On 5/22/18 9:07 AM, adam.manzanares@xxxxxxx wrote:
> From: Adam Manzanares <adam.manzanares@xxxxxxx>
>
> In order to avoid kiocb bloat for per command iopriority support, rw_hint
> is converted from enum to a u16. Added a guard around ki_hint assignment.
>
> Signed-off-by: Adam Manzanares <adam.manzanares@xxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> ---
> include/linux/fs.h | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 7f07977bdfd7..50de40dbbb85 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -284,6 +284,8 @@ enum rw_hint {
> WRITE_LIFE_EXTREME = RWH_WRITE_LIFE_EXTREME,
> };
>
> +#define MAX_KI_HINT ((1 << 16) - 1) /* ki_hint type is u16 */
Instead of having to do this and now rely on those now being synced,
how about something like the below.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 760d8da1b6c7..070438d0b62d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -299,7 +299,7 @@ struct kiocb {
void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
void *private;
int ki_flags;
- enum rw_hint ki_hint;
+ u16 ki_hint;
} __randomize_layout;
static inline bool is_sync_kiocb(struct kiocb *kiocb)
@@ -1927,12 +1927,22 @@ static inline enum rw_hint file_write_hint(struct file *file)
static inline int iocb_flags(struct file *file);
+static inline u16 ki_hint_validate(enum rw_hint hint)
+{
+ typeof(((struct kiocb *)0)->ki_hint) max_hint = -1;
+
+ if (hint <= max_hint)
+ return hint;
+
+ return 0;
+}
+
static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
{
*kiocb = (struct kiocb) {
.ki_filp = filp,
.ki_flags = iocb_flags(filp),
- .ki_hint = file_write_hint(filp),
+ .ki_hint = ki_hint_validate(file_write_hint(filp)),
};
}
--
Jens Axboe
