On Fri, 2017-08-04 at 16:52 +0900, Damien Le Moal wrote: > Releasing the write lock of a zone when the write commnand that > acquired the lock completes can cause deadlocks with scsi-mq due to > potential queue reordering if the lock owning request is requeued and > not executed. > > Since sd_uninit_cmnd() is always called when a request is requeued, > call sd_zbc_write_unlock_zone() from that function for write requests > that acquired a zone lock. Acquisition of a zone lock by a write command > is indicated using the new command flag SCMD_ZONE_WRITE_LOCK. > > Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx> Hello Damien, Should "Cc: <stable@xxxxxxxxxxxxxxx>" be added to this patch? > diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c > index 96855df9f49d..6423ae70477e 100644 > --- a/drivers/scsi/sd_zbc.c > +++ b/drivers/scsi/sd_zbc.c > @@ -294,6 +294,9 @@ int sd_zbc_write_lock_zone(struct scsi_cmnd *cmd) > test_and_set_bit(zno, sdkp->zones_wlock)) > return BLKPREP_DEFER; > > + WARN_ON(cmd->flags & SCMD_ZONE_WRITE_LOCK); > + cmd->flags |= SCMD_ZONE_WRITE_LOCK; > + > return BLKPREP_OK; > } Did you perhaps intend WARN_ON_ONCE() instead of WARN_ON()? Thanks, Bart.
