[PATCH 2/3] NFSv4: run lease renewal on a freezable workqueue

[Andrew Pam]

The renewal work is queued on system_percpu_wq, which is not frozen
during system sleep. During hibernation it can therefore fire after the
snapshot has been taken, while the image is written. It then queues
renewal and DELEGRETURN RPCs and can wake the state manager, all on
behalf of a kernel image whose state is about to be discarded.

With rpciod frozen across system sleep (previous patch) those RPCs are
not transmitted until after resume. Run the renewal itself on
system_freezable_wq too, so it does not run in that window at all; the
delayed work fires after thaw if its time has passed.

Tested together with the previous patch, as described there.

Drafted with an AI coding assistant (Claude).

Signed-off-by: Andrew Pam <andrew@xxxxxxxxxxxxxx>
---
 fs/nfs/nfs4renewd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 30065df1482e..a0326f830bca 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -122,7 +122,7 @@ nfs4_schedule_state_renewal(struct nfs_client *clp)
 		timeout = 5 * HZ;
 	dprintk("%s: requeueing work. Lease period = %ld\n",
 			__func__, (timeout + HZ - 1) / HZ);
-	mod_delayed_work(system_percpu_wq, &clp->cl_renewd, timeout);
+	mod_delayed_work(system_freezable_wq, &clp->cl_renewd, timeout);
 	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
 	spin_unlock(&clp->cl_lock);
 }
-- 
2.53.0