[PATCH 3/4] nfsd: check delegation status in nfsd4_cb_notify_done

[Jeff Layton]

If a delegation has been closed or revoked (sc_status is set), the
NFS4ERR_DELAY retry loop in nfsd4_cb_notify_done will spin
indefinitely. This holds the sc_count reference and prevents the
delegation from being freed.

Add a check for sc_status at the top of the function, matching the
pattern used in nfsd4_cb_recall_done, to terminate the callback
promptly when the delegation is no longer valid.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/nfsd/nfs4state.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index acddd55a99d8..5e391f01d753 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3593,6 +3593,9 @@ nfsd4_cb_notify_done(struct nfsd4_callback *cb,
 	struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb);
 	struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
 
+	if (dp->dl_stid.sc_status)
+		return 1;
+
 	switch (task->tk_status) {
 	case -NFS4ERR_DELAY:
 		rpc_delay(task, 2 * HZ);

-- 
2.54.0