From: Eric Work Date: Tue, 19 May 2015 06:26:23 +0000 (-0700) Subject: md/raid0: fix restore to sector variable in raid0_make_request X-Git-Tag: v3.18.16~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=343971da1ddea0363e385879f4c8908592358049;p=thirdparty%2Fkernel%2Fstable.git md/raid0: fix restore to sector variable in raid0_make_request [ Upstream commit a81157768a00e8cf8a7b43b5ea5cac931262374f ] 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 Fixes: 47d68979cc96 ("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 Signed-off-by: Sasha Levin --- diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index d5c12e5b6125f..b974ff29b55c4 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -530,6 +530,9 @@ 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); @@ -537,7 +540,6 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio) split = bio; } - sector = bio->bi_iter.bi_sector; zone = find_zone(mddev->private, §or); tmp_dev = map_sector(mddev, zone, sector, §or); split->bi_bdev = tmp_dev->bdev;