[PATCH v2 8/9] block, scsi, ide: Only process PM requests if rpm_status != RPM_ACTIVE

Bart Van Assche
2020-11-16T03:05:31Z

Instead of submitting all SCSI commands submitted with scsi_execute() to
a SCSI device if rpm_status != RPM_ACTIVE, only submit RQF_PM (power
management requests) if rpm_status != RPM_ACTIVE. Remove flag
RQF_PREEMPT since it is no longer necessary.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Can Guo <cang@codeaurora.org>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
block/blk-core.c | 6 +++---
block/blk-mq-debugfs.c | 1 -
block/blk-mq.c | 4 ++--
drivers/ide/ide-io.c | 3 +--
drivers/ide/ide-pm.c | 2 +-
drivers/scsi/scsi_lib.c | 27 ++++++++++++++-------------
include/linux/blk-mq.h | 4 ++--
include/linux/blkdev.h | 6 +-----
8 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 2db8bda43b6e..a00bce9f46d8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -424,11 +424,11 @@ EXPORT_SYMBOL(blk_cleanup_queue);
/**
* blk_queue_enter() - try to increase q->q_usage_counter
* @q: request queue pointer
- * @flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PREEMPT
+ * @flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PM
*/
int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
{
- const bool pm = flags & BLK_MQ_REQ_PREEMPT;
+ const bool pm = flags & BLK_MQ_REQ_PM;

while (true) {
bool success = false;
@@ -630,7 +630,7 @@ struct request *blk_get_request(struct request_queue *q, unsigned int op,
struct request *req;

WARN_ON_ONCE(op & REQ_NOWAIT);
- WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PREEMPT));
+ WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PM));

req = blk_mq_alloc_request(q, op, flags);
if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 3094542e12ae..9336a6f8d6ef 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -297,7 +297,6 @@ static const char *const rqf_name[] = {
RQF_NAME(MIXED_MERGE),
RQF_NAME(MQ_INFLIGHT),
RQF_NAME(DONTPREP),
- RQF_NAME(PREEMPT),
RQF_NAME(FAILED),
RQF_NAME(QUIET),
RQF_NAME(ELVPRIV),
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1b25ec2fe9be..d50504888b68 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -292,8 +292,8 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
rq->mq_hctx = data->hctx;
rq->rq_flags = 0;
rq->cmd_flags = data->cmd_flags;
- if (data->flags & BLK_MQ_REQ_PREEMPT)
- rq->rq_flags |= RQF_PREEMPT;
+ if (data->flags & BLK_MQ_REQ_PM)
+ rq->rq_flags |= RQF_PM;
if (blk_queue_io_stat(data->q))
rq->rq_flags |= RQF_IO_STAT;
INIT_LIST_HEAD(&rq->queuelist);
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 1a53c7a75224..beb850679fa9 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -522,8 +522,7 @@ blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
* state machine.
*/
if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
- ata_pm_request(rq) == 0 &&
- (rq->rq_flags & RQF_PREEMPT) == 0) {
+ ata_pm_request(rq) == 0) {
/* there should be no pending command at this point */
ide_unlock_port(hwif);
goto plug_device;
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index 192e6c65d34e..82ab308f1aaf 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -77,7 +77,7 @@ int generic_ide_resume(struct device *dev)
}

memset(&rqpm, 0, sizeof(rqpm));
- rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, BLK_MQ_REQ_PREEMPT);
+ rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, BLK_MQ_REQ_PM);
ide_req(rq)->type = ATA_PRIV_PM_RESUME;
ide_req(rq)->special = &rqpm;
rqpm.pm_step = IDE_PM_START_RESUME;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index df1f22b32964..fd8d2f4d71f8 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -248,7 +248,8 @@ int __scsi_execute(struct request_queue *q, const unsigned char *cmd,
int ret = DRIVER_ERROR << 24;

