Messages in this thread | | | Date | Mon, 28 Oct 2013 10:59:32 -0600 | From | Jens Axboe <> | Subject | Re: blk-mq flush fix |
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On 10/28/2013 10:46 AM, Christoph Hellwig wrote: > On Mon, Oct 28, 2013 at 10:29:11AM -0600, Jens Axboe wrote: >> It's not that I think the existing patch is THAT bad, it fits in alright >> with the reserved tagging and works regardless of whether a driver uses >> reserved tags or not. And it does have the upside of not requiring >> special checks or logic for this special non-tagged request that using >> the preallocated would might need. > > The problem with it is that it will pass a tag number to the low level > driver which it doesn't expect. In case the tags are used 1:1 as > hardware tags that would lead to nasy bugs. > > At vefy least we'd need to mess with ->tag for this special request.
Yes indeed. Actually the more I think about it, the better I like just using the normal tagging infrastructure and punting to a reserved tag for the flush. Just needs adding of the check whether it actually needs it or not.
-- Jens Axboe
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