blktrace: Remove blk_fill_rwbs_rq.

If we enable trace events to trace block actions, We use
blk_fill_rwbs_rq to analyze the corresponding actions
in request's cmd_flags, but we only choose the minor 2 bits
from it, so most of other flags(e.g, REQ_SYNC) are missing.
For example, with a sync write we get:
write_test-2409  [001]   160.013869: block_rq_insert: 3,64 W 0 () 258135 + =
8 [write_test]

Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and
blk_fill_rwbs_rq isn't needed any more.

With this patch, after a sync write we get:
write_test-2417  [000]   226.603878: block_rq_insert: 3,64 WS 0 () 258135 +=
 8 [write_test]
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

include/linux/blktrace_api.h

@@ -245,7 +245,6 @@ static inline int blk_cmd_buf_len(struct request *rq)
 
 extern void blk_dump_cmd(char *buf, struct request *rq);
 extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
-extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);
 
 #endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
 

include/trace/events/block.h

@@ -31,7 +31,7 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
 					0 : blk_rq_sectors(rq);
 		__entry->errors    = rq->errors;
 
-		blk_fill_rwbs_rq(__entry->rwbs, rq);
+		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		blk_dump_cmd(__get_str(cmd), rq);
 	),
 
@@ -118,7 +118,7 @@ DECLARE_EVENT_CLASS(block_rq,
 		__entry->bytes     = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
 					blk_rq_bytes(rq) : 0;
 
-		blk_fill_rwbs_rq(__entry->rwbs, rq);
+		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		blk_dump_cmd(__get_str(cmd), rq);
 		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
 	),
@@ -563,7 +563,7 @@ TRACE_EVENT(block_rq_remap,
 		__entry->nr_sector	= blk_rq_sectors(rq);
 		__entry->old_dev	= dev;
 		__entry->old_sector	= from;
-		blk_fill_rwbs_rq(__entry->rwbs, rq);
+		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 	),
 
 	TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",

kernel/trace/blktrace.c

@@ -1827,21 +1827,5 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
 	rwbs[i] = '\0';
 }
 
-void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
-{
-	int rw = rq->cmd_flags & 0x03;
-	int bytes;
-
-	if (rq->cmd_flags & REQ_DISCARD)
-		rw |= REQ_DISCARD;
-
-	if (rq->cmd_flags & REQ_SECURE)
-		rw |= REQ_SECURE;
-
-	bytes = blk_rq_bytes(rq);
-
-	blk_fill_rwbs(rwbs, rw, bytes);
-}
-
 #endif /* CONFIG_EVENT_TRACING */