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

Since commit 20d0189b10
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: 20d0189b10
Cc: stable@vger.kernel.org (3.14 and later).
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2015-04-10 13:19:04 +10:00
parent 74672d069b
commit 47d68979cc
1 changed files with 2 additions and 1 deletions

View File

@ -313,7 +313,7 @@ static struct strip_zone *find_zone(struct r0conf *conf,
/* /*
* remaps the bio to the target device. we separate two flows. * 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, static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
sector_t sector, sector_t *sector_offset) sector_t sector, sector_t *sector_offset)
@ -524,6 +524,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
split = bio; split = bio;
} }
sector = bio->bi_iter.bi_sector;
zone = find_zone(mddev->private, &sector); zone = find_zone(mddev->private, &sector);
tmp_dev = map_sector(mddev, zone, sector, &sector); tmp_dev = map_sector(mddev, zone, sector, &sector);
split->bi_bdev = tmp_dev->bdev; split->bi_bdev = tmp_dev->bdev;