On Wed, 2016-12-07 at 10:16 -0800, James Bottomley wrote: > On Wed, 2016-12-07 at 12:40 -0500, Ewan D. Milne wrote: > > On Wed, 2016-12-07 at 08:55 -0800, Bart Van Assche wrote: > > > On 12/07/2016 08:48 AM, Bart Van Assche wrote: > > > > It's a known bug. Some time ago I posted a patch that serializes > > > > all scsi_device_set_state() calls but I have not yet found it in > > > > the list archives. However, that patch has not yet been merged. > > > > > > See also https://www.spinics.net/lists/linux-scsi/msg66966.html. > > > > > > Bart. > > > > > > -- > > > 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 > > > > Yes, however that patch does not fix Wei Fang's issue. In fact I > > just received a crash dump that appears to be the same thing. It > > looks like the rport went away right after the initial INQUIRY, so we > > set the state to SDEV_BLOCK and stop the queue, and then the scan > > code continues and sets the state back to SDEV_RUNNING. > > So here's the violation of the state model. the rport went CREATED > ->BLOCK which is wrong: it should go CREATED->CREATED_BLOCK and then > the add code would set it to BLOCK instead of RUNNING. > > The question to diagnose is why CREATED->BLOCK worked. > > James > I believe scsi_add_lun() changed the state from CREATED->RUNNING which allowed the state to change from RUNNING->BLOCK, and then scsi_sysfs_add_sdev() called scsi_device_set_state() which changed the state from BLOCK->RUNNING. But did not restart the queue. I have a debug kernel out to the site that found this to make sure, assuming they can reproduce this, but I don't see any other way it could have happened. -Ewan -- 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
