From: no-reply@sashiko.virtuozzo.com
To: Konstantin Khorenko <khorenko@virtuozzo.com>, devel@openvz.org
Subject: Re: [Devel] [PATCH hci-8.1 v3] block: let container root set the block size of and flush its device
Date: Thu, 29 Oct 2026 16:04:23 +0000 [thread overview]
Message-ID: <010701a18867c1d1-550e6d72-3781-42a1-98b9-163c02ffd2f5-000000@eu-central-1.amazonses.com> (raw)
In-Reply-To: <20261029-vstor-137668-block-let-container-root-set-the-block-size-v3-1-c3fd7db3777c@virtuozzo.com>
> From: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
>
> BLKBSZSET and BLKFLSBUF check CAP_SYS_ADMIN in the initial user
> namespace, so root in a container cannot set the block size of a block
> device it has been given, nor flush its buffers, and mkfs.xfs on a loop
> device there stops with "cannot set blocksize 512 on block device
> /dev/loopN: Permission denied", or with "Flushing the data device
> failed, err=13" once it gets past the first.
>
> Check the capability relative to the container, as the other block
> code adapted for containers does, and let container root through only
> where its device cgroup grants write access to the device: a device
> handed to a container read-only may be held by a filesystem outside
> it, and neither its cache nor its block size should be touched from
> inside.
>
> https://virtuozzo.atlassian.net/browse/VSTOR-137668
> Feature: ve: allow various syscalls in CT root userns
>
> Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
> Reviewed-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
> Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.vzint.dev/#/patchset/20261029-vstor-137668-block-let-container-root-set-the-block-size-v3-1-c3fd7db3777c@virtuozzo.com?part=1
_______________________________________________
Devel mailing list
Devel@openvz.org
https://lists.openvz.org/mailman/listinfo/devel
next prev parent reply other threads:[~2026-10-29 16:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-29 16:00 Konstantin Khorenko
2026-10-29 16:04 ` no-reply [this message]
2026-10-29 16:06 ` Eva Kurchatova (Virtuozzo)
2026-10-29 16:10 ` Konstantin Khorenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=010701a18867c1d1-550e6d72-3781-42a1-98b9-163c02ffd2f5-000000@eu-central-1.amazonses.com \
--to=no-reply@sashiko.virtuozzo.com \
--cc=devel@openvz.org \
--cc=khorenko@virtuozzo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.