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Btrfs: early work to file_write in big extents

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-04-16 09:22:45 -04:00 committed by David Woodhouse
parent b4100d6424
commit 6567e837df
4 changed files with 232 additions and 23 deletions
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54
fs/btrfs/ctree.c
View File

@ -1249,6 +1249,60 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
return ret;
}
int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, u32 data_size)
{
int ret = 0;
int slot;
int slot_orig;
struct btrfs_leaf *leaf;
struct buffer_head *leaf_buf;
u32 nritems;
unsigned int data_end;
unsigned int old_data;
unsigned int old_size;
int i;
slot_orig = path->slots[0];
leaf_buf = path->nodes[0];
leaf = btrfs_buffer_leaf(leaf_buf);
nritems = btrfs_header_nritems(&leaf->header);
data_end = leaf_data_end(root, leaf);
if (btrfs_leaf_free_space(root, leaf) < data_size)
BUG();
slot = path->slots[0];
old_data = btrfs_item_end(leaf->items + slot);
BUG_ON(slot < 0);
BUG_ON(slot >= nritems);
/*
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
for (i = slot; i < nritems; i++) {
u32 ioff = btrfs_item_offset(leaf->items + i);
btrfs_set_item_offset(leaf->items + i,
ioff - data_size);
}
/* shift the data */
btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) +
data_end - data_size, btrfs_leaf_data(leaf) +
data_end, old_data - data_end);
data_end = old_data;
old_size = btrfs_item_size(leaf->items + slot);
btrfs_set_item_size(leaf->items + slot, old_size + data_size);
btrfs_mark_buffer_dirty(leaf_buf);
ret = 0;
if (btrfs_leaf_free_space(root, leaf) < 0)
BUG();
check_leaf(root, path, 0);
return ret;
}
/*
* Given a key and some data, insert an item into the tree.
* This does all the path init required, making room in the tree if needed.

15
fs/btrfs/ctree.h
View File

@ -227,6 +227,7 @@ struct btrfs_file_extent_item {
} __attribute__ ((__packed__));
struct btrfs_csum_item {
__le64 extent_offset;
u8 csum[BTRFS_CSUM_SIZE];
} __attribute__ ((__packed__));
@ -924,6 +925,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct
e->num_blocks = cpu_to_le64(val);
}
static inline u64 btrfs_csum_extent_offset(struct btrfs_csum_item *c)
{
return le64_to_cpu(c->extent_offset);
}
static inline void btrfs_set_csum_extent_offset(struct btrfs_csum_item *c,
u64 val)
{
c->extent_offset = cpu_to_le64(val);
}
static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d)
{
return le16_to_cpu(d->pathlen);
@ -1002,6 +1014,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
btrfs_root *root);
/* ctree.c */
int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, u32 data_size);
int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_path *p, int
ins_len, int cow);
@ -1071,6 +1085,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
u64 extent_offset,
char *data, size_t len);
int btrfs_csum_verify_file_block(struct btrfs_root *root,
u64 objectid, u64 offset,

111
fs/btrfs/file-item.c
View File

@ -3,6 +3,9 @@
#include "disk-io.h"
#include "transaction.h"
#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
sizeof(struct btrfs_item)) / \
sizeof(struct btrfs_csum_item)) - 1))
int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
@ -43,6 +46,54 @@ int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
return 0;
}
static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset)
{
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_csum_item *item;
struct btrfs_leaf *leaf;
u64 csum_offset = 0;
file_key.objectid = objectid;
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
if (ret < 0)
goto fail;
leaf = btrfs_buffer_leaf(path->nodes[0]);
if (ret > 0) {
ret = 1;
if (path->slots[0] == 0)
goto fail;
path->slots[0]--;
btrfs_disk_key_to_cpu(&found_key,
&leaf->items[path->slots[0]].key);
if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
found_key.objectid != objectid) {
goto fail;
}
csum_offset = (offset - found_key.offset) >>
root->fs_info->sb->s_blocksize_bits;
if (csum_offset >=
btrfs_item_size(leaf->items + path->slots[0]) /
sizeof(struct btrfs_csum_item)) {
goto fail;
}
}
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
item += csum_offset;
return item;
fail:
if (ret > 0)
ret = -EIO;
return ERR_PTR(ret);
}
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
@ -52,11 +103,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_key file_key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
struct btrfs_csum_item *csum_item;
csum_item = __lookup_csum_item(root, path, objectid, offset);
if (IS_ERR(csum_item))
return PTR_ERR(csum_item);
file_key.objectid = objectid;
file_key.offset = offset;
file_key.offset = btrfs_csum_extent_offset(csum_item);
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
return ret;
}
@ -64,12 +120,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
u64 extent_offset,
char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_path *path;
struct btrfs_csum_item *item;
struct btrfs_leaf *leaf;
u64 csum_offset;
path = btrfs_alloc_path();
BUG_ON(!path);
@ -78,14 +138,50 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
ret = btrfs_search_slot(trans, root, &file_key, path,
sizeof(struct btrfs_csum_item), 1);
if (ret < 0)
goto fail;
if (ret == 0) {
csum_offset = 0;
goto csum;
}
if (path->slots[0] == 0) {
btrfs_release_path(root, path);
goto insert;
}
path->slots[0]--;
leaf = btrfs_buffer_leaf(path->nodes[0]);
btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
csum_offset = (offset - found_key.offset) >>
root->fs_info->sb->s_blocksize_bits;
if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
found_key.objectid != objectid ||
csum_offset >= MAX_CSUM_ITEMS(root)) {
btrfs_release_path(root, path);
goto insert;
}
if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
sizeof(struct btrfs_csum_item)) {
ret = btrfs_extend_item(trans, root, path,
sizeof(struct btrfs_csum_item));
BUG_ON(ret);
goto csum;
}
insert:
csum_offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
BTRFS_CSUM_SIZE);
sizeof(struct btrfs_csum_item));
if (ret != 0 && ret != -EEXIST)
goto fail;
csum:
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_csum_item);
ret = 0;
item += csum_offset;
ret = btrfs_csum_data(root, data, len, item->csum);
btrfs_set_csum_extent_offset(item, extent_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
btrfs_release_path(root, path);
@ -111,12 +207,13 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
mutex_lock(&root->fs_info->fs_mutex);
ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
if (ret)
item = __lookup_csum_item(root, path, objectid, offset);
if (IS_ERR(item)) {
ret = PTR_ERR(item);
goto fail;
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_csum_item);
ret = 0;
}
ret = btrfs_csum_data(root, data, len, result);
WARN_ON(ret);
if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))

