Merge tag 'for-linus-20180413' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Followup fixes for this merge window. This contains:

   - Series from Ming, fixing corner cases in our CPU <-> queue mapping.

     This triggered repeated warnings on especially s390, but I also hit
     it in cpu hot plug/unplug testing while doing IO on NVMe on x86-64.

   - Another fix from Ming, ensuring that we always order budget and
     driver tag identically, avoiding a deadlock on QD=1 devices.

   - Loop locking regression fix from this merge window, from Omar.

   - Another loop locking fix, this time missing an unlock, from Tetsuo
     Handa.

   - Fix for racing IO submission with device removal from Bart.

   - sr reference fix from me, fixing a case where disk change or
     getevents can race with device removal.

   - Set of nvme fixes by way of Keith, from various contributors"

* tag 'for-linus-20180413' of git://git.kernel.dk/linux-block: (28 commits)
  nvme: expand nvmf_check_if_ready checks
  nvme: Use admin command effects for admin commands
  nvmet: fix space padding in serial number
  nvme: check return value of init_srcu_struct function
  nvmet: Fix nvmet_execute_write_zeroes sector count
  nvme-pci: Separate IO and admin queue IRQ vectors
  nvme-pci: Remove unused queue parameter
  nvme-pci: Skip queue deletion if there are no queues
  nvme: target: fix buffer overflow
  nvme: don't send keep-alives to the discovery controller
  nvme: unexport nvme_start_keep_alive
  nvme-loop: fix kernel oops in case of unhandled command
  nvme: enforce 64bit offset for nvme_get_log_ext fn
  sr: get/drop reference to device in revalidate and check_events
  blk-mq: Revert "blk-mq: reimplement blk_mq_hw_queue_mapped"
  blk-mq: Avoid that submitting a bio concurrently with device removal triggers a crash
  backing: silence compiler warning using __printf
  blk-mq: remove code for dealing with remapping queue
  blk-mq: reimplement blk_mq_hw_queue_mapped
  blk-mq: don't check queue mapped in __blk_mq_delay_run_hw_queue()
  ...

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 0cf25d789d05..3f3cb72e0c0c 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -587,18 +587,28 @@ out:
 static unsigned int sr_block_check_events(struct gendisk *disk,
 					  unsigned int clearing)
 {
-	struct scsi_cd *cd = scsi_cd(disk);
+	unsigned int ret = 0;
+	struct scsi_cd *cd;
 
-	if (atomic_read(&cd->device->disk_events_disable_depth))
+	cd = scsi_cd_get(disk);
+	if (!cd)
 		return 0;
 
-	return cdrom_check_events(&cd->cdi, clearing);
+	if (!atomic_read(&cd->device->disk_events_disable_depth))
+		ret = cdrom_check_events(&cd->cdi, clearing);
+
+	scsi_cd_put(cd);
+	return ret;
 }
 
 static int sr_block_revalidate_disk(struct gendisk *disk)
 {
-	struct scsi_cd *cd = scsi_cd(disk);
 	struct scsi_sense_hdr sshdr;
+	struct scsi_cd *cd;
+
+	cd = scsi_cd_get(disk);
+	if (!cd)
+		return -ENXIO;
 
 	/* if the unit is not ready, nothing more to do */
 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
@@ -607,6 +617,7 @@ static int sr_block_revalidate_disk(struct gendisk *disk)
 	sr_cd_check(&cd->cdi);
 	get_sectorsize(cd);
 out:
+	scsi_cd_put(cd);
 	return 0;
 }