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Btrfs: Extent based page cache code. This uses an rbtree of extents and tests
instead of buffer heads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
parent
83df7c1d8b
commit
a52d9a8033
@ -4,7 +4,8 @@ ifneq ($(KERNELRELEASE),)
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obj-m := btrfs.o
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btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
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hash.o file-item.o inode-item.o inode-map.o disk-io.o \
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transaction.o bit-radix.o inode.o file.o tree-defrag.o
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transaction.o bit-radix.o inode.o file.o tree-defrag.o \
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extent_map.o
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#btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
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# root-tree.o dir-item.o hash.o file-item.o inode-item.o \
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@ -19,11 +19,14 @@
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#ifndef __BTRFS_I__
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#define __BTRFS_I__
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#include "extent_map.h"
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/* in memory btrfs inode */
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struct btrfs_inode {
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struct btrfs_root *root;
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struct btrfs_block_group_cache *block_group;
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struct btrfs_key location;
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struct extent_map_tree extent_tree;
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struct inode vfs_inode;
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/*
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@ -1176,7 +1176,14 @@ int btrfs_commit_write(struct file *file, struct page *page,
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unsigned from, unsigned to);
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int btrfs_get_block(struct inode *inode, sector_t iblock,
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struct buffer_head *result, int create);
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struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
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size_t page_offset, u64 start, u64 end,
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int create);
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int btrfs_update_inode(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct inode *inode);
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/* file.c */
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int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end);
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extern struct file_operations btrfs_file_operations;
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int btrfs_drop_extents(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct inode *inode,
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@ -77,7 +77,6 @@ int btrfs_insert_dev_radix(struct btrfs_root *root,
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u64 num_blocks);
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int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
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u64 logical);
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int btrfs_releasepage(struct page *page, gfp_t flags);
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void btrfs_btree_balance_dirty(struct btrfs_root *root);
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int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
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void btrfs_mark_buffer_dirty(struct buffer_head *bh);
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1656
fs/btrfs/extent_map.c
Normal file
1656
fs/btrfs/extent_map.c
Normal file
File diff suppressed because it is too large
Load Diff
89
fs/btrfs/extent_map.h
Normal file
89
fs/btrfs/extent_map.h
Normal file
@ -0,0 +1,89 @@
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#ifndef __EXTENTMAP__
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#define __EXTENTMAP__
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#include <linux/rbtree.h>
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#define EXTENT_MAP_INLINE (u64)-2
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#define EXTENT_MAP_DELALLOC (u64)-1
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struct extent_map_tree {
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struct rb_root map;
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struct rb_root state;
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struct address_space *mapping;
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rwlock_t lock;
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};
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/* note, this must start with the same fields as fs/extent_map.c:tree_entry */
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struct extent_map {
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u64 start;
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u64 end; /* inclusive */
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int in_tree;
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struct rb_node rb_node;
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/* block_start and block_end are in bytes */
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u64 block_start;
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u64 block_end; /* inclusive */
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struct block_device *bdev;
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atomic_t refs;
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};
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/* note, this must start with the same fields as fs/extent_map.c:tree_entry */
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struct extent_state {
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u64 start;
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u64 end; /* inclusive */
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int in_tree;
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struct rb_node rb_node;
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wait_queue_head_t wq;
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atomic_t refs;
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unsigned long state;
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struct list_head list;
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};
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struct extent_buffer {
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u64 start;
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u64 end; /* inclusive */
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char *addr;
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struct page *pages[];
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};
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typedef struct extent_map *(get_extent_t)(struct inode *inode,
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struct page *page,
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size_t page_offset,
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u64 start, u64 end,
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int create);
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void extent_map_tree_init(struct extent_map_tree *tree,
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struct address_space *mapping, gfp_t mask);
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struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
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u64 start, u64 end);
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int add_extent_mapping(struct extent_map_tree *tree,
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struct extent_map *em);
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int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
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int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page);
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int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask);
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int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask);
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struct extent_map *alloc_extent_map(gfp_t mask);
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void free_extent_map(struct extent_map *em);
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int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
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get_extent_t *get_extent);
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void __init extent_map_init(void);
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void __exit extent_map_exit(void);
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int extent_clean_all_trees(struct extent_map_tree *tree);
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int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end,
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gfp_t mask);
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int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
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gfp_t mask);
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int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
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gfp_t mask);
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int extent_invalidatepage(struct extent_map_tree *tree,
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struct page *page, unsigned long offset);
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int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
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get_extent_t *get_extent,
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struct writeback_control *wbc);
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int extent_prepare_write(struct extent_map_tree *tree,
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struct inode *inode, struct page *page,
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unsigned from, unsigned to, get_extent_t *get_extent);
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int extent_commit_write(struct extent_map_tree *tree,
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struct inode *inode, struct page *page,
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unsigned from, unsigned to);
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int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end);
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#endif
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295
fs/btrfs/file.c
295
fs/btrfs/file.c
@ -81,14 +81,14 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
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}
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}
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static int insert_inline_extent(struct btrfs_root *root, struct inode *inode,
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static int insert_inline_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct inode *inode,
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u64 offset, ssize_t size,
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struct buffer_head *bh)
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struct page *page, size_t page_offset)
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{
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struct btrfs_key key;
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struct btrfs_path *path;
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char *ptr, *kaddr;
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struct btrfs_trans_handle *trans;
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struct btrfs_file_extent_item *ei;
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u32 datasize;
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int err = 0;
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@ -98,8 +98,6 @@ static int insert_inline_extent(struct btrfs_root *root, struct inode *inode,
