Re: libata error handling
From: Luben Tuikov <hidden>
Date: 2005-08-19 18:46:39
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On 08/18/05 23:49, Jeff Garzik wrote:
1) The fine-grained hooks of the SCSI layer are somewhat standard for block devices. The events they signify -- timeout, abort cmd, dev reset, bus reset, and host reset -- map precisely to the events that we must deal with at the ATA level.
"dev reset, bus reset" -- non existant, as I'm sure you're aware of, depending on what _transport_ you use. ;-)
2) When libata SAT translation layer becomes optional, and libata drives a "true" block device,
Yes, this will be very cool! (when (S)ATA(PI) devices become true block devices.
use of ->eh_strategy_handler() will actually be an obstacle due to false sharing of code paths. ->eh_strategy_handler()
I fully agree.
is indeed a single "do it all" EH entrypoint, but within that entrypoint you must perform several SCSI-specific tasks. 3) ->eh_strategy_handler() has continually proven to be a method of error handling poorly supported by the SCSI layer. There are many assumption coded into the SCSI layer that this is -not- the path taken by LLD EH code, and libata must constantly work around these assumptions.
I agree.
4) libata is the -only- user of ->eh_strategy_handler(), and oddballs
Not any more ;-) Using the command time out hook and the strategy routine, gives _complete_ control over host recovery, and I really do mean _complete_. Luben
must be stomped out. It creates a maintenance burden on the SCSI layer that should be eliminated. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html