Commit f333adb5 authored by Li Zefan's avatar Li Zefan
Browse files

btrfs: Check mergeable free space when removing a cluster 



After returing extents from a cluster to the block group, some
extents in the block group may be mergeable.

Reviewed-by: default avatarJosef Bacik <josef@redhat.com>
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent 120d66ee

fs/btrfs/free-space-cache.c

+20 −6
Original line number Diff line number Diff line
@@ -987,11 +987,18 @@ tree_search_offset(struct btrfs_block_group_cache *block_group, 
	return entry;

}



static void unlink_free_space(struct btrfs_block_group_cache *block_group,

static inline void

__unlink_free_space(struct btrfs_block_group_cache *block_group,

		    struct btrfs_free_space *info)

{

	rb_erase(&info->offset_index, &block_group->free_space_offset);

	block_group->free_extents--;

}



static void unlink_free_space(struct btrfs_block_group_cache *block_group,

			      struct btrfs_free_space *info)

{

	__unlink_free_space(block_group, info);

	block_group->free_space -= info->bytes;

}
@@ -1364,7 +1371,7 @@ static int insert_into_bitmap(struct btrfs_block_group_cache *block_group, 
}



bool try_merge_free_space(struct btrfs_block_group_cache *block_group,

			  struct btrfs_free_space *info)

			  struct btrfs_free_space *info, bool update_stat)

{

	struct btrfs_free_space *left_info;

	struct btrfs_free_space *right_info;
@@ -1385,7 +1392,10 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group, 
		left_info = tree_search_offset(block_group, offset - 1, 0, 0);



	if (right_info && !right_info->bitmap) {

		if (update_stat)

			unlink_free_space(block_group, right_info);

		else

			__unlink_free_space(block_group, right_info);

		info->bytes += right_info->bytes;

		kfree(right_info);

		merged = true;
@@ -1393,7 +1403,10 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group, 


	if (left_info && !left_info->bitmap &&

	    left_info->offset + left_info->bytes == offset) {

		if (update_stat)

			unlink_free_space(block_group, left_info);

		else

			__unlink_free_space(block_group, left_info);

		info->offset = left_info->offset;

		info->bytes += left_info->bytes;

		kfree(left_info);
@@ -1418,7 +1431,7 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group, 


	spin_lock(&block_group->tree_lock);



	if (try_merge_free_space(block_group, info))

	if (try_merge_free_space(block_group, info, true))

		goto link;



	/*
@@ -1636,6 +1649,7 @@ __btrfs_return_cluster_to_free_space( 
		node = rb_next(&entry->offset_index);

		rb_erase(&entry->offset_index, &cluster->root);

		BUG_ON(entry->bitmap);

		try_merge_free_space(block_group, entry, false);

		tree_insert_offset(&block_group->free_space_offset,

				   entry->offset, &entry->offset_index, 0);

	}