diff options
Diffstat (limited to 'fs/btrfs/extent_map.c')
| -rw-r--r-- | fs/btrfs/extent_map.c | 75 |
1 files changed, 39 insertions, 36 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 6092a4eedc92..be94030e1dfb 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -3,6 +3,7 @@ #include <linux/err.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include "messages.h" #include "ctree.h" #include "volumes.h" #include "extent_map.h" @@ -27,12 +28,9 @@ void __cold extent_map_exit(void) kmem_cache_destroy(extent_map_cache); } -/** - * extent_map_tree_init - initialize extent map tree - * @tree: tree to initialize - * - * Initialize the extent tree @tree. Should be called for each new inode - * or other user of the extent_map interface. +/* + * Initialize the extent tree @tree. Should be called for each new inode or + * other user of the extent_map interface. */ void extent_map_tree_init(struct extent_map_tree *tree) { @@ -41,12 +39,9 @@ void extent_map_tree_init(struct extent_map_tree *tree) rwlock_init(&tree->lock); } -/** - * alloc_extent_map - allocate new extent map structure - * - * Allocate a new extent_map structure. The new structure is - * returned with a reference count of one and needs to be - * freed using free_extent_map() +/* + * Allocate a new extent_map structure. The new structure is returned with a + * reference count of one and needs to be freed using free_extent_map() */ struct extent_map *alloc_extent_map(void) { @@ -61,12 +56,9 @@ struct extent_map *alloc_extent_map(void) return em; } -/** - * free_extent_map - drop reference count of an extent_map - * @em: extent map being released - * - * Drops the reference out on @em by one and free the structure - * if the reference count hits zero. +/* + * Drop the reference out on @em by one and free the structure if the reference + * count hits zero. */ void free_extent_map(struct extent_map *em) { @@ -81,7 +73,7 @@ void free_extent_map(struct extent_map *em) } } -/* simple helper to do math around the end of an extent, handling wrap */ +/* Do the math around the end of an extent, handling wrapping. */ static u64 range_end(u64 start, u64 len) { if (start + len < start) @@ -137,8 +129,8 @@ static int tree_insert(struct rb_root_cached *root, struct extent_map *em) } /* - * search through the tree for an extent_map with a given offset. If - * it can't be found, try to find some neighboring extents + * 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_or_next_ret) @@ -190,7 +182,7 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, return NULL; } -/* check to see if two extent_map structs are adjacent and safe to merge */ +/* 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)) @@ -288,8 +280,9 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) } } -/** - * unpin_extent_cache - unpin an extent from the cache +/* + * Unpin an extent from the cache. + * * @tree: tree to unpin the extent in * @start: logical offset in the file * @len: length of the extent @@ -392,7 +385,7 @@ static void extent_map_device_clear_bits(struct extent_map *em, unsigned bits) } } -/** +/* * Add new extent map to the extent tree * * @tree: tree to insert new map in @@ -451,8 +444,9 @@ __lookup_extent_mapping(struct extent_map_tree *tree, return em; } -/** - * lookup_extent_mapping - lookup extent_map +/* + * Lookup extent_map that intersects @start + @len range. + * * @tree: tree to lookup in * @start: byte offset to start the search * @len: length of the lookup range @@ -468,8 +462,9 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, return __lookup_extent_mapping(tree, start, len, 1); } -/** - * search_extent_mapping - find a nearby extent map +/* + * Find a nearby extent map intersecting @start + @len (not an exact search). + * * @tree: tree to lookup in * @start: byte offset to start the search * @len: length of the lookup range @@ -485,13 +480,14 @@ struct extent_map *search_extent_mapping(struct extent_map_tree *tree, return __lookup_extent_mapping(tree, start, len, 0); } -/** - * remove_extent_mapping - removes an extent_map from the extent tree +/* + * Remove an extent_map from the extent tree. + * * @tree: extent tree to remove from * @em: extent map being removed * - * Removes @em from @tree. No reference counts are dropped, and no checks - * are done to see if the range is in use + * Remove @em from @tree. No reference counts are dropped, and no checks + * are done to see if the range is in use. */ void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) { @@ -523,7 +519,7 @@ void replace_extent_mapping(struct extent_map_tree *tree, setup_extent_mapping(tree, new, modified); } -static struct extent_map *next_extent_map(struct extent_map *em) +static struct extent_map *next_extent_map(const struct extent_map *em) { struct rb_node *next; @@ -585,8 +581,8 @@ static noinline int merge_extent_mapping(struct extent_map_tree *em_tree, return add_extent_mapping(em_tree, em, 0); } -/** - * Add extent mapping into em_tree +/* + * Add extent mapping into em_tree. * * @fs_info: the filesystem * @em_tree: extent tree into which we want to insert the extent mapping @@ -613,6 +609,13 @@ int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info, int ret; struct extent_map *em = *em_in; + /* + * Tree-checker should have rejected any inline extent with non-zero + * file offset. Here just do a sanity check. + */ + if (em->block_start == EXTENT_MAP_INLINE) + ASSERT(em->start == 0); + ret = add_extent_mapping(em_tree, em, 0); /* it is possible that someone inserted the extent into the tree * while we had the lock dropped. It is also possible that |