio_start,
__btrfs_submit_bio_done);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
if (ret)
goto out;
}
mapit:
ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
out:
if (ret < 0) {
bio->bi_error = ret;
bio_endio(bio);
}
return ret;
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_offset,
struct list_head *list)
{
struct btrfs_ordered_sum *sum;
list_for_each_entry(sum, list, list) {
trans->adding_csums = 1;
btrfs_csum_file_blocks(trans,
BTRFS_I(inode)->root->fs_info->csum_root, sum);
trans->adding_csums = 0;
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
struct extent_state **cached_state)
{
WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
cached_state, GFP_NOFS);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct btrfs_work work;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct page *page;
struct inode *inode;
u64 page_start;
u64 page_end;
int ret;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
again:
lock_page(page);
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
ClearPageChecked(page);
goto out_page;
}
inode = page->mapping->host;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
/* already ordered? We're done */
if (PagePrivate2(page))
goto out;
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
page_end, &cached_state, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_delalloc_reserve_space(inode, page_start,
PAGE_CACHE_SIZE);
if (ret) {
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
ClearPageChecked(page);
goto out;
}
btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
ClearPageChecked(page);
set_page_dirty(page);
out:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
out_page:
unlock_page(page);
page_cache_release(page);
kfree(fixup);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_writepage_fixup *fixup;
struct btrfs_root *root = BTRFS_I(inode)->root;
/* this page is properly in the ordered list */
if (TestClearPagePrivate2(page))
return 0;
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
SetPageChecked(page);
page_cache_get(page);
btrfs_init_work(&fixup->work, btrfs_fixup_helper,
btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
return -EBUSY;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_pos,
u64 disk_bytenr, u64 disk_num_bytes,
u64 num_bytes, u64 ram_bytes,
u8 compression, u8 encryption,
u16 other_encoding, int extent_type)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *fi;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
int extent_inserted = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
file_pos + num_bytes, NULL, 0,
1, sizeof(*fi), &extent_inserted);
if (ret)
goto out;
if (!extent_inserted) {
ins.objectid = btrfs_ino(inode);
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*fi));
if (ret)
goto out;
}
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, extent_type);
btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
btrfs_set_file_extent_offset(leaf, fi, 0);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
btrfs_set_file_extent_compression(leaf, fi, compression);
btrfs_set_file_extent_encryption(leaf, fi, encryption);
btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_alloc_reserved_file_extent(trans, root,
root->root_key.objectid,
btrfs_ino(inode), file_pos,
ram_bytes, &ins);
/*
* Release the reserved range from inode dirty range map, as it is
* already moved into delayed_ref_head
*/
btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
out:
btrfs_free_path(path);
return ret;
}
/* snapshot-aware defrag */
struct sa_defrag_extent_backref {
struct rb_node node;
struct old_sa_defrag_extent *old;
u64 root_id;
u64 inum;
u64 file_pos;
u64 extent_offset;
u64 num_bytes;
u64 generation;
};
struct old_sa_defrag_extent {
struct list_head list;
struct new_sa_defrag_extent *new;
u64 extent_offset;
u64 bytenr;
u64 offset;
u64 len;
int count;
};
struct new_sa_defrag_extent {
struct rb_root root;
struct list_head head;
struct btrfs_path *path;
struct inode *inode;
u64 file_pos;
u64 len;
u64 bytenr;
u64 disk_len;
u8 compress_type;
};
static int backref_comp(struct sa_defrag_extent_backref *b1,
struct sa_defrag_extent_backref *b2)
{
if (b1->root_id < b2->root_id)
return -1;
else if (b1->root_id > b2->root_id)
return 1;
if (b1->inum < b2->inum)
return -1;
else if (b1->inum > b2->inum)
return 1;
if (b1->file_pos < b2->file_pos)
return -1;
else if (b1->file_pos > b2->file_pos)
return 1;
/*
* [------------------------------] ===> (a range of space)
* |<--->| |<---->| =============> (fs/file tree A)
* |<---------------------------->| ===> (fs/file tree B)
*
* A range of space can refer to two file extents in one tree while
* refer to only one file extent in another tree.
*
* So we may process a disk offset more than one time(two extents in A)
* and locate at the same extent(one extent in B), then insert two same
* backrefs(both refer to the extent in B).
*/
return 0;
}
static void backref_insert(struct rb_root *root,
struct sa_defrag_extent_backref *backref)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct sa_defrag_extent_backref *entry;
int ret;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
ret = backref_comp(backref, entry);
if (ret < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&backref->node, parent, p);
rb_insert_color(&backref->node, root);
}
/*
* Note the backref might has changed, and in this case we just return 0.
*/
static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
void *ctx)
{
struct btrfs_file_extent_item *extent;
struct btrfs_fs_info *fs_info;
struct old_sa_defrag_extent *old = ctx;
struct new_sa_defrag_extent *new = old->new;
struct btrfs_path *path = new->path;
struct btrfs_key key;
struct btrfs_root *root;
struct sa_defrag_extent_backref *backref;
struct extent_buffer *leaf;
struct inode *inode = new->inode;
int slot;
int ret;
u64 extent_offset;
u64 num_bytes;
if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
inum == btrfs_ino(inode))
return 0;
key.objectid = root_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info = BTRFS_I(inode)->root->fs_info;
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
if (PTR_ERR(root) == -ENOENT)
return 0;
WARN_ON(1);
pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
inum, offset, root_id);
return PTR_ERR(root);
}
key.objectid = inum;
key.type = BTRFS_EXTENT_DATA_KEY;
if (offset > (u64)-1 << 32)
key.offset = 0;
else
key.offset = offset;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (WARN_ON(ret < 0))
return ret;
ret = 0;
while (1) {
cond_resched();
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = 0;
goto out;
}
continue;
}
path->slots[0]++;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid > inum)
goto out;
if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
continue;
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
continue;
/*
* 'offset' refers to the exact key.offset,
* NOT the 'offset' field in btrfs_extent_data_ref, ie.
* (key.offset - extent_offset).
*/
if (key.offset != offset)
continue;
extent_offset = btrfs_file_extent_offset(leaf, extent);
num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
if (extent_offset >= old->extent_offset + old->offset +
old->len || extent_offset + num_bytes <=
old->extent_offset + old->offset)
continue;
break;
}
backref = kmalloc(sizeof(*backref), GFP_NOFS);
if (!backref) {
ret = -ENOENT;
goto out;
}
backref->root_id = root_id;
backref->inum = inum;
backref->file_pos = offset;
backref->num_bytes = num_bytes;
backref->extent_offset = extent_offset;
backref->generation = btrfs_file_extent_generation(leaf, extent);
backref->old = old;
backref_insert(&new->root, backref);
old->count++;
out:
btrfs_release_path(path);
WARN_ON(ret);
return ret;
}
static noinline bool record_extent_backrefs(struct btrfs_path *path,
struct new_sa_defrag_extent *new)
{
struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
struct old_sa_defrag_extent *old, *tmp;
int ret;
new->path = path;
list_for_each_entry_safe(old, tmp, &new->head, list) {
ret = iterate_inodes_from_logical(old->bytenr +
old->extent_offset, fs_info,
path, record_one_backref,
old);
if (ret < 0 && ret != -ENOENT)
return false;
/* no backref to be processed for this extent */
if (!old->count) {
list_del(&old->list);
kfree(old);
}
}
if (list_empty(&new->head))
return false;
return true;
}
static int relink_is_mergable(struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi,
struct new_sa_defrag_extent *new)
{
if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
return 0;
if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
return 0;
if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
return 0;
if (btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
return 0;
return 1;
}
/*
* Note the backref might has changed, and in this case we just return 0.
*/
static noinline int relink_extent_backref(struct btrfs_path *path,
struct sa_defrag_extent_backref *prev,
struct sa_defrag_extent_backref *backref)
{
struct btrfs_file_extent_item *extent;
struct btrfs_file_extent_item *item;
struct btrfs_ordered_extent *ordered;
struct btrfs_trans_handle *trans;
struct btrfs_fs_info *fs_info;
struct btrfs_root *root;
struct btrfs_key key;
struct extent_buffer *leaf;
struct old_sa_defrag_extent *old = backref->old;
struct new_sa_defrag_extent *new = old->new;
struct inode *src_inode = new->inode;
struct inode *inode;
struct extent_state *cached = NULL;
int ret = 0;
u64 start;
u64 len;
u64 lock_start;
u64 lock_end;
bool merge = false;
int index;
if (prev && prev->root_id == backref->root_id &&
prev->inum == backref->inum &&
prev->file_pos + prev->num_bytes == backref->file_pos)
merge = true;
/* step 1: get root */
key.objectid = backref->root_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info = BTRFS_I(src_inode)->root->fs_info;
index = srcu_read_lock(&fs_info->subvol_srcu);
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
if (PTR_ERR(root) == -ENOENT)
return 0;
return PTR_ERR(root);
}
if (btrfs_root_readonly(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
return 0;
}
/* step 2: get inode */
key.objectid = backref->inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, root, NULL);
if (IS_ERR(inode)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
return 0;
}
srcu_read_unlock(&fs_info->subvol_srcu, index);
/* step 3: relink backref */
lock_start = backref->file_pos;
lock_end = backref->file_pos + backref->num_bytes - 1;
lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
&cached);
ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
if (ordered) {
btrfs_put_ordered_extent(ordered);
goto out_unlock;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_unlock;
}
key.objectid = backref->inum;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = backref->file_pos;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
goto out_free_path;
} else if (ret > 0) {
ret = 0;
goto out_free_path;
}
extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_generation(path->nodes[0], extent) !=
backref->generation)
goto out_free_path;
btrfs_release_path(path);
start = backref->file_pos;
if (backref->extent_offset < old->extent_offset + old->offset)
start += old->extent_offset + old->offset -
backref->extent_offset;
len = min(backref->extent_offset + backref->num_bytes,
old->extent_offset + old->offset + old->len);
len -= max(backref->extent_offset, old->extent_offset + old->offset);
ret = btrfs_drop_extents(trans, root, inode, start,
start + len, 1);
if (ret)
goto out_free_path;
again:
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = start;
path->leave_spinning = 1;
if (merge) {
struct btrfs_file_extent_item *fi;
u64 extent_len;
struct btrfs_key found_key;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out_free_path;
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_len = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_len + found_key.offset == start &&
relink_is_mergable(leaf, fi, new)) {
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_len + len);
btrfs_mark_buffer_dirty(leaf);
inode_add_bytes(inode, len);
ret = 1;
goto out_free_path;
} else {
merge = false;
btrfs_release_path(path);
goto again;
}
}
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*extent));
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_free_path;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
btrfs_set_file_extent_num_bytes(leaf, item, len);
btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
btrfs_set_file_extent_generation(leaf, item, trans->transid);
btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_compression(leaf, item, new->compress_type);
btrfs_set_file_extent_encryption(leaf, item, 0);
btrfs_set_file_extent_other_encoding(leaf, item, 0);
btrfs_mark_buffer_dirty(leaf);
inode_add_bytes(inode, len);
btrfs_release_path(path);
ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
new->disk_len, 0,
backref->root_id, backref->inum,
new->file_pos); /* start - extent_offset */
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_free_path;
}
ret = 1;
out_free_path:
btrfs_release_path(path);
path->leave_spinning = 0;
btrfs_end_transaction(trans, root);
out_unlock:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
&cached, GFP_NOFS);
iput(inode);
return ret;
}
static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
{
struct old_sa_defrag_extent *old, *tmp;
if (!new)
return;
list_for_each_entry_safe(old, tmp, &new->head, list) {
kfree(old);
}
kfree(new);
}
static void relink_file_extents(struct new_sa_defrag_extent *new)
{
struct btrfs_path *path;
struct sa_defrag_extent_backref *backref;
struct sa_defrag_extent_backref *prev = NULL;
struct inode *inode;
struct btrfs_root *root;
struct rb_node *node;
int ret;
inode = new->inode;
root = BTRFS_I(inode)->root;
path = btrfs_alloc_path();
if (!path)
return;
if (!record_extent_backrefs(path, new)) {
btrfs_free_path(path);
goto out;
}
btrfs_release_path(path);
while (1) {
node = rb_first(&new->root);
if (!node)
break;
rb_erase(node, &new->root);
backref = rb_entry(node, struct sa_defrag_extent_backref, node);
ret = relink_extent_backref(path, prev, backref);
WARN_ON(ret < 0);
kfree(prev);
if (ret == 1)
prev = backref;
else
prev = NULL;
cond_resched();
}
kfree(prev);
btrfs_free_path(path);
out:
free_sa_defrag_extent(new);
atomic_dec(&root->fs_info->defrag_running);
wake_up(&root->fs_info->transaction_wait);
}
static struct new_sa_defrag_extent *
record_old_file_extents(struct inode *inode,
struct btrfs_ordered_extent *ordered)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct old_sa_defrag_extent *old;
struct new_sa_defrag_extent *new;
int ret;
new = kmalloc(sizeof(*new), GFP_NOFS);
if (!new)
return NULL;
new->inode = inode;
new->file_pos = ordered->file_offset;
new->len = ordered->len;
new->bytenr = ordered->start;
new->disk_len = ordered->disk_len;
new->compress_type = ordered->compress_type;
new->root = RB_ROOT;
INIT_LIST_HEAD(&new->head);
path = btrfs_alloc_path();
if (!path)
goto out_kfree;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = new->file_pos;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out_free_path;
if (ret > 0 && path->slots[0] > 0)
path->slots[0]--;
/* find out all the old extents for the file range */
while (1) {
struct btrfs_file_extent_item *extent;
struct extent_buffer *l;
int slot;
u64 num_bytes;
u64 offset;
u64 end;
u64 disk_bytenr;
u64 extent_offset;
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out_free_path;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid != btrfs_ino(inode))
break;
if (key.type != BTRFS_EXTENT_DATA_KEY)
break;
if (key.offset >= new->file_pos + new->len)
break;
extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
num_bytes = btrfs_file_extent_num_bytes(l, extent);
if (key.offset + num_bytes < new->file_pos)
goto next;
disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
if (!disk_bytenr)
goto next;
extent_offset = btrfs_file_extent_offset(l, extent);
old = kmalloc(sizeof(*old), GFP_NOFS);
if (!old)
goto out_free_path;
offset = max(new->file_pos, key.offset);
end = min(new->file_pos + new->len, key.offset + num_bytes);
old->bytenr = disk_bytenr;
old->extent_offset = extent_offset;
old->offset = offset - key.offset;
old->len = end - offset;
old->new = new;
old->count = 0;
list_add_tail(&old->list, &new->head);
next:
path->slots[0]++;
cond_resched();
}
btrfs_free_path(path);
atomic_inc(&root->fs_info->defrag_running);
return new;
out_free_path:
btrfs_free_path(path);
out_kfree:
free_sa_defrag_extent(new);
return NULL;
}
static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
u64 start, u64 len)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_block_group(root->fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
/* as ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
{
struct inode *inode = ordered_extent->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
struct new_sa_defrag_extent *new = NULL;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->len;
bool nolock;
bool truncated = false;
nolock = btrfs_is_free_space_inode(inode);
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
/*
* For mwrite(mmap + memset to write) case, we still reserve
* space for NOCOW range.
