[PATCH v6 08/12] block, scsi: Introduce blk_pm_runtime_exit()

Bart Van Assche
2018-08-09T22:08:34Z

Since it is possible to unbind a SCSI ULD and since unbinding
removes the association between a request queue and struct device,
the q->dev pointer has to be reset during unbind. Hence introduce
a function in the block layer that clears request_queue.dev.

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>
---
block/blk-pm.c | 18 ++++++++++++++++++
drivers/scsi/sd.c | 9 ++++-----
drivers/scsi/sr.c | 3 ++-
include/linux/blk-pm.h | 2 ++
4 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/block/blk-pm.c b/block/blk-pm.c
index 9b636960d285..bf8532da952d 100644
--- a/block/blk-pm.c
+++ b/block/blk-pm.c
@@ -40,6 +40,24 @@ void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
}
EXPORT_SYMBOL(blk_pm_runtime_init);

+/**
+ * blk_pm_runtime_exit - runtime PM exit routine
+ * @q: the queue of the device
+ *
+ * This function should be called from the device_driver.remove() callback
+ * function to avoid that further calls to runtime power management functions
+ * occur.
+ */
+void blk_pm_runtime_exit(struct request_queue *q)
+{
+ if (!q->dev)
+ return;
+
+ pm_runtime_get_sync(q->dev);
+ q->dev = NULL;
+}
+EXPORT_SYMBOL(blk_pm_runtime_exit);
+
/**
* blk_pre_runtime_suspend - Pre runtime suspend check
* @q: the queue of the device
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 69ab459abb98..5537762dfcfd 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3420,12 +3420,11 @@ static int sd_probe(struct device *dev)
**/
static int sd_remove(struct device *dev)
{
- struct scsi_disk *sdkp;
- dev_t devt;
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+ struct scsi_device *sdp = sdkp->device;
+ dev_t devt = disk_devt(sdkp->disk);

- sdkp = dev_get_drvdata(dev);
- devt = disk_devt(sdkp->disk);
- scsi_autopm_get_device(sdkp->device);
+ blk_pm_runtime_exit(sdp->request_queue);

async_synchronize_full_domain(&scsi_sd_pm_domain);
async_synchronize_full_domain(&scsi_sd_probe_domain);
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index de4413e66eca..476987f7ed48 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -1002,8 +1002,9 @@ static void sr_kref_release(struct kref *kref)
static int sr_remove(struct device *dev)
{
struct scsi_cd *cd = dev_get_drvdata(dev);
+ struct scsi_device *sdev = cd->device;

- scsi_autopm_get_device(cd->device);
+ blk_pm_runtime_exit(sdev->request_queue);

del_gendisk(cd->disk);
dev_set_drvdata(dev, NULL);
diff --git a/include/linux/blk-pm.h b/include/linux/blk-pm.h
index b80c65aba249..6d654f41acbf 100644
--- a/include/linux/blk-pm.h
+++ b/include/linux/blk-pm.h
@@ -11,6 +11,7 @@ struct request_queue;
*/
#ifdef CONFIG_PM
extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
+extern void blk_pm_runtime_exit(struct request_queue *q);
extern int blk_pre_runtime_suspend(struct request_queue *q);
extern void blk_post_runtime_suspend(struct request_queue *q, int err);
extern void blk_pre_runtime_resume(struct request_queue *q);
@@ -19,6 +20,7 @@ extern void blk_set_runtime_active(struct request_queue *q);
#else
static inline void blk_pm_runtime_init(struct request_queue *q,
struct device *dev) {}
+static inline void blk_pm_runtime_exit(struct request_queue *q) {}
#endif

#endif /* _BLK_PM_H_ */
--
2.18.0