From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Mon, 29 Jul 2019 18:25:00 +0100
Subject: [PATCH] NFSv4: Check the return value of update_open_stateid()
Git-commit: e3c8dc761ead061da2220ee8f8132f729ac3ddfe
Patch-mainline: v5.3
References: git-fixes boo#1154189 bsc#1154747

Ensure that we always check the return value of update_open_stateid()
so that we can retry if the update of local state failed. This fixes
infinite looping on state recovery.

(Bug references are for a previous version of this patch which introduced
 a regression)

Fixes: e23008ec81ef3 ("NFSv4 reduce attribute requests for open reclaim")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v3.7+
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs4proc.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1813,8 +1813,9 @@ _nfs4_opendata_reclaim_to_nfs4_state(str
 	if (data->o_res.delegation_type != 0)
 		nfs4_opendata_check_deleg(data, state);
 update:
-	update_open_stateid(state, &data->o_res.stateid, NULL,
-			    data->o_arg.fmode);
+	if (!update_open_stateid(state, &data->o_res.stateid,
+				NULL, data->o_arg.fmode))
+		return ERR_PTR(-EAGAIN);
 	atomic_inc(&state->count);
 
 	return state;
@@ -1846,8 +1847,11 @@ _nfs4_opendata_to_nfs4_state(struct nfs4
 		goto err_put_inode;
 	if (data->o_res.delegation_type != 0)
 		nfs4_opendata_check_deleg(data, state);
-	update_open_stateid(state, &data->o_res.stateid, NULL,
-			data->o_arg.fmode);
+	if (!update_open_stateid(state, &data->o_res.stateid,
+				NULL, data->o_arg.fmode)) {
+		nfs4_put_open_state(state);
+		state = ERR_PTR(-EAGAIN);
+	}
 	iput(inode);
 out:
 	nfs_release_seqid(data->o_arg.seqid);