[Devel] [PATCH VZ10 0/5] vhost-blk: fix protocol handling and backend setup

[Andrey Zhadchenko <andrey.zhadchenko@virtuozzo.com>]

This series fixes several vhost-blk bugs and harden some userspace
interactions.

First patch hardens VIRTIO_BLK_T_GET_ID. Leave the serial empty and
copy the null terminator, just as QEMU.

The second patch reports the correct used-ring length: the number of
bytes written to the guest, including status.

The third patch fixes flush. REQ_OP_FLUSH is not a valid bio op; use
REQ_OP_WRITE | REQ_PREFLUSH as blkdev_issue_flush() does.

The fourth patch fixes sector alignment checks. SECTOR_MASK is 7, not
a bitmask, so the code was checking 8-byte alignment. Use
(SECTOR_SIZE - 1).

The last patch reworks queue/backend setup. vhost_blk_setup() silently
ignored a changed vq->num once requests were allocated and
double-fetched user input. Request allocation is now tied to backend
existence, and drop_backend/flush/fput are consolidated.

Andrey Zhadchenko (5):
  drivers/vhost/blk: harden get_id command
  drivers/vhost/blk: report correct used-ring lengths
  drivers/vhost/blk: fix flush support
  drivers/vhost/blk: fix sector alignment calculation
  drivers/vhost/blk: rework queue/backend setup

 drivers/vhost/blk.c | 162 ++++++++++++++++++++------------------------
 1 file changed, 74 insertions(+), 88 deletions(-)

-- 
2.43.5