[3.13.y-ckt stable] Patch "ext4: call sync_blockdev() before invalidate_bdev() in put_super()" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ext4: call sync_blockdev() before invalidate_bdev() in put_super()

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt24.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 6cb0b02cb4477051372b44c19d90b00f95445311 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso at mit.edu>
Date: Sat, 20 Jun 2015 22:50:33 -0400
Subject: ext4: call sync_blockdev() before invalidate_bdev() in put_super()

commit 89d96a6f8e6491f24fc8f99fd6ae66820e85c6c1 upstream.

Normally all of the buffers will have been forced out to disk before
we call invalidate_bdev(), but there will be some cases, where a file
system operation was aborted due to an ext4_error(), where there may
still be some dirty buffers in the buffer cache for the device.  So
try to force them out to memory before calling invalidate_bdev().

This fixes a warning triggered by generic/081:

WARNING: CPU: 1 PID: 3473 at /usr/projects/linux/ext4/fs/block_dev.c:56 __blkdev_put+0xb5/0x16f()

Signed-off-by: Theodore Ts'o <tytso at mit.edu>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/ext4/super.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9fb3e6c..a07af5b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -832,6 +832,7 @@ static void ext4_put_super(struct super_block *sb)
 		dump_orphan_list(sb, sbi);
 	J_ASSERT(list_empty(&sbi->s_orphan));

+	sync_blockdev(sb->s_bdev);
 	invalidate_bdev(sb->s_bdev);
 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 		/*
--
1.9.1