Re: [REGRESSION 6.1.70] system calls with CIFS mounts failing with "Resource temporarily unavailable"

[Salvatore Bonaccorso <carnil@debian.org>]

Hi Paulo, hi Greg,

Note this is about the 5.10.y backports of the cifs issue, were system
calls fail with "Resource temporarily unavailable".

On Mon, Jan 08, 2024 at 12:58:49PM -0300, Paulo Alcantara wrote:
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> writes:
> 
> > Why can't we just include eb3e28c1e89b ("smb3: Replace smb2pdu 1-element
> > arrays with flex-arrays") to resolve this?
> 
> Yep, this is the right way to go.
> 
> > I've queued it up now.
> 
> Thanks!

Is the underlying issue by picking the three commits:

3080ea5553cc ("stddef: Introduce DECLARE_FLEX_ARRAY() helper")
eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays")

and the last commit in linux-stable-rc for 5.10.y:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit?id=a280ecca48beb40ca6c0fc20dd5a7fdd9b3ee0b7

really fixing the issue?

Since we need to release a new update in Debian, I picked those three
for testing on top of the 5.10.209-1 and while testing explicitly a
cifs mount, I still get:

statfs(".", 0x7ffd809d5a70)             = -1 EAGAIN (Resource temporarily unavailable)

The same happens if I build
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit?id=a280ecca48beb40ca6c0fc20dd5a7fdd9b3ee0b7
(knowing that it is not yet ready for review).

I'm slight confused as a280ecca48be ("cifs: fix off-by-one in
SMB2_query_info_init()") says in the commit message:

[...]
	v5.10.y doesn't have

        eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays")

	and the commit does
[...]

and in meanwhile though the eb3e28c1e89b was picked (in a backported
version). As 6.1.75-rc2 itself does not show the same problem, might
there be a prerequisite missing in the backports for 5.10.y or a
backport being wrong?

Regards,
Salvatore