fs: Convert kiocb rw_hint from enum to u16
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@wdc.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/aio.c b/fs/aio.c
index b850e92..33299ec 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1434,7 +1434,7 @@
req->ki_flags = iocb_flags(req->ki_filp);
if (iocb->aio_flags & IOCB_FLAG_RESFD)
req->ki_flags |= IOCB_EVENTFD;
- req->ki_hint = file_write_hint(req->ki_filp);
+ req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp));
ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
if (unlikely(ret))
fput(req->ki_filp);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4b6045e..b432fc3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -299,7 +299,7 @@
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)
@@ -1929,12 +1929,21 @@
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)),
};
}