Messages in this thread | | | Subject | Re: [PATCH] scsi: mpt3sas: fix hang on ata passthru commands | From | Jason Baron <> | Date | Thu, 29 Dec 2016 11:02:58 -0500 |
| |
On 12/29/2016 03:02 AM, Christoph Hellwig wrote:
> On Wed, Dec 28, 2016 at 11:30:24PM -0500, Jason Baron wrote: >> Add a new parameter to scsi_internal_device_block() to decide whether >> or not to invoke scsi_wait_for_queuecommand(). > We'll also need to deal with the blk-mq wait path that Bart has been > working on (I think it's already in the scsi tree, but I'd have to > check). Ok, I'm not sure either.
> Also adding a bool flag for the last call in a function is style that's > a little annoying. > > I'd prefer to add a scsi_internal_device_block_nowait that contains > all the code except for the waiting, and then make > scsi_internal_device_block_nowait a wrapper around it. Or drop the > annoying internal for both while we're at it :)
The proposed patch brings the code in-line with what is in 4.8 stable where scsi_internal_device_block() does not call scsi_wait_for_queuecommand(). So I saw it as a minimal fix to make my system boot again :)
I was wondering if the original fix is racy in that there could be multiple threads in the queuecommand. Perhaps we should do something like:
if (ata_12_16_cmd(scmd)) {
if (!test_and_set_bit(MPT_DEVICE_EXCLUSIVE, &sas_device_priv_data->flags)) { scsi_internal_device_block(scmd->device);
} else
return SCSI_MLQUEUE_HOST_BUSY;
}
where scsi_internal_device_block() could be taught to wait for request_fn_active becoming 1 instead of 0.
Thanks,
-Jason
| |