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[3.16.y-ckt,stable] Patch "md/raid0: fix bug with chunksize not a power of 2." has been added to staging queue

Message ID 1430905858-27084-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques May 6, 2015, 9:50 a.m. UTC 
This is a note to let you know that I have just added a patch titled

    md/raid0: fix bug with chunksize not a power of 2.

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt11.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From fe825a41aaf4d8b0902d6ff4d0899ea595c46db3 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Fri, 10 Apr 2015 13:19:04 +1000
Subject: md/raid0: fix bug with chunksize not a power of 2.

commit 47d68979cc968535cb87f3e5f2e6a3533ea48fbd upstream.

Since commit 20d0189b1012a37d2533a87fb451f7852f2418d1
in v3.14-rc1 RAID0 has performed incorrect calculations
when the chunksize is not a power of 2.

This happens because "sector_div()" modifies its first argument, but
this wasn't taken into account in the patch.

So restore that first arg before re-using the variable.

Reported-by: Joe Landman <joe.landman@gmail.com>
Reported-by: Dave Chinner <david@fromorbit.com>
Fixes: 20d0189b1012a37d2533a87fb451f7852f2418d1
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/md/raid0.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
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Patch

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 407a99e46f69..683e685ed697 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -320,7 +320,7 @@  static struct strip_zone *find_zone(struct r0conf *conf,

 /*
  * remaps the bio to the target device. we separate two flows.
- * power 2 flow and a general flow for the sake of perfromance
+ * power 2 flow and a general flow for the sake of performance
 */
 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
 				sector_t sector, sector_t *sector_offset)
@@ -538,6 +538,7 @@  static void raid0_make_request(struct mddev *mddev, struct bio *bio)
 			split = bio;
 		}

+		sector = bio->bi_iter.bi_sector;
 		zone = find_zone(mddev->private, &sector);
 		tmp_dev = map_sector(mddev, zone, sector, &sector);
 		split->bi_bdev = tmp_dev->bdev;