fcntl: fix typo in RWH_WRITE_LIFE_NOT_SET r/w hint name

According to commit message in the original commit c75b1d94 ("fs:
add fcntl() interface for setting/getting write life time hints"),
as well as userspace library[1] and man page update[2], R/W hint constants
are intended to have RWH_* prefix. However, RWF_WRITE_LIFE_NOT_SET retained
"RWF_*" prefix used in the early versions of the proposed patch set[3].
Rename it and provide the old name as a synonym for the new one
for backward compatibility.

[1] https://github.com/axboe/fio/commit/bd553af6c849
[2] https://github.com/mkerrisk/man-pages/commit/580082a186fd
[3] https://www.mail-archive.com/linux-block@vger.kernel.org/msg09638.html

Fixes: c75b1d94 ("fs: add fcntl() interface for setting/getting write life time hints")
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/fcntl.c

@@ -261,7 +261,7 @@ static int f_getowner_uids(struct file *filp, unsigned long arg)
 static bool rw_hint_valid(enum rw_hint hint)
 {
 	switch (hint) {
-	case RWF_WRITE_LIFE_NOT_SET:
+	case RWH_WRITE_LIFE_NOT_SET:
 	case RWH_WRITE_LIFE_NONE:
 	case RWH_WRITE_LIFE_SHORT:
 	case RWH_WRITE_LIFE_MEDIUM:

include/uapi/linux/fcntl.h

@@ -58,13 +58,20 @@
  * Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
  * used to clear any hints previously set.
  */
-#define RWF_WRITE_LIFE_NOT_SET	0
+#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
 
+/*
+ * The originally introduced spelling is remained from the first
+ * versions of the patch set that introduced the feature, see commit
+ * v4.13-rc1~212^2~51.
+ */
+#define RWF_WRITE_LIFE_NOT_SET	RWH_WRITE_LIFE_NOT_SET
+
 /*
  * Types of directory notifications that may be requested.
  */

tools/include/uapi/linux/fcntl.h

@@ -58,13 +58,20 @@
  * Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
  * used to clear any hints previously set.
  */
-#define RWF_WRITE_LIFE_NOT_SET	0
+#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
 
+/*
+ * The originally introduced spelling is remained from the first
+ * versions of the patch set that introduced the feature, see commit
+ * v4.13-rc1~212^2~51.
+ */
+#define RWF_WRITE_LIFE_NOT_SET	RWH_WRITE_LIFE_NOT_SET
+
 /*
  * Types of directory notifications that may be requested.
  */