Messages in this thread | | | Date | Mon, 28 Oct 2013 13:39:09 -0600 | From | Jens Axboe <> | Subject | Re: blk-mq flush fix |
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On 10/28/2013 01:30 PM, Christoph Hellwig wrote: > On Mon, Oct 28, 2013 at 10:59:32AM -0600, Jens Axboe wrote: >>> 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. > > That issue happens when using reserved tags as-is: e.g. the device > supports 32 hardware tag, first reserved one is 33, something the > hardware can't handle. > > So either way we'll have to copy over the tag from the original request. > > I don't think I can come up with something sane for that ASAP, so I'd > suggest you actually do take my patch for now, and we'll sort something > out less in a hurry.
Agree, I will queue it up.
-- Jens Axboe
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