btrfs: handle errors while updating refcounts in update_ref_for_cow (692826b2) · Commits · 戴 / test

Since commit (btrfs: qgroup: Move half of the qgroup accounting time out of commit trans) the assumption that btrfs_add_delayed_{data,tree}_ref can only return 0 or -ENOMEM has been false. The qgroup operations call into btrfs_search_slot and friends and can now return the full spectrum of error codes. Fortunately, the fix here is easy since update_ref_for_cow failing is already handled so we just need to bail early with the error code. Fixes: (btrfs: qgroup: Move half of the qgroup accounting ...) Cc: <stable@vger.kernel.org> # v4.11+ Signed-off-by:

Jeff Mahoney <jeffm@suse.com> Reviewed-by:

Edmund Nadolski <enadolski@suse.com> Reviewed-by:

Qu Wenruo <wqu@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

+12 −6

Original line number	Diff line number	Diff line
		@@ -1032,14 +1032,17 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
		root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
		!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
		ret = btrfs_inc_ref(trans, root, buf, 1);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;

		if (root->root_key.objectid ==
		BTRFS_TREE_RELOC_OBJECTID) {
		ret = btrfs_dec_ref(trans, root, buf, 0);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;
		ret = btrfs_inc_ref(trans, root, cow, 1);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;
		}
		new_flags \|= BTRFS_BLOCK_FLAG_FULL_BACKREF;
		} else {
		@@ -1049,7 +1052,8 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
		ret = btrfs_inc_ref(trans, root, cow, 1);
		else
		ret = btrfs_inc_ref(trans, root, cow, 0);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;
		}
		if (new_flags != 0) {
		int level = btrfs_header_level(buf);
		@@ -1068,9 +1072,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
		ret = btrfs_inc_ref(trans, root, cow, 1);
		else
		ret = btrfs_inc_ref(trans, root, cow, 0);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;
		ret = btrfs_dec_ref(trans, root, buf, 1);
		BUG_ON(ret); /* -ENOMEM */
		if (ret)
		return ret;
		}
		clean_tree_block(fs_info, buf);
		*last_ref = 1;

Admin message