On Thu, 2017-08-17 at 21:19 +0900, Damien Le Moal wrote: > On 8/17/17 16:59, Christoph Hellwig wrote: > > On Thu, Aug 17, 2017 at 11:45:50AM +0900, Damien Le Moal wrote: > > > blk-mq may not maintain write requests order at dispatch time. So host > > > managed drives will not reliably work. Worse, potential reordering of > > > write requests on requeue may cause the zone write locking code to > > > deadlock command dispatch to the disk. So for now, until the write > > > ordering issue is fixed, do not support zoned block devices with > > > scsi-mq by showing a 0 LBA capacity disk. > > > > NAK. Please fix the issue instead of this. > > I do have a fix ready to send. All the fixes are at blk-mq level and > basically ensure that dispatch from the hctx->dispatch list are in order > for write commands (regular writes, write same and write zeroes). > It is well tested and at least fixes all the problems I have seen with > dm-zoned and f2fs. Hello Damien, Another possible approach is to fix the ipr driver and to resubmit the "scsi-mq: Always unprepare before requeuing a request" and "scsi: sd_zbc: Write unlock zone from sd_uninit_cmnd()" patches. Bart.
