[LTP] [PATCH] configure.ac: fix mount_attr detection

[Petr Vorel]

Hi all,

...
> > I wonder if we can get this whole mess of two different fallback headers
> > simplified. Looking at the glibc implementation it seems to include
> > "linux/mount.h" if it does exist. So most reasonable solution would do
> > the same I guess which we did before the commit you reference.


> This is indeed correct if only face the latest Glibc, but that might have
> problems when building LTP on a middle version of Glibc/Kernel-headers.
> The bug I mentioned in the last email was fixed since glibc-2.37~426.
Do you know which exact commit has fixed it? It'd help us to realize when this
fix is not needed any more (it'd be good to put it into the commit message).

> @Fabrice, what kind of version of Glibc/Kernel-headers do you use? and
> which platform?

http://autobuild.buildroot.org/results/4dbb72e1bf081afd3cd944571b9beeefc7608865/config
arch: arm
# Buildroot 2023.02-rc1-22-ga39e328bb2 Configuration
=> 2.36-81-g4f4d7a13edfd2fdc57c9d76e1fd6d017fb47550c
kernel headers 5.10.
Specific Buildroot toolchain.

> Btw, this patch builds LTP successfully in CI:
>   - https://github.com/wangli5665/ltp/actions/runs/4380739470
Buildroot often founds problems for embedded folks, because they use different
toolchain than traditional linux distros.

> And I manually tried with fedora-rawhide/fedora34/35/37/38 all looks good.
Thanks for checking.

> Maybe we can just apply this patch to keep everything with no big changes.

> @Cyril, Petr, what do you think?
Unless there is a simple way to improve things, I'm for merging this.