On Thu, Sep 03 2009 at 11:47am -0400, Mark McLoughlin <markmc@xxxxxxxxxx> wrote: > With 2.6.31-rc5 in a KVM guest using dm and virtio_blk, we see the > following errors: > > end_request: I/O error, dev vda, sector 0 > end_request: I/O error, dev vda, sector 0 > > The errors go away if dm stops submitting empty barriers, by reverting: > > commit 52b1fd5a27c625c78373e024bf570af3c9d44a79 > Author: Mikulas Patocka <mpatocka@xxxxxxxxxx> > dm: send empty barriers to targets in dm_flush > > We should error all barriers, even empty barriers, on devices like > virtio_blk which don't support them. > > See also: > > https://bugzilla.redhat.com/514901 > > Signed-off-by: Mark McLoughlin <markmc@xxxxxxxxxx> > Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx> > Cc: Alasdair G Kergon <agk@xxxxxxxxxx> > Cc: Neil Brown <neilb@xxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > --- > block/blk-core.c | 3 +-- > 1 files changed, 1 insertions(+), 2 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index e3299a7..35ad2bb 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1163,8 +1163,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) > const int unplug = bio_unplug(bio); > int rw_flags; > > - if (bio_barrier(bio) && bio_has_data(bio) && > - (q->next_ordered == QUEUE_ORDERED_NONE)) { > + if (bio_barrier(bio) && (q->next_ordered == QUEUE_ORDERED_NONE)) { > bio_endio(bio, -EOPNOTSUPP); > return 0; > } Jens, Any chance we can get this fix upstream for 2.6.32? I refreshed the patch to work on 2.6.32-rc5: From: Mark McLoughlin <markmc@xxxxxxxxxx> With 2.6.32-rc5 in a KVM guest using dm and virtio_blk, we see the following errors: end_request: I/O error, dev vda, sector 0 end_request: I/O error, dev vda, sector 0 The errors go away if dm stops submitting empty barriers, by reverting: commit 52b1fd5a27c625c78373e024bf570af3c9d44a79 Author: Mikulas Patocka <mpatocka@xxxxxxxxxx> dm: send empty barriers to targets in dm_flush We should silently error all barriers, even empty barriers, on devices like virtio_blk which don't support them. See also: https://bugzilla.redhat.com/514901 Signed-off-by: Mark McLoughlin <markmc@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Acked-by: Alasdair G Kergon <agk@xxxxxxxxxx> Acked-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Cc: Neil Brown <neilb@xxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> --- block/blk-core.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ac0fa10..71da511 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1161,7 +1161,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK; int rw_flags; - if (bio_rw_flagged(bio, BIO_RW_BARRIER) && bio_has_data(bio) && + if (bio_rw_flagged(bio, BIO_RW_BARRIER) && (q->next_ordered == QUEUE_ORDERED_NONE)) { bio_endio(bio, -EOPNOTSUPP); return 0; -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
