Btrfs: Make free space cache code generic
So we can re-use the code to cache free inode numbers.
The change is quite straightforward. Two new structures are introduced.
- struct btrfs_free_space_ctl
We move those variables that are used for caching free space from
struct btrfs_block_group_cache to this new struct.
- struct btrfs_free_space_op
We do block group specific work (e.g. calculation of extents threshold)
through functions registered in this struct.
And then we can remove references to struct btrfs_block_group_cache.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index 12b2b51..a64a23f 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -27,6 +27,25 @@
struct list_head list;
};
+struct btrfs_free_space_ctl {
+ spinlock_t tree_lock;
+ struct rb_root free_space_offset;
+ u64 free_space;
+ int extents_thresh;
+ int free_extents;
+ int total_bitmaps;
+ int unit;
+ u64 start;
+ struct btrfs_free_space_op *op;
+ void *private;
+};
+
+struct btrfs_free_space_op {
+ void (*recalc_thresholds)(struct btrfs_free_space_ctl *ctl);
+ bool (*use_bitmap)(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info);
+};
+
struct inode *lookup_free_space_inode(struct btrfs_root *root,
struct btrfs_block_group_cache
*block_group, struct btrfs_path *path);
@@ -45,6 +64,7 @@
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path);
+void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group);
int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
u64 bytenr, u64 size);
int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,