[4.2.y-ckt stable] Patch "ext4: iterate over buffer heads correctly in move_extent_per_page()" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    ext4: iterate over buffer heads correctly in move_extent_per_page()

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt6.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 62e236b9c509b546e558066e515054b10cf83a5e Mon Sep 17 00:00:00 2001
From: Eryu Guan <guaneryu at gmail.com>
Date: Sun, 21 Feb 2016 18:38:44 -0500
Subject: ext4: iterate over buffer heads correctly in move_extent_per_page()

commit 6ffe77bad545f4a7c8edd2a4ee797ccfcd894ab4 upstream.

In commit bcff24887d00 ("ext4: don't read blocks from disk after extents
being swapped") bh is not updated correctly in the for loop and wrong
data has been written to disk. generic/324 catches this on sub-page
block size ext4.

Fixes: bcff24887d00 ("ext4: don't read blocks from disk after extentsbeing swapped")
Signed-off-by: Eryu Guan <guaneryu at gmail.com>
Signed-off-by: Theodore Ts'o <tytso at mit.edu>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/ext4/move_extent.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index e032a04..4098acc 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -390,6 +390,7 @@ data_copy:
 		*err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
 		if (*err < 0)
 			break;
+		bh = bh->b_this_page;
 	}
 	if (!*err)
 		*err = block_commit_write(pagep[0], from, from + replaced_size);
--
2.7.0