[PATCH 2/5 -tip] cifs: umount_begin BKL pushdown

[Alessio Igor Bogani <abogani@texware.it>]

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
---
 fs/cifs/cifsfs.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 38491fd..9517ae1 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -35,6 +35,7 @@
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
+#include <linux/smp_lock.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #define DECLARE_GLOBALS_HERE
@@ -525,18 +526,26 @@ static void cifs_umount_begin(struct super_block *sb)
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 	struct cifsTconInfo *tcon;
 
-	if (cifs_sb == NULL)
+	lock_kernel();
+
+	if (cifs_sb == NULL) {
+		unlock_kernel();
 		return;
+	}
 
 	tcon = cifs_sb->tcon;
-	if (tcon == NULL)
+	if (tcon == NULL) {
+		unlock_kernel();
 		return;
+	}
 
 	read_lock(&cifs_tcp_ses_lock);
 	if (tcon->tc_count == 1)
 		tcon->tidStatus = CifsExiting;
 	read_unlock(&cifs_tcp_ses_lock);
 
+	unlock_kernel();
+
 	/* cancel_brl_requests(tcon); */ /* BB mark all brl mids as exiting */
 	/* cancel_notify_requests(tcon); */
 	if (tcon->ses && tcon->ses->server) {
-- 
1.6.0.4