block: don't try to discard from __blkdev_issue_zeroout

Discard can return -EIO asynchronously if the alignment for the request
isn't suitable for the driver, which makes a proper fallback to other
methods in __blkdev_issue_zeroout impossible.  Thus only issue a sync
discard from blkdev_issue_zeroout an don't try discard at all from
__blkdev_issue_zeroout as a non-invasive workaround.

One more reason why abusing discard for zeroing must die..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Eryu Guan <eguan@redhat.com>
Fixes: e73c23ff ("block: add async variant of blkdev_issue_zeroout")
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2017-01-13 15:18:16 -07:00 committed by Jens Axboe
parent f80de881d8
commit bef13315e9

View File

@ -301,13 +301,6 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
if ((sector | nr_sects) & bs_mask)
return -EINVAL;
if (discard) {
ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
BLKDEV_DISCARD_ZERO, biop);
if (ret == 0 || (ret && ret != -EOPNOTSUPP))
goto out;
}
ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
biop);
if (ret == 0 || (ret && ret != -EOPNOTSUPP))
@ -370,6 +363,12 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
struct bio *bio = NULL;
struct blk_plug plug;
if (discard) {
if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
BLKDEV_DISCARD_ZERO))
return 0;
}
blk_start_plug(&plug);
ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
&bio, discard);