diff options
Diffstat (limited to 'fs/btrfs/extent_map.h')
| -rw-r--r-- | fs/btrfs/extent_map.h | 78 |
1 files changed, 62 insertions, 16 deletions
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index c5a098c99cc6..cd123b266b64 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -4,12 +4,11 @@ #define BTRFS_EXTENT_MAP_H #include <linux/compiler_types.h> -#include <linux/rwlock_types.h> +#include <linux/spinlock_types.h> #include <linux/rbtree.h> #include <linux/list.h> #include <linux/refcount.h> #include "misc.h" -#include "extent_map.h" #include "compression.h" struct btrfs_inode; @@ -30,29 +29,65 @@ enum { ENUM_BIT(EXTENT_FLAG_PREALLOC), /* Logging this extent */ ENUM_BIT(EXTENT_FLAG_LOGGING), - /* Filling in a preallocated extent */ - ENUM_BIT(EXTENT_FLAG_FILLING), /* This em is merged from two or more physically adjacent ems */ ENUM_BIT(EXTENT_FLAG_MERGED), }; /* + * This structure represents file extents and holes. + * + * Unlike on-disk file extent items, extent maps can be merged to save memory. + * This means members only match file extent items before any merging. + * * Keep this structure as compact as possible, as we can have really large * amounts of allocated extent maps at any time. */ struct extent_map { struct rb_node rb_node; - /* all of these are in bytes */ + /* All of these are in bytes. */ + + /* File offset matching the offset of a BTRFS_EXTENT_ITEM_KEY key. */ u64 start; + + /* + * Length of the file extent. + * + * For non-inlined file extents it's btrfs_file_extent_item::num_bytes. + * For inline extents it's sectorsize, since inline data starts at + * offsetof(struct btrfs_file_extent_item, disk_bytenr) thus + * btrfs_file_extent_item::num_bytes is not valid. + */ u64 len; - u64 mod_start; - u64 mod_len; - u64 orig_start; - u64 orig_block_len; + + /* + * The bytenr of the full on-disk extent. + * + * For regular extents it's btrfs_file_extent_item::disk_bytenr. + * For holes it's EXTENT_MAP_HOLE and for inline extents it's + * EXTENT_MAP_INLINE. + */ + u64 disk_bytenr; + + /* + * The full on-disk extent length, matching + * btrfs_file_extent_item::disk_num_bytes. + */ + u64 disk_num_bytes; + + /* + * Offset inside the decompressed extent. + * + * For regular extents it's btrfs_file_extent_item::offset. + * For holes and inline extents it's 0. + */ + u64 offset; + + /* + * The decompressed size of the whole on-disk extent, matching + * btrfs_file_extent_item::ram_bytes. + */ u64 ram_bytes; - u64 block_start; - u64 block_len; /* * Generation of the extent map, for merged em it's the highest @@ -66,7 +101,7 @@ struct extent_map { }; struct extent_map_tree { - struct rb_root_cached map; + struct rb_root root; struct list_head modified_extents; rwlock_t lock; }; @@ -114,6 +149,16 @@ static inline int extent_map_in_tree(const struct extent_map *em) return !RB_EMPTY_NODE(&em->rb_node); } +static inline u64 extent_map_block_start(const struct extent_map *em) +{ + if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE) { + if (extent_map_is_compressed(em)) + return em->disk_bytenr; + return em->disk_bytenr + em->offset; + } + return em->disk_bytenr; +} + static inline u64 extent_map_end(const struct extent_map *em) { if (em->start + em->len < em->start) @@ -124,7 +169,7 @@ static inline u64 extent_map_end(const struct extent_map *em) void extent_map_tree_init(struct extent_map_tree *tree); struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, u64 start, u64 len); -void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em); +void remove_extent_mapping(struct btrfs_inode *inode, struct extent_map *em); int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre, u64 new_logical); @@ -133,11 +178,10 @@ void free_extent_map(struct extent_map *em); int __init extent_map_init(void); void __cold extent_map_exit(void); int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen); -void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em); +void clear_em_logging(struct btrfs_inode *inode, struct extent_map *em); struct extent_map *search_extent_mapping(struct extent_map_tree *tree, u64 start, u64 len); -int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info, - struct extent_map_tree *em_tree, +int btrfs_add_extent_mapping(struct btrfs_inode *inode, struct extent_map **em_in, u64 start, u64 len); void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end, @@ -145,5 +189,7 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, int btrfs_replace_extent_map_range(struct btrfs_inode *inode, struct extent_map *new_em, bool modified); +void btrfs_free_extent_maps(struct btrfs_fs_info *fs_info, long nr_to_scan); +void btrfs_init_extent_map_shrinker_work(struct btrfs_fs_info *fs_info); #endif |