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if (!path)
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return -ENOMEM;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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btrfs_set_trans_block_group(trans, inode);
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key.objectid = inode->i_ino;
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@ -122,18 +120,13 @@ static int insert_inline_extent(struct btrfs_root *root, struct inode *inode,
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BTRFS_FILE_EXTENT_INLINE);
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ptr = btrfs_file_extent_inline_start(ei);
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kaddr = kmap_atomic(bh->b_page, KM_USER0);
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kaddr = kmap_atomic(page, KM_USER0);
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btrfs_memcpy(root, path->nodes[0]->b_data,
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ptr, kaddr + bh_offset(bh),
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size);
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ptr, kaddr + page_offset, size);
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kunmap_atomic(kaddr, KM_USER0);
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btrfs_mark_buffer_dirty(path->nodes[0]);
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fail:
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btrfs_free_path(path);
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ret = btrfs_end_transaction(trans, root);
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if (ret && !err)
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err = ret;
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mutex_unlock(&root->fs_info->fs_mutex);
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return err;
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}
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@ -145,45 +138,143 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
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loff_t pos,
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size_t write_bytes)
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{
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int i;
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int offset;
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int err = 0;
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int ret;
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int this_write;
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int i;
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struct inode *inode = file->f_path.dentry->d_inode;
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struct buffer_head *bh;
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struct extent_map *em;
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struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
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struct btrfs_key ins;
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u64 hint_block;
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u64 num_blocks;
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u64 start_pos;
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u64 end_of_last_block;
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u64 end_pos = pos + write_bytes;
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loff_t isize = i_size_read(inode);
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for (i = 0; i < num_pages; i++) {
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offset = pos & (PAGE_CACHE_SIZE -1);
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this_write = min((size_t)PAGE_CACHE_SIZE - offset, write_bytes);
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em = alloc_extent_map(GFP_NOFS);
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if (!em)
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return -ENOMEM;
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/* FIXME, one block at a time */
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bh = page_buffers(pages[i]);
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em->bdev = inode->i_sb->s_bdev;
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if (buffer_mapped(bh) && bh->b_blocknr == 0) {
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ret = insert_inline_extent(root, inode,
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pages[i]->index << PAGE_CACHE_SHIFT,
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offset + this_write, bh);
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if (ret) {
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err = ret;
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goto failed;
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}
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}
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start_pos = pos & ~((u64)root->blocksize - 1);
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num_blocks = (write_bytes + pos - start_pos + root->blocksize - 1) >>
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inode->i_blkbits;
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ret = btrfs_commit_write(file, pages[i], offset,
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offset + this_write);
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pos += this_write;
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if (ret) {
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err = ret;
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end_of_last_block = start_pos + (num_blocks << inode->i_blkbits) - 1;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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if (!trans) {
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err = -ENOMEM;
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goto out_unlock;
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}
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btrfs_set_trans_block_group(trans, inode);
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inode->i_blocks += num_blocks << 3;
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hint_block = 0;
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if ((end_of_last_block & 4095) == 0) {
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printk("strange end of last %Lu %lu %Lu\n", start_pos, write_bytes, end_of_last_block);
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}
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set_extent_uptodate(em_tree, start_pos, end_of_last_block, GFP_NOFS);
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/* FIXME...EIEIO, ENOSPC and more */
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/* step one, delete the existing extents in this range */
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/* FIXME blocksize != pagesize */
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if (start_pos < inode->i_size) {
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err = btrfs_drop_extents(trans, root, inode,
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start_pos, (pos + write_bytes + root->blocksize -1) &
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~((u64)root->blocksize - 1), &hint_block);
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if (err)
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goto failed;
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}
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/* insert any holes we need to create */
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if (inode->i_size < start_pos) {
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u64 last_pos_in_file;
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u64 hole_size;
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u64 mask = root->blocksize - 1;
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last_pos_in_file = (isize + mask) & ~mask;
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hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
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hole_size >>= inode->i_blkbits;
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if (last_pos_in_file < start_pos) {
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err = btrfs_insert_file_extent(trans, root,
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inode->i_ino,
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last_pos_in_file,
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0, 0, hole_size);
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}
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WARN_ON(this_write > write_bytes);
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write_bytes -= this_write;
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if (err)
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goto failed;
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}
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/*
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* either allocate an extent for the new bytes or setup the key
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* to show we are doing inline data in the extent
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*/
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if (isize >= PAGE_CACHE_SIZE || pos + write_bytes < inode->i_size ||
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pos + write_bytes - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
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err = btrfs_alloc_extent(trans, root, inode->i_ino,
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num_blocks, 0, hint_block, (u64)-1,
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&ins, 1);
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BUG_ON(err);
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err = btrfs_insert_file_extent(trans, root, inode->i_ino,
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start_pos, ins.objectid, ins.offset,
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ins.offset);
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BUG_ON(err);
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em->start = start_pos;
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em->end = end_of_last_block;
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em->block_start = ins.objectid << inode->i_blkbits;
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em->block_end = em->block_start +
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(ins.offset << inode->i_blkbits) - 1;
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set_extent_dirty(em_tree, start_pos, end_of_last_block,
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GFP_NOFS);
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err = add_extent_mapping(em_tree, em);
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for (i = 0; i < num_pages; i++) {
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struct page *p = pages[i];
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SetPageUptodate(p);
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__set_page_dirty_nobuffers(p);
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}
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} else {
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struct page *p = pages[0];
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err = insert_inline_extent(trans, root, inode, start_pos,
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end_pos - start_pos, p, 0);
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BUG_ON(err);
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em->start = start_pos;
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em->end = end_pos;
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em->block_start = EXTENT_MAP_INLINE;
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em->block_end = EXTENT_MAP_INLINE;
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add_extent_mapping(em_tree, em);
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}
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if (end_pos > isize) {
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i_size_write(inode, end_pos);
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btrfs_update_inode(trans, root, inode);
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}
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failed:
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err = btrfs_end_transaction(trans, root);
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out_unlock:
