6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jeff Layton <jlayton@kernel.org>
commit 2327ba1d9546727a35b17888777e991f68a9b305 upstream.
nfsd4_lock() only checks the namespace-wide grace flag when deciding
whether to accept a reclaim LOCK. It does not check the per-client
NFSD4_CLIENT_RECLAIM_COMPLETE bit. An NFSv4.1+ client that has
already sent RECLAIM_COMPLETE can submit lk_reclaim=1 while grace is
still active (e.g. lockd holds the grace list open), and the server
accepts it instead of returning NFS4ERR_NO_GRACE as required by
RFC 8881 section 18.51.3.
The OPEN path already enforces both tiers: the grace check plus the
per-client RECLAIM_COMPLETE check in nfs4_check_open_reclaim(). Add
the equivalent per-client check to the LOCK path.
Fixes: 3b3e7b72239a ("nfsd: reject reclaim request when client has already sent RECLAIM_COMPLETE")
Cc: <redacted>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: Correct the RFC citations in the commit message ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-14-5b90e276f2d9@kernel.org (local)
Signed-off-by: Chuck Lever <cel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/nfsd/nfs4state.c | 3 +++
1 file changed, 3 insertions(+)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7618,6 +7618,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struc
status = nfserr_no_grace;
if (!locks_in_grace(net) && lock->lk_reclaim)
goto out;
+ if (lock->lk_reclaim &&
+ test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &cstate->clp->cl_flags))
+ goto out;
if (lock->lk_reclaim)
fl_flags |= FL_RECLAIM;