* As NOCOW won't cause a new delayed ref, just free the space
*/
btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
ordered_extent->len);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, root, ret);
goto out;
}
lock_extent_bits(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
&cached_state);
ret = test_range_bit(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
EXTENT_DEFRAG, 1, cached_state);
if (ret) {
u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
if (0 && last_snapshot >= BTRFS_I(inode)->generation)
/* the inode is shared */
new = record_old_file_extents(inode, ordered_extent);
clear_extent_bit(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
}
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out_unlock;
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
ret = btrfs_mark_extent_written(trans, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
} else {
BUG_ON(root == root->fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode,
ordered_extent->file_offset,
ordered_extent->start,
ordered_extent->disk_len,
logical_len, logical_len,
compress_type, 0, 0,
BTRFS_FILE_EXTENT_REG);
if (!ret)
btrfs_release_delalloc_bytes(root,
ordered_extent->start,
ordered_extent->disk_len);
}
unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
ordered_extent->file_offset, ordered_extent->len,
trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, root, ret);
goto out_unlock;
}
add_pending_csums(trans, inode, ordered_extent->file_offset,
&ordered_extent->list);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, root, ret);
goto out_unlock;
}
ret = 0;
out_unlock:
unlock_extent_cached(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1, &cached_state, GFP_NOFS);
out:
if (root != root->fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, ordered_extent->len);
if (trans)
btrfs_end_transaction(trans, root);
if (ret || truncated) {
u64 start, end;
if (truncated)
start = ordered_extent->file_offset + logical_len;
else
start = ordered_extent->file_offset;
end = ordered_extent->file_offset + ordered_extent->len - 1;
clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
/* Drop the cache for the part of the extent we didn't write. */
btrfs_drop_extent_cache(inode, start, end, 0);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*/
if ((ret || !logical_len) &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
btrfs_free_reserved_extent(root, ordered_extent->start,
ordered_extent->disk_len, 1);
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* for snapshot-aware defrag */
if (new) {
if (ret) {
free_sa_defrag_extent(new);
atomic_dec(&root->fs_info->defrag_running);
} else {
relink_file_extents(new);
}
}
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate)
{
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_extent *ordered_extent = NULL;
struct btrfs_workqueue *wq;
btrfs_work_func_t func;
trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
ClearPagePrivate2(page);
if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
end - start + 1, uptodate))
return 0;
if (btrfs_is_free_space_inode(inode)) {
wq = root->fs_info->endio_freespace_worker;
func = btrfs_freespace_write_helper;
} else {
wq = root->fs_info->endio_write_workers;
func = btrfs_endio_write_helper;
}
btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
NULL);
btrfs_queue_work(wq, &ordered_extent->work);
return 0;
}
static int __readpage_endio_check(struct inode *inode,
struct btrfs_io_bio *io_bio,
int icsum, struct page *page,
int pgoff, u64 start, size_t len)
{
char *kaddr;
u32 csum_expected;
u32 csum = ~(u32)0;
csum_expected = *(((u32 *)io_bio->csum) + icsum);
kaddr = kmap_atomic(page);
csum = btrfs_csum_data(kaddr + pgoff, csum, len);
btrfs_csum_final(csum, (char *)&csum);
if (csum != csum_expected)
goto zeroit;
kunmap_atomic(kaddr);
return 0;
zeroit:
btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
"csum failed ino %llu off %llu csum %u expected csum %u",
btrfs_ino(inode), start, csum, csum_expected);
memset(kaddr + pgoff, 1, len);
flush_dcache_page(page);
kunmap_atomic(kaddr);
if (csum_expected == 0)
return 0;
return -EIO;
}
/*
* when reads are done, we need to check csums to verify the data is correct
* if there's a match, we allow the bio to finish. If not, the code in
* extent_io.c will try to find good copies for us.
*/
static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
u64 phy_offset, struct page *page,
u64 start, u64 end, int mirror)
{
size_t offset = start - page_offset(page);
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
if (PageChecked(page)) {
ClearPageChecked(page);
return 0;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return 0;
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
GFP_NOFS);
return 0;
}
phy_offset >>= inode->i_sb->s_blocksize_bits;
return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
start, (size_t)(end - start + 1));
}
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_inode *binode = BTRFS_I(inode);
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
spin_lock(&fs_info->delayed_iput_lock);
if (binode->delayed_iput_count == 0) {
ASSERT(list_empty(&binode->delayed_iput));
list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
} else {
binode->delayed_iput_count++;
}
spin_unlock(&fs_info->delayed_iput_lock);
}
void btrfs_run_delayed_iputs(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
down_read(&fs_info->delayed_iput_sem);
spin_lock(&fs_info->delayed_iput_lock);
while (!list_empty(&fs_info->delayed_iputs)) {
struct btrfs_inode *inode;
inode = list_first_entry(&fs_info->delayed_iputs,
struct btrfs_inode, delayed_iput);
if (inode->delayed_iput_count) {
inode->delayed_iput_count--;
list_move_tail(&inode->delayed_iput,
&fs_info->delayed_iputs);
} else {
list_del_init(&inode->delayed_iput);
}
spin_unlock(&fs_info->delayed_iput_lock);
iput(&inode->vfs_inode);
spin_lock(&fs_info->delayed_iput_lock);
}
spin_unlock(&fs_info->delayed_iput_lock);
up_read(&root->fs_info->delayed_iput_sem);
}
/*
* This is called in transaction commit time. If there are no orphan
* files in the subvolume, it removes orphan item and frees block_rsv
* structure.
*/
void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv;
int ret;
if (atomic_read(&root->orphan_inodes) ||
root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
return;
spin_lock(&root->orphan_lock);
if (atomic_read(&root->orphan_inodes)) {
spin_unlock(&root->orphan_lock);
return;
}
if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
spin_unlock(&root->orphan_lock);
return;
}
block_rsv = root->orphan_block_rsv;
root->orphan_block_rsv = NULL;
spin_unlock(&root->orphan_lock);
if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
btrfs_root_refs(&root->root_item) > 0) {
ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
if (ret)
btrfs_abort_transaction(trans, root, ret);
else
clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
&root->state);
}
if (block_rsv) {
WARN_ON(block_rsv->size > 0);
btrfs_free_block_rsv(root, block_rsv);
}
}
/*
* This creates an orphan entry for the given inode in case something goes
* wrong in the middle of an unlink/truncate.
*
* NOTE: caller of this function should reserve 5 units of metadata for
* this function.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = NULL;
int reserve = 0;
int insert = 0;
int ret;
if (!root->orphan_block_rsv) {
block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!block_rsv)
return -ENOMEM;
}
spin_lock(&root->orphan_lock);
if (!root->orphan_block_rsv) {
root->orphan_block_rsv = block_rsv;
} else if (block_rsv) {
btrfs_free_block_rsv(root, block_rsv);
block_rsv = NULL;
}
if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags)) {
#if 0
/*
* For proper ENOSPC handling, we should do orphan
* cleanup when mounting. But this introduces backward
* compatibility issue.
*/
if (!xchg(&root->orphan_item_inserted, 1))
insert = 2;
else
insert = 1;
#endif
insert = 1;
atomic_inc(&root->orphan_inodes);
}
if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
reserve = 1;
spin_unlock(&root->orphan_lock);
/* grab metadata reservation from transaction handle */
if (reserve) {
ret = btrfs_orphan_reserve_metadata(trans, inode);
BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
}
/* insert an orphan item to track this unlinked/truncated file */
if (insert >= 1) {
ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
if (ret) {
atomic_dec(&root->orphan_inodes);
if (reserve) {
clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags);
btrfs_orphan_release_metadata(inode);
}
if (ret != -EEXIST) {
clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags);
btrfs_abort_transaction(trans, root, ret);
return ret;
}
}
ret = 0;
}
/* insert an orphan item to track subvolume contains orphan files */
if (insert >= 2) {
ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
if (ret && ret != -EEXIST) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
}
return 0;
}
/*
* We have done the truncate/delete so we can go ahead and remove the orphan
* item for this particular inode.
*/
static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int delete_item = 0;
int release_rsv = 0;
int ret = 0;
spin_lock(&root->orphan_lock);
if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags))
delete_item = 1;
if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
release_rsv = 1;
spin_unlock(&root->orphan_lock);
if (delete_item) {
atomic_dec(&root->orphan_inodes);
if (trans)
ret = btrfs_del_orphan_item(trans, root,
btrfs_ino(inode));
}
if (release_rsv)
btrfs_orphan_release_metadata(inode);
return ret;
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0, nr_truncate = 0;
if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->reada = READA_BACK;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
if (found_key.offset == last_objectid) {
btrfs_err(root->fs_info,
"Error removing orphan entry, stopping orphan cleanup");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
ret = PTR_ERR_OR_ZERO(inode);
if (ret && ret != -ESTALE)
goto out;
if (ret == -ESTALE && root == root->fs_info->tree_root) {
struct btrfs_root *dead_root;
struct btrfs_fs_info *fs_info = root->fs_info;
int is_dead_root = 0;
/*
* this is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a snapshot deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the snapshot
* orphan must not get deleted.
* find_dead_roots already ran before us, so if this
* is a snapshot deletion, we should find the root
* in the dead_roots list
*/
spin_lock(&fs_info->trans_lock);
list_for_each_entry(dead_root, &fs_info->dead_roots,
root_list) {
if (dead_root->root_key.objectid ==
found_key.objectid) {
is_dead_root = 1;
break;
}
}
spin_unlock(&fs_info->trans_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* Inode is already gone but the orphan item is still there,
* kill the orphan item.
*/
if (ret == -ESTALE) {
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_debug(root->fs_info, "auto deleting %Lu",
found_key.objectid);
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans, root);
if (ret)
goto out;
continue;
}
/*
* add this inode to the orphan list so btrfs_orphan_del does
* the proper thing when we hit it
*/
set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags);
atomic_inc(&root->orphan_inodes);
/* if we have links, this was a truncate, lets do that */
if (inode->i_nlink) {
if (WARN_ON(!S_ISREG(inode->i_mode))) {
iput(inode);
continue;
}
nr_truncate++;
/* 1 for the orphan item deletion. */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
iput(inode);
ret = PTR_ERR(trans);
goto out;
}
ret = btrfs_orphan_add(trans, inode);
btrfs_end_transaction(trans, root);
if (ret) {
iput(inode);
goto out;
}
ret = btrfs_truncate(inode);
if (ret)
btrfs_orphan_del(NULL, inode);
} else {
nr_unlink++;
}
/* this will do delete_inode and everything for us */
iput(inode);
if (ret)
goto out;
}
/* release the path since we're done with it */
btrfs_release_path(path);
root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
if (root->orphan_block_rsv)
btrfs_block_rsv_release(root, root->orphan_block_rsv,
(u64)-1);
if (root->orphan_block_rsv ||
test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans, root);
}
if (nr_unlink)
btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
if (nr_truncate)
btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
out:
if (ret)
btrfs_err(root->fs_info,
"could not do orphan cleanup %d", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid,
int *first_xattr_slot)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
static u64 xattr_access = 0;
static u64 xattr_default = 0;
int scanned = 0;
if (!xattr_access) {
xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
strlen(POSIX_ACL_XATTR_ACCESS));
xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
strlen(POSIX_ACL_XATTR_DEFAULT));
}
slot++;
*first_xattr_slot = -1;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
if (found_key.offset == xattr_access ||
found_key.offset == xattr_default)
return 1;
}
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
unsigned long ptr;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
int first_xattr_slot;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
path = btrfs_alloc_path();
if (!path)
goto make_bad;
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret)
goto make_bad;
leaf = path->nodes[0];
if (filled)
goto cache_index;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
BTRFS_I(inode)->i_otime.tv_sec =
btrfs_timespec_sec(leaf, &inode_item->otime);
BTRFS_I(inode)->i_otime.tv_nsec =
btrfs_timespec_nsec(leaf, &inode_item->otime);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
inode->i_version = btrfs_inode_sequence(leaf, inode_item);
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
cache_index:
/*
* If we were modified in the current generation and evicted from memory
* and then re-read we need to do a full sync since we don't have any
* idea about which extents were modified before we were evicted from
* cache.
*
* This is required for both inode re-read from disk and delayed inode
* in delayed_nodes_tree.
*/
if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
/*
* We don't persist the id of the transaction where an unlink operation
* against the inode was last made. So here we assume the inode might
* have been evicted, and therefore the exact value of last_unlink_trans
* lost, and set it to last_trans to avoid metadata inconsistencies
* between the inode and its parent if the inode is fsync'ed and the log
* replayed. For example, in the scenario:
*
* touch mydir/foo
* ln mydir/foo mydir/bar
* sync
* unlink mydir/bar
* echo 2 > /proc/sys/vm/drop_caches # evicts inode
* xfs_io -c fsync mydir/foo
* <power failure>
* mount fs, triggers fsync log replay
*
* We must make sure that when we fsync our inode foo we also log its
* parent inode, otherwise after log replay the parent still has the
* dentry with the "bar" name but our inode foo has a link count of 1
* and doesn't have an inode ref with the name "bar" anymore.
*
* Setting last_unlink_trans to last_trans is a pessimistic approach,
* but it guarantees correctness at the expense of ocassional full
* transaction commits on fsync if our inode is a directory, or if our
* inode is not a directory, logging its parent unnecessarily.
*/
BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
path->slots[0]++;
if (inode->i_nlink != 1 ||
path->slots[0] >= btrfs_header_nritems(leaf))
goto cache_acl;
btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
if (location.objectid != btrfs_ino(inode))
goto cache_acl;
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
if (location.type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
extref);
}
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(inode), &first_xattr_slot);
if (first_xattr_slot != -1) {
path->slots[0] = first_xattr_slot;
ret = btrfs_load_inode_props(inode, path);
if (ret)
btrfs_err(root->fs_info,
"error loading props for ino %llu (root %llu): %d",
btrfs_ino(inode),
root->root_key.objectid, ret);
}
btrfs_free_path(path);
if (!maybe_acls)
cache_no_acl(inode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
if (root == root->fs_info->tree_root)
inode->i_op = &btrfs_dir_ro_inode_operations;
else
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
break;
default:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_update_iflags(inode);
return;
make_bad:
btrfs_free_path(path);
make_bad_inode(inode);
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token);
btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
&token);
btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
btrfs_set_token_timespec_sec(leaf, &item->atime,
inode->i_atime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->atime,
inode->i_atime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->mtime,
inode->i_mtime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->mtime,
inode->i_mtime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->ctime,
inode->i_ctime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->ctime,
inode->i_ctime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_nsec, &token);
btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
&token);
btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
&token);
btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
btrfs_set_token_inode_block_group(leaf, item, 0, &token);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(inode)
&& root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& !root->fs_info->log_root_recovering) {
btrfs_update_root_times(trans, root);
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
struct btrfs_path *path;
int ret = 0;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->leave_spinning = 1;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(path);
/*
* If we don't have dir index, we have to get it by looking up
* the inode ref, since we get the inode ref, remove it directly,
* it is unnecessary to do delayed deletion.
*
* But if we have dir index, needn't search inode ref to get it.
* Since the inode ref is close to the inode item, it is better
* that we delay to delete it, and just do this deletion when
* we update the inode item.
*/
if (BTRFS_I(inode)->dir_index) {
ret = btrfs_delayed_delete_inode_ref(inode);
if (!ret) {
index = BTRFS_I(inode)->dir_index;
goto skip_backref;
}
}
ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
dir_ino, &index);
if (ret) {
btrfs_info(root->fs_info,
"failed to delete reference to %.*s, inode %llu parent %llu",
name_len, name, ino, dir_ino);
btrfs_abort_transaction(trans, root, ret);
goto err;
}
skip_backref:
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto err;
}
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
inode, dir_ino);
if (ret != 0 && ret != -ENOENT) {
btrfs_abort_transaction(trans, root, ret);
goto err;
}
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
dir, index);
if (ret == -ENOENT)
ret = 0;
else if (ret)
btrfs_abort_transaction(trans, root, ret);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode_inc_iversion(inode);
inode_inc_iversion(dir);
inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root, dir);
out:
return ret;
}
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
int ret;
ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
if (!ret) {
drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
}
return ret;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space, so
* if we cannot make our reservations the normal way try and see if there is
* plenty of slack room in the global reserve to migrate, otherwise we cannot
* allow the unlink to occur.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
/*
* 1 for the possible orphan item
* 1 for the dir item
* 1 for the dir index
* 1 for the inode ref
* 1 for the inode
*/
return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
struct inode *inode = d_inode(dentry);
int ret;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
dentry->d_name.name, dentry->d_name.len);
if (ret)
goto out;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out;
}
out:
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
return ret;
}
int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, u64 objectid,
const char *name, int name_len)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
int ret;
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
goto out;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
btrfs_release_path(path);
ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir_ino, &index, name, name_len);
if (ret < 0) {
if (ret != -ENOENT) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
btrfs_abort_transaction(trans, root, ret);
goto out;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
index = key.offset;
}
btrfs_release_path(path);
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode_inc_iversion(dir);
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode_fallback(trans, root, dir);
if (ret)
btrfs_abort_transaction(trans, root, ret);
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
int err = 0;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
return -EPERM;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, root, dir,
BTRFS_I(inode)->location.objectid,
dentry->d_name.name,
dentry->d_name.len);
goto out;
}
err = btrfs_orphan_add(trans, inode);
if (err)
goto out;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
dentry->d_name.name, dentry->d_name.len);
if (!err)
btrfs_i_size_write(inode, 0);
out:
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
return err;
}
static int truncate_space_check(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytes_deleted)
{
int ret;
bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
if (!ret)
trans->bytes_reserved += bytes_deleted;
return ret;
}
static int truncate_inline_extent(struct inode *inode,
struct btrfs_path *path,
struct btrfs_key *found_key,
const u64 item_end,
const u64 new_size)
{
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_file_extent_item *fi;
u32 size = (u32)(new_size - found_key->offset);
struct btrfs_root *root = BTRFS_I(inode)->root;
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
loff_t offset = new_size;
loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
/*
* Zero out the remaining of the last page of our inline extent,
* instead of directly truncating our inline extent here - that
* would be much more complex (decompressing all the data, then
* compressing the truncated data, which might be bigger than
* the size of the inline extent, resize the extent, etc).