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mutex_unlock(&root->fs_info->fs_mutex);
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free_extent_map(em);
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return err;
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}
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int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
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{
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struct extent_map *em;
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struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
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while(1) {
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em = lookup_extent_mapping(em_tree, start, end);
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if (!em)
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break;
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remove_extent_mapping(em_tree, em);
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/* once for us */
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free_extent_map(em);
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/* once for the tree*/
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free_extent_map(em);
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}
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return 0;
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}
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/*
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* this is very complex, but the basic idea is to drop all extents
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* in the range start - end. hint_block is filled in with a block number
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@ -213,6 +304,8 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans,
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int found_inline;
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int recow;
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btrfs_drop_extent_cache(inode, start, end - 1);
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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@ -434,18 +527,9 @@ static int prepare_pages(struct btrfs_root *root,
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int i;
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unsigned long index = pos >> PAGE_CACHE_SHIFT;
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struct inode *inode = file->f_path.dentry->d_inode;
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int offset;
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int err = 0;
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int this_write;
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struct buffer_head *bh;
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struct buffer_head *head;
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loff_t isize = i_size_read(inode);
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struct btrfs_trans_handle *trans;
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u64 hint_block;
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u64 num_blocks;
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u64 alloc_extent_start;
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u64 start_pos;
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struct btrfs_key ins;
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start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
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num_blocks = (write_bytes + pos - start_pos + root->blocksize - 1) >>
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@ -457,119 +541,17 @@ static int prepare_pages(struct btrfs_root *root,
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pages[i] = grab_cache_page(inode->i_mapping, index + i);
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if (!pages[i]) {
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err = -ENOMEM;
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goto failed_release;
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BUG_ON(1);
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}
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cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
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wait_on_page_writeback(pages[i]);
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}
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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if (!trans) {
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err = -ENOMEM;
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mutex_unlock(&root->fs_info->fs_mutex);
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goto out_unlock;
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}
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btrfs_set_trans_block_group(trans, inode);
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/* FIXME blocksize != 4096 */
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inode->i_blocks += num_blocks << 3;
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hint_block = 0;
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/* FIXME...EIEIO, ENOSPC and more */
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/* step one, delete the existing extents in this range */
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/* FIXME blocksize != pagesize */
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if (start_pos < inode->i_size) {
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err = btrfs_drop_extents(trans, root, inode,
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start_pos, (pos + write_bytes + root->blocksize -1) &
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||||
~((u64)root->blocksize - 1), &hint_block);
|
||||
if (err)
|
||||
goto failed_release;
|
||||
}
|
||||
|
||||
/* insert any holes we need to create */
|
||||
if (inode->i_size < start_pos) {
|
||||
u64 last_pos_in_file;
|
||||
u64 hole_size;
|
||||
u64 mask = root->blocksize - 1;
|
||||
last_pos_in_file = (isize + mask) & ~mask;
|
||||
hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
|
||||
hole_size >>= inode->i_blkbits;
|
||||
if (last_pos_in_file < start_pos) {
|
||||
err = btrfs_insert_file_extent(trans, root,
|
||||
inode->i_ino,
|
||||
last_pos_in_file,
|
||||
0, 0, hole_size);
|
||||
if (!PagePrivate(pages[i])) {
|
||||
SetPagePrivate(pages[i]);
|
||||
set_page_private(pages[i], 1);
|
||||
page_cache_get(pages[i]);
|
||||
}
|
||||
if (err)
|
||||
goto failed_release;
|
||||
}
|
||||
|
||||
/*
|
||||
* either allocate an extent for the new bytes or setup the key
|
||||
* to show we are doing inline data in the extent
|
||||
*/
|
||||
if (isize >= PAGE_CACHE_SIZE || pos + write_bytes < inode->i_size ||
|
||||
pos + write_bytes - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
|
||||
err = btrfs_alloc_extent(trans, root, inode->i_ino,
|
||||
num_blocks, 0, hint_block, (u64)-1,
|
||||
&ins, 1);
|
||||
if (err)
|
||||
goto failed_truncate;
|
||||
err = btrfs_insert_file_extent(trans, root, inode->i_ino,
|
||||
start_pos, ins.objectid, ins.offset,
|
||||
ins.offset);
|
||||
if (err)
|
||||
goto failed_truncate;
|
||||
} else {
|
||||
ins.offset = 0;
|
||||
ins.objectid = 0;
|
||||
}
|
||||
BUG_ON(err);
|
||||
alloc_extent_start = ins.objectid;
|
||||
err = btrfs_end_transaction(trans, root);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
|
||||
for (i = 0; i < num_pages; i++) {
|
||||
offset = pos & (PAGE_CACHE_SIZE -1);
|
||||
this_write = min((size_t)PAGE_CACHE_SIZE - offset, write_bytes);
|
||||
if (!page_has_buffers(pages[i])) {
|
||||
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;
|
||||
if (alloc_extent_start)
|
||||
alloc_extent_start++;
|
||||
} while (bh != head);
|
||||
pos += this_write;
|
||||
WARN_ON(this_write > write_bytes);
|
||||
write_bytes -= this_write;
|
||||
}
|
||||
return 0;
|
||||
|
||||
failed_release:
|
||||
btrfs_drop_pages(pages, num_pages);
|
||||
return err;
|
||||
|
||||
failed_truncate:
|
||||
btrfs_drop_pages(pages, num_pages);
|
||||
if (pos > isize)
|
||||
vmtruncate(inode, isize);
|
||||
return err;
|
||||
|
||||
out_unlock:
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
goto failed_release;
|
||||
|
||||
}
|
||||
|
||||
static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
|
||||
@ -685,7 +667,6 @@ out:
|
||||
page_cache_release(pinned[1]);
|
||||
*ppos = pos;
|
||||
current->backing_dev_info = NULL;
|
||||
mark_inode_dirty(inode);
|
||||
return num_written ? num_written : err;
|
||||
}
|
||||
|
||||
@ -714,8 +695,8 @@ static int btrfs_sync_file(struct file *file,
|
||||
mutex_unlock(&root->fs_info->trans_mutex);
|
||||
|
||||
/*
|
||||
* ok we haven't committed the transaction yet, lets do a commit
|
||||
*/
|
||||
* ok we haven't committed the transaction yet, lets do a commit
|
||||
*/
|
||||
trans = btrfs_start_transaction(root, 1);
|
||||
if (!trans) {
|
||||
ret = -ENOMEM;
|
||||
|
836
fs/btrfs/inode.c
836
fs/btrfs/inode.c
@ -121,6 +121,8 @@ void btrfs_read_locked_inode(struct inode *inode)
|
||||
switch (inode->i_mode & S_IFMT) {
|
||||
case S_IFREG:
|
||||
inode->i_mapping->a_ops = &btrfs_aops;
|
||||
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
|
||||
inode->i_mapping, GFP_NOFS);
|
||||
inode->i_fop = &btrfs_file_operations;
|
||||
inode->i_op = &btrfs_file_inode_operations;
|
||||
break;
|
||||
@ -169,7 +171,7 @@ static void fill_inode_item(struct btrfs_inode_item *item,
|
||||
BTRFS_I(inode)->block_group->key.objectid);
|
||||
}
|
||||
|
||||
static int btrfs_update_inode(struct btrfs_trans_handle *trans,
|
||||
int btrfs_update_inode(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root,
|
||||
struct inode *inode)
|
||||
{
|
||||
@ -400,6 +402,7 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
|
||||
int found_extent;
|
||||
int del_item;
|
||||
|
||||
btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
|
||||
path = btrfs_alloc_path();
|
||||
path->reada = -1;
|
||||
BUG_ON(!path);
|
||||
@ -511,47 +514,27 @@ error:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* taken from block_truncate_page, but does cow as it zeros out
|
||||
* any bytes left in the last page in the file.
|
||||
*/
|
||||
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
|
||||
static int btrfs_cow_one_page(struct btrfs_trans_handle *trans,
|
||||
struct inode *inode, struct page *page,
|
||||
size_t zero_start)
|
||||
{
|
||||
struct inode *inode = mapping->host;
|
||||
unsigned blocksize = 1 << inode->i_blkbits;
|
||||
pgoff_t index = from >> PAGE_CACHE_SHIFT;
|
||||
unsigned offset = from & (PAGE_CACHE_SIZE-1);
|
||||
struct page *page;
|
||||
char *kaddr;
|
||||
int ret = 0;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
u64 alloc_hint = 0;
|
||||
u64 page_start = page->index << PAGE_CACHE_SHIFT;
|
||||
struct btrfs_key ins;
|
||||
struct btrfs_trans_handle *trans;
|
||||
|
||||
if ((offset & (blocksize - 1)) == 0)
|
||||
goto out;
|
||||
|
||||
ret = -ENOMEM;
|
||||
page = grab_cache_page(mapping, index);
|
||||
if (!page)
|
||||
goto out;
|
||||
|
||||
if (!PageUptodate(page)) {
|
||||
ret = btrfs_readpage(NULL, page);
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
if (!PagePrivate(page)) {
|
||||
SetPagePrivate(page);
|
||||
set_page_private(page, 1);
|
||||
page_cache_get(page);
|
||||
}
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
trans = btrfs_start_transaction(root, 1);
|
||||
|
||||
btrfs_set_trans_block_group(trans, inode);
|
||||
|
||||
ret = btrfs_drop_extents(trans, root, inode,
|
||||
page->index << PAGE_CACHE_SHIFT,
|
||||
(page->index + 1) << PAGE_CACHE_SHIFT,
|
||||
page_start, page_start + PAGE_CACHE_SIZE,
|
||||
&alloc_hint);
|
||||
if (ret)
|
||||
goto out;
|
||||
@ -560,22 +543,70 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
|
||||
if (ret)
|
||||
goto out;
|
||||
ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
|
||||
page->index << PAGE_CACHE_SHIFT,
|
||||
ins.objectid, 1, 1);
|
||||
page_start, ins.objectid, 1, 1);
|
||||
if (ret)
|
||||
goto out;
|
||||
SetPageChecked(page);
|
||||
kaddr = kmap(page);
|
||||
memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
|
||||
flush_dcache_page(page);
|
||||
ret = btrfs_csum_file_block(trans, root, inode->i_ino,
|
||||
page->index << PAGE_CACHE_SHIFT,
|
||||
kaddr, PAGE_CACHE_SIZE);
|
||||
if (zero_start != PAGE_CACHE_SIZE) {
|
||||
memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
|
||||
flush_dcache_page(page);
|
||||
}
|
||||
kunmap(page);
|
||||
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* taken from block_truncate_page, but does cow as it zeros out
|
||||
* any bytes left in the last page in the file.
