On 05/25/2016 09:55 AM, mchristi@xxxxxxxxxx wrote: > From: Mike Christie <mchristi@xxxxxxxxxx> > > Currently, if the SCSI eh runs then before we do a LUN_RESET > we stop the host. This patch and the block layer one before it > begin to add infrastructure to be able to do a LUN_RESET and > eventually do a transport level recovery without having to stop the > host. > > For LUn-reset, this patch adds a new callout, eh_async_device_reset_handler, > which works similar to how LLDs handle SG_SCSI_RESET_DEVICE where the > LLD manages the commands that are affected. > > eh_async_device_reset_handler: > > The LLD should perform a LUN RESET that affects all commands > that have been accepted by its queuecommand callout for the > device passed in to the callout. While the reset handler is running, > queuecommand will not be running or called for the device. > > Unlike eh_device_reset_handler, queuecommand may still be > called for other devices, and the LLD must call scsi_done for the > commands that have been affected by the reset. > > If SUCCESS or FAST_IO_FAIL is returned, the scsi_cmnds cleaned up > must be failed with DID_ABORT. > Hmm. With this patch you essentially just replaced the existing eh_device_reset_handler() with eh_async_device_request_handler(). So how does this differ from the original behaviour? By the time we're calling it the SCSI host is already in EH, ie all commands have been completed or failed, so why again do we need to wait for the queue to be empty? And how exactly can queuecommand be called for other devices, as the host is already in EH? Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- 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
