Re: [PATCH v2] fs: Add aio iopriority support for block_dev

From: Matthew Wilcox
Date: Thu May 03 2018 - 14:34:03 EST


On Thu, May 03, 2018 at 11:21:14AM -0700, adam.manzanares@xxxxxxx wrote:
> If we want to avoid bloating struct kiocb, I suggest we turn the private field
> into a union of the private and ki_ioprio field. It seems like the users of
> the private field all use it at a point where we can yank the priority from
> the kiocb before the private field is used. Comments and suggestions welcome.

Or we could just make ki_hint a u8 or u16 ... seems unlikely we'll need
32 bits of ki_hint. (currently defined values are 1-5)

> @@ -300,6 +301,7 @@ struct kiocb {
> void *private;
> int ki_flags;
> enum rw_hint ki_hint;
> + u16 ki_ioprio; /* See linux/ioprio.h */
> } __randomize_layout;
>
> static inline bool is_sync_kiocb(struct kiocb *kiocb)