[PATCH v8 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 v8
 - Remove __UBLK_IO_OP_DRV_*
 - Move report zones command identifier (UBLK_IO_OP_REPORT_ZONES) next to other
   zone management operations

Changes for v7
 - Style fixes
 - Rework error handling for `ublk_ctrl_start_dev()`
 - Remove `BLK_DEV_UBLK_ZONED`
 - Add check for IO command support on command enqueue
 - Remove check from `ublk_report_zones()`
 - Hoist check out of `ublk_revalidate_disk_zones()`
 - Remove check from `ublk_dev_param_zoned_apply()` when !CONFIG_BLK_DEV_ZONED
 - Rename `get_nr_zones()` -> `ublk_get_nr_zones()`
 - Open code `set_nr_zones()` in `ublk_param_zoned_apply()`
 - Reorder fields of `struct ublk_rq_data` to pack better
 - Remove redundant checks for chunk_sectors
 - Hoist check for user not setting zoned parameters for zoned ublk device out
   of `ublk_param_zoned_validate()`
 - Remove helper `ublk_dev_params_zoned()`

[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      | 321 ++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  36 +++-
 2 files changed, 337 insertions(+), 20 deletions(-)


base-commit: 3261ea42710e9665c9151006049411bd23b5411f
-- 
2.41.0