diff options
| author | Christoph Hellwig <hch@lst.de> | 2007-09-10 20:02:30 -0400 |
|---|---|---|
| committer | David Woodhouse <dwmw2@hera.kernel.org> | 2007-09-10 20:02:30 -0400 |
| commit | d396c6f554d182b7bce4e2bb2acb47f80430c05f (patch) | |
| tree | 2bc7b567310474ed4562d4e1246efd69a868f8cd | |
| parent | 90f1c19a9fd2a943adc69d2b9b8c83bcc4bba6f9 (diff) | |
Btrfs: [PATCH] extent_map: provide generic bmap
generic_bmap is completely trivial, while the extent to bh mapping in
btrfs is rather complex. So provide a extent_bmap instead that takes
a get_extent callback and can be used by filesystem using the extent_map
code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
| -rw-r--r-- | fs/btrfs/extent_map.c | 19 | ||||
| -rw-r--r-- | fs/btrfs/extent_map.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 23 |
3 files changed, 23 insertions, 21 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 3021564ac62..ff2b1dd25bf 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1816,3 +1816,22 @@ int try_release_extent_mapping(struct extent_map_tree *tree, struct page *page) } EXPORT_SYMBOL(try_release_extent_mapping); +sector_t extent_bmap(struct address_space *mapping, sector_t iblock, + get_extent_t *get_extent) +{ + struct inode *inode = mapping->host; + u64 start = iblock << inode->i_blkbits; + u64 end = start + (1 << inode->i_blkbits) - 1; + struct extent_map *em; + + em = get_extent(inode, NULL, 0, start, end, 0); + if (!em || IS_ERR(em)) + return 0; + + // XXX(hch): block 0 is valid in some cases, e.g. XFS RT device + if (em->block_start == EXTENT_MAP_INLINE || + em->block_start == 0) + return 0; + + return (em->block_start + start - em->start) >> inode->i_blkbits; +} diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index 0eae6c420ac..da41aca74e0 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -99,6 +99,8 @@ int extent_prepare_write(struct extent_map_tree *tree, int extent_commit_write(struct extent_map_tree *tree, struct inode *inode, struct page *page, unsigned from, unsigned to); +sector_t extent_bmap(struct address_space *mapping, sector_t iblock, + get_extent_t *get_extent); int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end); int set_state_private(struct extent_map_tree *tree, u64 start, u64 private); int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1ace6d11e09..39c1fe178f4 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1567,28 +1567,9 @@ out: return em; } -static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock, - struct buffer_head *result, int create) +static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock) { - struct btrfs_root *root = BTRFS_I(inode)->root; - 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; -} - -static sector_t btrfs_bmap(struct address_space *as, sector_t block) -{ - return generic_block_bmap(as, block, btrfs_get_block_bmap); + return extent_bmap(mapping, iblock, btrfs_get_extent); } static int btrfs_prepare_write(struct file *file, struct page *page, |