@@ -3052,11 +3052,12 @@ scsi_device_quiesce(struct scsi_device *sdev)
int err;
/*
- * It is allowed to call scsi_device_quiesce() multiple times from
- * the same context but concurrent scsi_device_quiesce() calls are
- * not allowed.
+ * Since all scsi_device_quiesce() and scsi_device_resume() calls
+ * are serialized it is safe here to check the device state without
+ * holding the SCSI device state mutex.
*/
- WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current);
+ if (sdev->sdev_state == SDEV_QUIESCE)
+ return 0;
blk_set_preempt_only(q);
@@ -3072,9 +3073,7 @@ scsi_device_quiesce(struct scsi_device *sdev)
mutex_lock(&sdev->state_mutex);
err = scsi_device_set_state(sdev, SDEV_QUIESCE);
- if (err == 0)
- sdev->quiesced_by = current;
- else
+ if (err)
blk_clear_preempt_only(q);
mutex_unlock(&sdev->state_mutex);
@@ -3098,8 +3097,6 @@ void scsi_device_resume(struct scsi_device *sdev)
* device deleted during suspend)
*/
mutex_lock(&sdev->state_mutex);
- WARN_ON_ONCE(!sdev->quiesced_by);
- sdev->quiesced_by = NULL;
blk_clear_preempt_only(sdev->request_queue);
if (sdev->sdev_state == SDEV_QUIESCE)
scsi_device_set_state(sdev, SDEV_RUNNING);
@@ -226,7 +226,6 @@ struct scsi_device {
unsigned char access_state;
struct mutex state_mutex;
enum scsi_device_state sdev_state;
- struct task_struct *quiesced_by;
unsigned long sdev_data[0];
} __attribute__((aligned(sizeof(unsigned long))));
Although the power management code never calls the system-wide and runtime suspend callbacks concurrently, runtime power state changes can happen while the system is being suspended or resumed. See also the dpm_suspend() and dpm_resume() calls in hibernation_snapshot(). Make sure the sd driver supports this. This patch avoids that the following call trace is reported during system-wide suspend: WARNING: CPU: 0 PID: 701 at drivers/scsi/scsi_lib.c:3047 scsi_device_quiesce+0x4b/0xd0 Workqueue: events_unbound async_run_entry_fn RIP: 0010:scsi_device_quiesce+0x4b/0xd0 Call Trace: scsi_bus_suspend_common+0x71/0xe0 scsi_bus_freeze+0x15/0x20 dpm_run_callback+0x88/0x360 __device_suspend+0x1c4/0x840 async_suspend+0x1f/0xb0 async_run_entry_fn+0x6e/0x2c0 process_one_work+0x4ae/0xa20 worker_thread+0x63/0x5a0 kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 Fixes: cd84a62e0078 ("block, scsi: Change the preempt-only flag into a counter") Cc: Lee Duncan <lduncan@suse.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/scsi_lib.c | 15 ++++++--------- include/scsi/scsi_device.h | 1 - 2 files changed, 6 insertions(+), 10 deletions(-)