Commit bf8ff4b9 authored by Mark Harmstone's avatar Mark Harmstone Committed by David Sterba
Browse files

btrfs: rename struct btrfs_block_group field commit_used to last_used 



Rename the field commit_used in struct btrfs_block_group to last_used,
for clarity and consistency with the similar fields we're about to add.
It's not obvious that commit_flags means "flags as of the last commit"
rather than "flags related to a commit".

Signed-off-by: default avatarMark Harmstone <mark@harmstone.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent efcab317

fs/btrfs/block-group.c

+12 −12
Original line number Diff line number Diff line
@@ -2387,7 +2387,7 @@ static int read_one_block_group(struct btrfs_fs_info *info, 


	cache->length = key->offset;

	cache->used = btrfs_stack_block_group_used(bgi);

	cache->commit_used = cache->used;

	cache->last_used = cache->used;

	cache->flags = btrfs_stack_block_group_flags(bgi);

	cache->global_root_id = btrfs_stack_block_group_chunk_objectid(bgi);

	cache->space_info = btrfs_find_space_info(info, cache->flags);
@@ -2666,7 +2666,7 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans, 
	struct btrfs_block_group_item bgi;

	struct btrfs_root *root = btrfs_block_group_root(fs_info);

	struct btrfs_key key;

	u64 old_commit_used;

	u64 old_last_used;

	int ret;



	spin_lock(&block_group->lock);
@@ -2674,8 +2674,8 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans, 
	btrfs_set_stack_block_group_chunk_objectid(&bgi,

						   block_group->global_root_id);

	btrfs_set_stack_block_group_flags(&bgi, block_group->flags);

	old_commit_used = block_group->commit_used;

	block_group->commit_used = block_group->used;

	old_last_used = block_group->last_used;

	block_group->last_used = block_group->used;

	key.objectid = block_group->start;

	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;

	key.offset = block_group->length;
@@ -2684,7 +2684,7 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans, 
	ret = btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));

	if (ret < 0) {

		spin_lock(&block_group->lock);

		block_group->commit_used = old_commit_used;

		block_group->last_used = old_last_used;

		spin_unlock(&block_group->lock);

	}
@@ -3134,7 +3134,7 @@ static int update_block_group_item(struct btrfs_trans_handle *trans, 
	struct extent_buffer *leaf;

	struct btrfs_block_group_item bgi;

	struct btrfs_key key;

	u64 old_commit_used;

	u64 old_last_used;

	u64 used;



	/*
@@ -3144,14 +3144,14 @@ static int update_block_group_item(struct btrfs_trans_handle *trans, 
	 * may be changed.

	 */

	spin_lock(&cache->lock);

	old_commit_used = cache->commit_used;

	old_last_used = cache->last_used;

	used = cache->used;

	/* No change in used bytes, can safely skip it. */

	if (cache->commit_used == used) {

	if (cache->last_used == used) {

		spin_unlock(&cache->lock);

		return 0;

	}

	cache->commit_used = used;

	cache->last_used = used;

	spin_unlock(&cache->lock);



	key.objectid = cache->start;
@@ -3175,17 +3175,17 @@ static int update_block_group_item(struct btrfs_trans_handle *trans, 
fail:

	btrfs_release_path(path);

	/*

	 * We didn't update the block group item, need to revert commit_used

	 * We didn't update the block group item, need to revert last_used

	 * unless the block group item didn't exist yet - this is to prevent a

	 * race with a concurrent insertion of the block group item, with

	 * insert_block_group_item(), that happened just after we attempted to

	 * update. In that case we would reset commit_used to 0 just after the

	 * update. In that case we would reset last_used to 0 just after the

	 * insertion set it to a value greater than 0 - if the block group later

	 * becomes with 0 used bytes, we would incorrectly skip its update.

	 */

	if (ret < 0 && ret != -ENOENT) {

		spin_lock(&cache->lock);

		cache->commit_used = old_commit_used;

		cache->last_used = old_last_used;

		spin_unlock(&cache->lock);

	}

	return ret;

fs/btrfs/block-group.h

+2 −2
Original line number Diff line number Diff line
@@ -132,10 +132,10 @@ struct btrfs_block_group { 


	/*

	 * The last committed used bytes of this block group, if the above @used

	 * is still the same as @commit_used, we don't need to update block

	 * is still the same as @last_used, we don't need to update block

	 * group item of this block group.

	 */

	u64 commit_used;

	u64 last_used;

	/*

	 * If the free space extent count exceeds this number, convert the block

	 * group to bitmaps.