md/raid0: fix restore to sector variable in raid0_make_request (a8115776) · Commits · 戴 / test

The variable "sector" in "raid0_make_request()" was improperly updated by a call to "sector_div()" which modifies its first argument in place. Commit 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: ("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

drivers/md/raid0.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -524,6 +524,9 @@ static void raid0_make_request(struct mddev mddev, struct bio bio)
	? (sector & (chunk_sects-1))		? (sector & (chunk_sects-1))
	: sector_div(sector, chunk_sects));		: sector_div(sector, chunk_sects));

			/* Restore due to sector_div */
			sector = bio->bi_iter.bi_sector;

	if (sectors < bio_sectors(bio)) {		if (sectors < bio_sectors(bio)) {
	split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);		split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);
	bio_chain(split, bio);		bio_chain(split, bio);
	@@ -531,7 +534,6 @@ 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;

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