On 05/27/2016 10:23 AM, Christoph Hellwig wrote:
Adding Hannes to the Cc list as he's been looking into EH improvements
in this area.
On Wed, May 25, 2016 at 02:55:02AM -0500, 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.
Signed-off-by: Mike Christie <mchristi@xxxxxxxxxx>
In general I like the approach.
I'll be looking into it more closely next week.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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