1 files changed, 13 insertions, 4 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index e9f7a754c4f7..3589eab02a2f 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -36,6 +36,7 @@
 #include <linux/mount.h>
 #include <linux/math64.h>
 #include <linux/writeback.h>
+#include <linux/smp_lock.h>
 #include "ubifs.h"
 
 /*
@@ -447,9 +448,6 @@ static int ubifs_sync_fs(struct super_block *sb, int wait)
         if (!wait)
                 return 0;
 
-        if (sb->s_flags & MS_RDONLY)
-                return 0;
-
         /*
          * VFS calls '->sync_fs()' before synchronizing all dirty inodes and
          * pages, so synchronize them first, then commit the journal. Strictly
@@ -1687,6 +1685,9 @@ static void ubifs_put_super(struct super_block *sb)
 
         ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
                   c->vi.vol_id);
+
+        lock_kernel();
+
         /*
          * The following asserts are only valid if there has not been a failure
          * of the media. For example, there will be dirty inodes if we failed
@@ -1753,6 +1754,8 @@ static void ubifs_put_super(struct super_block *sb)
         ubi_close_volume(c->ubi);
         mutex_unlock(&c->umount_mutex);
         kfree(c);
+
+        unlock_kernel();
 }
 
 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
@@ -1768,17 +1771,22 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
                 return err;
         }
 
+        lock_kernel();
         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
                 if (c->ro_media) {
                         ubifs_msg("cannot re-mount due to prior errors");
+                        unlock_kernel();
                         return -EROFS;
                 }
                 err = ubifs_remount_rw(c);
-                if (err)
+                if (err) {
+                        unlock_kernel();
                         return err;
+                }
         } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
                 if (c->ro_media) {
                         ubifs_msg("cannot re-mount due to prior errors");
+                        unlock_kernel();
                         return -EROFS;
                 }
                 ubifs_remount_ro(c);
@@ -1793,6 +1801,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
         }
 
         ubifs_assert(c->lst.taken_empty_lebs > 0);
+        unlock_kernel();
         return 0;
 }