diff options
| -rw-r--r-- | fs/btrfs/ioctl.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index de46fa21859..6c39d1a5590 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -784,6 +784,31 @@ none: return -ENOENT; } +/* + * Validaty check of prev em and next em: + * 1) no prev/next em + * 2) prev/next em is an hole/inline extent + */ +static int check_adjacent_extents(struct inode *inode, struct extent_map *em) +{ + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_map *prev = NULL, *next = NULL; + int ret = 0; + + read_lock(&em_tree->lock); + prev = lookup_extent_mapping(em_tree, em->start - 1, (u64)-1); + next = lookup_extent_mapping(em_tree, em->start + em->len, (u64)-1); + read_unlock(&em_tree->lock); + + if ((!prev || prev->block_start >= EXTENT_MAP_LAST_BYTE) && + (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)) + ret = 1; + free_extent_map(prev); + free_extent_map(next); + + return ret; +} + static int should_defrag_range(struct inode *inode, u64 start, u64 len, int thresh, u64 *last_len, u64 *skip, u64 *defrag_end) @@ -821,8 +846,16 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len, } /* this will cover holes, and inline extents */ - if (em->block_start >= EXTENT_MAP_LAST_BYTE) + if (em->block_start >= EXTENT_MAP_LAST_BYTE) { + ret = 0; + goto out; + } + + /* If we have nothing to merge with us, just skip. */ + if (check_adjacent_extents(inode, em)) { ret = 0; + goto out; + } /* * we hit a real extent, if it is big don't bother defragging it again @@ -830,6 +863,7 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len, if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh) ret = 0; +out: /* * last_len ends up being a counter of how many bytes we've defragged. * every time we choose not to defrag an extent, we reset *last_len |