scsi: core: Support setting BLK_MQ_F_BLOCKING

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@oracle.com/

Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230529202640.11883-3-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2023-05-29 13:26:37 -07:00 committed by Martin K. Petersen
parent c854bcdf5e
commit b125bb9955
3 changed files with 11 additions and 7 deletions

View File

@ -441,6 +441,7 @@ struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int priv
shost->cmd_per_lun = sht->cmd_per_lun;
shost->no_write_same = sht->no_write_same;
shost->host_tagset = sht->host_tagset;
shost->queuecommand_may_block = sht->queuecommand_may_block;
if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
shost->eh_deadline = -1;

View File

@ -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->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 +2970,8 @@ 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();
/* Wait for ongoing scsi_queue_rq() calls to finish. */
blk_mq_wait_quiesce_done(&shost->tag_set);
return 0;
}

View File

@ -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.
*/
@ -653,6 +656,9 @@ struct Scsi_Host {
/* 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;
/* Host responded with short (<36 bytes) INQUIRY result */
unsigned short_inquiry:1;