[Devel] [PATCH hci-8.1 v2 0/3] dm-qcow2: keep images of a read-only table unmodified

[Konstantin Khorenko]

On Thu, 29 Oct 2026 15:43:55 +0100, Alexander Ivanov wrote:
> dm-qcow2: keep images of a read-only table unmodified
> 
> A read-only dm-qcow2 table does not protect its images. Writes to the
> device pass through bio_check_ro() with a warning and allocate clusters
> in the top image, the unaligned tail of an O_RDWR top image is padded
> on .ctr and .preresume, and merge_backward modifies the lower image.
> Since the header is not updated for a read-only table, persistent
> bitmaps stay marked consistent while the data under them changes.
> 
> [...]

Applied to branch-rh10-6.12.0-211.52.1.22.x.vz10-ovz, will be released in rh10-6.12.0-211.52.1.22.17.vz10, thanks!

[1/3] drivers/md/dm-qcow2: treat images of a read-only table as read-only
      https://bitbucket.org/virtuozzocore/vzkernel.vzs/commits/59e7fee12e85
[2/3] drivers/md/dm-qcow2: fail writes to a read-only table
      https://bitbucket.org/virtuozzocore/vzkernel.vzs/commits/409d7e697578
[3/3] drivers/md/dm-qcow2: do not revalidate inconsistent persistent bitmaps
      https://bitbucket.org/virtuozzocore/vzkernel.vzs/commits/8be5099f6e51

-- 
Konstantin Khorenko,
Virtuozzo Linux Kernel Team