* We release the path because to get the page we might need to
* read the extent item from disk (data not in the page cache).
*/
btrfs_release_path(path);
return btrfs_truncate_page(inode, offset, page_end - offset, 0);
}
btrfs_set_file_extent_ram_bytes(leaf, fi, size);
size = btrfs_file_extent_calc_inline_size(size);
btrfs_truncate_item(root, path, size, 1);
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
inode_sub_bytes(inode, item_end + 1 - new_size);
return 0;
}
/*
* this can truncate away extent items, csum items and directory items.
* It starts at a high offset and removes keys until it can't find
* any higher than new_size
*
* csum items that cross the new i_size are truncated to the new size
* as well.
*
* min_type is the minimum key type to truncate down to. If set to 0, this
* will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u64 last_size = new_size;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int ret;
int err = 0;
u64 ino = btrfs_ino(inode);
u64 bytes_deleted = 0;
bool be_nice = 0;
bool should_throttle = 0;
bool should_end = 0;
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
/*
* for non-free space inodes and ref cows, we want to back off from
* time to time
*/
if (!btrfs_is_free_space_inode(inode) &&
test_bit(BTRFS_ROOT_REF_COWS, &root->state))
be_nice = 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
/*
* We want to drop from the next block forward in case this new size is
* not block aligned since we will be keeping the last block of the
* extent just the way it is.
*/
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == root->fs_info->tree_root)
btrfs_drop_extent_cache(inode, ALIGN(new_size,
root->sectorsize), (u64)-1, 0);
/*
* This function is also used to drop the items in the log tree before
* we relog the inode, so if root != BTRFS_I(inode)->root, it means
* it is used to drop the loged items. So we shouldn't kill the delayed
* items.
*/
if (min_type == 0 && root == BTRFS_I(inode)->root)
btrfs_kill_delayed_inode_items(inode);
key.objectid = ino;
key.offset = (u64)-1;
key.type = (u8)-1;
search_again:
/*
* with a 16K leaf size and 128MB extents, you can actually queue
* up a huge file in a single leaf. Most of the time that
* bytes_deleted is > 0, it will be huge by the time we get here
*/
if (be_nice && bytes_deleted > SZ_32M) {
if (btrfs_should_end_transaction(trans, root)) {
err = -EAGAIN;
goto error;
}
}
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
/* there are no items in the tree for us to truncate, we're
* done
*/
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
while (1) {
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != ino)
break;
if (found_type < min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
}
item_end--;
}
if (found_type > min_type) {
del_item = 1;
} else {
if (item_end < new_size)
break;
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
}
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
if (del_item)
last_size = found_key.offset;
else
last_size = new_size;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = ALIGN(new_size -
found_key.offset,
root->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes);
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state) &&
extent_start != 0)
inode_sub_bytes(inode, num_dec);
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
extent_offset = found_key.offset -
btrfs_file_extent_offset(leaf, fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0) {
found_extent = 1;
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state))
inode_sub_bytes(inode, num_dec);
}
}
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* we can't truncate inline items that have had
* special encodings
*/
if (!del_item &&
btrfs_file_extent_encryption(leaf, fi) == 0 &&
btrfs_file_extent_other_encoding(leaf, fi) == 0) {
/*
* Need to release path in order to truncate a
* compressed extent. So delete any accumulated
* extent items so far.
*/
if (btrfs_file_extent_compression(leaf, fi) !=
BTRFS_COMPRESS_NONE && pending_del_nr) {
err = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (err) {
btrfs_abort_transaction(trans,
root,
err);
goto error;
}
pending_del_nr = 0;
}
err = truncate_inline_extent(inode, path,
&found_key,
item_end,
new_size);
if (err) {
btrfs_abort_transaction(trans,
root, err);
goto error;
}
} else if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state)) {
inode_sub_bytes(inode, item_end + 1 - new_size);
}
}
delete:
if (del_item) {
if (!pending_del_nr) {
/* no pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
} else {
BUG();
}
} else {
break;
}
should_throttle = 0;
if (found_extent &&
(test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == root->fs_info->tree_root)) {
btrfs_set_path_blocking(path);
bytes_deleted += extent_num_bytes;
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_bytes, 0,
btrfs_header_owner(leaf),
ino, extent_offset);
BUG_ON(ret);
if (btrfs_should_throttle_delayed_refs(trans, root))
btrfs_async_run_delayed_refs(root,
trans->delayed_ref_updates * 2, 0);
if (be_nice) {
if (truncate_space_check(trans, root,
extent_num_bytes)) {
should_end = 1;
}
if (btrfs_should_throttle_delayed_refs(trans,
root)) {
should_throttle = 1;
}
}
}
if (found_type == BTRFS_INODE_ITEM_KEY)
break;
if (path->slots[0] == 0 ||
path->slots[0] != pending_del_slot ||
should_throttle || should_end) {
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (ret) {
btrfs_abort_transaction(trans,
root, ret);
goto error;
}
pending_del_nr = 0;
}
btrfs_release_path(path);
if (should_throttle) {
unsigned long updates = trans->delayed_ref_updates;
if (updates) {
trans->delayed_ref_updates = 0;
ret = btrfs_run_delayed_refs(trans, root, updates * 2);
if (ret && !err)
err = ret;
}
}
/*
* if we failed to refill our space rsv, bail out
* and let the transaction restart
*/
if (should_end) {
err = -EAGAIN;
goto error;
}
goto search_again;
} else {
path->slots[0]--;
}
}
out:
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
if (ret)
btrfs_abort_transaction(trans, root, ret);
}
error:
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
btrfs_ordered_update_i_size(inode, last_size, NULL);
btrfs_free_path(path);
if (be_nice && bytes_deleted > SZ_32M) {
unsigned long updates = trans->delayed_ref_updates;
if (updates) {
trans->delayed_ref_updates = 0;
ret = btrfs_run_delayed_refs(trans, root, updates * 2);
if (ret && !err)
err = ret;
}
}
return err;
}
/*
* btrfs_truncate_page - read, zero a chunk and write a page
* @inode - inode that we're zeroing
* @from - the offset to start zeroing
* @len - the length to zero, 0 to zero the entire range respective to the
* offset
* @front - zero up to the offset instead of from the offset on
*
* This will find the page for the "from" offset and cow the page and zero the
* part we want to zero. This is used with truncate and hole punching.
*/
int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
int front)
{
struct address_space *mapping = inode->i_mapping;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
char *kaddr;
u32 blocksize = root->sectorsize;
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE-1);
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(mapping);
int ret = 0;
u64 page_start;
u64 page_end;
if ((offset & (blocksize - 1)) == 0 &&
(!len || ((len & (blocksize - 1)) == 0)))
goto out;
ret = btrfs_delalloc_reserve_space(inode,
round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
if (ret)
goto out;
again:
page = find_or_create_page(mapping, index, mask);
if (!page) {
btrfs_delalloc_release_space(inode,
round_down(from, PAGE_CACHE_SIZE),
PAGE_CACHE_SIZE);
ret = -ENOMEM;
goto out;
}
page_start = page_offset(page);
page_end = page_start + PAGE_CACHE_SIZE - 1;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
page_cache_release(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
set_page_extent_mapped(page);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state, GFP_NOFS);
ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
goto out_unlock;
}
if (offset != PAGE_CACHE_SIZE) {
if (!len)
len = PAGE_CACHE_SIZE - offset;
kaddr = kmap(page);
if (front)
memset(kaddr, 0, offset);
else
memset(kaddr + offset, 0, len);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
GFP_NOFS);
out_unlock:
if (ret)
btrfs_delalloc_release_space(inode, page_start,
PAGE_CACHE_SIZE);
unlock_page(page);
page_cache_release(page);
out:
return ret;
}
static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
u64 offset, u64 len)
{
struct btrfs_trans_handle *trans;
int ret;
/*
* Still need to make sure the inode looks like it's been updated so
* that any holes get logged if we fsync.
*/
if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
BTRFS_I(inode)->last_trans = root->fs_info->generation;
BTRFS_I(inode)->last_sub_trans = root->log_transid;
BTRFS_I(inode)->last_log_commit = root->last_log_commit;
return 0;
}
/*
* 1 - for the one we're dropping
* 1 - for the one we're adding
* 1 - for updating the inode.
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
btrfs_end_transaction(trans, root);
return ret;
}
ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
0, 0, len, 0, len, 0, 0, 0);
if (ret)
btrfs_abort_transaction(trans, root, ret);
else
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
return ret;
}
/*
* This function puts in dummy file extents for the area we're creating a hole
* for. So if we are truncating this file to a larger size we need to insert
* these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
* the range between oldsize and size
*/
int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
u64 hole_start = ALIGN(oldsize, root->sectorsize);
u64 block_end = ALIGN(size, root->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
int err = 0;
/*
* If our size started in the middle of a page we need to zero out the
* rest of the page before we expand the i_size, otherwise we could
* expose stale data.
*/
err = btrfs_truncate_page(inode, oldsize, 0, 0);
if (err)
return err;
if (size <= hole_start)
return 0;
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent_bits(io_tree, hole_start, block_end - 1,
&cached_state);
ordered = btrfs_lookup_ordered_range(inode, hole_start,
block_end - hole_start);
if (!ordered)
break;
unlock_extent_cached(io_tree, hole_start, block_end - 1,
&cached_state, GFP_NOFS);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
}
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
block_end - cur_offset, 0);
if (IS_ERR(em)) {
err = PTR_ERR(em);
em = NULL;
break;
}
last_byte = min(extent_map_end(em), block_end);
last_byte = ALIGN(last_byte , root->sectorsize);
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
hole_size = last_byte - cur_offset;
err = maybe_insert_hole(root, inode, cur_offset,
hole_size);
if (err)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + hole_size - 1, 0);
hole_em = alloc_extent_map();
if (!hole_em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
hole_em->start = cur_offset;
hole_em->len = hole_size;
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->orig_block_len = 0;
hole_em->ram_bytes = hole_size;
hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
hole_em->compress_type = BTRFS_COMPRESS_NONE;
hole_em->generation = root->fs_info->generation;
while (1) {
write_lock(&em_tree->lock);
err = add_extent_mapping(em_tree, hole_em, 1);
write_unlock(&em_tree->lock);
if (err != -EEXIST)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset +
hole_size - 1, 0);
}
free_extent_map(hole_em);
}
next:
free_extent_map(em);
em = NULL;
cur_offset = last_byte;
if (cur_offset >= block_end)
break;
}
free_extent_map(em);
unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
GFP_NOFS);
return err;
}
static int wait_snapshoting_atomic_t(atomic_t *a)
{
schedule();
return 0;
}
static void wait_for_snapshot_creation(struct btrfs_root *root)
{
while (true) {
int ret;
ret = btrfs_start_write_no_snapshoting(root);
if (ret)
break;
wait_on_atomic_t(&root->will_be_snapshoted,
wait_snapshoting_atomic_t,
TASK_UNINTERRUPTIBLE);
}
}
static int btrfs_setsize(struct inode *inode, struct iattr *attr)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
loff_t oldsize = i_size_read(inode);
loff_t newsize = attr->ia_size;
int mask = attr->ia_valid;
int ret;
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
if (newsize != oldsize) {
inode_inc_iversion(inode);
if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
inode->i_ctime = inode->i_mtime =
current_fs_time(inode->i_sb);
}
if (newsize > oldsize) {
truncate_pagecache(inode, newsize);
/*
* Don't do an expanding truncate while snapshoting is ongoing.
* This is to ensure the snapshot captures a fully consistent
* state of this file - if the snapshot captures this expanding
* truncation, it must capture all writes that happened before
* this truncation.
*/
wait_for_snapshot_creation(root);
ret = btrfs_cont_expand(inode, oldsize, newsize);
if (ret) {
btrfs_end_write_no_snapshoting(root);
return ret;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_end_write_no_snapshoting(root);
return PTR_ERR(trans);
}
i_size_write(inode, newsize);
btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
ret = btrfs_update_inode(trans, root, inode);
btrfs_end_write_no_snapshoting(root);
btrfs_end_transaction(trans, root);
} else {
/*
* We're truncating a file that used to have good data down to
* zero. Make sure it gets into the ordered flush list so that
* any new writes get down to disk quickly.
*/
if (newsize == 0)
set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
&BTRFS_I(inode)->runtime_flags);
/*
* 1 for the orphan item we're going to add
* 1 for the orphan item deletion.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans))
return PTR_ERR(trans);
/*
* We need to do this in case we fail at _any_ point during the
* actual truncate. Once we do the truncate_setsize we could
* invalidate pages which forces any outstanding ordered io to
* be instantly completed which will give us extents that need
* to be truncated. If we fail to get an orphan inode down we
* could have left over extents that were never meant to live,
* so we need to garuntee from this point on that everything
* will be consistent.
*/
ret = btrfs_orphan_add(trans, inode);
btrfs_end_transaction(trans, root);
if (ret)
return ret;
/* we don't support swapfiles, so vmtruncate shouldn't fail */
truncate_setsize(inode, newsize);
/* Disable nonlocked read DIO to avoid the end less truncate */
btrfs_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
btrfs_inode_resume_unlocked_dio(inode);
ret = btrfs_truncate(inode);
if (ret && inode->i_nlink) {
int err;
/*
* failed to truncate, disk_i_size is only adjusted down
* as we remove extents, so it should represent the true
* size of the inode, so reset the in memory size and
* delete our orphan entry.
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_orphan_del(NULL, inode);
return ret;
}
i_size_write(inode, BTRFS_I(inode)->disk_i_size);
err = btrfs_orphan_del(trans, inode);
if (err)
btrfs_abort_transaction(trans, root, err);
btrfs_end_transaction(trans, root);
}
}
return ret;
}
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
if (btrfs_root_readonly(root))
return -EROFS;
err = inode_change_ok(inode, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
err = btrfs_setsize(inode, attr);
if (err)
return err;
}
if (attr->ia_valid) {
setattr_copy(inode, attr);
inode_inc_iversion(inode);
err = btrfs_dirty_inode(inode);
if (!err && attr->ia_valid & ATTR_MODE)
err = posix_acl_chmod(inode, inode->i_mode);
}
return err;
}
/*
* While truncating the inode pages during eviction, we get the VFS calling
* btrfs_invalidatepage() against each page of the inode. This is slow because
* the calls to btrfs_invalidatepage() result in a huge amount of calls to
* lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
* extent_state structures over and over, wasting lots of time.
*
* Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
* those expensive operations on a per page basis and do only the ordered io
* finishing, while we release here the extent_map and extent_state structures,
* without the excessive merging and splitting.
*/
static void evict_inode_truncate_pages(struct inode *inode)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
struct rb_node *node;
ASSERT(inode->i_state & I_FREEING);
truncate_inode_pages_final(&inode->i_data);
write_lock(&map_tree->lock);
while (!RB_EMPTY_ROOT(&map_tree->map)) {
struct extent_map *em;
node = rb_first(&map_tree->map);
em = rb_entry(node, struct extent_map, rb_node);
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
remove_extent_mapping(map_tree, em);
free_extent_map(em);
if (need_resched()) {
write_unlock(&map_tree->lock);
cond_resched();
write_lock(&map_tree->lock);
}
}
write_unlock(&map_tree->lock);
/*
* Keep looping until we have no more ranges in the io tree.
* We can have ongoing bios started by readpages (called from readahead)
* that have their endio callback (extent_io.c:end_bio_extent_readpage)
* still in progress (unlocked the pages in the bio but did not yet
* unlocked the ranges in the io tree). Therefore this means some
* ranges can still be locked and eviction started because before
* submitting those bios, which are executed by a separate task (work
* queue kthread), inode references (inode->i_count) were not taken
* (which would be dropped in the end io callback of each bio).
* Therefore here we effectively end up waiting for those bios and
* anyone else holding locked ranges without having bumped the inode's
* reference count - if we don't do it, when they access the inode's
* io_tree to unlock a range it may be too late, leading to an
* use-after-free issue.
*/
spin_lock(&io_tree->lock);
while (!RB_EMPTY_ROOT(&io_tree->state)) {
struct extent_state *state;
struct extent_state *cached_state = NULL;
u64 start;
u64 end;
node = rb_first(&io_tree->state);
state = rb_entry(node, struct extent_state, rb_node);
start = state->start;
end = state->end;
spin_unlock(&io_tree->lock);
lock_extent_bits(io_tree, start, end, &cached_state);
/*
* If still has DELALLOC flag, the extent didn't reach disk,
* and its reserved space won't be freed by delayed_ref.