|
||||
*/
|
||||
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
|
||||
{
|
||||
struct inode *inode = mapping->host;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
struct btrfs_trans_handle *trans;
|
||||
unsigned blocksize = 1 << inode->i_blkbits;
|
||||
pgoff_t index = from >> PAGE_CACHE_SHIFT;
|
||||
unsigned offset = from & (PAGE_CACHE_SIZE-1);
|
||||
struct page *page;
|
||||
int ret = 0;
|
||||
u64 page_start;
|
||||
|
||||
if ((offset & (blocksize - 1)) == 0)
|
||||
goto out;
|
||||
|
||||
ret = -ENOMEM;
|
||||
page = grab_cache_page(mapping, index);
|
||||
if (!page)
|
||||
goto out;
|
||||
if (!PageUptodate(page)) {
|
||||
ret = btrfs_readpage(NULL, page);
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
page_start = page->index << PAGE_CACHE_SHIFT;
|
||||
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
trans = btrfs_start_transaction(root, 1);
|
||||
ret = btrfs_cow_one_page(trans, inode, page, offset);
|
||||
if (!ret) {
|
||||
char *kaddr = kmap(page);
|
||||
ret = btrfs_csum_file_block(trans, root, inode->i_ino,
|
||||
page_start, kaddr, PAGE_CACHE_SIZE);
|
||||
kunmap(page);
|
||||
}
|
||||
set_extent_dirty(&BTRFS_I(inode)->extent_tree,
|
||||
page_start, page_start + PAGE_CACHE_SIZE - 1,
|
||||
GFP_NOFS);
|
||||
set_page_dirty(page);
|
||||
btrfs_end_transaction(trans, root);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
|
||||
set_page_dirty(page);
|
||||
unlock_page(page);
|
||||
page_cache_release(page);
|
||||
out:
|
||||
@ -1095,6 +1126,8 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
|
||||
inode->i_mapping->a_ops = &btrfs_aops;
|
||||
inode->i_fop = &btrfs_file_operations;
|
||||
inode->i_op = &btrfs_file_inode_operations;
|
||||
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
|
||||
inode->i_mapping, GFP_NOFS);
|
||||
}
|
||||
dir->i_sb->s_dirt = 1;
|
||||
btrfs_update_inode_block_group(trans, inode);
|
||||
@ -1238,6 +1271,182 @@ out_unlock:
|
||||
return err;
|
||||
}
|
||||
|
||||
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
|
||||
size_t page_offset, u64 start, u64 end,
|
||||
int create)
|
||||
{
|
||||
int ret;
|
||||
int err = 0;
|
||||
u64 blocknr;
|
||||
u64 extent_start = 0;
|
||||
u64 extent_end = 0;
|
||||
u64 objectid = inode->i_ino;
|
||||
u32 found_type;
|
||||
int failed_insert = 0;
|
||||
struct btrfs_path *path;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
struct btrfs_file_extent_item *item;
|
||||
struct btrfs_leaf *leaf;
|
||||
struct btrfs_disk_key *found_key;
|
||||
struct extent_map *em = NULL;
|
||||
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
|
||||
struct btrfs_trans_handle *trans = NULL;
|
||||
|
||||
path = btrfs_alloc_path();
|
||||
BUG_ON(!path);
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
|
||||
again:
|
||||
em = lookup_extent_mapping(em_tree, start, end);
|
||||
if (em) {
|
||||
goto out;
|
||||
}
|
||||
if (!em) {
|
||||
em = alloc_extent_map(GFP_NOFS);
|
||||
if (!em) {
|
||||
err = -ENOMEM;
|
||||
goto out;
|
||||
}
|
||||
em->start = 0;
|
||||
em->end = 0;
|
||||
}
|
||||
em->bdev = inode->i_sb->s_bdev;
|
||||
ret = btrfs_lookup_file_extent(NULL, root, path,
|
||||
objectid, start, 0);
|
||||
if (ret < 0) {
|
||||
err = ret;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (ret != 0) {
|
||||
if (path->slots[0] == 0)
|
||||
goto not_found;
|
||||
path->slots[0]--;
|
||||
}
|
||||
|
||||
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
|
||||
struct btrfs_file_extent_item);
|
||||
leaf = btrfs_buffer_leaf(path->nodes[0]);
|
||||
blocknr = btrfs_file_extent_disk_blocknr(item);
|
||||
blocknr += btrfs_file_extent_offset(item);
|
||||
|
||||
/* are we inside the extent that was found? */
|
||||
found_key = &leaf->items[path->slots[0]].key;
|
||||
found_type = btrfs_disk_key_type(found_key);
|
||||
if (btrfs_disk_key_objectid(found_key) != objectid ||
|
||||
found_type != BTRFS_EXTENT_DATA_KEY) {
|
||||
goto not_found;
|
||||
}
|
||||
|
||||
found_type = btrfs_file_extent_type(item);
|
||||
extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
|
||||
if (found_type == BTRFS_FILE_EXTENT_REG) {
|
||||
extent_end = extent_start +
|
||||
(btrfs_file_extent_num_blocks(item) << inode->i_blkbits);
|
||||
err = 0;
|
||||
if (start < extent_start || start > extent_end) {
|
||||
em->start = start;
|
||||
if (start < extent_start) {
|
||||
em->end = extent_end - 1;
|
||||
} else {
|
||||
em->end = end;
|
||||
}
|
||||
goto not_found_em;
|
||||
}
|
||||
if (btrfs_file_extent_disk_blocknr(item) == 0) {
|
||||
em->start = extent_start;
|
||||
em->end = extent_end - 1;
|
||||
em->block_start = 0;
|
||||
em->block_end = 0;
|
||||
goto insert;
|
||||
}
|
||||
em->block_start = blocknr << inode->i_blkbits;
|
||||
em->block_end = em->block_start +
|
||||
(btrfs_file_extent_num_blocks(item) <<
|
||||
inode->i_blkbits) - 1;
|
||||
em->start = extent_start;
|
||||
em->end = extent_end - 1;
|
||||
goto insert;
|
||||