req = blk_get_request(q, data_direction == DMA_TO_DEVICE ?
- REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
+ REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
+ rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0);
if (IS_ERR(req))
return ret;
rq = scsi_req(req);
@@ -1204,6 +1205,8 @@ static blk_status_t
scsi_device_state_check(struct scsi_device *sdev, struct request *req)
{
switch (sdev->sdev_state) {
+ case SDEV_CREATED:
+ return BLK_STS_OK;
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
/*
@@ -1230,18 +1233,18 @@ scsi_device_state_check(struct scsi_device *sdev, struct request *req)
return BLK_STS_RESOURCE;
case SDEV_QUIESCE:
/*
- * If the devices is blocked we defer normal commands.
+ * If the device is blocked we only accept power management
+ * commands.
*/
- if (req && !(req->rq_flags & RQF_PREEMPT))
+ if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM)))
return BLK_STS_RESOURCE;
return BLK_STS_OK;
default:
/*
* For any other not fully online state we only allow
- * special commands. In particular any user initiated
- * command is not allowed.
+ * power management commands.
*/
- if (req && !(req->rq_flags & RQF_PREEMPT))
+ if (req && !(req->rq_flags & RQF_PM))
return BLK_STS_IOERR;
return BLK_STS_OK;
}
@@ -2517,15 +2520,13 @@ void sdev_evt_send_simple(struct scsi_device *sdev,
EXPORT_SYMBOL_GPL(sdev_evt_send_simple);

/**
- * scsi_device_quiesce - Block user issued commands.
+ * scsi_device_quiesce - Block all commands except power management.
* @sdev: scsi device to quiesce.
*
* This works by trying to transition to the SDEV_QUIESCE state
* (which must be a legal transition). When the device is in this
- * state, only special requests will be accepted, all others will
- * be deferred. Since special requests may also be requeued requests,
- * a successful return doesn't guarantee the device will be
- * totally quiescent.
+ * state, only power management requests will be accepted, all others will
+ * be deferred.
*
* Must be called with user context, may sleep.
*
@@ -2586,12 +2587,12 @@ void scsi_device_resume(struct scsi_device *sdev)
* device deleted during suspend)
*/
mutex_lock(&sdev->state_mutex);
+ if (sdev->sdev_state == SDEV_QUIESCE)
+ scsi_device_set_state(sdev, SDEV_RUNNING);
if (sdev->quiesced_by) {
sdev->quiesced_by = NULL;
blk_clear_pm_only(sdev->request_queue);
}
- if (sdev->sdev_state == SDEV_QUIESCE)
- scsi_device_set_state(sdev, SDEV_RUNNING);
mutex_unlock(&sdev->state_mutex);
}
EXPORT_SYMBOL(scsi_device_resume);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index b23eeca4d677..1fa350592830 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -444,8 +444,8 @@ enum {
BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0),
/* allocate from reserved pool */
BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1),
- /* set RQF_PREEMPT */
- BLK_MQ_REQ_PREEMPT = (__force blk_mq_req_flags_t)(1 << 3),
+ /* set RQF_PM */
+ BLK_MQ_REQ_PM = (__force blk_mq_req_flags_t)(1 << 3),
};

struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 639cae2c158b..7d4b746f7e6a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -79,9 +79,6 @@ typedef __u32 __bitwise req_flags_t;
#define RQF_MQ_INFLIGHT ((__force req_flags_t)(1 << 6))
/* don't call prep for this one */
#define RQF_DONTPREP ((__force req_flags_t)(1 << 7))
-/* set for "ide_preempt" requests and also for requests for which the SCSI
- "quiesce" state must be ignored. */
-#define RQF_PREEMPT ((__force req_flags_t)(1 << 8))
/* vaguely specified driver internal error. Ignored by the block layer */
#define RQF_FAILED ((__force req_flags_t)(1 << 10))
/* don't warn about errors */
@@ -430,8 +427,7 @@ struct request_queue {
unsigned long queue_flags;
/*
* Number of contexts that have called blk_set_pm_only(). If this
- * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
- * processed.
+ * counter is above zero then only RQF_PM requests are processed.
*/
atomic_t pm_only;