* So we need to free its reserved space here.
* (Refer to comment in btrfs_invalidatepage, case 2)
*
* Note, end is the bytenr of last byte, so we need + 1 here.
*/
if (state->state & EXTENT_DELALLOC)
btrfs_qgroup_free_data(inode, start, end - start + 1);
clear_extent_bit(io_tree, start, end,
EXTENT_LOCKED | EXTENT_DIRTY |
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 1,
&cached_state, GFP_NOFS);
cond_resched();
spin_lock(&io_tree->lock);
}
spin_unlock(&io_tree->lock);
}
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv, *global_rsv;
int steal_from_global = 0;
u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
int ret;
trace_btrfs_inode_evict(inode);
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&
((btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
btrfs_is_free_space_inode(inode)))
goto no_delete;
if (is_bad_inode(inode)) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
if (!special_file(inode->i_mode))
btrfs_wait_ordered_range(inode, 0, (u64)-1);
btrfs_free_io_failure_record(inode, 0, (u64)-1);
if (root->fs_info->log_root_recovering) {
BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags));
goto no_delete;
}
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
goto no_delete;
}
ret = btrfs_commit_inode_delayed_inode(inode);
if (ret) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!rsv) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
rsv->size = min_size;
rsv->failfast = 1;
global_rsv = &root->fs_info->global_block_rsv;
btrfs_i_size_write(inode, 0);
/*
* This is a bit simpler than btrfs_truncate since we've already
* reserved our space for our orphan item in the unlink, so we just
* need to reserve some slack space in case we add bytes and update
* inode item when doing the truncate.
*/
while (1) {
ret = btrfs_block_rsv_refill(root, rsv, min_size,
BTRFS_RESERVE_FLUSH_LIMIT);
/*
* Try and steal from the global reserve since we will
* likely not use this space anyway, we want to try as
* hard as possible to get this to work.
*/
if (ret)
steal_from_global++;
else
steal_from_global = 0;
ret = 0;
/*
* steal_from_global == 0: we reserved stuff, hooray!
* steal_from_global == 1: we didn't reserve stuff, boo!
* steal_from_global == 2: we've committed, still not a lot of
* room but maybe we'll have room in the global reserve this
* time.
* steal_from_global == 3: abandon all hope!
*/
if (steal_from_global > 2) {
btrfs_warn(root->fs_info,
"Could not get space for a delete, will truncate on mount %d",
ret);
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
/*
* We can't just steal from the global reserve, we need tomake
* sure there is room to do it, if not we need to commit and try
* again.
*/
if (steal_from_global) {
if (!btrfs_check_space_for_delayed_refs(trans, root))
ret = btrfs_block_rsv_migrate(global_rsv, rsv,
min_size);
else
ret = -ENOSPC;
}
/*
* Couldn't steal from the global reserve, we have too much
* pending stuff built up, commit the transaction and try it
* again.
*/
if (ret) {
ret = btrfs_commit_transaction(trans, root);
if (ret) {
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
continue;
} else {
steal_from_global = 0;
}
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
if (ret != -ENOSPC && ret != -EAGAIN)
break;
trans->block_rsv = &root->fs_info->trans_block_rsv;
btrfs_end_transaction(trans, root);
trans = NULL;
btrfs_btree_balance_dirty(root);
}
btrfs_free_block_rsv(root, rsv);
/*
* Errors here aren't a big deal, it just means we leave orphan items
* in the tree. They will be cleaned up on the next mount.
*/
if (ret == 0) {
trans->block_rsv = root->orphan_block_rsv;
btrfs_orphan_del(trans, inode);
} else {
btrfs_orphan_del(NULL, inode);
}
trans->block_rsv = &root->fs_info->trans_block_rsv;
if (!(root == root->fs_info->tree_root ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
btrfs_return_ino(root, btrfs_ino(inode));
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
no_delete:
btrfs_remove_delayed_node(inode);
clear_inode(inode);
}
/*
* this returns the key found in the dir entry in the location pointer.
* If no dir entries were found, location->objectid is 0.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
namelen, 0);
if (IS_ERR(di))
ret = PTR_ERR(di);
if (IS_ERR_OR_NULL(di))
goto out_err;
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
out:
btrfs_free_path(path);
return ret;
out_err:
location->objectid = 0;
goto out;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_root *root,
struct inode *dir,
struct dentry *dentry,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root *new_root;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
err = -ENOENT;
key.objectid = BTRFS_I(dir)->root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = location->objectid;
ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
0, 0);
if (ret) {
if (ret < 0)
err = ret;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
goto out;
ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
(unsigned long)(ref + 1),
dentry->d_name.len);
if (ret)
goto out;
btrfs_release_path(path);
new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
if (IS_ERR(new_root)) {
err = PTR_ERR(new_root);
goto out;
}
*sub_root = new_root;
location->objectid = btrfs_root_dirid(&new_root->root_item);
location->type = BTRFS_INODE_ITEM_KEY;
location->offset = 0;
err = 0;
out:
btrfs_free_path(path);
return err;
}
static void inode_tree_add(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
struct rb_node *new = &BTRFS_I(inode)->rb_node;
u64 ino = btrfs_ino(inode);
if (inode_unhashed(inode))
return;
parent = NULL;
spin_lock(&root->inode_lock);
p = &root->inode_tree.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_inode, rb_node);
if (ino < btrfs_ino(&entry->vfs_inode))
p = &parent->rb_left;
else if (ino > btrfs_ino(&entry->vfs_inode))
p = &parent->rb_right;
else {
WARN_ON(!(entry->vfs_inode.i_state &
(I_WILL_FREE | I_FREEING)));
rb_replace_node(parent, new, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
return;
}
}
rb_link_node(new, parent, p);
rb_insert_color(new, &root->inode_tree);
spin_unlock(&root->inode_lock);
}
static void inode_tree_del(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
synchronize_srcu(&root->fs_info->subvol_srcu);
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
void btrfs_invalidate_inodes(struct btrfs_root *root)
{
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < btrfs_ino(&entry->vfs_inode))
node = node->rb_left;
else if (objectid > btrfs_ino(&entry->vfs_inode))
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= btrfs_ino(&entry->vfs_inode)) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = btrfs_ino(&entry->vfs_inode) + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will have it removed from
* the inode cache when its usage count
* hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->location->objectid;
memcpy(&BTRFS_I(inode)->location, args->location,
sizeof(*args->location));
BTRFS_I(inode)->root = args->root;
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return args->location->objectid == BTRFS_I(inode)->location.objectid &&
args->root == BTRFS_I(inode)->root;
}
static struct inode *btrfs_iget_locked(struct super_block *s,
struct btrfs_key *location,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
unsigned long hashval = btrfs_inode_hash(location->objectid, root);
args.location = location;
args.root = root;
inode = iget5_locked(s, hashval, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/* Get an inode object given its location and corresponding root.
* Returns in *is_new if the inode was read from disk
*/
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
struct btrfs_root *root, int *new)
{
struct inode *inode;
inode = btrfs_iget_locked(s, location, root);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
btrfs_read_locked_inode(inode);
if (!is_bad_inode(inode)) {
inode_tree_add(inode);
unlock_new_inode(inode);
if (new)
*new = 1;
} else {
unlock_new_inode(inode);
iput(inode);
inode = ERR_PTR(-ESTALE);
}
}
return inode;
}
static struct inode *new_simple_dir(struct super_block *s,
struct btrfs_key *key,
struct btrfs_root *root)
{
struct inode *inode = new_inode(s);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = root;
memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
inode->i_op = &btrfs_dir_ro_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
inode->i_mtime = CURRENT_TIME;
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
return inode;
}
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int index;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &location);
if (ret < 0)
return ERR_PTR(ret);
if (location.objectid == 0)
return ERR_PTR(-ENOENT);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root, NULL);
return inode;
}
BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
index = srcu_read_lock(&root->fs_info->subvol_srcu);
ret = fixup_tree_root_location(root, dir, dentry,
&location, &sub_root);
if (ret < 0) {
if (ret != -ENOENT)
inode = ERR_PTR(ret);
else
inode = new_simple_dir(dir->i_sb, &location, sub_root);
} else {
inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
}
srcu_read_unlock(&root->fs_info->subvol_srcu, index);
if (!IS_ERR(inode) && root != sub_root) {
down_read(&root->fs_info->cleanup_work_sem);
if (!(inode->i_sb->s_flags & MS_RDONLY))
ret = btrfs_orphan_cleanup(sub_root);
up_read(&root->fs_info->cleanup_work_sem);
if (ret) {
iput(inode);
inode = ERR_PTR(ret);
}
}
return inode;
}
static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
struct inode *inode = d_inode(dentry);
if (!inode && !IS_ROOT(dentry))
inode = d_inode(dentry->d_parent);
if (inode) {
root = BTRFS_I(inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return 1;
}
return 0;
}
static void btrfs_dentry_release(struct dentry *dentry)
{
kfree(dentry->d_fsdata);
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode;
inode = btrfs_lookup_dentry(dir, dentry);
if (IS_ERR(inode)) {
if (PTR_ERR(inode) == -ENOENT)
inode = NULL;
else
return ERR_CAST(inode);
}
return d_splice_alias(inode, dentry);
}
unsigned char btrfs_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};
static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_item *item;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
struct list_head ins_list;
struct list_head del_list;
int ret;
struct extent_buffer *leaf;
int slot;
unsigned char d_type;
int over = 0;
u32 di_cur;
u32 di_total;
u32 di_len;
int key_type = BTRFS_DIR_INDEX_KEY;
char tmp_name[32];
char *name_ptr;
int name_len;
int is_curr = 0; /* ctx->pos points to the current index? */
/* FIXME, use a real flag for deciding about the key type */
if (root->fs_info->tree_root == root)
key_type = BTRFS_DIR_ITEM_KEY;
if (!dir_emit_dots(file, ctx))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
if (key_type == BTRFS_DIR_INDEX_KEY) {
INIT_LIST_HEAD(&ins_list);
INIT_LIST_HEAD(&del_list);
btrfs_get_delayed_items(inode, &ins_list, &del_list);
}
key.type = key_type;
key.offset = ctx->pos;
key.objectid = btrfs_ino(inode);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while (1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
else if (ret > 0)
break;
continue;
}
item = btrfs_item_nr(slot);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (found_key.type != key_type)
break;
if (found_key.offset < ctx->pos)
goto next;
if (key_type == BTRFS_DIR_INDEX_KEY &&
btrfs_should_delete_dir_index(&del_list,
found_key.offset))
goto next;
ctx->pos = found_key.offset;
is_curr = 1;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf, item);
while (di_cur < di_total) {
struct btrfs_key location;
if (verify_dir_item(root, leaf, di))
break;
name_len = btrfs_dir_name_len(leaf, di);
if (name_len <= sizeof(tmp_name)) {
name_ptr = tmp_name;
} else {
name_ptr = kmalloc(name_len, GFP_NOFS);
if (!name_ptr) {
ret = -ENOMEM;
goto err;
}
}
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
/* is this a reference to our own snapshot? If so
* skip it.
*
* In contrast to old kernels, we insert the snapshot's
* dir item and dir index after it has been created, so
* we won't find a reference to our own snapshot. We
* still keep the following code for backward
* compatibility.
*/
if (location.type == BTRFS_ROOT_ITEM_KEY &&
location.objectid == root->root_key.objectid) {
over = 0;
goto skip;
}
over = !dir_emit(ctx, name_ptr, name_len,
location.objectid, d_type);
skip:
if (name_ptr != tmp_name)
kfree(name_ptr);
if (over)
goto nopos;
di_len = btrfs_dir_name_len(leaf, di) +
btrfs_dir_data_len(leaf, di) + sizeof(*di);
di_cur += di_len;
di = (struct btrfs_dir_item *)((char *)di + di_len);
}
next:
path->slots[0]++;
}
if (key_type == BTRFS_DIR_INDEX_KEY) {
if (is_curr)
ctx->pos++;
ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
if (ret)
goto nopos;
}
/* Reached end of directory/root. Bump pos past the last item. */
ctx->pos++;
/*
* Stop new entries from being returned after we return the last
* entry.
*
* New directory entries are assigned a strictly increasing
* offset. This means that new entries created during readdir
* are *guaranteed* to be seen in the future by that readdir.
* This has broken buggy programs which operate on names as
* they're returned by readdir. Until we re-use freed offsets
* we have this hack to stop new entries from being returned
* under the assumption that they'll never reach this huge
* offset.
*
* This is being careful not to overflow 32bit loff_t unless the
* last entry requires it because doing so has broken 32bit apps
* in the past.
*/
if (key_type == BTRFS_DIR_INDEX_KEY) {
if (ctx->pos >= INT_MAX)
ctx->pos = LLONG_MAX;
else
ctx->pos = INT_MAX;
}
nopos:
ret = 0;
err:
if (key_type == BTRFS_DIR_INDEX_KEY)
btrfs_put_delayed_items(&ins_list, &del_list);
btrfs_free_path(path);
return ret;
}
int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
bool nolock = false;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
nolock = true;
if (wbc->sync_mode == WB_SYNC_ALL) {
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_commit_transaction(trans, root);
}
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
static int btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
if (ret && ret == -ENOSPC) {
/* whoops, lets try again with the full transaction */
btrfs_end_transaction(trans, root);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans, root);
if (BTRFS_I(inode)->delayed_node)
btrfs_balance_delayed_items(root);
return ret;
}
/*
* This is a copy of file_update_time. We need this so we can return error on
* ENOSPC for updating the inode in the case of file write and mmap writes.
*/
static int btrfs_update_time(struct inode *inode, struct timespec *now,
int flags)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (btrfs_root_readonly(root))
return -EROFS;
if (flags & S_VERSION)
inode_inc_iversion(inode);
if (flags & S_CTIME)
inode->i_ctime = *now;
if (flags & S_MTIME)
inode->i_mtime = *now;
if (flags & S_ATIME)
inode->i_atime = *now;
return btrfs_dirty_inode(inode);
}
/*
* find the highest existing sequence number in a directory
* and then set the in-memory index_cnt variable to reflect
* free sequence numbers
*/
static int btrfs_set_inode_index_count(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
/*
* MAGIC NUMBER EXPLANATION:
* since we search a directory based on f_pos we have to start at 2
* since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
* else has to start at 2
*/
if (path->slots[0] == 0) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != btrfs_ino(inode) ||
found_key.type != BTRFS_DIR_INDEX_KEY) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
BTRFS_I(inode)->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
int btrfs_set_inode_index(struct inode *dir, u64 *index)
{
int ret = 0;
if (BTRFS_I(dir)->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
return ret;
}
}
*index = BTRFS_I(dir)->index_cnt;
BTRFS_I(dir)->index_cnt++;
return ret;
}
static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
args.location = &BTRFS_I(inode)->location;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
btrfs_find_actor, &args);
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
const char *name, int name_len,
u64 ref_objectid, u64 objectid,
umode_t mode, u64 *index)
{
struct inode *inode;
struct btrfs_inode_item *inode_item;
struct btrfs_key *location;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
int nitems = name ? 2 : 1;
unsigned long ptr;
int ret;
path = btrfs_alloc_path();
if (!path)
return ERR_PTR(-ENOMEM);
inode = new_inode(root->fs_info->sb);
if (!inode) {
btrfs_free_path(path);
return ERR_PTR(-ENOMEM);
}
/*
* O_TMPFILE, set link count to 0, so that after this point,
* we fill in an inode item with the correct link count.
*/
if (!name)
set_nlink(inode, 0);
/*
* we have to initialize this early, so we can reclaim the inode
* number if we fail afterwards in this function.
*/
inode->i_ino = objectid;
if (dir && name) {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(dir, index);
if (ret) {
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
} else if (dir) {
*index = 0;
}
/*
* index_cnt is ignored for everything but a dir,
* btrfs_get_inode_index_count has an explanation for the magic
* number
*/
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->dir_index = *index;
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->generation = trans->transid;
inode->i_generation = BTRFS_I(inode)->generation;
/*
* We could have gotten an inode number from somebody who was fsynced
* and then removed in this same transaction, so let's just set full
* sync since it will be a full sync anyway and this will blow away the
* old info in the log.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
key[0].objectid = objectid;
key[0].type = BTRFS_INODE_ITEM_KEY;
key[0].offset = 0;
sizes[0] = sizeof(struct btrfs_inode_item);
if (name) {
/*
* Start new inodes with an inode_ref. This is slightly more
* efficient for small numbers of hard links since they will
* be packed into one item. Extended refs will kick in if we
* add more hard links than can fit in the ref item.