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
|
||||
char *ptr;
|
||||
char *map;
|
||||
u32 size;
|
||||
|
||||
size = btrfs_file_extent_inline_len(leaf->items +
|
||||
path->slots[0]);
|
||||
extent_end = extent_start + size;
|
||||
if (start < extent_start || start > extent_end) {
|
||||
em->start = start;
|
||||
if (start < extent_start) {
|
||||
em->end = extent_end - 1;
|
||||
} else {
|
||||
em->end = end;
|
||||
}
|
||||
goto not_found_em;
|
||||
}
|
||||
em->block_start = EXTENT_MAP_INLINE;
|
||||
em->block_end = EXTENT_MAP_INLINE;
|
||||
em->start = extent_start;
|
||||
em->end = extent_end - 1;
|
||||
if (!page) {
|
||||
goto insert;
|
||||
}
|
||||
ptr = btrfs_file_extent_inline_start(item);
|
||||
map = kmap(page);
|
||||
memcpy(map + page_offset, ptr, size);
|
||||
flush_dcache_page(result->b_page);
|
||||
kunmap(page);
|
||||
set_extent_uptodate(em_tree, extent_start,
|
||||
extent_end, GFP_NOFS);
|
||||
goto insert;
|
||||
} else {
|
||||
printk("unkknown found_type %d\n", found_type);
|
||||
WARN_ON(1);
|
||||
}
|
||||
not_found:
|
||||
em->start = start;
|
||||
em->end = end;
|
||||
not_found_em:
|
||||
em->block_start = 0;
|
||||
em->block_end = 0;
|
||||
insert:
|
||||
btrfs_release_path(root, path);
|
||||
if (em->start > start || em->end < start) {
|
||||
printk("bad extent! %Lu %Lu start %Lu end %Lu\n", em->start, em->end, start, end);
|
||||
WARN_ON(1);
|
||||
err = -EIO;
|
||||
goto out;
|
||||
}
|
||||
ret = add_extent_mapping(em_tree, em);
|
||||
if (ret == -EEXIST) {
|
||||
free_extent_map(em);
|
||||
failed_insert++;
|
||||
if (failed_insert > 5) {
|
||||
printk("failing to insert %Lu %Lu\n", start, end);
|
||||
err = -EIO;
|
||||
goto out;
|
||||
}
|
||||
em = NULL;
|
||||
goto again;
|
||||
}
|
||||
err = 0;
|
||||
out:
|
||||
btrfs_free_path(path);
|
||||
if (trans) {
|
||||
ret = btrfs_end_transaction(trans, root);
|
||||
if (!err)
|
||||
err = ret;
|
||||
}
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
if (err) {
|
||||
free_extent_map(em);
|
||||
WARN_ON(1);
|
||||
return ERR_PTR(err);
|
||||
}
|
||||
return em;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* FIBMAP and others want to pass in a fake buffer head. They need to
|
||||
* use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
|
||||
@ -1398,46 +1607,22 @@ int btrfs_get_block(struct inode *inode, sector_t iblock,
|
||||
return err;
|
||||
}
|
||||
|
||||
static int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
|
||||
struct buffer_head *result, int create)
|
||||
{
|
||||
int ret;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
struct page *page = result->b_page;
|
||||
u64 offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(result);
|
||||
struct btrfs_csum_item *item;
|
||||
struct btrfs_path *path = NULL;
|
||||
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
ret = btrfs_get_block_lock(inode, iblock, result, create);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
path = btrfs_alloc_path();
|
||||
item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, offset, 0);
|
||||
if (IS_ERR(item)) {
|
||||
ret = PTR_ERR(item);
|
||||
/* a csum that isn't present is a preallocated region. */
|
||||
if (ret == -ENOENT || ret == -EFBIG)
|
||||
ret = 0;
|
||||
result->b_private = NULL;
|
||||
goto out;
|
||||
}
|
||||
memcpy((char *)&result->b_private, &item->csum, BTRFS_CRC32_SIZE);
|
||||
out:
|
||||
if (path)
|
||||
btrfs_free_path(path);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
|
||||
struct buffer_head *result, int create)
|
||||
{
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
u64 start = iblock << inode->i_blkbits;
|
||||
u64 end = start + root->blocksize -1;
|
||||
struct extent_map *em;
|
||||
|
||||
em = btrfs_get_extent(inode, NULL, 0, start, end, 0);
|
||||
if (em && !IS_ERR(em) && em->block_start != EXTENT_MAP_INLINE &&
|
||||
em->block_start != 0) {
|
||||
u64 offset;
|
||||
offset = start - em->start;
|
||||
start = (em->block_start + offset) >> inode->i_blkbits;
|
||||
btrfs_map_bh_to_logical(root, result, start);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -1449,442 +1634,50 @@ static sector_t btrfs_bmap(struct address_space *as, sector_t block)
|
||||
static int btrfs_prepare_write(struct file *file, struct page *page,
|
||||
unsigned from, unsigned to)
|
||||
{
|
||||
return block_prepare_write(page, from, to, btrfs_get_block);
|
||||
return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
|
||||
page->mapping->host, page, from, to,
|
||||
btrfs_get_extent);
|
||||
}
|
||||
|
||||
static void buffer_io_error(struct buffer_head *bh)
|
||||
{
|
||||
char b[BDEVNAME_SIZE];
|
||||
|
||||
printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
|
||||
bdevname(bh->b_bdev, b),
|
||||
(unsigned long long)bh->b_blocknr);
|
||||
}
|
||||
|
||||
/*
|
||||
* I/O completion handler for block_read_full_page() - pages
|
||||
* which come unlocked at the end of I/O.
