[ 119/122] JFFS2: fix unmount regression

Greg Kroah-Hartman
2012-10-11T00:36:57Z

From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

commit a445f784ae5558a3da680aa6b39ed53c95a551c1 upstream.

This patch fixes regression introduced by
"8bdc81c jffs2: get rid of jffs2_sync_super". We submit a delayed work in order
to make sure the write-buffer is synchronized at some point. But we do not
flush it when we unmount, which causes an oops when we unmount the file-system
and then the delayed work is executed.

This patch fixes the issue by adding a "cancel_delayed_work_sync()" infocation
in the '->sync_fs()' handler. This will make sure the delayed work is canceled
on sync, unmount and re-mount. And because VFS always callse 'sync_fs()' before
unmounting or remounting, this fixes the issue.

Reported-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/jffs2/super.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -100,6 +100,10 @@ static int jffs2_sync_fs(struct super_bl
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ cancel_delayed_work_sync(&c->wbuf_dwork);
+#endif
+
mutex_lock(&c->alloc_sem);
jffs2_flush_wbuf_pad(c);
mutex_unlock(&c->alloc_sem);