*/
key[1].objectid = objectid;
key[1].type = BTRFS_INODE_REF_KEY;
key[1].offset = ref_objectid;
sizes[1] = name_len + sizeof(*ref);
}
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
location->type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0)
goto fail;
path->leave_spinning = 1;
ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
if (ret != 0)
goto fail_unlock;
inode_init_owner(inode, dir, mode);
inode_set_bytes(inode, 0);
inode->i_mtime = CURRENT_TIME;
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
if (name) {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(path->nodes[0], name, ptr, name_len);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
btrfs_inherit_iflags(inode, dir);
if (S_ISREG(mode)) {
if (btrfs_test_opt(root, NODATASUM))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
if (btrfs_test_opt(root, NODATACOW))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
}
inode_tree_add(inode);
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, inode);
btrfs_update_root_times(trans, root);
ret = btrfs_inode_inherit_props(trans, inode, dir);
if (ret)
btrfs_err(root->fs_info,
"error inheriting props for ino %llu (root %llu): %d",
btrfs_ino(inode), root->root_key.objectid, ret);
return inode;
fail_unlock:
unlock_new_inode(inode);
fail:
if (dir && name)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct inode *parent_inode, struct inode *inode,
const char *name, int name_len, int add_backref, u64 index)
{
int ret = 0;
struct btrfs_key key;
struct btrfs_root *root = BTRFS_I(parent_inode)->root;
u64 ino = btrfs_ino(inode);
u64 parent_ino = btrfs_ino(parent_inode);
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
} else {
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
}
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
key.objectid, root->root_key.objectid,
parent_ino, index, name, name_len);
} else if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
parent_ino, index);
}
/* Nothing to clean up yet */
if (ret)
return ret;
ret = btrfs_insert_dir_item(trans, root, name, name_len,
parent_inode, &key,
btrfs_inode_type(inode), index);
if (ret == -EEXIST || ret == -EOVERFLOW)
goto fail_dir_item;
else if (ret) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
btrfs_i_size_write(parent_inode, parent_inode->i_size +
name_len * 2);
inode_inc_iversion(parent_inode);
parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root, parent_inode);
if (ret)
btrfs_abort_transaction(trans, root, ret);
return ret;
fail_dir_item:
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
u64 local_index;
int err;
err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
key.objectid, root->root_key.objectid,
parent_ino, &local_index, name, name_len);
} else if (add_backref) {
u64 local_index;
int err;
err = btrfs_del_inode_ref(trans, root, name, name_len,
ino, parent_ino, &local_index);
}
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct inode *dir, struct dentry *dentry,
struct inode *inode, int backref, u64 index)
{
int err = btrfs_add_link(trans, dir, inode,
dentry->d_name.name, dentry->d_name.len,
backref, index);
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err) {
goto out_unlock_inode;
} else {
btrfs_update_inode(trans, root, inode);
unlock_new_inode(inode);
d_instantiate(dentry, inode);
}
out_unlock:
btrfs_end_transaction(trans, root);
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
return err;
out_unlock_inode:
drop_inode = 1;
unlock_new_inode(inode);
goto out_unlock;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool excl)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int drop_inode_on_err = 0;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
drop_inode_on_err = 1;
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_unlock_inode;
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err)
goto out_unlock_inode;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
if (err && drop_inode_on_err) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return err;
out_unlock_inode:
unlock_new_inode(inode);
goto out_unlock;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans = NULL;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(old_dentry);
u64 index;
int err;
int drop_inode = 0;
/* do not allow sys_link's with other subvols of the same device */
if (root->objectid != BTRFS_I(inode)->root->objectid)
return -EXDEV;
if (inode->i_nlink >= BTRFS_LINK_MAX)
return -EMLINK;
err = btrfs_set_inode_index(dir, &index);
if (err)
goto fail;
/*
* 2 items for inode and inode ref
* 2 items for dir items
* 1 item for parent inode
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
trans = NULL;
goto fail;
}
/* There are several dir indexes for this inode, clear the cache. */
BTRFS_I(inode)->dir_index = 0ULL;
inc_nlink(inode);
inode_inc_iversion(inode);
inode->i_ctime = CURRENT_TIME;
ihold(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
if (err) {
drop_inode = 1;
} else {
struct dentry *parent = dentry->d_parent;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto fail;
if (inode->i_nlink == 1) {
/*
* If new hard link count is 1, it's a file created
* with open(2) O_TMPFILE flag.
*/
err = btrfs_orphan_del(trans, inode);
if (err)
goto fail;
}
d_instantiate(dentry, inode);
btrfs_log_new_name(trans, inode, NULL, parent);
}
btrfs_balance_delayed_items(root);
fail:
if (trans)
btrfs_end_transaction(trans, root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
int drop_on_err = 0;
u64 objectid = 0;
u64 index = 0;
/*
* 2 items for inode and ref
* 2 items for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_fail;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
S_IFDIR | mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fail;
}
drop_on_err = 1;
/* these must be set before we unlock the inode */
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_fail_inode;
btrfs_i_size_write(inode, 0);
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail_inode;
err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
dentry->d_name.len, 0, index);
if (err)
goto out_fail_inode;
d_instantiate(dentry, inode);
/*
* mkdir is special. We're unlocking after we call d_instantiate
* to avoid a race with nfsd calling d_instantiate.
*/
unlock_new_inode(inode);
drop_on_err = 0;
out_fail:
btrfs_end_transaction(trans, root);
if (drop_on_err) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return err;
out_fail_inode:
unlock_new_inode(inode);
goto out_fail;
}
/* Find next extent map of a given extent map, caller needs to ensure locks */
static struct extent_map *next_extent_map(struct extent_map *em)
{
struct rb_node *next;
next = rb_next(&em->rb_node);
if (!next)
return NULL;
return container_of(next, struct extent_map, rb_node);
}
static struct extent_map *prev_extent_map(struct extent_map *em)
{
struct rb_node *prev;
prev = rb_prev(&em->rb_node);
if (!prev)
return NULL;
return container_of(prev, struct extent_map, rb_node);
}
/* helper for btfs_get_extent. Given an existing extent in the tree,
* the existing extent is the nearest extent to map_start,
* and an extent that you want to insert, deal with overlap and insert
* the best fitted new extent into the tree.
*/
static int merge_extent_mapping(struct extent_map_tree *em_tree,
struct extent_map *existing,
struct extent_map *em,
u64 map_start)
{
struct extent_map *prev;
struct extent_map *next;
u64 start;
u64 end;
u64 start_diff;
BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
if (existing->start > map_start) {
next = existing;
prev = prev_extent_map(next);
} else {
prev = existing;
next = next_extent_map(prev);
}
start = prev ? extent_map_end(prev) : em->start;
start = max_t(u64, start, em->start);
end = next ? next->start : extent_map_end(em);
end = min_t(u64, end, extent_map_end(em));
start_diff = start - em->start;
em->start = start;
em->len = end - start;
if (em->block_start < EXTENT_MAP_LAST_BYTE &&
!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
em->block_start += start_diff;
em->block_len -= start_diff;
}
return add_extent_mapping(em_tree, em, 0);
}
static noinline int uncompress_inline(struct btrfs_path *path,
struct page *page,
size_t pg_offset, u64 extent_offset,
struct btrfs_file_extent_item *item)
{
int ret;
struct extent_buffer *leaf = path->nodes[0];
char *tmp;
size_t max_size;
unsigned long inline_size;
unsigned long ptr;
int compress_type;
WARN_ON(pg_offset != 0);
compress_type = btrfs_file_extent_compression(leaf, item);
max_size = btrfs_file_extent_ram_bytes(leaf, item);
inline_size = btrfs_file_extent_inline_item_len(leaf,
btrfs_item_nr(path->slots[0]));
tmp = kmalloc(inline_size, GFP_NOFS);
if (!tmp)
return -ENOMEM;
ptr = btrfs_file_extent_inline_start(item);
read_extent_buffer(leaf, tmp, ptr, inline_size);
max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
ret = btrfs_decompress(compress_type, tmp, page,
extent_offset, inline_size, max_size);
kfree(tmp);
return ret;
}
/*
* a bit scary, this does extent mapping from logical file offset to the disk.
* the ugly parts come from merging extents from the disk with the in-ram
* representation. This gets more complex because of the data=ordered code,
* where the in-ram extents might be locked pending data=ordered completion.
*
* This also copies inline extents directly into the page.
*/
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create)
{
int ret;
int err = 0;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = btrfs_ino(inode);
u32 found_type;
struct btrfs_path *path = NULL;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_trans_handle *trans = NULL;
const bool new_inline = !page || create;
again:
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em)
em->bdev = root->fs_info->fs_devices->latest_bdev;
read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
if (!path) {
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
/*
* Chances are we'll be called again, so go ahead and do
* readahead
*/
path->reada = READA_FORWARD;
}
ret = btrfs_lookup_file_extent(trans, root, path,
objectid, start, trans != NULL);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
/* are we inside the extent that was found? */
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != objectid ||
found_type != BTRFS_EXTENT_DATA_KEY) {
/*
* If we backup past the first extent we want to move forward
* and see if there is an extent in front of us, otherwise we'll
* say there is a hole for our whole search range which can
* cause problems.
*/
extent_end = start;
goto next;
}
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size_t size;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
extent_end = ALIGN(extent_start + size, root->sectorsize);
}
next:
if (start >= extent_end) {
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0)
goto not_found;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
if (start + len <= found_key.offset)
goto not_found;
if (start > found_key.offset)
goto next;
em->start = start;
em->orig_start = start;
em->len = found_key.offset - start;
goto not_found_em;
}
btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
goto insert;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
if (new_inline)
goto out;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
extent_offset = page_offset(page) + pg_offset - extent_start;
copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->len = ALIGN(copy_size, root->sectorsize);
em->orig_block_len = em->len;
em->orig_start = em->start;
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
if (create == 0 && !PageUptodate(page)) {
if (btrfs_file_extent_compression(leaf, item) !=
BTRFS_COMPRESS_NONE) {
ret = uncompress_inline(path, page, pg_offset,
extent_offset, item);
if (ret) {
err = ret;
goto out;
}
} else {
map = kmap(page);
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
memset(map + pg_offset + copy_size, 0,
PAGE_CACHE_SIZE - pg_offset -
copy_size);
}
kunmap(page);
}
flush_dcache_page(page);
} else if (create && PageUptodate(page)) {
BUG();
if (!trans) {
kunmap(page);
free_extent_map(em);
em = NULL;
btrfs_release_path(path);
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return ERR_CAST(trans);
goto again;
}
map = kmap(page);
write_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
kunmap(page);
btrfs_mark_buffer_dirty(leaf);
}
set_extent_uptodate(io_tree, em->start,
extent_map_end(em) - 1, NULL, GFP_NOFS);
goto insert;
}
not_found:
em->start = start;
em->orig_start = start;
em->len = len;
not_found_em:
em->block_start = EXTENT_MAP_HOLE;
set_bit(EXTENT_FLAG_VACANCY, &em->flags);
insert:
btrfs_release_path(path);
if (em->start > start || extent_map_end(em) <= start) {
btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
em->start, em->len, start, len);
err = -EIO;
goto out;
}
err = 0;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 0);
/* it is possible that someone inserted the extent into the tree
* while we had the lock dropped. It is also possible that
* an overlapping map exists in the tree
*/
if (ret == -EEXIST) {
struct extent_map *existing;
ret = 0;
existing = search_extent_mapping(em_tree, start, len);
/*
* existing will always be non-NULL, since there must be
* extent causing the -EEXIST.
*/
if (start >= extent_map_end(existing) ||
start <= existing->start) {
/*
* The existing extent map is the one nearest to
* the [start, start + len) range which overlaps
*/
err = merge_extent_mapping(em_tree, existing,
em, start);
free_extent_map(existing);
if (err) {
free_extent_map(em);
em = NULL;
}
} else {
free_extent_map(em);
em = existing;
err = 0;
}
}
write_unlock(&em_tree->lock);
out:
trace_btrfs_get_extent(root, em);
btrfs_free_path(path);
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err)
err = ret;
}
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
BUG_ON(!em); /* Error is always set */
return em;
}
struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create)
{
struct extent_map *em;
struct extent_map *hole_em = NULL;
u64 range_start = start;
u64 end;
u64 found;
u64 found_end;
int err = 0;
em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
if (IS_ERR(em))
return em;
if (em) {
/*
* if our em maps to
* - a hole or
* - a pre-alloc extent,
* there might actually be delalloc bytes behind it.
*/
if (em->block_start != EXTENT_MAP_HOLE &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
return em;
else
hole_em = em;
}
/* check to see if we've wrapped (len == -1 or similar) */
end = start + len;
if (end < start)
end = (u64)-1;
else
end -= 1;
em = NULL;
/* ok, we didn't find anything, lets look for delalloc */
found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
end, len, EXTENT_DELALLOC, 1);
found_end = range_start + found;
if (found_end < range_start)
found_end = (u64)-1;
/*
* we didn't find anything useful, return
* the original results from get_extent()
*/
if (range_start > end || found_end <= start) {
em = hole_em;
hole_em = NULL;
goto out;
}
/* adjust the range_start to make sure it doesn't
* go backwards from the start they passed in
*/
range_start = max(start, range_start);
found = found_end - range_start;
if (found > 0) {
u64 hole_start = start;
u64 hole_len = len;
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
/*
* when btrfs_get_extent can't find anything it
* returns one huge hole
*
* make sure what it found really fits our range, and
* adjust to make sure it is based on the start from
* the caller
*/
if (hole_em) {
u64 calc_end = extent_map_end(hole_em);
if (calc_end <= start || (hole_em->start > end)) {
free_extent_map(hole_em);
hole_em = NULL;
} else {
hole_start = max(hole_em->start, start);
hole_len = calc_end - hole_start;
}
}
em->bdev = NULL;
if (hole_em && range_start > hole_start) {
/* our hole starts before our delalloc, so we
* have to return just the parts of the hole
* that go until the delalloc starts
*/
em->len = min(hole_len,
range_start - hole_start);
em->start = hole_start;
em->orig_start = hole_start;
/*
* don't adjust block start at all,
* it is fixed at EXTENT_MAP_HOLE
*/
em->block_start = hole_em->block_start;
em->block_len = hole_len;
if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
} else {
em->start = range_start;
em->len = found;
em->orig_start = range_start;
em->block_start = EXTENT_MAP_DELALLOC;
em->block_len = found;
}
} else if (hole_em) {
return hole_em;
}
out:
free_extent_map(hole_em);
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
return em;
}
static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
u64 start, u64 len)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len);
ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
alloc_hint, &ins, 1, 1);
if (ret)
return ERR_PTR(ret);
em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
ins.offset, ins.offset, ins.offset, 0);
if (IS_ERR(em)) {
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
return em;
}
ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
ins.offset, ins.offset, 0);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
free_extent_map(em);
return ERR_PTR(ret);
}
return em;
}
/*
* returns 1 when the nocow is safe, < 1 on error, 0 if the
* block must be cow'd
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes)
{
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
int ret;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 disk_bytenr;
u64 backref_offset;
u64 extent_end;
u64 num_bytes;
int slot;
int found_type;
bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
offset, 0);
if (ret < 0)
goto out;
slot = path->slots[0];
if (ret == 1) {
if (slot == 0) {
/* can't find the item, must cow */
ret = 0;
goto out;
}
slot--;
}
ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
/* not our file or wrong item type, must cow */
goto out;
}
if (key.offset > offset) {
/* Wrong offset, must cow */
goto out;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, fi);
if (found_type != BTRFS_FILE_EXTENT_REG &&
found_type != BTRFS_FILE_EXTENT_PREALLOC) {
/* not a regular extent, must cow */
goto out;
}
if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
goto out;
extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
if (extent_end <= offset)
goto out;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (disk_bytenr == 0)
goto out;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out;
backref_offset = btrfs_file_extent_offset(leaf, fi);
if (orig_start) {
*orig_start = key.offset - backref_offset;
*orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
}
if (btrfs_extent_readonly(root, disk_bytenr))
goto out;
num_bytes = min(offset + *len, extent_end) - offset;
if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 range_end;
range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
ret = test_range_bit(io_tree, offset, range_end,
EXTENT_DELALLOC, 0, NULL);
if (ret) {
ret = -EAGAIN;
goto out;
}
}
btrfs_release_path(path);
/*
* look for other files referencing this extent, if we
* find any we must cow
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = 0;
goto out;
}
ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
key.offset - backref_offset, disk_bytenr);
btrfs_end_transaction(trans, root);
if (ret) {
ret = 0;
goto out;
}
/*
* adjust disk_bytenr and num_bytes to cover just the bytes
* in this extent we are about to write. If there
* are any csums in that range we have to cow in order
* to keep the csums correct
*/
disk_bytenr += backref_offset;
disk_bytenr += offset - key.offset;
if (csum_exist_in_range(root, disk_bytenr, num_bytes))
goto out;
/*
* all of the above have passed, it is safe to overwrite this extent
* without cow
*/
*len = num_bytes;
ret = 1;
out:
btrfs_free_path(path);
return ret;
}
bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
{
struct radix_tree_root *root = &inode->i_mapping->page_tree;
int found = false;
void **pagep = NULL;
struct page *page = NULL;
int start_idx;
int end_idx;
start_idx = start >> PAGE_CACHE_SHIFT;
/*
* end is the last byte in the last page. end == start is legal
*/
end_idx = end >> PAGE_CACHE_SHIFT;
rcu_read_lock();
/* Most of the code in this while loop is lifted from
* find_get_page. It's been modified to begin searching from a
* page and return just the first page found in that range. If the
* found idx is less than or equal to the end idx then we know that
* a page exists. If no pages are found or if those pages are
* outside of the range then we're fine (yay!) */
while (page == NULL &&
radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
page = radix_tree_deref_slot(pagep);
if (unlikely(!page))
break;
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
page = NULL;
continue;
}
/*
* Otherwise, shmem/tmpfs must be storing a swap entry
* here as an exceptional entry: so return it without
* attempting to raise page count.
