From 9fb4dfb8e2120b7d4153ea83601367b04db8dfd4 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Sun, 17 Sep 2023 19:05:50 -0400
Subject: [PATCH] NFSv4: Fix a nfs4_state_manager() race
[ Upstream commit ed1cc05aa1f7fe8197d300e914afc28ab9818f89 ]
If the NFS4CLNT_RUN_MANAGER flag got set just before we cleared
NFS4CLNT_MANAGER_RUNNING, then we might have won the race against
nfs4_schedule_state_manager(), and are responsible for handling the
recovery situation.
Fixes: aeabb3c96186 ("NFSv4: Fix a NFSv4 state manager deadlock")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4state.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 7590d059eb78..258e6b167285 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2699,6 +2699,13 @@ static void nfs4_state_manager(struct nfs_client *clp)
nfs4_end_drain_session(clp);
nfs4_clear_state_manager_bit(clp);
+ if (test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
+ !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING,
+ &clp->cl_state)) {
+ memflags = memalloc_nofs_save();
+ continue;
+ }
+
if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
nfs_client_return_marked_delegations(clp);