block: kill off REQ_UNPLUG

With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 9 insertions, 21 deletions

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 16b286473042..be50d9e70a7d 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -128,7 +128,6 @@ enum rq_flag_bits {
         __REQ_NOIDLE,           /* don't anticipate more IO after this one */
 
         /* bio only flags */
-        __REQ_UNPLUG,           /* unplug the immediately after submission */
         __REQ_RAHEAD,           /* read ahead, can fail anytime */
         __REQ_THROTTLED,        /* This bio has already been subjected to
                                  * throttling rules. Don't do it again. */
@@ -172,7 +171,6 @@ enum rq_flag_bits {
          REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 #define REQ_CLONE_MASK          REQ_COMMON_MASK
 
-#define REQ_UNPLUG              (1 << __REQ_UNPLUG)
 #define REQ_RAHEAD              (1 << __REQ_RAHEAD)
 #define REQ_THROTTLED           (1 << __REQ_THROTTLED)
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9f2cf69911b8..543e226ea6a3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,16 +135,10 @@ struct inodes_stat_t {
  *                      block layer could (in theory) choose to ignore this
  *                      request if it runs into resource problems.
  * WRITE                A normal async write. Device will be plugged.
- * WRITE_SYNC_PLUG      Synchronous write. Identical to WRITE, but passes down
+ * WRITE_SYNC           Synchronous write. Identical to WRITE, but passes down
  *                      the hint that someone will be waiting on this IO
- *                      shortly. The device must still be unplugged explicitly,
- *                      WRITE_SYNC_PLUG does not do this as we could be
- *                      submitting more writes before we actually wait on any
- *                      of them.
- * WRITE_SYNC           Like WRITE_SYNC_PLUG, but also unplugs the device
- *                      immediately after submission. The write equivalent
- *                      of READ_SYNC.
- * WRITE_ODIRECT_PLUG   Special case write for O_DIRECT only.
+ *                      shortly. The write equivalent of READ_SYNC.
+ * WRITE_ODIRECT        Special case write for O_DIRECT only.
  * WRITE_FLUSH          Like WRITE_SYNC but with preceding cache flush.
  * WRITE_FUA            Like WRITE_SYNC but data is guaranteed to be on
  *                      non-volatile media on completion.
@@ -160,18 +154,14 @@ struct inodes_stat_t {
 #define WRITE                   RW_MASK
 #define READA                   RWA_MASK
 
-#define READ_SYNC               (READ | REQ_SYNC | REQ_UNPLUG)
+#define READ_SYNC               (READ | REQ_SYNC)
 #define READ_META               (READ | REQ_META)
-#define WRITE_SYNC_PLUG         (WRITE | REQ_SYNC | REQ_NOIDLE)
-#define WRITE_SYNC              (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
-#define WRITE_ODIRECT_PLUG      (WRITE | REQ_SYNC)
+#define WRITE_SYNC              (WRITE | REQ_SYNC | REQ_NOIDLE)
+#define WRITE_ODIRECT           (WRITE | REQ_SYNC)
 #define WRITE_META              (WRITE | REQ_META)
-#define WRITE_FLUSH             (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
-                                 REQ_FLUSH)
-#define WRITE_FUA               (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
-                                 REQ_FUA)
-#define WRITE_FLUSH_FUA         (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
-                                 REQ_FLUSH | REQ_FUA)
+#define WRITE_FLUSH             (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
+#define WRITE_FUA               (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
+#define WRITE_FLUSH_FUA         (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 
 #define SEL_IN          1
 #define SEL_OUT         2