Re: [PATCH] xfs: don't reuse busy extents on extent trim

[Brian Foster <bfoster@redhat.com>]

On Fri, May 27, 2022 at 10:06:46AM +0300, Amir Goldstein wrote:
> On Thu, May 26, 2022 at 11:56 PM Amir Goldstein <amir73il@gmail.com> wrote:
> >
> > > > I tested it on top of 5.10.109 + these 5 patches:
> > > > https://github.com/amir73il/linux/commits/xfs-5.10.y-1
> > > >
> > > > I can test it in isolation if you like. Let me know if there are
> > > > other forensics that you would like me to collect.
> > > >
> > >
> > > Hm. Still no luck if I move to .109 and pull in those few patches. I
> > > assume there's nothing else potentially interesting about the test env
> > > other than the sparse file scratch dev (i.e., default mkfs options,
> >
> > Oh! right, this guest is debian/10 with xfsprogs 4.20, so the defaults
> > are reflink=0.
> >
> > Actually, the section I am running is reflink_normapbt, but...
> >
> > ** mkfs failed with extra mkfs options added to "-f -m
> > reflink=1,rmapbt=0, -i sparse=1," by test 076 **
> > ** attempting to mkfs using only test 076 options: -m crc=1 -i sparse **
> > ** mkfs failed with extra mkfs options added to "-f -m
> > reflink=1,rmapbt=0, -i sparse=1," by test 076 **
> > ** attempting to mkfs using only test 076 options: -d size=50m -m
> > crc=1 -i sparse **
> >
> > mkfs.xfs does not accept double sparse argument, so the
> > test falls back to mkfs defaults (+ sparse)
> >
> > I checked and xfsprogs 5.3 behaves the same, I did not check newer
> > xfsprogs, but that seems like a test bug(?)
> >
> 
> xfsprogs 5.16 still behaves the same, meaning that xfs/076 and many many
> other tests ignore the custom mkfs options for the specific sections.
> That is a big test coverage issue!
> 
> > IWO, unless xfsprogs was changed to be more tolerable to repeating
> > arguments, then maybe nobody is testing xfs/076 with reflink=0 (?)
> >
> 
> Bingo!
> Test passes 100 runs with debian/testing - xfsprogs v5.16
> 
> I shall try to amend the test to force reflink=0 to see what happens.
> You should try it as well.
> 

Interesting. If I set -mreflink=0 xfs/076 seems to do the right thing
and format the scratch device as expected, but I'm still not seeing a
failure on my system for whatever reason.

Brian

> Thanks,
> Amir.
>