----- Original Message ----- > From: "Hannes Reinecke" <hare@xxxxxxx> > To: emilne@xxxxxxxxxx, "Christoph Hellwig" <hch@xxxxxxxxxxxxx> > Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>, "Johannes Thumshirn" <jthumshirn@xxxxxxx>, "Laurence Oberman" > <loberman@xxxxxxxxxx>, "Eyal Ben David" <bdeyal@xxxxxxxxx>, dgilbert@xxxxxxxxxxxx, linux-scsi@xxxxxxxxxxxxxxx > Sent: Friday, December 2, 2016 9:10:01 AM > Subject: Re: SG does not ignore dxferp (direct io + mmap) > > On 12/02/2016 02:29 PM, Ewan D. Milne wrote: > > On Fri, 2016-12-02 at 04:21 -0800, Christoph Hellwig wrote: > >> On Thu, Dec 01, 2016 at 08:40:31AM -0500, Martin K. Petersen wrote: > >>> Specifically, the problem appears to be caused by the removal of > >>> the setting of bio->bi_bdev, which would previously be set to NULL. > >>> If I add: > >> > >> Very odd. For one I would expect it to be NULL anyway, second > >> I don't see why the behavior changed. But given that this reverts > >> to the original assignment and makes things work I'll happily hack it > >> to get things working again: > >> > >> Acked-by: Christoph Hellwig <hch@xxxxxx> > > > > Yeah, I'm not sure I understand this either, apart from the change > > adjusting the code to effectively do what it used to and making the > > test case work. I'm reluctant to cc: stable yet, let me look at this > > a bit more and I'll post the actual patch soon. > > > Plus we found that this is basically a timing issue; we've found that > supposedly fixed bugs will crop up after ~4k iterations. > (Johannes did a _lot_ of testing here :-) > So just because the bug failed to materialize can also mean that you > simply didn't test long enough. > > Cheers, > > Hannes > -- > Dr. Hannes Reinecke Teamlead Storage & Networking > hare@xxxxxxx +49 911 74053 688 > SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg > GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton > HRB 21284 (AG Nürnberg) > Hannes, Just to clarify, my original test reverting commit 3fa6c507319c897598512da91c010a4ad2ed682c, what Ewan originally bisected to and running > 100000 iterations never failed. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
