[PATCH v9 0/2] ublk: enable zoned storage support

[Andreas Hindborg <nmi@metaspace.dk>]

From: Andreas Hindborg <a.hindborg@samsung.com>

Hi All,

This patch set adds zoned storage support to `ublk`. The first patch does some
house cleaning in preparation for the last patch. The last patch adds support
for report_zones and the following operations:

 - REQ_OP_ZONE_OPEN
 - REQ_OP_ZONE_CLOSE
 - REQ_OP_ZONE_FINISH
 - REQ_OP_ZONE_RESET
 - REQ_OP_ZONE_APPEND

A user space component based on ubdsrv is available for testing [1] with the
"loop" target.

Read/write and zone operations are tested with zenfs [2].

The zone append path is tested with fio -> zonefs -> ublk -> null_blk.

The implementation of zone append requires ublk user copy feature, and therefore
the series is based on branch for-next (6afa337a3789) of [3].

Changes for v9
 - Move setup of IO descriptor for zoned operations into separate function
 - Fix an issue in `ublk_report_zones()` where zone report size was set to `remaining_zones` instead of `zones_in_request`
 - Do not truncate bufsize to `queue_max_segments` pages in `ublk_alloc_report_buffer()`
 - Do not change signature of `ublk_dev_param_basic_apply()` (not needed)

[1] https://github.com/metaspace/ubdsrv/tree/acc072e077bceea390bae14b6ccb8087f6d0cf1a
[2] https://github.com/westerndigitalcorporation/zenfs
[3] https://git.kernel.dk/linux.git

Andreas Hindborg (2):
  ublk: add helper to check if device supports user copy
  ublk: enable zoned storage support

 drivers/block/ublk_drv.c      | 342 ++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  36 +++-
 2 files changed, 360 insertions(+), 18 deletions(-)


base-commit: 3261ea42710e9665c9151006049411bd23b5411f
-- 
2.41.0