Re: [PATCH hci-8.1 0/5] scsi-disk: fix UNMAP and WRITE SAME racing with inactivation #VSTOR-151532

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

Let's hear what the upstream block maintainers have to say about this first:

https://lore.kernel.org/qemu-devel/20261026174220.674460-1-den@openvz.org

Andrey

On 10/26/26 7:49 PM, Denis V. Lunev wrote:
> scsi-disk splits UNMAP into one discard per descriptor and a non-zero
> WRITE SAME into 512 KiB writes, submitting each step from the
> completion callback of the previous one. A drain in between only waits
> for the step in flight; the next one is queued by
> blk_wait_while_drained() and resumed by drain_end. When the drain is
> the one in bdrv_inactivate_all() (end of live migration,
> blockdev-set-active), the resumed request hits an inactive node:
> 
>   bdrv_co_write_req_prepare: Assertion
>   `!(bs->open_flags & BDRV_O_INACTIVE)' failed.
> 
> We hit this in production on a guest UNMAP with 38 descriptors.
> 
> The fix follows the one Kevin did for IDE TRIM:
> https://lore.kernel.org/qemu-devel/20260421161132.99878-1-kwolf@redhat.com/
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Hanna Reitz <hreitz@redhat.com>
> Cc: Fabiano Rosas <farosas@suse.de>
> Cc: Laurent Vivier <lvivier@redhat.com>
> Cc: qemu-stable@nongnu.org
> 
> Denis V. Lunev (5):
>   scsi-disk: check all UNMAP descriptors before discarding any
>     #VSTOR-151532
>   scsi-disk: fix UNMAP racing with inactivation of block nodes
>     #VSTOR-151532
>   scsi-disk: fix WRITE SAME racing with inactivation of block nodes
>     #VSTOR-151532
>   virtio-scsi-test: split virtio_scsi_do_command() into submit and wait
>     #VSTOR-151532
>   virtio-scsi-test: test UNMAP and WRITE SAME during inactivation
>     #VSTOR-151532
> 
>  hw/scsi/scsi-disk.c            | 278 +++++++++++++++++++--------------
>  tests/qtest/virtio-scsi-test.c | 173 +++++++++++++++++---
>  2 files changed, 309 insertions(+), 142 deletions(-)
> 
> base-commit: 81aea91c7f71cba39b4c3340579d45f0256a91d8
>