[GIT PULL] SCSI fixes for 5.14-rc7

From: James Bottomley
Date: Sat Aug 28 2021 - 14:10:00 EST


A single fix for a race introduced by a fix that went up in 5.14-rc5.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Li Jinlin (1):
scsi: core: Fix hang of freezing queue between blocking and running device

And the diffstat:

drivers/scsi/scsi_sysfs.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

With full diff below.

James

---

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index ae9bfc658203..c0d31119d6d7 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -808,12 +808,15 @@ store_state_field(struct device *dev, struct device_attribute *attr,
ret = scsi_device_set_state(sdev, state);
/*
* If the device state changes to SDEV_RUNNING, we need to
- * rescan the device to revalidate it, and run the queue to
- * avoid I/O hang.
+ * run the queue to avoid I/O hang, and rescan the device
+ * to revalidate it. Running the queue first is necessary
+ * because another thread may be waiting inside
+ * blk_mq_freeze_queue_wait() and because that call may be
+ * waiting for pending I/O to finish.
*/
if (ret == 0 && state == SDEV_RUNNING) {
- scsi_rescan_device(dev);
blk_mq_run_hw_queues(sdev->request_queue, true);
+ scsi_rescan_device(dev);
}
mutex_unlock(&sdev->state_mutex);