|
||||
*/
|
||||
static void btrfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
|
||||
{
|
||||
unsigned long flags;
|
||||
struct buffer_head *first;
|
||||
struct buffer_head *tmp;
|
||||
struct page *page;
|
||||
int page_uptodate = 1;
|
||||
struct inode *inode;
|
||||
int ret;
|
||||
|
||||
BUG_ON(!buffer_async_read(bh));
|
||||
|
||||
page = bh->b_page;
|
||||
inode = page->mapping->host;
|
||||
if (uptodate) {
|
||||
void *kaddr;
|
||||
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
|
||||
if (bh->b_private) {
|
||||
char csum[BTRFS_CRC32_SIZE];
|
||||
kaddr = kmap_atomic(page, KM_IRQ0);
|
||||
ret = btrfs_csum_data(root, kaddr + bh_offset(bh),
|
||||
bh->b_size, csum);
|
||||
BUG_ON(ret);
|
||||
if (memcmp(csum, &bh->b_private, BTRFS_CRC32_SIZE)) {
|
||||
u64 offset;
|
||||
offset = (page->index << PAGE_CACHE_SHIFT) +
|
||||
bh_offset(bh);
|
||||
printk("btrfs csum failed ino %lu off %llu\n",
|
||||
page->mapping->host->i_ino,
|
||||
(unsigned long long)offset);
|
||||
memset(kaddr + bh_offset(bh), 1, bh->b_size);
|
||||
flush_dcache_page(page);
|
||||
}
|
||||
kunmap_atomic(kaddr, KM_IRQ0);
|
||||
}
|
||||
set_buffer_uptodate(bh);
|
||||
} else {
|
||||
clear_buffer_uptodate(bh);
|
||||
if (printk_ratelimit())
|
||||
buffer_io_error(bh);
|
||||
SetPageError(page);
|
||||
}
|
||||
|
||||
/*
|
||||
* Be _very_ careful from here on. Bad things can happen if
|
||||
* two buffer heads end IO at almost the same time and both
|
||||
* decide that the page is now completely done.
|
||||
*/
|
||||
first = page_buffers(page);
|
||||
local_irq_save(flags);
|
||||
bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
|
||||
clear_buffer_async_read(bh);
|
||||
unlock_buffer(bh);
|
||||
tmp = bh;
|
||||
do {
|
||||
if (!buffer_uptodate(tmp))
|
||||
page_uptodate = 0;
|
||||
if (buffer_async_read(tmp)) {
|
||||
BUG_ON(!buffer_locked(tmp));
|
||||
goto still_busy;
|
||||
}
|
||||
tmp = tmp->b_this_page;
|
||||
} while (tmp != bh);
|
||||
bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
|
||||
local_irq_restore(flags);
|
||||
|
||||
/*
|
||||
* If none of the buffers had errors and they are all
|
||||
* uptodate then we can set the page uptodate.
|
||||
*/
|
||||
if (page_uptodate && !PageError(page))
|
||||
SetPageUptodate(page);
|
||||
unlock_page(page);
|
||||
return;
|
||||
|
||||
still_busy:
|
||||
bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
|
||||
local_irq_restore(flags);
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Generic "read page" function for block devices that have the normal
|
||||
* get_block functionality. This is most of the block device filesystems.
|
||||
* Reads the page asynchronously --- the unlock_buffer() and
|
||||
* set/clear_buffer_uptodate() functions propagate buffer state into the
|
||||
* page struct once IO has completed.
|
||||
*/
|
||||
int btrfs_readpage(struct file *file, struct page *page)
|
||||
{
|
||||
struct inode *inode = page->mapping->host;
|
||||
sector_t iblock, lblock;
|
||||
struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
|
||||
unsigned int blocksize;
|
||||
int nr, i;
|
||||
int fully_mapped = 1;
|
||||
|
||||
BUG_ON(!PageLocked(page));
|
||||
blocksize = 1 << inode->i_blkbits;
|
||||
if (!page_has_buffers(page))
|
||||
create_empty_buffers(page, blocksize, 0);
|
||||
head = page_buffers(page);
|
||||
|
||||
iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
|
||||
lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
|
||||
bh = head;
|
||||
nr = 0;
|
||||
i = 0;
|
||||
|
||||
do {
|
||||
if (buffer_uptodate(bh))
|
||||
continue;
|
||||
|
||||
if (!buffer_mapped(bh)) {
|
||||
int err = 0;
|
||||
|
||||
fully_mapped = 0;
|
||||
if (iblock < lblock) {
|
||||
WARN_ON(bh->b_size != blocksize);
|
||||
err = btrfs_get_block_csum(inode, iblock,
|
||||
bh, 0);
|
||||
if (err)
|
||||
SetPageError(page);
|
||||
}
|
||||
if (!buffer_mapped(bh)) {
|
||||
void *kaddr = kmap_atomic(page, KM_USER0);
|
||||
memset(kaddr + i * blocksize, 0, blocksize);
|
||||
flush_dcache_page(page);
|
||||
kunmap_atomic(kaddr, KM_USER0);
|
||||
if (!err)
|
||||
set_buffer_uptodate(bh);
|
||||
continue;
|
||||
}
|
||||
/*
|
||||
* get_block() might have updated the buffer
|
||||
* synchronously
|
||||
*/
|
||||
if (buffer_uptodate(bh))
|
||||
continue;
|
||||
}
|
||||
arr[nr++] = bh;
|
||||
} while (i++, iblock++, (bh = bh->b_this_page) != head);
|
||||
|
||||
if (fully_mapped)
|
||||
SetPageMappedToDisk(page);
|
||||
|
||||
if (!nr) {
|
||||
/*
|
||||
* All buffers are uptodate - we can set the page uptodate
|
||||
* as well. But not if get_block() returned an error.
|
||||
*/
|
||||
if (!PageError(page))
|
||||
SetPageUptodate(page);
|
||||
unlock_page(page);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Stage two: lock the buffers */
|
||||
for (i = 0; i < nr; i++) {
|
||||
bh = arr[i];
|
||||
lock_buffer(bh);
|
||||
bh->b_end_io = btrfs_end_buffer_async_read;
|
||||
set_buffer_async_read(bh);
|
||||
}
|
||||
|
||||
/*
|
||||
* Stage 3: start the IO. Check for uptodateness
|
||||
* inside the buffer lock in case another process reading
|
||||
* the underlying blockdev brought it uptodate (the sct fix).
|
||||
*/
|
||||
for (i = 0; i < nr; i++) {
|
||||
bh = arr[i];
|
||||
if (buffer_uptodate(bh))
|
||||
btrfs_end_buffer_async_read(bh, 1);
|
||||
else
|
||||
submit_bh(READ, bh);
|
||||
}
|
||||
return 0;
|
||||
struct extent_map_tree *tree;
|
||||
tree = &BTRFS_I(page->mapping->host)->extent_tree;
|
||||
return extent_read_full_page(tree, page, btrfs_get_extent);
|
||||
}
|
||||
|
||||
/*
|
||||
* Aside from a tiny bit of packed file data handling, this is the
|
||||
* same as the generic code.
|
||||
*
|
||||
* While block_write_full_page is writing back the dirty buffers under
|
||||
* the page lock, whoever dirtied the buffers may decide to clean them
|
||||
* again at any time. We handle that by only looking at the buffer
|
||||
* state inside lock_buffer().
|
||||
*
|
||||
* If block_write_full_page() is called for regular writeback
|
||||
* (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
|
||||
* locked buffer. This only can happen if someone has written the buffer
|
||||
* directly, with submit_bh(). At the address_space level PageWriteback
|
||||
* prevents this contention from occurring.
