Update API for file write hints

This is now queued up for 4.13 inclusion. Adjust the bits we need
to conform to what is queued up.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

ioengines.c

@@ -476,8 +476,19 @@ int td_io_open_file(struct thread_data *td, struct fio_file *f)
 	if (fio_option_is_set(&td->o, write_hint) &&
 	    (f->filetype == FIO_TYPE_BLOCK || f->filetype == FIO_TYPE_FILE)) {
 		uint64_t hint = td->o.write_hint;
+		int cmd;
 
-		if (fcntl(f->fd, F_SET_RW_HINT, &hint) < 0) {
+		/*
+		 * For direct IO, we just need/want to set the hint on
+		 * the file descriptor. For buffered IO, we need to set
+		 * it on the inode.
+		 */
+		if (td->o.odirect)
+			cmd = F_SET_FILE_RW_HINT;
+		else
+			cmd = F_SET_RW_HINT;
+
+		if (fcntl(f->fd, cmd, &hint) < 0) {
 			td_verror(td, errno, "fcntl write hint");
 			goto err;
 		}

os/os-linux.h

@@ -309,14 +309,17 @@ static inline int fio_set_sched_idle(void)
 #endif
 #define F_GET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 11)
 #define F_SET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 12)
+#define F_GET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 13)
+#define F_SET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 14)
 #endif
 
 #ifndef RWH_WRITE_LIFE_NONE
-#define RWH_WRITE_LIFE_NONE	0
-#define RWH_WRITE_LIFE_SHORT	1
-#define RWH_WRITE_LIFE_MEDIUM	2
-#define RWH_WRITE_LIFE_LONG	3
-#define RWH_WRITE_LIFE_EXTREME	4
+#define RWH_WRITE_LIFE_NOT_SET	0
+#define RWH_WRITE_LIFE_NONE	1
+#define RWH_WRITE_LIFE_SHORT	2
+#define RWH_WRITE_LIFE_MEDIUM	3
+#define RWH_WRITE_LIFE_LONG	4
+#define RWH_WRITE_LIFE_EXTREME	5
 #endif
 
 #define FIO_HAVE_WRITE_HINT