*/
page = NULL;
break; /* TODO: Is this relevant for this use case? */
}
if (!page_cache_get_speculative(page)) {
page = NULL;
continue;
}
/*
* Has the page moved?
* This is part of the lockless pagecache protocol. See
* include/linux/pagemap.h for details.
*/
if (unlikely(page != *pagep)) {
page_cache_release(page);
page = NULL;
}
}
if (page) {
if (page->index <= end_idx)
found = true;
page_cache_release(page);
}
rcu_read_unlock();
return found;
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state, int writing)
{
struct btrfs_ordered_extent *ordered;
int ret = 0;
while (1) {
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
/*
* We're concerned with the entire range that we're going to be
* doing DIO to, so we need to make sure theres no ordered
* extents in this range.
*/
ordered = btrfs_lookup_ordered_range(inode, lockstart,
lockend - lockstart + 1);
/*
* We need to make sure there are no buffered pages in this
* range either, we could have raced between the invalidate in
* generic_file_direct_write and locking the extent. The
* invalidate needs to happen so that reads after a write do not
* get stale data.
*/
if (!ordered &&
(!writing ||
!btrfs_page_exists_in_range(inode, lockstart, lockend)))
break;
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state, GFP_NOFS);
if (ordered) {
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
} else {
/*
* We could trigger writeback for this range (and wait
* for it to complete) and then invalidate the pages for
* this range (through invalidate_inode_pages2_range()),
* but that can lead us to a deadlock with a concurrent
* call to readpages() (a buffered read or a defrag call
* triggered a readahead) on a page lock due to an
* ordered dio extent we created before but did not have
* yet a corresponding bio submitted (whence it can not
* complete), which makes readpages() wait for that
* ordered extent to complete while holding a lock on
* that page.
*/
ret = -ENOTBLK;
break;
}
cond_resched();
}
return ret;
}
static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
u64 len, u64 orig_start,
u64 block_start, u64 block_len,
u64 orig_block_len, u64 ram_bytes,
int type)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
if (!em)
return ERR_PTR(-ENOMEM);
em->start = start;
em->orig_start = orig_start;
em->mod_start = start;
em->mod_len = len;
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->orig_block_len = orig_block_len;
em->ram_bytes = ram_bytes;
em->generation = -1;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
if (type == BTRFS_ORDERED_PREALLOC)
set_bit(EXTENT_FLAG_FILLING, &em->flags);
do {
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
} while (ret == -EEXIST);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
return em;
}
static void adjust_dio_outstanding_extents(struct inode *inode,
struct btrfs_dio_data *dio_data,
const u64 len)
{
unsigned num_extents;
num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
/*
* If we have an outstanding_extents count still set then we're
* within our reservation, otherwise we need to adjust our inode
* counter appropriately.
*/
if (dio_data->outstanding_extents) {
dio_data->outstanding_extents -= num_extents;
} else {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents += num_extents;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = NULL;
u64 start = iblock << inode->i_blkbits;
u64 lockstart, lockend;
u64 len = bh_result->b_size;
int unlock_bits = EXTENT_LOCKED;
int ret = 0;
if (create)
unlock_bits |= EXTENT_DIRTY;
else
len = min_t(u64, len, root->sectorsize);
lockstart = start;
lockend = start + len - 1;
if (current->journal_info) {
/*
* Need to pull our outstanding extents and set journal_info to NULL so
* that anything that needs to check if there's a transction doesn't get
* confused.
*/
dio_data = current->journal_info;
current->journal_info = NULL;
}
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered.
*/
if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
create)) {
ret = -ENOTBLK;
goto err;
}
em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
* io. INLINE is special, and we could probably kludge it in here, but
* it's still buffered so for safety lets just fall back to the generic
* buffered path.
*
* For COMPRESSED we _have_ to read the entire extent in so we can
* decompress it, so there will be buffering required no matter what we
* do, so go ahead and fallback to buffered.
*
* We return -ENOTBLK because thats what makes DIO go ahead and go back
* to buffered IO. Don't blame me, this is the price we pay for using
* the generic code.
*/
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
ret = -ENOTBLK;
goto unlock_err;
}
/* Just a good old fashioned hole, return */
if (!create && (em->block_start == EXTENT_MAP_HOLE ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
free_extent_map(em);
goto unlock_err;
}
/*
* We don't allocate a new extent in the following cases
*
* 1) The inode is marked as NODATACOW. In this case we'll just use the
* existing extent.
* 2) The extent is marked as PREALLOC. We're good to go here and can
* just use the extent.
*
*/
if (!create) {
len = min(len, em->len - (start - em->start));
lockstart = start + len;
goto unlock;
}
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
em->block_start != EXTENT_MAP_HOLE)) {
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
type = BTRFS_ORDERED_PREALLOC;
else
type = BTRFS_ORDERED_NOCOW;
len = min(len, em->len - (start - em->start));
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
&orig_block_len, &ram_bytes) == 1) {
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
em = create_pinned_em(inode, start, len,
orig_start,
block_start, len,
orig_block_len,
ram_bytes, type);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
}
ret = btrfs_add_ordered_extent_dio(inode, start,
block_start, len, len, type);
if (ret) {
free_extent_map(em);
goto unlock_err;
}
goto unlock;
}
}
/*
* this will cow the extent, reset the len in case we changed
* it above
*/
len = bh_result->b_size;
free_extent_map(em);
em = btrfs_new_extent_direct(inode, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
len = min(len, em->len - (start - em->start));
unlock:
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
inode->i_blkbits;
bh_result->b_size = len;
bh_result->b_bdev = em->bdev;
set_buffer_mapped(bh_result);
if (create) {
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
set_buffer_new(bh_result);
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
adjust_dio_outstanding_extents(inode, dio_data, len);
btrfs_free_reserved_data_space(inode, start, len);
WARN_ON(dio_data->reserve < len);
dio_data->reserve -= len;
dio_data->unsubmitted_oe_range_end = start + len;
current->journal_info = dio_data;
}
/*
* In the case of write we need to clear and unlock the entire range,
* in the case of read we need to unlock only the end area that we
* aren't using if there is any left over space.
*/
if (lockstart < lockend) {
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
lockend, unlock_bits, 1, 0,
&cached_state, GFP_NOFS);
} else {
free_extent_state(cached_state);
}
free_extent_map(em);
return 0;
unlock_err:
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
unlock_bits, 1, 0, &cached_state, GFP_NOFS);
err:
if (dio_data)
current->journal_info = dio_data;
/*
* Compensate the delalloc release we do in btrfs_direct_IO() when we
* write less data then expected, so that we don't underflow our inode's
* outstanding extents counter.
*/
if (create && dio_data)
adjust_dio_outstanding_extents(inode, dio_data, len);
return ret;
}
static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
int rw, int mirror_num)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
BUG_ON(rw & REQ_WRITE);
bio_get(bio);
ret = btrfs_bio_wq_end_io(root->fs_info, bio,
BTRFS_WQ_ENDIO_DIO_REPAIR);
if (ret)
goto err;
ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
err:
bio_put(bio);
return ret;
}
static int btrfs_check_dio_repairable(struct inode *inode,
struct bio *failed_bio,
struct io_failure_record *failrec,
int failed_mirror)
{
int num_copies;
num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
failrec->logical, failrec->len);
if (num_copies == 1) {
/*
* we only have a single copy of the data, so don't bother with
* all the retry and error correction code that follows. no
* matter what the error is, it is very likely to persist.
*/
pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
failrec->failed_mirror = failed_mirror;
failrec->this_mirror++;
if (failrec->this_mirror == failed_mirror)
failrec->this_mirror++;
if (failrec->this_mirror > num_copies) {
pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
return 1;
}
static int dio_read_error(struct inode *inode, struct bio *failed_bio,
struct page *page, u64 start, u64 end,
int failed_mirror, bio_end_io_t *repair_endio,
void *repair_arg)
{
struct io_failure_record *failrec;
struct bio *bio;
int isector;
int read_mode;
int ret;
BUG_ON(failed_bio->bi_rw & REQ_WRITE);
ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
if (ret)
return ret;
ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
failed_mirror);
if (!ret) {
free_io_failure(inode, failrec);
return -EIO;
}
if (failed_bio->bi_vcnt > 1)
read_mode = READ_SYNC | REQ_FAILFAST_DEV;
else
read_mode = READ_SYNC;
isector = start - btrfs_io_bio(failed_bio)->logical;
isector >>= inode->i_sb->s_blocksize_bits;
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
0, isector, repair_endio, repair_arg);
if (!bio) {
free_io_failure(inode, failrec);
return -EIO;
}
btrfs_debug(BTRFS_I(inode)->root->fs_info,
"Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
read_mode, failrec->this_mirror, failrec->in_validation);
ret = submit_dio_repair_bio(inode, bio, read_mode,
failrec->this_mirror);
if (ret) {
free_io_failure(inode, failrec);
bio_put(bio);
}
return ret;
}
struct btrfs_retry_complete {
struct completion done;
struct inode *inode;
u64 start;
int uptodate;
};
static void btrfs_retry_endio_nocsum(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct bio_vec *bvec;
int i;
if (bio->bi_error)
goto end;
done->uptodate = 1;
bio_for_each_segment_all(bvec, bio, i)
clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
end:
complete(&done->done);
bio_put(bio);
}
static int __btrfs_correct_data_nocsum(struct inode *inode,
struct btrfs_io_bio *io_bio)
{
struct bio_vec *bvec;
struct btrfs_retry_complete done;
u64 start;
int i;
int ret;
start = io_bio->logical;
done.inode = inode;
bio_for_each_segment_all(bvec, &io_bio->bio, i) {
try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
start + bvec->bv_len - 1,
io_bio->mirror_num,
btrfs_retry_endio_nocsum, &done);
if (ret)
return ret;
wait_for_completion(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto try_again;
}
start += bvec->bv_len;
}
return 0;
}
static void btrfs_retry_endio(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct bio_vec *bvec;
int uptodate;
int ret;
int i;
if (bio->bi_error)
goto end;
uptodate = 1;
bio_for_each_segment_all(bvec, bio, i) {
ret = __readpage_endio_check(done->inode, io_bio, i,
bvec->bv_page, 0,
done->start, bvec->bv_len);
if (!ret)
clean_io_failure(done->inode, done->start,
bvec->bv_page, 0);
else
uptodate = 0;
}
done->uptodate = uptodate;
end:
complete(&done->done);
bio_put(bio);
}
static int __btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, int err)
{
struct bio_vec *bvec;
struct btrfs_retry_complete done;
u64 start;
u64 offset = 0;
int i;
int ret;
err = 0;
start = io_bio->logical;
done.inode = inode;
bio_for_each_segment_all(bvec, &io_bio->bio, i) {
ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
0, start, bvec->bv_len);
if (likely(!ret))
goto next;
try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
start + bvec->bv_len - 1,
io_bio->mirror_num,
btrfs_retry_endio, &done);
if (ret) {
err = ret;
goto next;
}
wait_for_completion(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto try_again;
}
next:
offset += bvec->bv_len;
start += bvec->bv_len;
}
return err;
}
static int btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, int err)
{
bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (skip_csum) {
if (unlikely(err))
return __btrfs_correct_data_nocsum(inode, io_bio);
else
return 0;
} else {
return __btrfs_subio_endio_read(inode, io_bio, err);
}
}
static void btrfs_endio_direct_read(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct inode *inode = dip->inode;
struct bio *dio_bio;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
int err = bio->bi_error;
if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
err = btrfs_subio_endio_read(inode, io_bio, err);
unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
dip->logical_offset + dip->bytes - 1);
dio_bio = dip->dio_bio;
kfree(dip);
dio_end_io(dio_bio, bio->bi_error);
if (io_bio->end_io)
io_bio->end_io(io_bio, err);
bio_put(bio);
}
static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
const u64 offset,
const u64 bytes,
const int uptodate)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_extent *ordered = NULL;
u64 ordered_offset = offset;
u64 ordered_bytes = bytes;
int ret;
again:
ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
&ordered_offset,
ordered_bytes,
uptodate);
if (!ret)
goto out_test;
btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
finish_ordered_fn, NULL, NULL);
btrfs_queue_work(root->fs_info->endio_write_workers,
&ordered->work);
out_test:
/*
* our bio might span multiple ordered extents. If we haven't
* completed the accounting for the whole dio, go back and try again
*/
if (ordered_offset < offset + bytes) {
ordered_bytes = offset + bytes - ordered_offset;
ordered = NULL;
goto again;
}
}
static void btrfs_endio_direct_write(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct bio *dio_bio = dip->dio_bio;
btrfs_endio_direct_write_update_ordered(dip->inode,
dip->logical_offset,
dip->bytes,
!bio->bi_error);
kfree(dip);
dio_end_io(dio_bio, bio->bi_error);
bio_put(bio);
}
static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags, u64 offset)
{
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
static void btrfs_end_dio_bio(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
int err = bio->bi_error;
if (err)
btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
"direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
btrfs_ino(dip->inode), bio->bi_rw,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, err);
if (dip->subio_endio)
err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
if (err) {
dip->errors = 1;
/*
* before atomic variable goto zero, we must make sure
* dip->errors is perceived to be set.
*/
smp_mb__before_atomic();
}
/* if there are more bios still pending for this dio, just exit */
if (!atomic_dec_and_test(&dip->pending_bios))
goto out;
if (dip->errors) {
bio_io_error(dip->orig_bio);
} else {
dip->dio_bio->bi_error = 0;
bio_endio(dip->orig_bio);
}
out:
bio_put(bio);
}
static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
u64 first_sector, gfp_t gfp_flags)
{
struct bio *bio;
bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
if (bio)
bio_associate_current(bio);
return bio;
}
static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
struct inode *inode,
struct btrfs_dio_private *dip,
struct bio *bio,
u64 file_offset)
{
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
int ret;
/*
* We load all the csum data we need when we submit
* the first bio to reduce the csum tree search and
* contention.
*/
if (dip->logical_offset == file_offset) {
ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
file_offset);
if (ret)
return ret;
}
if (bio == dip->orig_bio)
return 0;
file_offset -= dip->logical_offset;
file_offset >>= inode->i_sb->s_blocksize_bits;
io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
return 0;
}
static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
int rw, u64 file_offset, int skip_sum,
int async_submit)
{
struct btrfs_dio_private *dip = bio->bi_private;
int write = rw & REQ_WRITE;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
if (async_submit)
async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
bio_get(bio);
if (!write) {
ret = btrfs_bio_wq_end_io(root->fs_info, bio,
BTRFS_WQ_ENDIO_DATA);
if (ret)
goto err;
}
if (skip_sum)
goto map;
if (write && async_submit) {
ret = btrfs_wq_submit_bio(root->fs_info,
inode, rw, bio, 0, 0,
file_offset,
__btrfs_submit_bio_start_direct_io,
__btrfs_submit_bio_done);
goto err;
} else if (write) {
/*
* If we aren't doing async submit, calculate the csum of the
* bio now.
