tree 10573dfdd504619f235661f85a08807dbd04b8d0
parent 425c6ed6486f1e2ed892eadb94fd4829c299493e
author Qu Wenruo <wqu@suse.com> 1595573169 +0800
committer David Sterba <dsterba@suse.com> 1602065533 +0200

btrfs: qgroup: fix wrong qgroup metadata reserve for delayed inode

For delayed inode facility, qgroup metadata is reserved for it, and
later freed.

However we're freeing more bytes than we reserved.
In btrfs_delayed_inode_reserve_metadata():

	num_bytes = btrfs_calc_metadata_size(fs_info, 1);
	...
		ret = btrfs_qgroup_reserve_meta_prealloc(root,
				fs_info->nodesize, true);
		...
		if (!ret) {
			node->bytes_reserved = num_bytes;

But in btrfs_delayed_inode_release_metadata():

	if (qgroup_free)
		btrfs_qgroup_free_meta_prealloc(node->root,
				node->bytes_reserved);
	else
		btrfs_qgroup_convert_reserved_meta(node->root,
				node->bytes_reserved);

This means, we're always releasing more qgroup metadata rsv than we have
reserved.

This won't trigger selftest warning, as btrfs qgroup metadata rsv has
extra protection against cases like quota enabled half-way.

But we still need to fix this problem any way.

This patch will use the same num_bytes for qgroup metadata rsv so we
could handle it correctly.

Fixes: f218ea6c4792 ("btrfs: delayed-inode: Remove wrong qgroup meta reservation calls")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>