xfs: fix parent pointer scrubber bailing out on unallocated inodes

mainline inclusion
from mainline-v5.10-rc5
commit da531cc4
category: bugfix
bugzilla: 187526,https://gitee.com/openeuler/kernel/issues/I4KIAO

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=da531cc46ef16301b1bc5bc74acbaacc628904f5

--------------------------------

xfs_iget can return -ENOENT for a file that the inobt thinks is
allocated but has zeroed mode.  This currently causes scrub to exit
with an operational error instead of flagging this as a corruption.  The
end result is that scrub mistakenly reports the ENOENT to the user
instead of "directory parent pointer corrupt" like we do for EINVAL.

Fixes: 5927268f ("xfs: flag inode corruption if parent ptr doesn't get us a real inode")
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NGuo Xuenan <guoxuenan@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/xfs/scrub/parent.c

@@ -164,13 +164,13 @@ xchk_parent_validate(
 	 * can't use DONTCACHE here because DONTCACHE inodes can trigger
 	 * immediate inactive cleanup of the inode.
 	 *
-	 * If _iget returns -EINVAL then the parent inode number is garbage
-	 * and the directory is corrupt.  If the _iget returns -EFSCORRUPTED
-	 * or -EFSBADCRC then the parent is corrupt which is a cross
-	 * referencing error.  Any other error is an operational error.
+	 * If _iget returns -EINVAL or -ENOENT then the parent inode number is
+	 * garbage and the directory is corrupt.  If the _iget returns
+	 * -EFSCORRUPTED or -EFSBADCRC then the parent is corrupt which is a
+	 *  cross referencing error.  Any other error is an operational error.
 	 */
 	error = xfs_iget(mp, sc->tp, dnum, XFS_IGET_UNTRUSTED, 0, &dp);
-	if (error == -EINVAL) {
+	if (error == -EINVAL || error == -ENOENT) {
 		error = -EFSCORRUPTED;
 		xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error);
 		goto out;