Looks fine, although I'd split it into a aio and block_dev patch.
Also please wire this up for the fs/iomap.c direct I/O code, it should be essentially the same sniplet as in the block_dev.c code.
- [PATCH v4 0/3] AIO add per-command iopriority adam . manzanares
- [PATCH v4 1/3] block: add ioprio_check_cap function adam . manzanares
- Re: [PATCH v4 1/3] block: add ioprio_check_cap ... Christoph Hellwig
- [PATCH v4 2/3] fs: Convert kiocb rw_hint from enum ... adam . manzanares
- Re: [PATCH v4 2/3] fs: Convert kiocb rw_hint fr... Christoph Hellwig
- Re: [PATCH v4 2/3] fs: Convert kiocb rw_hin... Adam Manzanares
- [PATCH v4 3/3] fs: Add aio iopriority support for b... adam . manzanares
- Re: [PATCH v4 3/3] fs: Add aio iopriority suppo... Jens Axboe
- Re: [PATCH v4 3/3] fs: Add aio iopriority s... Adam Manzanares
- Re: [PATCH v4 3/3] fs: Add aio iopriority suppo... Christoph Hellwig
- Re: [PATCH v4 3/3] fs: Add aio iopriority s... Adam Manzanares
- Re: [PATCH v4 3/3] fs: Add aio iopriority suppo... kbuild test robot
- Re: [PATCH v4 0/3] AIO add per-command iopriority Jens Axboe
- Re: [PATCH v4 0/3] AIO add per-command iopriori... Adam Manzanares