*/
ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
if (ret)
goto err;
} else {
ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
file_offset);
if (ret)
goto err;
}
map:
ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
err:
bio_put(bio);
return ret;
}
static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
int skip_sum)
{
struct inode *inode = dip->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct bio *bio;
struct bio *orig_bio = dip->orig_bio;
struct bio_vec *bvec = orig_bio->bi_io_vec;
u64 start_sector = orig_bio->bi_iter.bi_sector;
u64 file_offset = dip->logical_offset;
u64 submit_len = 0;
u64 map_length;
int nr_pages = 0;
int ret;
int async_submit = 0;
map_length = orig_bio->bi_iter.bi_size;
ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
&map_length, NULL, 0);
if (ret)
return -EIO;
if (map_length >= orig_bio->bi_iter.bi_size) {
bio = orig_bio;
dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
goto submit;
}
/* async crcs make it difficult to collect full stripe writes. */
if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
async_submit = 0;
else
async_submit = 1;
bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
if (!bio)
return -ENOMEM;
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
atomic_inc(&dip->pending_bios);
while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
if (map_length < submit_len + bvec->bv_len ||
bio_add_page(bio, bvec->bv_page, bvec->bv_len,
bvec->bv_offset) < bvec->bv_len) {
/*
* inc the count before we submit the bio so
* we know the end IO handler won't happen before
* we inc the count. Otherwise, the dip might get freed
* before we're done setting it up
*/
atomic_inc(&dip->pending_bios);
ret = __btrfs_submit_dio_bio(bio, inode, rw,
file_offset, skip_sum,
async_submit);
if (ret) {
bio_put(bio);
atomic_dec(&dip->pending_bios);
goto out_err;
}
start_sector += submit_len >> 9;
file_offset += submit_len;
submit_len = 0;
nr_pages = 0;
bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
start_sector, GFP_NOFS);
if (!bio)
goto out_err;
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
map_length = orig_bio->bi_iter.bi_size;
ret = btrfs_map_block(root->fs_info, rw,
start_sector << 9,
&map_length, NULL, 0);
if (ret) {
bio_put(bio);
goto out_err;
}
} else {
submit_len += bvec->bv_len;
nr_pages++;
bvec++;
}
}
submit:
ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
async_submit);
if (!ret)
return 0;
bio_put(bio);
out_err:
dip->errors = 1;
/*
* before atomic variable goto zero, we must
* make sure dip->errors is perceived to be set.
*/
smp_mb__before_atomic();
if (atomic_dec_and_test(&dip->pending_bios))
bio_io_error(dip->orig_bio);
/* bio_end_io() will handle error, so we needn't return it */
return 0;
}
static void btrfs_submit_direct(int rw, struct bio *dio_bio,
struct inode *inode, loff_t file_offset)
{
struct btrfs_dio_private *dip = NULL;
struct bio *io_bio = NULL;
struct btrfs_io_bio *btrfs_bio;
int skip_sum;
int write = rw & REQ_WRITE;
int ret = 0;
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
if (!io_bio) {
ret = -ENOMEM;
goto free_ordered;
}
dip = kzalloc(sizeof(*dip), GFP_NOFS);
if (!dip) {
ret = -ENOMEM;
goto free_ordered;
}
dip->private = dio_bio->bi_private;
dip->inode = inode;
dip->logical_offset = file_offset;
dip->bytes = dio_bio->bi_iter.bi_size;
dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
io_bio->bi_private = dip;
dip->orig_bio = io_bio;
dip->dio_bio = dio_bio;
atomic_set(&dip->pending_bios, 0);
btrfs_bio = btrfs_io_bio(io_bio);
btrfs_bio->logical = file_offset;
if (write) {
io_bio->bi_end_io = btrfs_endio_direct_write;
} else {
io_bio->bi_end_io = btrfs_endio_direct_read;
dip->subio_endio = btrfs_subio_endio_read;
}
/*
* Reset the range for unsubmitted ordered extents (to a 0 length range)
* even if we fail to submit a bio, because in such case we do the
* corresponding error handling below and it must not be done a second
* time by btrfs_direct_IO().
*/
if (write) {
struct btrfs_dio_data *dio_data = current->journal_info;
dio_data->unsubmitted_oe_range_end = dip->logical_offset +
dip->bytes;
dio_data->unsubmitted_oe_range_start =
dio_data->unsubmitted_oe_range_end;
}
ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
if (!ret)
return;
if (btrfs_bio->end_io)
btrfs_bio->end_io(btrfs_bio, ret);
free_ordered:
/*
* If we arrived here it means either we failed to submit the dip
* or we either failed to clone the dio_bio or failed to allocate the
* dip. If we cloned the dio_bio and allocated the dip, we can just
* call bio_endio against our io_bio so that we get proper resource
* cleanup if we fail to submit the dip, otherwise, we must do the
* same as btrfs_endio_direct_[write|read] because we can't call these
* callbacks - they require an allocated dip and a clone of dio_bio.
*/
if (io_bio && dip) {
io_bio->bi_error = -EIO;
bio_endio(io_bio);
/*
* The end io callbacks free our dip, do the final put on io_bio
* and all the cleanup and final put for dio_bio (through
* dio_end_io()).
*/
dip = NULL;
io_bio = NULL;
} else {
if (write)
btrfs_endio_direct_write_update_ordered(inode,
file_offset,
dio_bio->bi_iter.bi_size,
0);
else
unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
file_offset + dio_bio->bi_iter.bi_size - 1);
dio_bio->bi_error = -EIO;
/*
* Releases and cleans up our dio_bio, no need to bio_put()
* nor bio_endio()/bio_io_error() against dio_bio.
*/
dio_end_io(dio_bio, ret);
}
if (io_bio)
bio_put(io_bio);
kfree(dip);
}
static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
const struct iov_iter *iter, loff_t offset)
{
int seg;
int i;
unsigned blocksize_mask = root->sectorsize - 1;
ssize_t retval = -EINVAL;
if (offset & blocksize_mask)
goto out;
if (iov_iter_alignment(iter) & blocksize_mask)
goto out;
/* If this is a write we don't need to check anymore */
if (iov_iter_rw(iter) == WRITE)
return 0;
/*
* Check to make sure we don't have duplicate iov_base's in this
* iovec, if so return EINVAL, otherwise we'll get csum errors
* when reading back.
*/
for (seg = 0; seg < iter->nr_segs; seg++) {
for (i = seg + 1; i < iter->nr_segs; i++) {
if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
goto out;
}
}
retval = 0;
out:
return retval;
}
static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
loff_t offset)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_dio_data dio_data = { 0 };
size_t count = 0;
int flags = 0;
bool wakeup = true;
bool relock = false;
ssize_t ret;
if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
return 0;
inode_dio_begin(inode);
smp_mb__after_atomic();
/*
* The generic stuff only does filemap_write_and_wait_range, which
* isn't enough if we've written compressed pages to this area, so
* we need to flush the dirty pages again to make absolutely sure
* that any outstanding dirty pages are on disk.
*/
count = iov_iter_count(iter);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_fdatawrite_range(inode->i_mapping, offset,
offset + count - 1);
if (iov_iter_rw(iter) == WRITE) {
/*
* If the write DIO is beyond the EOF, we need update
* the isize, but it is protected by i_mutex. So we can
* not unlock the i_mutex at this case.
*/
if (offset + count <= inode->i_size) {
mutex_unlock(&inode->i_mutex);
relock = true;
}
ret = btrfs_delalloc_reserve_space(inode, offset, count);
if (ret)
goto out;
dio_data.outstanding_extents = div64_u64(count +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
/*
* We need to know how many extents we reserved so that we can
* do the accounting properly if we go over the number we
* originally calculated. Abuse current->journal_info for this.
*/
dio_data.reserve = round_up(count, root->sectorsize);
dio_data.unsubmitted_oe_range_start = (u64)offset;
dio_data.unsubmitted_oe_range_end = (u64)offset;
current->journal_info = &dio_data;
} else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
&BTRFS_I(inode)->runtime_flags)) {
inode_dio_end(inode);
flags = DIO_LOCKING | DIO_SKIP_HOLES;
wakeup = false;
}
ret = __blockdev_direct_IO(iocb, inode,
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
iter, offset, btrfs_get_blocks_direct, NULL,
btrfs_submit_direct, flags);
if (iov_iter_rw(iter) == WRITE) {
current->journal_info = NULL;
if (ret < 0 && ret != -EIOCBQUEUED) {
if (dio_data.reserve)
btrfs_delalloc_release_space(inode, offset,
dio_data.reserve);
/*
* On error we might have left some ordered extents
* without submitting corresponding bios for them, so
* cleanup them up to avoid other tasks getting them
* and waiting for them to complete forever.
*/
if (dio_data.unsubmitted_oe_range_start <
dio_data.unsubmitted_oe_range_end)
btrfs_endio_direct_write_update_ordered(inode,
dio_data.unsubmitted_oe_range_start,
dio_data.unsubmitted_oe_range_end -
dio_data.unsubmitted_oe_range_start,
0);
} else if (ret >= 0 && (size_t)ret < count)
btrfs_delalloc_release_space(inode, offset,
count - (size_t)ret);
}
out:
if (wakeup)
inode_dio_end(inode);
if (relock)
mutex_lock(&inode->i_mutex);
return ret;
}
#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
int ret;
ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
if (ret)
return ret;
return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btrfs_get_extent, 0);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_io_tree *tree;
struct inode *inode = page->mapping->host;
int ret;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
/*
* If we are under memory pressure we will call this directly from the
* VM, we need to make sure we have the inode referenced for the ordered
* extent. If not just return like we didn't do anything.
*/
if (!igrab(inode)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
}
tree = &BTRFS_I(page->mapping->host)->io_tree;
ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
btrfs_add_delayed_iput(inode);
return ret;
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_readpages(tree, mapping, pages, nr_pages,
btrfs_get_extent);
}
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
struct extent_io_tree *tree;
struct extent_map_tree *map;
int ret;
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(map, tree, page, gfp_flags);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
return ret;
}
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
if (PageWriteback(page) || PageDirty(page))
return 0;
return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
}
static void btrfs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct inode *inode = page->mapping->host;
struct extent_io_tree *tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
u64 page_start = page_offset(page);
u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
int inode_evicting = inode->i_state & I_FREEING;
/*
* we have the page locked, so new writeback can't start,
* and the dirty bit won't be cleared while we are here.
*
* Wait for IO on this page so that we can safely clear
* the PagePrivate2 bit and do ordered accounting
*/
wait_on_page_writeback(page);
tree = &BTRFS_I(inode)->io_tree;
if (offset) {
btrfs_releasepage(page, GFP_NOFS);
return;
}
if (!inode_evicting)
lock_extent_bits(tree, page_start, page_end, &cached_state);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
/*
* IO on this page will never be started, so we need
* to account for any ordered extents now
*/
if (!inode_evicting)
clear_extent_bit(tree, page_start, page_end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 0, &cached_state,
GFP_NOFS);
/*
* whoever cleared the private bit is responsible
* for the finish_ordered_io
*/
if (TestClearPagePrivate2(page)) {
struct btrfs_ordered_inode_tree *tree;
u64 new_len;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
new_len = page_start - ordered->file_offset;
if (new_len < ordered->truncated_len)
ordered->truncated_len = new_len;
spin_unlock_irq(&tree->lock);
if (btrfs_dec_test_ordered_pending(inode, &ordered,
page_start,
PAGE_CACHE_SIZE, 1))
btrfs_finish_ordered_io(ordered);
}
btrfs_put_ordered_extent(ordered);
if (!inode_evicting) {
cached_state = NULL;
lock_extent_bits(tree, page_start, page_end,
&cached_state);
}
}
/*
* Qgroup reserved space handler
* Page here will be either
* 1) Already written to disk
* In this case, its reserved space is released from data rsv map
* and will be freed by delayed_ref handler finally.
* So even we call qgroup_free_data(), it won't decrease reserved
* space.
* 2) Not written to disk
* This means the reserved space should be freed here.
*/
btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
if (!inode_evicting) {
clear_extent_bit(tree, page_start, page_end,
EXTENT_LOCKED | EXTENT_DIRTY |
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 1,
&cached_state, GFP_NOFS);
__btrfs_releasepage(page, GFP_NOFS);
}
ClearPageChecked(page);
if (PagePrivate(page)) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* vmtruncate() writes the inode size before removing pages, once we have the
* page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vma->vm_file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
char *kaddr;
unsigned long zero_start;
loff_t size;
int ret;
int reserved = 0;
u64 page_start;
u64 page_end;
sb_start_pagefault(inode->i_sb);
page_start = page_offset(page);
page_end = page_start + PAGE_CACHE_SIZE - 1;
ret = btrfs_delalloc_reserve_space(inode, page_start,
PAGE_CACHE_SIZE);
if (!ret) {
ret = file_update_time(vma->vm_file);
reserved = 1;
}
if (ret) {
if (ret == -ENOMEM)
ret = VM_FAULT_OOM;
else /* -ENOSPC, -EIO, etc */
ret = VM_FAULT_SIGBUS;
if (reserved)
goto out;
goto out_noreserve;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
set_page_extent_mapped(page);
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
/*
* XXX - page_mkwrite gets called every time the page is dirtied, even
* if it was already dirty, so for space accounting reasons we need to
* clear any delalloc bits for the range we are fixing to save. There
* is probably a better way to do this, but for now keep consistent with
* prepare_pages in the normal write path.
*/
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state, GFP_NOFS);
ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
ret = 0;
/* page is wholly or partially inside EOF */
if (page_start + PAGE_CACHE_SIZE > size)
zero_start = size & ~PAGE_CACHE_MASK;
else
zero_start = PAGE_CACHE_SIZE;
if (zero_start != PAGE_CACHE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
SetPageUptodate(page);
BTRFS_I(inode)->last_trans = root->fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
out_unlock:
if (!ret) {
sb_end_pagefault(inode->i_sb);
return VM_FAULT_LOCKED;
}
unlock_page(page);
out:
btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
out_noreserve:
sb_end_pagefault(inode->i_sb);
return ret;
}
static int btrfs_truncate(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret = 0;
int err = 0;
struct btrfs_trans_handle *trans;
u64 mask = root->sectorsize - 1;
u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
(u64)-1);
if (ret)
return ret;
/*
* Yes ladies and gentelment, this is indeed ugly. The fact is we have
* 3 things going on here
*
* 1) We need to reserve space for our orphan item and the space to
* delete our orphan item. Lord knows we don't want to have a dangling
* orphan item because we didn't reserve space to remove it.
*
* 2) We need to reserve space to update our inode.
*
* 3) We need to have something to cache all the space that is going to
* be free'd up by the truncate operation, but also have some slack
* space reserved in case it uses space during the truncate (thank you
* very much snapshotting).
*
* And we need these to all be seperate. The fact is we can use alot of
* space doing the truncate, and we have no earthly idea how much space
* we will use, so we need the truncate reservation to be seperate so it
* doesn't end up using space reserved for updating the inode or
* removing the orphan item. We also need to be able to stop the
* transaction and start a new one, which means we need to be able to
* update the inode several times, and we have no idea of knowing how
* many times that will be, so we can't just reserve 1 item for the
* entirety of the opration, so that has to be done seperately as well.
* Then there is the orphan item, which does indeed need to be held on
* to for the whole operation, and we need nobody to touch this reserved
* space except the orphan code.
*
* So that leaves us with
*
* 1) root->orphan_block_rsv - for the orphan deletion.
* 2) rsv - for the truncate reservation, which we will steal from the
* transaction reservation.
* 3) fs_info->trans_block_rsv - this will have 1 items worth left for
* updating the inode.