|
||||
*/
|
||||
static int __btrfs_write_full_page(struct inode *inode, struct page *page,
|
||||
struct writeback_control *wbc)
|
||||
{
|
||||
int err;
|
||||
sector_t block;
|
||||
sector_t last_block;
|
||||
struct buffer_head *bh, *head;
|
||||
const unsigned blocksize = 1 << inode->i_blkbits;
|
||||
int nr_underway = 0;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
|
||||
BUG_ON(!PageLocked(page));
|
||||
|
||||
last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
|
||||
|
||||
/* no csumming allowed when from PF_MEMALLOC */
|
||||
if (current->flags & PF_MEMALLOC) {
|
||||
redirty_page_for_writepage(wbc, page);
|
||||
unlock_page(page);
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (!page_has_buffers(page)) {
|
||||
create_empty_buffers(page, blocksize,
|
||||
(1 << BH_Dirty)|(1 << BH_Uptodate));
|
||||
}
|
||||
|
||||
/*
|
||||
* Be very careful. We have no exclusion from __set_page_dirty_buffers
|
||||
* here, and the (potentially unmapped) buffers may become dirty at
|
||||
* any time. If a buffer becomes dirty here after we've inspected it
|
||||
* then we just miss that fact, and the page stays dirty.
|
||||
*
|
||||
* Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
|
||||
* handle that here by just cleaning them.
|
||||
*/
|
||||
|
||||
block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
|
||||
head = page_buffers(page);
|
||||
bh = head;
|
||||
|
||||
/*
|
||||
* Get all the dirty buffers mapped to disk addresses and
|
||||
* handle any aliases from the underlying blockdev's mapping.
|
||||
*/
|
||||
do {
|
||||
if (block > last_block) {
|
||||
/*
|
||||
* mapped buffers outside i_size will occur, because
|
||||
* this page can be outside i_size when there is a
|
||||
* truncate in progress.
|
||||
*/
|
||||
/*
|
||||
* The buffer was zeroed by block_write_full_page()
|
||||
*/
|
||||
clear_buffer_dirty(bh);
|
||||
set_buffer_uptodate(bh);
|
||||
} else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
|
||||
WARN_ON(bh->b_size != blocksize);
|
||||
err = btrfs_get_block(inode, block, bh, 0);
|
||||
if (err) {
|
||||
goto recover;
|
||||
}
|
||||
if (buffer_new(bh)) {
|
||||
/* blockdev mappings never come here */
|
||||
clear_buffer_new(bh);
|
||||
}
|
||||
}
|
||||
bh = bh->b_this_page;
|
||||
block++;
|
||||
} while (bh != head);
|
||||
|
||||
do {
|
||||
if (!buffer_mapped(bh))
|
||||
continue;
|
||||
/*
|
||||
* If it's a fully non-blocking write attempt and we cannot
|
||||
* lock the buffer then redirty the page. Note that this can
|
||||
* potentially cause a busy-wait loop from pdflush and kswapd
|
||||
* activity, but those code paths have their own higher-level
|
||||
* throttling.
|
||||
*/
|
||||
if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
|
||||
lock_buffer(bh);
|
||||
} else if (test_set_buffer_locked(bh)) {
|
||||
redirty_page_for_writepage(wbc, page);
|
||||
continue;
|
||||
}
|
||||
if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
|
||||
struct btrfs_trans_handle *trans;
|
||||
int ret;
|
||||
u64 off = page->index << PAGE_CACHE_SHIFT;
|
||||
char *kaddr;
|
||||
|
||||
off += bh_offset(bh);
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
trans = btrfs_start_transaction(root, 1);
|
||||
btrfs_set_trans_block_group(trans, inode);
|
||||
kaddr = kmap(page);
|
||||
btrfs_csum_file_block(trans, root, inode->i_ino,
|
||||
off, kaddr + bh_offset(bh),
|
||||
bh->b_size);
|
||||
kunmap(page);
|
||||
ret = btrfs_end_transaction(trans, root);
|
||||
BUG_ON(ret);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
mark_buffer_async_write(bh);
|
||||
} else {
|
||||
unlock_buffer(bh);
|
||||
}
|
||||
} while ((bh = bh->b_this_page) != head);
|
||||
|
||||
/*
|
||||
* The page and its buffers are protected by PageWriteback(), so we can
|
||||
* drop the bh refcounts early.
|
||||
*/
|
||||
BUG_ON(PageWriteback(page));
|
||||
set_page_writeback(page);
|
||||
|
||||
do {
|
||||
struct buffer_head *next = bh->b_this_page;
|
||||
if (buffer_async_write(bh)) {
|
||||
submit_bh(WRITE, bh);
|
||||
nr_underway++;
|
||||
}
|
||||
bh = next;
|
||||
} while (bh != head);
|
||||
unlock_page(page);
|
||||
|
||||
err = 0;
|
||||
done:
|
||||
if (nr_underway == 0) {
|
||||
/*
|
||||
* The page was marked dirty, but the buffers were
|
||||
* clean. Someone wrote them back by hand with
|
||||
* ll_rw_block/submit_bh. A rare case.
|
||||
*/
|
||||
int uptodate = 1;
|
||||
do {
|
||||
if (!buffer_uptodate(bh)) {
|
||||
uptodate = 0;
|
||||
break;
|
||||
}
|
||||
bh = bh->b_this_page;
|
||||
} while (bh != head);
|
||||
if (uptodate)
|
||||
SetPageUptodate(page);
|
||||
end_page_writeback(page);
|
||||
}
|
||||
return err;
|
||||
|
||||
recover:
|
||||
/*
|
||||
* ENOSPC, or some other error. We may already have added some
|
||||
* blocks to the file, so we need to write these out to avoid
|
||||
* exposing stale data.
|
||||
* The page is currently locked and not marked for writeback
|
||||
*/
|
||||
bh = head;
|
||||
/* Recovery: lock and submit the mapped buffers */
|
||||
do {
|
||||
if (buffer_mapped(bh) && buffer_dirty(bh)) {
|
||||
lock_buffer(bh);
|
||||
mark_buffer_async_write(bh);
|
||||
} else {
|
||||
/*
|
||||
* The buffer may have been set dirty during
|
||||
* attachment to a dirty page.
|
||||
*/
|
||||
clear_buffer_dirty(bh);
|
||||
}
|
||||
} while ((bh = bh->b_this_page) != head);
|
||||
SetPageError(page);
|
||||
BUG_ON(PageWriteback(page));
|
||||
set_page_writeback(page);
|
||||
do {
|
||||
struct buffer_head *next = bh->b_this_page;
|
||||
if (buffer_async_write(bh)) {
|
||||
clear_buffer_dirty(bh);
|
||||
submit_bh(WRITE, bh);
|
||||
nr_underway++;
|
||||
}
|
||||
bh = next;
|
||||
} while (bh != head);
|
||||
unlock_page(page);
|
||||
goto done;
|
||||
}
|
||||
|
||||
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
|
||||
{
|
||||
struct inode * const inode = page->mapping->host;
|
||||
loff_t i_size = i_size_read(inode);
|
||||
const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
|
||||
unsigned offset;
|
||||
void *kaddr;
|
||||
struct extent_map_tree *tree;
|
||||
tree = &BTRFS_I(page->mapping->host)->extent_tree;
|
||||
return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
|
||||
}
|
||||
|
||||
/* Is the page fully inside i_size? */
|
||||
if (page->index < end_index)
|
||||
return __btrfs_write_full_page(inode, page, wbc);
|
||||
static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
|
||||
{
|
||||
struct extent_map_tree *tree;
|
||||
int ret;
|
||||
|
||||
/* Is the page fully outside i_size? (truncate in progress) */
|
||||
offset = i_size & (PAGE_CACHE_SIZE-1);
|
||||
if (page->index >= end_index+1 || !offset) {
|
||||
/*
|
||||
* The page may have dirty, unmapped buffers. For example,
|
||||
* they may have been added in ext3_writepage(). Make them
|
||||
* freeable here, so the page does not leak.
