[PATCH v2] block: Bundle together NONE and NOT_SET writehint types

[Avri Altman]

There are 6 writehint types, but the size of the write_hints array
in the request queue is BLK_MAX_WRITE_HINTS = 5,
which causes the EXTREME type to be ignored when iterating
over the hints.

We only have effectively 5 hints.
Bundle together NONE and NOT_SET, since they end up in the same
bucket on the driver side.

fixes: f793dfd3f39a (blk-mq: expose write hints through debugfs)

v1->v2:
Bundle together NONE and NOT_SET, instead of making the write_hints
array of the request queue larger.
Change the commit title accordingly.

Signed-off-by: Avri Altman <avri.alt...@wdc.com>
---
 fs/fcntl.c                       |  2 +-
 include/uapi/linux/fcntl.h       | 10 +++++-----
 tools/include/uapi/linux/fcntl.h | 10 +++++-----
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 4137d96..163cf5fd 100644
--- a/fs/fcntl.c
+++ b/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:
+       /* RWF_WRITE_LIFE_NOT_SET = RWH_WRITE_LIFE_NONE */
        case RWH_WRITE_LIFE_NONE:
        case RWH_WRITE_LIFE_SHORT:
        case RWH_WRITE_LIFE_MEDIUM:
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
index 6448cdd..ff048f8 100644
--- a/include/uapi/linux/fcntl.h
+++ b/include/uapi/linux/fcntl.h
@@ -58,11 +58,11 @@
  * used to clear any hints previously set.
  */
 #define RWF_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
+#define RWH_WRITE_LIFE_NONE    RWF_WRITE_LIFE_NOT_SET
+#define RWH_WRITE_LIFE_SHORT   1
+#define RWH_WRITE_LIFE_MEDIUM  2
+#define RWH_WRITE_LIFE_LONG    3
+#define RWH_WRITE_LIFE_EXTREME 4
 
 /*
  * Types of directory notifications that may be requested.
diff --git a/tools/include/uapi/linux/fcntl.h b/tools/include/uapi/linux/fcntl.h
index 6448cdd..ff048f8 100644
--- a/tools/include/uapi/linux/fcntl.h
+++ b/tools/include/uapi/linux/fcntl.h
@@ -58,11 +58,11 @@
  * used to clear any hints previously set.
  */
 #define RWF_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
+#define RWH_WRITE_LIFE_NONE    RWF_WRITE_LIFE_NOT_SET
+#define RWH_WRITE_LIFE_SHORT   1
+#define RWH_WRITE_LIFE_MEDIUM  2
+#define RWH_WRITE_LIFE_LONG    3
+#define RWH_WRITE_LIFE_EXTREME 4
 
 /*
  * Types of directory notifications that may be requested.
-- 
1.9.1