From: Ronnie Sahlberg <lsahlber@redhat.com>
To: linux-cifs <linux-cifs@vger.kernel.org>
Cc: Steve French <smfrench@gmail.com>,
Stable <stable@vger.kernel.org>,
Ronnie Sahlberg <lsahlber@redhat.com>
Subject: [PATCH] cifs: fix GlobalMid_Lock bug in cifs_reconnect
Date: Fri, 14 Jun 2019 13:02:29 +1000 [thread overview]
Message-ID: <20190614030229.22375-1-lsahlber@redhat.com> (raw)
We can not hold the GlobalMid_Lock spinlock during the
dfs processing in cifs_reconnect since it invokes things that may sleep
and thus trigger :
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23
Thus we need to drop the spinlock during this code block.
RHBZ: 1716743
Cc: stable@vger.kernel.org
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
fs/cifs/connect.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8c4121da624e..8dd6637a3cbb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -476,6 +476,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
spin_lock(&GlobalMid_Lock);
server->nr_targets = 1;
#ifdef CONFIG_CIFS_DFS_UPCALL
+ spin_unlock(&GlobalMid_Lock);
cifs_sb = find_super_by_tcp(server);
if (IS_ERR(cifs_sb)) {
rc = PTR_ERR(cifs_sb);
@@ -493,6 +494,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
}
cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__,
server->nr_targets);
+ spin_lock(&GlobalMid_Lock);
#endif
if (server->tcpStatus == CifsExiting) {
/* the demux thread will exit normally
--
2.13.6
next reply other threads:[~2019-06-14 3:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-14 3:02 Ronnie Sahlberg [this message]
2019-06-14 3:57 ` [PATCH] cifs: fix GlobalMid_Lock bug in cifs_reconnect Steve French
2019-06-17 21:25 ` Pavel Shilovsky
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