From: J. Bruce Fields <bfields@redhat.com>
Date: Mon, 8 Mar 2021 15:51:51 +0000 (-0500)
Subject: Revert "nfsd4: remove check_conflicting_opens warning"
X-Git-Tag: archive/raspbian/5.10.24-1+rpi1^2~34
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=358f7c5456258fcacbb6716da4174a5665b03c67;p=linux.git

Revert "nfsd4: remove check_conflicting_opens warning"

commit 4aa5e002034f0701c3335379fd6c22d7f3338cce upstream.

This reverts commit 50747dd5e47b "nfsd4: remove check_conflicting_opens
warning", as a prerequisite for reverting 94415b06eb8a, which has a
serious bug.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name revert-nfsd4-remove-check_conflicting_opens-warning.patch
---

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 47006eec724..894cba1294f 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4957,6 +4957,7 @@ static int nfsd4_check_conflicting_opens(struct nfs4_client *clp,
 		writes--;
 	if (fp->fi_fds[O_RDWR])
 		writes--;
+	WARN_ON_ONCE(writes < 0);
 	if (writes > 0)
 		return -EAGAIN;
 	spin_lock(&fp->fi_lock);