Hi,
On 7/12/23 08:56, Jens Axboe wrote:
On 7/11/23 6:53 PM, Dominique Martinet wrote:
Jens Axboe wrote on Tue, Jul 11, 2023 at 05:51:46PM -0600:
So what filesystem actually uses this new NOWAIT functionality?
Unless I'm blind (quite possibly) I don't see any filesystem
implementation of this functionality in the patch series.
I had implemented this for kernfs and libfs (so sysfs, debugfs, possibly
tmpfs/proc?) in v2
The patch as of v2's mail has a bug, but my branch has it fixed as of
https://github.com/martinetd/linux/commits/io_uring_getdents
(I guess these aren't "real" enough though)
No, I definitely think those are real and valid. But would be nice with
a "real" file system as well.
I know I posted a prototype for XFS to use it, and I expected that
it would become part of this patch series to avoid the "we don't add
unused code to the kernel" problem. i.e. the authors would take the
XFS prototype, make it work, add support into for the new io_uring
operation to fsstress in fstests and then use that to stress test
the new infrastructure before it gets merged....
But I don't see any of this?
That would indeed be great if we could get NOWAIT, that might finally
convince me that it's worth plumbing up! Do you have a link to that
prototype? That seems like what should be the base for this, and be an
inspiration for other file systems to get efficient getdents via this
(rather than io-wq punt, which I'm not a huge fan of...).
the xfs poc was in this mail:
https://lore.kernel.org/all/20230501071603.GE2155823@xxxxxxxxxxxxxxxxxxx/
I never spent time debugging it, but it should definitely be workable
If either you or Hao wants to take a stab at it and see how it goes,
I think that would be hugely beneficial for this patchset.
I can take the xfs and kernfs part if Dominique doesn't mind.
Regards,
Hao
