From: Christof Schmitt <christof.schmitt@xxxxxxxxxx> Deleting a SCSI device on a blocked fc_remote_port (before fast_io_fail_tmo fires) results in a hanging thread: STACK: 0 schedule+1108 [0x5cac48] 1 schedule_timeout+528 [0x5cb7fc] 2 wait_for_common+266 [0x5ca6be] 3 blk_execute_rq+160 [0x354054] 4 scsi_execute+324 [0x3b7ef4] 5 scsi_execute_req+162 [0x3b80ca] 6 sd_sync_cache+138 [0x3cf662] 7 sd_shutdown+138 [0x3cf91a] 8 sd_remove+112 [0x3cfe4c] 9 __device_release_driver+124 [0x3a08b8] 10 device_release_driver+60 [0x3a0a5c] 11 bus_remove_device+266 [0x39fa76] 12 device_del+340 [0x39d818] 13 __scsi_remove_device+204 [0x3bcc48] 14 scsi_remove_device+66 [0x3bcc8e] 15 sysfs_schedule_callback_work+50 [0x260d66] 16 worker_thread+622 [0x162326] 17 kthread+160 [0x1680b0] 18 kernel_thread_starter+6 [0x10aaea] During the delete, the SCSI device is moved to SDEV_CANCEL. When the FC transport class later calls scsi_target_unblock, this has no effect, since scsi_internal_device_unblock ignores SCSI devices in this state. Fix this by also accepting SDEV_CANCEL in scsi_internal_device_unblock. [michaelc@xxxxxxxxxxx: If the device goes from block to offline then the IO gets stuck in the queue and we can hang like above. The attached patch just modifies your patch to also handle the offline case. It looks like all these are regressions caused by: 5c10e63c943b4c67561ddc6bf61e01d4141f881f [SCSI] limit state transitions in scsi_internal_device_unblock] Cc: Mike Christie <michaelc@xxxxxxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Christof Schmitt <christof.schmitt@xxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2428,7 +2428,8 @@ scsi_internal_device_unblock(struct scsi sdev->sdev_state = SDEV_RUNNING; else if (sdev->sdev_state == SDEV_CREATED_BLOCK) sdev->sdev_state = SDEV_CREATED; - else + else if (sdev->sdev_state != SDEV_CANCEL && + sdev->sdev_state != SDEV_OFFLINE) return -EINVAL; spin_lock_irqsave(q->queue_lock, flags); -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
