Patch "md/raid0: fix restore to sector variable in raid0_make_request" has been added to the 4.0-stable tree

Patch "md/raid0: fix restore to sector variable in raid0_make_request" has been added to the 4.0-stable tree

[gregkh]

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

    md/raid0: fix restore to sector variable in raid0_make_request

to the 4.0-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:
     md-raid0-fix-restore-to-sector-variable-in-raid0_make_request.patch
and it can be found in the queue-4.0 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 a81157768a00e8cf8a7b43b5ea5cac931262374f Mon Sep 17 00:00:00 2001
From: Eric Work <work.eric@gmail.com>
Date: Mon, 18 May 2015 23:26:23 -0700
Subject: md/raid0: fix restore to sector variable in raid0_make_request

From: Eric Work <work.eric@gmail.com>

commit a81157768a00e8cf8a7b43b5ea5cac931262374f upstream.

The variable "sector" in "raid0_make_request()" was improperly updated
by a call to "sector_div()" which modifies its first argument in place.
Commit 47d68979cc968535cb87f3e5f2e6a3533ea48fbd restored this variable
after the call for later re-use.  Unfortunetly the restore was done after
the referenced variable "bio" was advanced.  This lead to the original
value and the restored value being different.  Here we move this line to
the proper place.

One observed side effect of this bug was discarding a file though
unlinking would cause an unrelated file's contents to be discarded.

Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: 47d68979cc96 ("md/raid0: fix bug with chunksize not a power of 2.")
URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/raid0.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -517,6 +517,9 @@ static void raid0_make_request(struct md
 			 ? (sector & (chunk_sects-1))
 			 : sector_div(sector, chunk_sects));
 
+		/* Restore due to sector_div */
+		sector = bio->bi_iter.bi_sector;
+
 		if (sectors < bio_sectors(bio)) {
 			split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);
 			bio_chain(split, bio);
@@ -524,7 +527,6 @@ static void raid0_make_request(struct md
 			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;


Patches currently in stable-queue which might be from work.eric@gmail.com are

queue-4.0/md-raid0-fix-restore-to-sector-variable-in-raid0_make_request.patch