[Devel] [PATCH rh7 3/3] ms/NFS: Fix a double unlock from nfs_match, get_client

[Andrey Ryabinin]

From: Benjamin Coddington <bcodding at redhat.com>

Now that nfs_match_client drops the nfs_client_lock, we should be
careful
to always return it in the same condition: locked.

Fixes: 950a578c6128 ("NFS: make nfs_match_client killable")
Reported-by: syzbot+228a82b263b5da91883d at syzkaller.appspotmail.com
Signed-off-by: Benjamin Coddington <bcodding at redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker at Netapp.com>

https://jira.sw.ru/browse/PSBM-98297
(cherry picked from commit c260121a97a3e4df6536edbc2f26e166eff370ce)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 fs/nfs/client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 09e6b85ab8fc..e82d9c5564e5 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -310,9 +310,9 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
 			spin_unlock(&nn->nfs_client_lock);
 			error = nfs_wait_client_init_complete(clp);
 			nfs_put_client(clp);
+			spin_lock(&nn->nfs_client_lock);
 			if (error < 0)
 				return ERR_PTR(error);
-			spin_lock(&nn->nfs_client_lock);
 			goto again;
 		}
 
-- 
2.21.0