From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Sun, 17 Sep 2023 23:05:50 +0000 (-0400)
Subject: NFSv4: Fix a nfs4_state_manager() race
X-Git-Tag: v6.1.63~934
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=99fe9a12072956aaa1b1ab9aa93b3362c352664d;p=sdk%2Femulator%2Femulator-kernel.git

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>
---

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index ed789e0cb943..457b2b2f804a 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2710,6 +2710,13 @@ 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);