1 files changed, 15 insertions, 11 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index a14703e0a9ad..1c1bbe4135c6 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1570,20 +1570,24 @@ out:
  * @c: UBIFS file-system description object
  *
  * This function is called during un-mounting and re-mounting, and it commits
- * the journal unless the "fast unmount" mode is enabled. It also avoids
- * committing the journal if it contains too few data.
+ * the journal unless the "fast unmount" mode is enabled.
  */
 static void commit_on_unmount(struct ubifs_info *c)
 {
-        if (!c->fast_unmount) {
-                long long bud_bytes;
+        struct super_block *sb = c->vfs_sb;
+        long long bud_bytes;
 
-                spin_lock(&c->buds_lock);
-                bud_bytes = c->bud_bytes;
-                spin_unlock(&c->buds_lock);
-                if (bud_bytes > c->leb_size)
-                        ubifs_run_commit(c);
-        }
+        /*
+         * This function is called before the background thread is stopped, so
+         * we may race with ongoing commit, which means we have to take
+         * @c->bud_lock to access @c->bud_bytes.
+         */
+        spin_lock(&c->buds_lock);
+        bud_bytes = c->bud_bytes;
+        spin_unlock(&c->buds_lock);
+
+        if (!c->fast_unmount && !(sb->s_flags & MS_RDONLY) && bud_bytes)
+                ubifs_run_commit(c);
 }
 
 /**
@@ -2009,7 +2013,7 @@ static void ubifs_kill_sb(struct super_block *sb)
          * We do 'commit_on_unmount()' here instead of 'ubifs_put_super()'
          * in order to be outside BKL.
          */
-        if (sb->s_root && !(sb->s_flags & MS_RDONLY))
+        if (sb->s_root)
                 commit_on_unmount(c);
         /* The un-mount routine is actually done in put_super() */
         generic_shutdown_super(sb);