Messages in this thread | | | Date | Mon, 13 Jun 2016 01:20:01 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH V2] block: correctly fallback for zeroout |
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On Fri, Jun 10, 2016 at 09:49:44PM -0400, Martin K. Petersen wrote: > >> What does the extra io_err buy us? Just have this function return an > >> error. And then in blkdev_issue_discard if you get -EOPNOTSUPP you > >> special case it there. > > Shaohua> The __blkdev_issue_discard returns -EOPNOTSUPP if disk doesn't > Shaohua> support discard. in that case, blkdev_issue_discard doesn't > Shaohua> return 0. blkdev_issue_discard only returns 0 if IO error is > Shaohua> -EOPNOTSUPP. > > Oh, I see. The sanity checks are now in __blkdev_issue_discard() so > there is no way to distinguish between -EOPNOTSUPP and the other > -EOPNOTSUPP. *sigh*
We can move the sanity checks out. Or even better get rid of the stupid behavior of ignoring the late -EOPNOTSUPP in this low level helper and instead leaving it to the caller(s) that care. So far the DM test suite seems to be the only one that does.
> I am OK with your patch as a stable fix but this really needs to be > fixed up properly.
And I'd much prefer to get this right now. It's not like this is recently introduced behavior.
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