diff options
Diffstat (limited to 'fs/btrfs/extent_map.c')
| -rw-r--r-- | fs/btrfs/extent_map.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 78ced11d18c7..74b2a29880d3 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -114,6 +114,10 @@ static struct rb_node *tree_insert(struct rb_root *root, u64 offset, return NULL; } +/* + * search through the tree for an extent_map with a given offset. If + * it can't be found, try to find some neighboring extents + */ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, struct rb_node **prev_ret, struct rb_node **next_ret) @@ -160,6 +164,10 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, return NULL; } +/* + * look for an offset in the tree, and if it can't be found, return + * the first offset we can find smaller than 'offset'. + */ static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) { struct rb_node *prev; @@ -170,6 +178,7 @@ static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) return ret; } +/* check to see if two extent_map structs are adjacent and safe to merge */ static int mergable_maps(struct extent_map *prev, struct extent_map *next) { if (test_bit(EXTENT_FLAG_PINNED, &prev->flags)) @@ -250,6 +259,7 @@ out: } EXPORT_SYMBOL(add_extent_mapping); +/* simple helper to do math around the end of an extent, handling wrap */ static u64 range_end(u64 start, u64 len) { if (start + len < start) |