*/
rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
return -ENOMEM;
rsv->size = min_size;
rsv->failfast = 1;
/*
* 1 for the truncate slack space
* 1 for updating the inode.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out;
}
/* Migrate the slack space for the truncate to our reserve */
ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
min_size);
BUG_ON(ret);
/*
* So if we truncate and then write and fsync we normally would just
* write the extents that changed, which is a problem if we need to
* first truncate that entire inode. So set this flag so we write out
* all of the extents in the inode to the sync log so we're completely
* safe.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
trans->block_rsv = rsv;
while (1) {
ret = btrfs_truncate_inode_items(trans, root, inode,
inode->i_size,
BTRFS_EXTENT_DATA_KEY);
if (ret != -ENOSPC && ret != -EAGAIN) {
err = ret;
break;
}
trans->block_rsv = &root->fs_info->trans_block_rsv;
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
err = ret;
break;
}
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = err = PTR_ERR(trans);
trans = NULL;
break;
}
ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
rsv, min_size);
BUG_ON(ret); /* shouldn't happen */
trans->block_rsv = rsv;
}
if (ret == 0 && inode->i_nlink > 0) {
trans->block_rsv = root->orphan_block_rsv;
ret = btrfs_orphan_del(trans, inode);
if (ret)
err = ret;
}
if (trans) {
trans->block_rsv = &root->fs_info->trans_block_rsv;
ret = btrfs_update_inode(trans, root, inode);
if (ret && !err)
err = ret;
ret = btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
}
out:
btrfs_free_block_rsv(root, rsv);
if (ret && !err)
err = ret;
return err;
}
/*
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root,
struct btrfs_root *parent_root,
u64 new_dirid)
{
struct inode *inode;
int err;
u64 index = 0;
inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
new_dirid, new_dirid,
S_IFDIR | (~current_umask() & S_IRWXUGO),
&index);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
set_nlink(inode, 1);
btrfs_i_size_write(inode, 0);
unlock_new_inode(inode);
err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
if (err)
btrfs_err(new_root->fs_info,
"error inheriting subvolume %llu properties: %d",
new_root->root_key.objectid, err);
err = btrfs_update_inode(trans, new_root, inode);
iput(inode);
return err;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_inode *ei;
struct inode *inode;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
ei->root = NULL;
ei->generation = 0;
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->dir_index = 0;
ei->last_unlink_trans = 0;
ei->last_log_commit = 0;
ei->delayed_iput_count = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;
ei->reserved_extents = 0;
ei->runtime_flags = 0;
ei->force_compress = BTRFS_COMPRESS_NONE;
ei->delayed_node = NULL;
ei->i_otime.tv_sec = 0;
ei->i_otime.tv_nsec = 0;
inode = &ei->vfs_inode;
extent_map_tree_init(&ei->extent_tree);
extent_io_tree_init(&ei->io_tree, &inode->i_data);
extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
ei->io_tree.track_uptodate = 1;
ei->io_failure_tree.track_uptodate = 1;
atomic_set(&ei->sync_writers, 0);
mutex_init(&ei->log_mutex);
mutex_init(&ei->delalloc_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->delalloc_inodes);
INIT_LIST_HEAD(&ei->delayed_iput);
RB_CLEAR_NODE(&ei->rb_node);
return inode;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_destroy_inode(struct inode *inode)
{
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
#endif
static void btrfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_root *root = BTRFS_I(inode)->root;
WARN_ON(!hlist_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
WARN_ON(BTRFS_I(inode)->outstanding_extents);
WARN_ON(BTRFS_I(inode)->reserved_extents);
WARN_ON(BTRFS_I(inode)->delalloc_bytes);
WARN_ON(BTRFS_I(inode)->csum_bytes);
WARN_ON(BTRFS_I(inode)->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also
* created the same inode and we need to destroy the one we already
* created.
*/
if (!root)
goto free;
if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags)) {
btrfs_info(root->fs_info, "inode %llu still on the orphan list",
btrfs_ino(inode));
atomic_dec(&root->orphan_inodes);
}
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
ordered->file_offset, ordered->len);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_qgroup_check_reserved_leak(inode);
inode_tree_del(inode);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
free:
call_rcu(&inode->i_rcu, btrfs_i_callback);
}
int btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (root == NULL)
return 1;
/* the snap/subvol tree is on deleting */
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
else
return generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void btrfs_destroy_cachep(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
if (btrfs_inode_cachep)
kmem_cache_destroy(btrfs_inode_cachep);
if (btrfs_trans_handle_cachep)
kmem_cache_destroy(btrfs_trans_handle_cachep);
if (btrfs_transaction_cachep)
kmem_cache_destroy(btrfs_transaction_cachep);
if (btrfs_path_cachep)
kmem_cache_destroy(btrfs_path_cachep);
if (btrfs_free_space_cachep)
kmem_cache_destroy(btrfs_free_space_cachep);
}
int btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
sizeof(struct btrfs_inode), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
sizeof(struct btrfs_trans_handle), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
sizeof(struct btrfs_transaction), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_transaction_cachep)
goto fail;
btrfs_path_cachep = kmem_cache_create("btrfs_path",
sizeof(struct btrfs_path), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
sizeof(struct btrfs_free_space), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_free_space_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct vfsmount *mnt,
struct dentry *dentry, struct kstat *stat)
{
u64 delalloc_bytes;
struct inode *inode = d_inode(dentry);
u32 blocksize = inode->i_sb->s_blocksize;
generic_fillattr(inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
stat->blksize = PAGE_CACHE_SIZE;
spin_lock(&BTRFS_I(inode)->lock);
delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
spin_unlock(&BTRFS_I(inode)->lock);
stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
ALIGN(delalloc_bytes, blocksize)) >> 9;
return 0;
}
static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
struct timespec ctime = CURRENT_TIME;
u64 index = 0;
u64 root_objectid;
int ret;
u64 old_ino = btrfs_ino(old_inode);
if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return -EPERM;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
(new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
return -ENOTEMPTY;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
/* check for collisions, even if the name isn't there */
ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
new_dentry->d_name.name,
new_dentry->d_name.len);
if (ret) {
if (ret == -EEXIST) {
/* we shouldn't get
* eexist without a new_inode */
if (WARN_ON(!new_inode)) {
return ret;
}
} else {
/* maybe -EOVERFLOW */
return ret;
}
}
ret = 0;
/*
* we're using rename to replace one file with another. Start IO on it
* now so we don't add too much work to the end of the transaction
*/
if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
filemap_flush(old_inode->i_mapping);
/* close the racy window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&root->fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume their normal
* inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
* should cover the worst case number of items we'll modify.
*/
trans = btrfs_start_transaction(root, 11);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root)
btrfs_record_root_in_trans(trans, dest);
ret = btrfs_set_inode_index(new_dir, &index);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(root->fs_info, trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(new_dir), index);
if (ret)
goto out_fail;
/*
* this is an ugly little race, but the rename is required
* to make sure that if we crash, the inode is either at the
* old name or the new one. pinning the log transaction lets
* us make sure we don't allow a log commit to come in after
* we unlink the name but before we add the new name back in.
*/
btrfs_pin_log_trans(root);
}
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
old_dir->i_ctime = old_dir->i_mtime = ctime;
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
if (old_dentry->d_parent != new_dentry->d_parent)
btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
old_dentry->d_name.name,
old_dentry->d_name.len);
} else {
ret = __btrfs_unlink_inode(trans, root, old_dir,
d_inode(old_dentry),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, old_inode);
}
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
if (new_inode) {
inode_inc_iversion(new_inode);
new_inode->i_ctime = CURRENT_TIME;
if (unlikely(btrfs_ino(new_inode) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
root_objectid = BTRFS_I(new_inode)->location.objectid;
ret = btrfs_unlink_subvol(trans, dest, new_dir,
root_objectid,
new_dentry->d_name.name,
new_dentry->d_name.len);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, dest, new_dir,
d_inode(new_dentry),
new_dentry->d_name.name,
new_dentry->d_name.len);
}
if (!ret && new_inode->i_nlink == 0)
ret = btrfs_orphan_add(trans, d_inode(new_dentry));
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
}
ret = btrfs_add_link(trans, new_dir, old_inode,
new_dentry->d_name.name,
new_dentry->d_name.len, 0, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = index;
if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
struct dentry *parent = new_dentry->d_parent;
btrfs_log_new_name(trans, old_inode, old_dir, parent);
btrfs_end_log_trans(root);
}
out_fail:
btrfs_end_transaction(trans, root);
out_notrans:
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&root->fs_info->subvol_sem);
return ret;
}
static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
}
static void btrfs_run_delalloc_work(struct btrfs_work *work)
{
struct btrfs_delalloc_work *delalloc_work;
struct inode *inode;
delalloc_work = container_of(work, struct btrfs_delalloc_work,
work);
inode = delalloc_work->inode;
filemap_flush(inode->i_mapping);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_flush(inode->i_mapping);
if (delalloc_work->delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
complete(&delalloc_work->completion);
}
struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
int delay_iput)
{
struct btrfs_delalloc_work *work;
work = kmalloc(sizeof(*work), GFP_NOFS);
if (!work)
return NULL;
init_completion(&work->completion);
INIT_LIST_HEAD(&work->list);
work->inode = inode;
work->delay_iput = delay_iput;
WARN_ON_ONCE(!inode);
btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
btrfs_run_delalloc_work, NULL, NULL);
return work;
}
void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
{
wait_for_completion(&work->completion);
kfree(work);
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
int nr)
{
struct btrfs_inode *binode;
struct inode *inode;
struct btrfs_delalloc_work *work, *next;
struct list_head works;
struct list_head splice;
int ret = 0;
INIT_LIST_HEAD(&works);
INIT_LIST_HEAD(&splice);
mutex_lock(&root->delalloc_mutex);
spin_lock(&root->delalloc_lock);
list_splice_init(&root->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
binode = list_entry(splice.next, struct btrfs_inode,
delalloc_inodes);
list_move_tail(&binode->delalloc_inodes,
&root->delalloc_inodes);
inode = igrab(&binode->vfs_inode);
if (!inode) {
cond_resched_lock(&root->delalloc_lock);
continue;
}
spin_unlock(&root->delalloc_lock);
work = btrfs_alloc_delalloc_work(inode, delay_iput);
if (!work) {
if (delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
ret = -ENOMEM;
goto out;
}
list_add_tail(&work->list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&work->work);
ret++;
if (nr != -1 && ret >= nr)
goto out;
cond_resched();
spin_lock(&root->delalloc_lock);
}
spin_unlock(&root->delalloc_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {
list_del_init(&work->list);
btrfs_wait_and_free_delalloc_work(work);
}
if (!list_empty_careful(&splice)) {
spin_lock(&root->delalloc_lock);
list_splice_tail(&splice, &root->delalloc_inodes);
spin_unlock(&root->delalloc_lock);
}
mutex_unlock(&root->delalloc_mutex);
return ret;
}
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
{
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
return -EROFS;
ret = __start_delalloc_inodes(root, delay_iput, -1);
if (ret > 0)
ret = 0;
/*
* the filemap_flush will queue IO into the worker threads, but
* we have to make sure the IO is actually started and that
* ordered extents get created before we return
*/
atomic_inc(&root->fs_info->async_submit_draining);
while (atomic_read(&root->fs_info->nr_async_submits) ||
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->nr_async_submits) == 0 &&
atomic_read(&root->fs_info->async_delalloc_pages) == 0));
}
atomic_dec(&root->fs_info->async_submit_draining);
return ret;
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
int nr)
{
struct btrfs_root *root;
struct list_head splice;
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->delalloc_root_mutex);
spin_lock(&fs_info->delalloc_root_lock);
list_splice_init(&fs_info->delalloc_roots, &splice);
while (!list_empty(&splice) && nr) {
root = list_first_entry(&splice, struct btrfs_root,
delalloc_root);
root = btrfs_grab_fs_root(root);
BUG_ON(!root);
list_move_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
ret = __start_delalloc_inodes(root, delay_iput, nr);
btrfs_put_fs_root(root);
if (ret < 0)
goto out;
if (nr != -1) {
nr -= ret;
WARN_ON(nr < 0);
}
spin_lock(&fs_info->delalloc_root_lock);
}
spin_unlock(&fs_info->delalloc_root_lock);
ret = 0;
atomic_inc(&fs_info->async_submit_draining);
while (atomic_read(&fs_info->nr_async_submits) ||
atomic_read(&fs_info->async_delalloc_pages)) {
wait_event(fs_info->async_submit_wait,
(atomic_read(&fs_info->nr_async_submits) == 0 &&
atomic_read(&fs_info->async_delalloc_pages) == 0));
}
atomic_dec(&fs_info->async_submit_draining);
out:
if (!list_empty_careful(&splice)) {
spin_lock(&fs_info->delalloc_root_lock);
list_splice_tail(&splice, &fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
mutex_unlock(&fs_info->delalloc_root_mutex);
return ret;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
u64 index = 0;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
name_len = strlen(symname);
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
/*
* 2 items for inode item and ref
* 2 items for dir items
* 1 item for updating parent inode item
* 1 item for the inline extent item
* 1 item for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 7);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
S_IFLNK|S_IRWXUGO, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock_inode;
}
key.objectid = btrfs_ino(inode);
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
btrfs_free_path(path);
goto out_unlock_inode;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode_set_bytes(inode, name_len);
btrfs_i_size_write(inode, name_len);
err = btrfs_update_inode(trans, root, inode);
/*
* Last step, add directory indexes for our symlink inode. This is the
* last step to avoid extra cleanup of these indexes if an error happens
* elsewhere above.
*/
if (!err)
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err) {
drop_inode = 1;
goto out_unlock_inode;
}
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
out_unlock_inode:
drop_inode = 1;
unlock_new_inode(inode);
goto out_unlock;
}
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint,
struct btrfs_trans_handle *trans)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 i_size;
u64 cur_bytes;
u64 last_alloc = (u64)-1;
int ret = 0;
bool own_trans = true;
if (trans)
own_trans = false;
while (num_bytes > 0) {
if (own_trans) {
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
}
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
* If we are severely fragmented we could end up with really
* small allocations, so if the allocator is returning small
* chunks lets make its job easier by only searching for those
* sized chunks.
*/
cur_bytes = min(cur_bytes, last_alloc);
ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
*alloc_hint, &ins, 1, 0);
if (ret) {
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
last_alloc = ins.offset;
ret = insert_reserved_file_extent(trans, inode,
cur_offset, ins.objectid,
ins.offset, ins.offset,
ins.offset, 0, 0, 0,
BTRFS_FILE_EXTENT_PREALLOC);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid,
ins.offset, 0);
btrfs_abort_transaction(trans, root, ret);
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset -1, 0);
em = alloc_extent_map();
if (!em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
em->start = cur_offset;
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ins.offset;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset - 1,
0);
}
free_extent_map(em);
next:
num_bytes -= ins.offset;
cur_offset += ins.offset;
*alloc_hint = ins.objectid + ins.offset;
inode_inc_iversion(inode);
inode->i_ctime = CURRENT_TIME;
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_ordered_update_i_size(inode, i_size, NULL);
}
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
if (own_trans)
btrfs_end_transaction(trans, root);
}
return ret;
}
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint,
NULL);
}
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint, trans);
}
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
}
static int btrfs_permission(struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
umode_t mode = inode->i_mode;
if (mask & MAY_WRITE &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
if (btrfs_root_readonly(root))
return -EROFS;
if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
return -EACCES;
}
return generic_permission(inode, mask);
}
static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
u64 objectid;
u64 index;
int ret = 0;
/*
* 5 units required for adding orphan entry
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_find_free_ino(root, &objectid);
if (ret)
goto out;
inode = btrfs_new_inode(trans, root, dir, NULL, 0,
btrfs_ino(dir), objectid, mode, &index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
inode = NULL;
goto out;
}
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
ret = btrfs_init_inode_security(trans, inode, dir, NULL);
if (ret)
goto out_inode;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
goto out_inode;
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out_inode;
/*
* We set number of links to 0 in btrfs_new_inode(), and here we set
* it to 1 because d_tmpfile() will issue a warning if the count is 0,
* through:
*
* d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
*/
set_nlink(inode, 1);
unlock_new_inode(inode);
d_tmpfile(dentry, inode);
mark_inode_dirty(inode);
out:
btrfs_end_transaction(trans, root);
if (ret)
iput(inode);
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return ret;
out_inode:
unlock_new_inode(inode);
goto out;
}
/* Inspired by filemap_check_errors() */
int btrfs_inode_check_errors(struct inode *inode)
{
int ret = 0;
if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
ret = -ENOSPC;
if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
ret = -EIO;
return ret;
}
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename2 = btrfs_rename2,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.tmpfile = btrfs_tmpfile,
};
static const struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate = btrfs_real_readdir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
static const struct extent_io_ops btrfs_extent_io_ops = {
.fill_delalloc = run_delalloc_range,
.submit_bio_hook = btrfs_submit_bio_hook,
.merge_bio_hook = btrfs_merge_bio_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
.writepage_end_io_hook = btrfs_writepage_end_io_hook,
.writepage_start_hook = btrfs_writepage_start_hook,
.set_bit_hook = btrfs_set_bit_hook,
.clear_bit_hook = btrfs_clear_bit_hook,
.merge_extent_hook = btrfs_merge_extent_hook,
.split_extent_hook = btrfs_split_extent_hook,
};
/*
* btrfs doesn't support the bmap operation because swapfiles
* use bmap to make a mapping of extents in the file. They assume
* these extents won't change over the life of the file and they
* use the bmap result to do IO directly to the drive.
*
* the btrfs bmap call would return logical addresses that aren't
* suitable for IO and they also will change frequently as COW
* operations happen. So, swapfile + btrfs == corruption.
*
* For now we're avoiding this by dropping bmap.
*/
static const struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readpages = btrfs_readpages,
.direct_IO = btrfs_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
.set_page_dirty = btrfs_set_page_dirty,
.error_remove_page = generic_error_remove_page,
};
static const struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
};
static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
.fiemap = btrfs_fiemap,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
.getxattr = btrfs_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.update_time = btrfs_update_time,
};
const struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
.d_release = btrfs_dentry_release,
};
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