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/hosts.c | 1 + drivers/scsi/scsi_lib.c | 11 ++++------- include/scsi/scsi_host.h | 6 ++++++ 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index f0bc8bbb3938..198edf03f929 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -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; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 5f29faa0560f..e0b5d35e7949 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1981,6 +1981,8 @@ 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; @@ -2969,13 +2971,8 @@ 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; } diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 0f29799efa02..70b7475dcf56 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. */ @@ -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;
