Commit 34d52cb6 authored by Li Zefan's avatar Li Zefan
Browse files

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: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent f38b6e75

fs/btrfs/ctree.h

+1 −6
Original line number Diff line number Diff line
@@ -830,9 +830,6 @@ struct btrfs_block_group_cache { 
	u64 bytes_super;

	u64 flags;

	u64 sectorsize;

	int extents_thresh;

	int free_extents;

	int total_bitmaps;

	unsigned int ro:1;

	unsigned int dirty:1;

	unsigned int iref:1;
@@ -847,9 +844,7 @@ struct btrfs_block_group_cache { 
	struct btrfs_space_info *space_info;



	/* free space cache stuff */

	spinlock_t tree_lock;

	struct rb_root free_space_offset;

	u64 free_space;

	struct btrfs_free_space_ctl *free_space_ctl;



	/* block group cache stuff */

	struct rb_node cache_node;

fs/btrfs/extent-tree.c

+19 −18
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ void btrfs_put_block_group(struct btrfs_block_group_cache *cache) 
		WARN_ON(cache->pinned > 0);

		WARN_ON(cache->reserved > 0);

		WARN_ON(cache->reserved_pinned > 0);

		kfree(cache->free_space_ctl);

		kfree(cache);

	}

}
@@ -4893,7 +4894,7 @@ wait_block_group_cache_progress(struct btrfs_block_group_cache *cache, 
		return 0;



	wait_event(caching_ctl->wait, block_group_cache_done(cache) ||

		   (cache->free_space >= num_bytes));

		   (cache->free_space_ctl->free_space >= num_bytes));



	put_caching_control(caching_ctl);

	return 0;
@@ -8551,10 +8552,16 @@ int btrfs_read_block_groups(struct btrfs_root *root) 
			ret = -ENOMEM;

			goto error;

		}

		cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),

						GFP_NOFS);

		if (!cache->free_space_ctl) {

			kfree(cache);

			ret = -ENOMEM;

			goto error;

		}



		atomic_set(&cache->count, 1);

		spin_lock_init(&cache->lock);

		spin_lock_init(&cache->tree_lock);

		cache->fs_info = info;

		INIT_LIST_HEAD(&cache->list);

		INIT_LIST_HEAD(&cache->cluster_list);
@@ -8562,14 +8569,6 @@ int btrfs_read_block_groups(struct btrfs_root *root) 
		if (need_clear)

			cache->disk_cache_state = BTRFS_DC_CLEAR;



		/*

		 * we only want to have 32k of ram per block group for keeping

		 * track of free space, and if we pass 1/2 of that we want to

		 * start converting things over to using bitmaps

		 */

		cache->extents_thresh = ((1024 * 32) / 2) /

			sizeof(struct btrfs_free_space);



		read_extent_buffer(leaf, &cache->item,

				   btrfs_item_ptr_offset(leaf, path->slots[0]),

				   sizeof(cache->item));
@@ -8580,6 +8579,8 @@ int btrfs_read_block_groups(struct btrfs_root *root) 
		cache->flags = btrfs_block_group_flags(&cache->item);

		cache->sectorsize = root->sectorsize;



		btrfs_init_free_space_ctl(cache);



		/*

		 * We need to exclude the super stripes now so that the space

		 * info has super bytes accounted for, otherwise we'll think
@@ -8666,6 +8667,12 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, 
	cache = kzalloc(sizeof(*cache), GFP_NOFS);

	if (!cache)

		return -ENOMEM;

	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),

					GFP_NOFS);

	if (!cache->free_space_ctl) {

		kfree(cache);

		return -ENOMEM;

	}



	cache->key.objectid = chunk_offset;

	cache->key.offset = size;
@@ -8673,19 +8680,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, 
	cache->sectorsize = root->sectorsize;

	cache->fs_info = root->fs_info;



	/*

	 * we only want to have 32k of ram per block group for keeping track

	 * of free space, and if we pass 1/2 of that we want to start

	 * converting things over to using bitmaps

	 */

	cache->extents_thresh = ((1024 * 32) / 2) /

		sizeof(struct btrfs_free_space);

	atomic_set(&cache->count, 1);

	spin_lock_init(&cache->lock);

	spin_lock_init(&cache->tree_lock);

	INIT_LIST_HEAD(&cache->list);

	INIT_LIST_HEAD(&cache->cluster_list);



	btrfs_init_free_space_ctl(cache);



	btrfs_set_block_group_used(&cache->item, bytes_used);

	btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);

	cache->flags = type;

fs/btrfs/free-space-cache.c

+231 −199

File changed.

Preview size limit exceeded, changes collapsed.

fs/btrfs/free-space-cache.h

+20 −0
Original line number Diff line number Diff line
@@ -27,6 +27,25 @@ struct btrfs_free_space { 
	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 @@ int btrfs_write_out_cache(struct btrfs_root *root, 
			  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,

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