md/raid0: fix restore to sector variable in raid0_make_request

The variable "sector" in "raid0_make_request()" was improperly updated
by a call to "sector_div()" which modifies its first argument in place.
Commit 47d68979cc 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: 47d68979cc ("md/raid0: fix bug with chunksize not a power of 2.")
Cc: stable@vger.kernel.org (any that received above backport)
URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501
This commit is contained in:
Eric Work 2015-05-18 23:26:23 -07:00 committed by NeilBrown
parent 487696957e
commit a81157768a

View File

@ -524,6 +524,9 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
? (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);
@ -531,7 +534,6 @@ 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;