Merge: NFSD: Fix problem of COMMIT and NFS4ERR_DELAY in infinite loop

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2499

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2196432

commit 147abca
Author: Dai Ngo <dai.ngo@oracle.com>
Date:   Wed Apr 19 10:53:18 2023 -0700

    NFSD: Fix problem of COMMIT and NFS4ERR_DELAY in infinite loop

    The following request sequence to the same file causes the NFS client and
    server getting into an infinite loop with COMMIT and NFS4ERR_DELAY:

    OPEN
    REMOVE
    WRITE
    COMMIT

    Problem reported by recall11, recall12, recall14, recall20, recall22,
    recall40, recall42, recall48, recall50 of nfstest suite.

    This patch restores the handling of race condition in nfsd_file_do_acquire
    with unlink to that prior of the regression.

    Fixes: ac3a258 ("nfsd: rework refcounting in filecache")
    Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
    Reviewed-by: Jeff Layton <jlayton@kernel.org>
    Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>

Approved-by: Scott Mayhew <smayhew@redhat.com>
Approved-by: Jeffrey Layton <jlayton@redhat.com>

Signed-off-by: Jan Stancek <jstancek@redhat.com>

Author: jstancek

fs/nfsd/filecache.c

@@ -1169,8 +1169,6 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	 * then unhash.
 	 */
 	if (status == nfs_ok && key.inode->i_nlink == 0)
-		status = nfserr_jukebox;
-	if (status != nfs_ok)
 		nfsd_file_unhash(nf);
 	clear_bit_unlock(NFSD_FILE_PENDING, &nf->nf_flags);
 	smp_mb__after_atomic();