Patch "dm raid: fix round up of default region size" has been added to the 4.2-stable tree

Patch "dm raid: fix round up of default region size" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    dm raid: fix round up of default region size

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-raid-fix-round-up-of-default-region-size.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 042745ee53a0a7c1f5aff191a4a24213c6dcfb52 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 2 Oct 2015 11:17:37 -0400
Subject: dm raid: fix round up of default region size

From: Mikulas Patocka <mpatocka@redhat.com>

commit 042745ee53a0a7c1f5aff191a4a24213c6dcfb52 upstream.

Commit 3a0f9aaee028 ("dm raid: round region_size to power of two")
intended to make sure that the default region size is a power of two.
However, the logic in that commit is incorrect and sets the variable
region_size to 0 or 1, depending on whether min_region_size is a power
of two.

Fix this logic, using roundup_pow_of_two(), so that region_size is
properly rounded up to the next power of two.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 3a0f9aaee028 ("dm raid: round region_size to power of two")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-raid.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -329,8 +329,7 @@ static int validate_region_size(struct r
 		 */
 		if (min_region_size > (1 << 13)) {
 			/* If not a power of 2, make it the next power of 2 */
-			if (min_region_size & (min_region_size - 1))
-				region_size = 1 << fls(region_size);
+			region_size = roundup_pow_of_two(min_region_size);
 			DMINFO("Choosing default region size of %lu sectors",
 			       region_size);
 		} else {


Patches currently in stable-queue which might be from mpatocka@redhat.com are

queue-4.2/dm-raid-fix-round-up-of-default-region-size.patch