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Commit 61cabc7b authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: fix GlobalMid_Lock bug in cifs_reconnect 



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: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Acked-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 8d526d62

fs/cifs/connect.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -476,6 +476,7 @@ cifs_reconnect(struct TCP_Server_Info *server) 
	spin_lock(&GlobalMid_Lock);

	spin_lock(&GlobalMid_Lock);

	server->nr_targets = 1;

	server->nr_targets = 1;

#ifdef CONFIG_CIFS_DFS_UPCALL

#ifdef CONFIG_CIFS_DFS_UPCALL

	spin_unlock(&GlobalMid_Lock);

	cifs_sb = find_super_by_tcp(server);

	cifs_sb = find_super_by_tcp(server);

	if (IS_ERR(cifs_sb)) {

	if (IS_ERR(cifs_sb)) {

		rc = PTR_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__,

	cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__,

		 server->nr_targets);

		 server->nr_targets);

	spin_lock(&GlobalMid_Lock);

#endif

#endif

	if (server->tcpStatus == CifsExiting) {

	if (server->tcpStatus == CifsExiting) {

		/* the demux thread will exit normally

		/* the demux thread will exit normally