[PATCH v4 0/3] AIO add per-command iopriority

[adam.manzanares@wdc.com]

From: Adam Manzanares <adam.manzanares@wdc.com>

This is the per-I/O equivalent of the ioprio_set system call.
See the following link for performance implications on a SATA HDD:
https://lkml.org/lkml/2016/12/6/495

First patch factors ioprio_check_cap function out of ioprio_set system call to
also be used by the aio ioprio interface.

Second patch converts kiocb ki_hint field to a u16 to avoid kiocb bloat.

Third patch passes ioprio hint from aio iocb to kiocb and enables block_dev
usage of the per I/O ioprio feature.

v2: merge patches
    use IOCB_FLAG_IOPRIO
    validate intended use with IOCB_IOPRIO
    add linux-api and linux-block to cc

v3: add ioprio_check_cap function
    convert kiocb ki_hint to u16
    use ioprio_check_cap when adding ioprio to kiocb in aio.c

v4: handle IOCB_IOPRIO in aio_prep_rw
    note patch 3 depends on patch 1 in commit msg

Adam Manzanares (3):
  block: add ioprio_check_cap function
  fs: Convert kiocb rw_hint from enum to u16
  fs: Add aio iopriority support for block_dev

 block/ioprio.c               | 22 ++++++++++++++++------
 fs/aio.c                     | 16 ++++++++++++++++
 fs/block_dev.c               |  2 ++
 include/linux/fs.h           | 17 +++++++++++++++--
 include/linux/ioprio.h       |  2 ++
 include/uapi/linux/aio_abi.h |  1 +
 6 files changed, 52 insertions(+), 8 deletions(-)

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2.15.1