[PATCH v6 0/3] 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 two patches do
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 v6:
 - Style fixes
 - Document __ULK_IO_OP_DRV_*
 - Remove "depends on BLK_DEV_UBLK && BLK_DEV_ZONED" from kconfig
 - Rework `get_nr_zones()`
 - Merge `ublk_disk_set_zoned()` and `ublk_dev_param_zoned_apply()`
 - Fix an exit condition bug in `ublk_report_zones()`
 - Only call `ublk_set_nr_zones()` if device is zoned
 - Change a config gate from BLK_DEV_ZONED to BLK_DEV_UBLK_ZONED
 - Simplify `ublk_alloc_report_buffer()`
 - Simplify `ublk_revalidate_disk_zones()`
 - Remove redundant parameter check from `ublk_dev_param_zoned_apply()`
 - Remove redundant zone size check from `ublk_set_nr_zones()`
 - Remove `ublk_zoned_commit_completion()` and open code instead
 - Do not add an extra translation unit (v5 added an extra C file)

[1] https://github.com/metaspace/ubdsrv/tree/1ac32cf841b07259cf8b075a5c0006803eeb3981
[2] https://github.com/westerndigitalcorporation/zenfs
[3] https://git.kernel.dk/linux.git

Andreas Hindborg (3):
  ublk: add opcode offsets for DRV_IN/DRV_OUT
  ublk: add helper to check if device supports user copy
  ublk: enable zoned storage support

 drivers/block/Kconfig         |   4 +
 drivers/block/ublk_drv.c      | 348 ++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  48 ++++-
 3 files changed, 383 insertions(+), 17 deletions(-)


base-commit: 3261ea42710e9665c9151006049411bd23b5411f
-- 
2.41.0