|
||||
*/
|
||||
block_invalidatepage(page, 0);
|
||||
unlock_page(page);
|
||||
return 0; /* don't care */
|
||||
if (page->private != 1) {
|
||||
WARN_ON(1);
|
||||
return try_to_free_buffers(page);
|
||||
}
|
||||
tree = &BTRFS_I(page->mapping->host)->extent_tree;
|
||||
ret = try_release_extent_mapping(tree, page);
|
||||
if (ret == 1) {
|
||||
ClearPagePrivate(page);
|
||||
set_page_private(page, 0);
|
||||
page_cache_release(page);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* The page straddles i_size. It must be zeroed out on each and every
|
||||
* writepage invokation because it may be mmapped. "A file is mapped
|
||||
* in multiples of the page size. For a file that is not a multiple of
|
||||
* the page size, the remaining memory is zeroed when mapped, and
|
||||
* writes to that region are not written out to the file."
|
||||
*/
|
||||
kaddr = kmap_atomic(page, KM_USER0);
|
||||
memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
|
||||
flush_dcache_page(page);
|
||||
kunmap_atomic(kaddr, KM_USER0);
|
||||
return __btrfs_write_full_page(inode, page, wbc);
|
||||
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
|
||||
{
|
||||
struct extent_map_tree *tree;
|
||||
|
||||
tree = &BTRFS_I(page->mapping->host)->extent_tree;
|
||||
extent_invalidatepage(tree, page, offset);
|
||||
btrfs_releasepage(page, GFP_NOFS);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -1905,28 +1698,39 @@ static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
|
||||
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
|
||||
{
|
||||
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
|
||||
struct btrfs_root *root = BTRFS_I(inode)->root;
|
||||
struct btrfs_trans_handle *trans;
|
||||
unsigned long end;
|
||||
loff_t size;
|
||||
int ret = -EINVAL;
|
||||
u64 page_start;
|
||||
|
||||
lock_page(page);
|
||||
wait_on_page_writeback(page);
|
||||
size = i_size_read(inode);
|
||||
page_start = page->index << PAGE_CACHE_SHIFT;
|
||||
|
||||
if ((page->mapping != inode->i_mapping) ||
|
||||
((page->index << PAGE_CACHE_SHIFT) > size)) {
|
||||
(page_start > size)) {
|
||||
/* page got truncated out from underneath us */
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
/* page is wholly or partially inside EOF */
|
||||
if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
|
||||
if (page_start + PAGE_CACHE_SIZE > size)
|
||||
end = size & ~PAGE_CACHE_MASK;
|
||||
else
|
||||
end = PAGE_CACHE_SIZE;
|
||||
|
||||
ret = btrfs_prepare_write(NULL, page, 0, end);
|
||||
if (!ret)
|
||||
ret = btrfs_commit_write(NULL, page, 0, end);
|
||||
mutex_lock(&root->fs_info->fs_mutex);
|
||||
trans = btrfs_start_transaction(root, 1);
|
||||
ret = btrfs_cow_one_page(trans, inode, page, end);
|
||||
btrfs_end_transaction(trans, root);
|
||||
mutex_unlock(&root->fs_info->fs_mutex);
|
||||
set_extent_dirty(&BTRFS_I(inode)->extent_tree,
|
||||
page_start, page_start + PAGE_CACHE_SIZE - 1,
|
||||
GFP_NOFS);
|
||||
set_page_dirty(page);
|
||||
|
||||
out_unlock:
|
||||
unlock_page(page);
|
||||
@ -1962,21 +1766,8 @@ static void btrfs_truncate(struct inode *inode)
|
||||
int btrfs_commit_write(struct file *file, struct page *page,
|
||||
unsigned from, unsigned to)
|
||||
{
|
||||
struct inode *inode = page->mapping->host;
|
||||
struct buffer_head *bh;
|
||||
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
|
||||
|
||||
SetPageUptodate(page);
|
||||
bh = page_buffers(page);
|
||||
set_buffer_uptodate(bh);
|
||||
if (buffer_mapped(bh) && bh->b_blocknr != 0) {
|
||||
set_page_dirty(page);
|
||||
}
|
||||
if (pos > inode->i_size) {
|
||||
i_size_write(inode, pos);
|
||||
mark_inode_dirty(inode);
|
||||
}
|
||||
return 0;
|
||||
return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
|
||||
page->mapping->host, page, from, to);
|
||||
}
|
||||
|
||||
static int create_subvol(struct btrfs_root *root, char *name, int namelen)
|
||||
@ -2471,6 +2262,8 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
|
||||
inode->i_mapping->a_ops = &btrfs_aops;
|
||||
inode->i_fop = &btrfs_file_operations;
|
||||
inode->i_op = &btrfs_file_inode_operations;
|
||||
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
|
||||
inode->i_mapping, GFP_NOFS);
|
||||
}
|
||||
dir->i_sb->s_dirt = 1;
|
||||
btrfs_update_inode_block_group(trans, inode);
|
||||
@ -2553,6 +2346,9 @@ static struct address_space_operations btrfs_aops = {
|
||||
.prepare_write = btrfs_prepare_write,
|
||||
.commit_write = btrfs_commit_write,
|
||||
.bmap = btrfs_bmap,
|
||||
.invalidatepage = btrfs_invalidatepage,
|
||||
.releasepage = btrfs_releasepage,
|
||||
.set_page_dirty = __set_page_dirty_nobuffers,
|
||||
};
|
||||
|
||||
static struct address_space_operations btrfs_symlink_aops = {
|
||||
|
@ -185,6 +185,7 @@ static int __init init_btrfs_fs(void)
|
||||
err = btrfs_init_cachep();
|
||||
if (err)
|
||||
return err;
|
||||
extent_map_init();
|
||||
return register_filesystem(&btrfs_fs_type);
|
||||
}
|
||||
|
||||
@ -192,6 +193,7 @@ static void __exit exit_btrfs_fs(void)
|
||||
{
|
||||
btrfs_exit_transaction_sys();
|
||||
btrfs_destroy_cachep();
|
||||
extent_map_exit();
|
||||
unregister_filesystem(&btrfs_fs_type);
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user