Commit 44a6c343 authored by David Sterba's avatar David Sterba
Browse files

btrfs: return errors from unpin_extent_range() 



Handle the lookup failure of the block group to unpin, this is a logic
error as the block group must exist at this point. If not, something else
must have freed it, like clean_pinned_extents() would do without locking
the unused_bg_unpin_mutex.

Push the errors to the callers, proper handling will be done in followup
patches.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c03c89f8

fs/btrfs/block-group.c

+1 −1
Original line number Diff line number Diff line
@@ -1429,7 +1429,7 @@ static bool clean_pinned_extents(struct btrfs_trans_handle *trans, 
	 * group in pinned_extents before we were able to clear the whole block

	 * group range from pinned_extents. This means that task can lookup for

	 * the block group after we unpinned it from pinned_extents and removed

	 * it, leading to a BUG_ON() at unpin_extent_range().

	 * it, leading to an error at unpin_extent_range().

	 */

	mutex_lock(&fs_info->unused_bg_unpin_mutex);

	if (prev_trans) {

fs/btrfs/extent-tree.c

+15 −4
Original line number Diff line number Diff line
@@ -2777,6 +2777,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, 
	u64 total_unpinned = 0;

	u64 empty_cluster = 0;

	bool readonly;

	int ret = 0;



	while (start <= end) {

		readonly = false;
@@ -2786,7 +2787,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, 
				btrfs_put_block_group(cache);

			total_unpinned = 0;

			cache = btrfs_lookup_block_group(fs_info, start);

			BUG_ON(!cache); /* Logic error */

			if (cache == NULL) {

				/* Logic error, something removed the block group. */

				ret = -EUCLEAN;

				goto out;

			}



			cluster = fetch_cluster_info(fs_info,

						     cache->space_info,
@@ -2855,7 +2860,8 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, 


	if (cache)

		btrfs_put_block_group(cache);

	return 0;

out:

	return ret;

}



int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
@@ -2885,7 +2891,8 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans) 
						   end + 1 - start, NULL);



		clear_extent_dirty(unpin, start, end, &cached_state);

		unpin_extent_range(fs_info, start, end, true);

		ret = unpin_extent_range(fs_info, start, end, true);

		BUG_ON(ret);

		mutex_unlock(&fs_info->unused_bg_unpin_mutex);

		free_extent_state(cached_state);

		cond_resched();
@@ -6167,7 +6174,11 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, 
int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,

				   u64 start, u64 end)

{

	return unpin_extent_range(fs_info, start, end, false);

	int ret;



	ret = unpin_extent_range(fs_info, start, end, false);

	BUG_ON(ret);

	return ret;

}



/*