Staging: Pohmelfs: Sync fs before killing it, since dentry cache is shrunk before writeback is invoked via generic_shutdown_super()

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c
index 3fef09fd712c..af99f6620b7e 100644
--- a/drivers/staging/pohmelfs/inode.c
+++ b/drivers/staging/pohmelfs/inode.c
@@ -1908,11 +1908,29 @@ static int pohmelfs_get_sb(struct file_system_type *fs_type,
                                 mnt);
 }
 
+/*
+ * We need this to sync all inodes earlier, since when writeback
+ * is invoked from the umount/mntput path dcache is already shrunk,
+ * see generic_shutdown_super(), and no inodes can access the path.
+ */
+static void pohmelfs_kill_super(struct super_block *sb)
+{
+        struct writeback_control wbc = {
+                .sync_mode      = WB_SYNC_ALL,
+                .range_start    = 0,
+                .range_end      = LLONG_MAX,
+                .nr_to_write    = LONG_MAX,
+        };
+        generic_sync_sb_inodes(sb, &wbc);
+
+        kill_anon_super(sb);
+}
+
 static struct file_system_type pohmel_fs_type = {
         .owner          = THIS_MODULE,
         .name           = "pohmel",
         .get_sb         = pohmelfs_get_sb,
-        .kill_sb        = kill_anon_super,
+        .kill_sb        = pohmelfs_kill_super,
 };
 
 /*