Hi Mickaël,

On Jul 3, 2025, at 11:29 AM, Mickaël Salaün [off-list ref] wrote:

On Mon, Jun 16, 2025 at 11:11:13PM -0700, Song Liu wrote:

quoted

Use path_walk_parent() to walk a path up to its parent.

No functional changes intended.

Using this helper actualy fixes the issue highlighted by Al.  Even if it
was reported after the first version of this patch series, the issue
should be explained in the commit message and these tags should be
added:

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Closes: https://lore.kernel.org/r/20250529231018.GP2023217@ZenIV (local) 
Fixes: cb2c7d1a1776 ("landlock: Support filesystem access-control")

I like this new helper but we should have a clear plan to be able to
call such helper in a RCU read-side critical section before we merge
this series.  We're still waiting for Christian.

I sent a patch to fix the handling of disconnected directories for
Landlock, and it will need to be backported:
https://lore.kernel.org/all/20250701183812.3201231-1-mic@digikod.net/ (local)
Unfortunately a rebase would be needed for the path_walk_parent patch,
but I can take it in my tree if everyone is OK.

The fix above also touches VFS code (makes path_connected available 
out of namei.c. It probably should also go through VFS tree? 

Maybe you can send 1/5 and 2/5 of this set (with necessary changes) 
and your fix together to VFS tree. Then, I will see how to route the
BPF side patches. 

Thanks,
Song