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

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 <[email protected]> know about it.

From: Eric Work <[email protected]>
Date: Mon, 18 May 2015 23:26:23 -0700
Subject: md/raid0: fix restore to sector variable in raid0_make_request

From: Eric Work <[email protected]>

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.

URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501

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

@@ -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 [email protected] are

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