[PATCH v6 03/12] scsi: Only set RQF_DV for requests used for domain validation

Bart Van Assche
2018-08-09T22:08:29Z

Instead of setting RQF_DV for all requests submitted by scsi_execute(),
only set that flag for requests that are used for domain validation.
Move the SCSI Parallel Interface (SPI) domain validation status from
the transport data to struct scsi_target such that this status
information can be accessed easily from inside scsi_execute(). This
patch prevents that e.g. event checking can occur during domain
validation.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
---
drivers/scsi/scsi_lib.c | 6 ++++--
drivers/scsi/scsi_transport_spi.c | 9 +++------
include/scsi/scsi_device.h | 1 +
include/scsi/scsi_transport_spi.h | 1 -
4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8685704f6c8b..4d7411a7985f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -268,8 +268,10 @@ int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,

if (rq_flags & RQF_PM)
blk_mq_req_flags |= BLK_MQ_REQ_PM;
- rq_flags |= RQF_DV;
- blk_mq_req_flags |= BLK_MQ_REQ_DV;
+ if (scsi_target(sdev)->spi_dv_context == current) {
+ rq_flags |= RQF_DV;
+ blk_mq_req_flags |= BLK_MQ_REQ_DV;
+ }
req = blk_get_request(sdev->request_queue,
data_direction == DMA_TO_DEVICE ?
REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, blk_mq_req_flags);
diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c
index 2ca150b16764..bf6b18768e79 100644
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -66,7 +66,6 @@ static struct {
};

/* Private data accessors (keep these out of the header file) */
-#define spi_dv_in_progress(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_in_progress)
#define spi_dv_mutex(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_mutex)

struct spi_internal {
@@ -268,7 +267,6 @@ static int spi_setup_transport_attrs(struct transport_container *tc,
spi_pcomp_en(starget) = 0;
spi_hold_mcs(starget) = 0;
spi_dv_pending(starget) = 0;
- spi_dv_in_progress(starget) = 0;
spi_initial_dv(starget) = 0;
mutex_init(&spi_dv_mutex(starget));

@@ -1018,14 +1016,12 @@ spi_dv_device(struct scsi_device *sdev)
*/
lock_system_sleep();

- if (unlikely(spi_dv_in_progress(starget)))
+ if (unlikely(starget->spi_dv_context))
goto unlock;

if (unlikely(scsi_device_get(sdev)))
goto unlock;

- spi_dv_in_progress(starget) = 1;
-
buffer = kzalloc(len, GFP_KERNEL);

if (unlikely(!buffer))
@@ -1043,7 +1039,9 @@ spi_dv_device(struct scsi_device *sdev)

starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");

+ starget->spi_dv_context = current;
spi_dv_device_internal(sdev, buffer);
+ starget->spi_dv_context = NULL;

starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");

@@ -1057,7 +1055,6 @@ spi_dv_device(struct scsi_device *sdev)
out_free:
kfree(buffer);
out_put:
- spi_dv_in_progress(starget) = 0;
scsi_device_put(sdev);
unlock:
unlock_system_sleep();
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 202f4d6a4342..440834f4252e 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -310,6 +310,7 @@ struct scsi_target {

char scsi_level;
enum scsi_target_state state;
+ struct task_struct *spi_dv_context;
void *hostdata; /* available to low-level driver */
unsigned long starget_data[0]; /* for the transport */
/* starget_data must be the last element!!!! */
diff --git a/include/scsi/scsi_transport_spi.h b/include/scsi/scsi_transport_spi.h
index a4fa52b4d5c5..36934ac0a5ca 100644
--- a/include/scsi/scsi_transport_spi.h
+++ b/include/scsi/scsi_transport_spi.h
@@ -56,7 +56,6 @@ struct spi_transport_attrs {
unsigned int support_qas; /* supports quick arbitration and selection */
/* Private Fields */
unsigned int dv_pending:1; /* Internal flag: DV Requested */
- unsigned int dv_in_progress:1; /* Internal: DV started */
struct mutex dv_mutex; /* semaphore to serialise dv */
};

--
2.18.0