On Mon, Sep 01, 2025 at 05:10:01PM +0530, Ojaswin Mujoo wrote: > On Sun, Aug 31, 2025 at 01:09:07AM +0800, Zorro Lang wrote: > > On Fri, Aug 29, 2025 at 10:29:47PM +0530, Ojaswin Mujoo wrote: > > > On Thu, Aug 28, 2025 at 08:09:05AM -0700, Darrick J. Wong wrote: > > > > On Wed, Aug 27, 2025 at 08:46:34PM +0530, Ojaswin Mujoo wrote: > > > > > On Tue, Aug 26, 2025 at 12:08:01AM +0800, Zorro Lang wrote: > > > > > > On Fri, Aug 22, 2025 at 01:32:01PM +0530, Ojaswin Mujoo wrote: > > > > > > > The main motivation of adding this function on top of _require_fio is > > > > > > > that there has been a case in fio where atomic= option was added but > > > > > > > later it was changed to noop since kernel didn't yet have support for > > > > > > > atomic writes. It was then again utilized to do atomic writes in a later > > > > > > > version, once kernel got the support. Due to this there is a point in > > > > > > > fio where _require_fio w/ atomic=1 will succeed even though it would > > > > > > > not be doing atomic writes. > > > > > > > > > > > > > > Hence, add an explicit helper to ensure tests to require specific > > > > > > > versions of fio to work past such issues. > > > > > > > > > > > > Actually I'm wondering if fstests really needs to care about this. This's > > > > > > just a temporary issue of fio, not kernel or any fs usespace program. Do > > > > > > we need to add a seperated helper only for a temporary fio issue? If fio > > > > > > doesn't break fstests running, let it run. Just the testers install proper > > > > > > fio (maybe latest) they need. What do you and others think? > > > > > > > > Are there obvious failures if you try to run these new atomic write > > > > tests on a system with the weird versions of fio that have the no-op > > > > atomic= functionality? I'm concerned that some QA person is going to do > > > > that unwittingly and report that everything is ok when in reality they > > > > didn't actually test anything. > > > > > > I think John has a bit more background but afaict, RWF_ATOMIC support > > > was added (fio commit: d01612f3ae25) but then removed (commit: > > > a25ba6c64fe1) since the feature didn't make it to kernel in time. > > > However the option seemed to be kept in place. Later, commit 40f1fc11d > > > added the support back in a later version of fio. > > > > > > So yes, I think there are some version where fio will accept atomic=1 > > > but not act upon it and the tests may start failing with no apparent > > > reason. > > > > The concern from Darrick might be a problem. May I ask which fio commit > > brought in this issue, and which fio commit fixed it? If this issue be > > brought in and fixed within a fio release, it might be better. But if it > > crosses fio release, that might be bad, then we might be better to have > > this helper. > > Hi Zorro, yes it does seem to cross version boundaries. The > functionality was removed in fio v3.33 and added back in v3.38. I Thanks, if so I think let's have this helper for that issue :) But I think we still prioritize _require_fio. If it helpless, then call _require_fio_version. Reviewed-by: Zorro Lang <zlang@xxxxxxxxxx> Thanks, Zorro > confirmed this by running generic/1226 with both (for v3.33 run i > commented out a few fio options that were added later but kept > atomic=1): > > Command: sudo perf record -e iomap:iomap_dio_rw_begin ./check generic/1226 > > perf script sample with fio v3.33: > > fio 6626 [000] 777.668017: iomap:iomap_dio_rw_begin: <.sniip.> flags DIRECT|WRITE|AIO_RW dio_flags aio 1 > > perf script sample with fio v3.39: > > fio 9830 [000] 895.042747: iomap:iomap_dio_rw_begin: <.snip> flags ATOMIC|DIRECT|WRITE|AIO_RW dio_flags aio 1 > > So as we can see, even though the test passes with atomic=1, fio is not > sending the RWF_ATOMIC flag in the older version. > > In which case I believe it should be okay to keep the helper, right? > > Thanks, > Ojaswin > > > > > Thanks, > > Zorro > > > > > > > > Regards, > > > ojaswin > > > > > > > > --D > > > > > > > > > > Thanks, > > > > > > Zorro >
