[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 2/2] block/xen-blkfront: Handle non-indirect grant with 64KB pages
On 12/11/15 17:51, Roger Pau Monnà wrote: > El 12/11/15 a les 18.30, Julien Grall ha escrit: >> Hi, >> >> On 12/11/15 16:40, Roger Pau Monnà wrote: >>>> [1] http://lists.xen.org/archives/html/xen-devel/2015-08/msg02200.html >>>> >>>> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx> >>> >>> LGTM, only a couple of typos and a simplification: >>> >>> Signed-off-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx> >> >> Do you mean Acked-by? ;) > > Yes, I also had problems with smtp, so I thought this one was actually > not sent. You have another one with a proper Ack :). > >>>> + >>>> + /* The I/O request may be split in two */ >>>> + if (unlikely(s->associated_id != NO_ASSOCIATED_ID)) { >>>> + struct blk_shadow *s2 = &info->shadow[s->associated_id]; >>>> + >>>> + /* Keep the status of the current response in shadow */ >>>> + s->status = (bret->status == BLKIF_RSP_OKAY) ? >>>> + REQ_DONE : REQ_FAIL; >>>> + >>>> + /* Wait the second response if not yet here */ >>>> + if (s2->status == REQ_WAITING) >>>> + return 0; >>>> + >>>> + /* >>>> + * The status of the current response will be used in >>>> + * order to know if the request has failed. >>>> + * Update the current response status only if has not >>>> + * failed. >>>> + */ >>>> + if (bret->status == BLKIF_RSP_OKAY && s2->status == REQ_FAIL) >>> >>> This could be simplified by only checking if s2->status == REQ_FAIL. >> >> I didn't do it because bret->status may be different than >> BLKIF_RSP_ERROR (for instance BLKIF_RSP_EOPNOTSUPP). > > I think this is not actually possible in practice, but what if > bret->status == BLKIF_RSP_OKAY and the bret from s2 actually had > BLKIF_RSP_EOPNOTSUPP, wouldn't we loose the EOPNOTSUPP by > unconditionally setting BLKIF_RSP_ERROR? No because EOPNOTSUPP are used when an operation is not supported. As the 2 ring request is coming from the same I/O request, it will always have the same operation. So if one get EOPNOTSUPP the other will get too. > > Should s->status be able to store all the possible return codes from the > response (OK/ERROR/NOTSUPP)? That could would work. However, how do you decide which will be the final status? Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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