On 5/4/23 6:50 PM, Bart Van Assche wrote: > Prepare for adding code in ufshcd_queuecommand() that may sleep. This > patch is similar to a patch posted last year by Mike Christie. See also > https://lore.kernel.org/all/20220308003957.123312-2-michael.christie@xxxxxxxxxx/ > > Cc: Mike Christie <michael.christie@xxxxxxxxxx> > Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> > --- > drivers/scsi/scsi_lib.c | 10 +++------- > include/scsi/scsi_host.h | 3 +++ > 2 files changed, 6 insertions(+), 7 deletions(-) > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 758a57616dd3..894af68babc2 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1982,6 +1982,8 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) > tag_set->flags = BLK_MQ_F_SHOULD_MERGE; > tag_set->flags |= > BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); > + if (shost->hostt->queuecommand_may_block) > + tag_set->flags |= BLK_MQ_F_BLOCKING; > tag_set->driver_data = shost; > if (shost->host_tagset) > tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; > @@ -2968,13 +2970,7 @@ scsi_host_block(struct Scsi_Host *shost) > } > } > > - /* > - * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so > - * calling synchronize_rcu() once is enough. > - */ > - WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING); > - > - synchronize_rcu(); > + blk_mq_wait_quiesce_done(&shost->tag_set); Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx> > > return 0; > } > diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h > index 0f29799efa02..37a8a2608dc2 100644 > --- a/include/scsi/scsi_host.h > +++ b/include/scsi/scsi_host.h > @@ -458,6 +458,9 @@ struct scsi_host_template { > /* True if the host uses host-wide tagspace */ > unsigned host_tagset:1; > > + /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ > + unsigned queuecommand_may_block:1; > + > /* > * Countdown for host blocking with no commands outstanding. > */