75
fs/btrfs/super.c
View File

@ -1027,8 +1027,10 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
if (create)
if (create) {
trans = btrfs_start_transaction(root, 1);
WARN_ON(1);
}
ret = btrfs_lookup_file_extent(trans, root, path,
inode->i_ino,
@ -1055,9 +1057,8 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
/* exact match found, use it, FIXME, deal with extents
* other than the page size
*/
if (ret == 0) {
if (0 && ret == 0) {
err = 0;
BUG_ON(btrfs_file_extent_disk_num_blocks(item) != 1);
if (create &&
btrfs_file_extent_generation(item) != trans->transid) {
struct btrfs_key ins;
@ -1072,7 +1073,6 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
blocknr = ins.objectid;
}
map_bh(result, inode->i_sb, blocknr);
btrfs_map_bh_to_logical(root, result, blocknr);
goto out;
}
@ -1231,6 +1231,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
struct file *file,
struct page **pages,
size_t num_pages,
u64 extent_offset,
loff_t pos,
size_t write_bytes)
{
@ -1250,6 +1251,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
trans = btrfs_start_transaction(root, 1);
btrfs_csum_file_block(trans, root, inode->i_ino,
pages[i]->index << PAGE_CACHE_SHIFT,
extent_offset,
kmap(pages[i]), PAGE_CACHE_SIZE);
kunmap(pages[i]);
SetPageChecked(pages[i]);
@ -1279,7 +1281,8 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
loff_t pos,
unsigned long first_index,
unsigned long last_index,
size_t write_bytes)
size_t write_bytes,
u64 alloc_extent_start)
{
int i;
unsigned long index = pos >> PAGE_CACHE_SHIFT;
@ -1288,6 +1291,8 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
int err = 0;
int ret;
int this_write;
struct buffer_head *bh;
struct buffer_head *head;
loff_t isize = i_size_read(inode);
memset(pages, 0, num_pages * sizeof(struct page *));
@ -1307,14 +1312,20 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
BUG_ON(ret);
lock_page(pages[i]);
}
ret = nobh_prepare_write(pages[i], offset,
offset + this_write,
btrfs_get_block);
create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
(1 << BH_Uptodate));
head = page_buffers(pages[i]);
bh = head;
do {
err = btrfs_map_bh_to_logical(root, bh,
alloc_extent_start);
BUG_ON(err);
if (err)
goto failed_truncate;
bh = bh->b_this_page;
alloc_extent_start++;
} while (bh != head);
pos += this_write;
if (ret) {
err = ret;
goto failed_truncate;
}
WARN_ON(this_write > write_bytes);
write_bytes -= this_write;
}
@ -1343,11 +1354,23 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
struct page *pages[1];
unsigned long first_index;
unsigned long last_index;
u64 start_pos;
u64 num_blocks;
u64 alloc_extent_start;
u64 orig_extent_start;
struct btrfs_trans_handle *trans;
if (file->f_flags & O_DIRECT)
return -EINVAL;
pos = *ppos;
start_pos = pos & ~(root->blocksize - 1);
/* FIXME */
if (start_pos != pos)
return -EINVAL;
num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
inode->i_blkbits;
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@ -1362,20 +1385,41 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
mutex_lock(&inode->i_mutex);
first_index = pos >> PAGE_CACHE_SHIFT;
last_index = (pos + count) >> PAGE_CACHE_SHIFT;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
if (!trans) {
err = -ENOMEM;
goto out_unlock;
}
ret = btrfs_alloc_file_extent(trans, root, inode->i_ino,
start_pos, num_blocks, 1,
&alloc_extent_start);
BUG_ON(ret);
orig_extent_start = start_pos;
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
while(count > 0) {
size_t offset = pos & (PAGE_CACHE_SIZE - 1);
size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
ret = prepare_pages(NULL, root, file, pages, num_pages,
pos, first_index, last_index, write_bytes);
pos, first_index, last_index,
write_bytes, alloc_extent_start);
BUG_ON(ret);
/* FIXME blocks != pagesize */
alloc_extent_start += num_pages;
ret = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, buf);
BUG_ON(ret);
ret = dirty_and_release_pages(NULL, root, file, pages,
num_pages, pos, write_bytes);
num_pages, orig_extent_start,
pos, write_bytes);
BUG_ON(ret);
btrfs_drop_pages(pages, num_pages);
@ -1387,6 +1431,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
balance_dirty_pages_ratelimited(inode->i_mapping);
cond_resched();
}
out_unlock:
mutex_unlock(&inode->i_mutex);
out:
*ppos = pos;
@ -1806,8 +1851,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
&new_root_item);
BUG_ON(ret);
printk("adding snapshot name %.*s root %Lu %Lu %u\n", namelen, name, key.objectid, key.offset, key.flags);
/*
* insert the directory item
*/