On 2025-10-08 22:42, Hongbo Li wrote:
Hi Geoffrey,
On 2025/10/9 7:22, Geoffrey Thorpe wrote:
Any trivial usage of hostfs seems to be broken since commit cd140ce9 ("hostfs: convert hostfs to use the new mount API") - I bisected it down to this commit to make sure.
Sorry to trouble you, can you provide your information about mount version and kernel version (use mount -v and uname -ar) ?
root@localhost:~# mount --version mount from util-linux 2.41 (libmount 2.41.0: selinux, smack, btrfs, verity, namespaces, idmapping, fd-based-mount, statmount, statx, assert, debug)
As for the kernel version, I have been bisecting different kernel versions to find the culprit commit. The problem occurs with the commit id I mentioned (cd140ce9: "hostfs: convert hostfs to use the new mount API"). This appears to be between v6.10 and v6.11. The most recent kernel releases all seem to exhibit the problem. My own code has been using kernel v6.6 up till now and that works fine.
By the way, did you try using the steps to reproduce? No pressure to do so, I am just curious if the instructions I provided work OK for other people (or whether I missed something essential). If you do follow those steps, you should be able to see success if you use v6.6 or older, and you should see failure with anything newer.
(Side note: when bisecting, I noticed that a number of commits had to be skipped because they seg-faulted during early boot. Fortunately, that didn't prevent me from finding the culprit. I mention this just in case you stumble across a commit that seg-faults too - it appears that's unrelated to the current regression.)
Regards, Geoff