[USERSPACE PATCH] blktrace: support discard requests

[David Woodhouse <dwmw2@infradead.org>]

Add support for discard requests to blktrace userspace tools.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/act_mask.c b/act_mask.c
index 40a4050..6632320 100644
--- a/act_mask.c
+++ b/act_mask.c
@@ -25,6 +25,7 @@ static struct mask_map mask_maps[] = {
 	DECLARE_MASK_MAP(PC),
 	DECLARE_MASK_MAP(AHEAD),
 	DECLARE_MASK_MAP(META),
+	DECLARE_MASK_MAP(DISCARD),
 };
 
 int find_mask_map(char *string)
diff --git a/blkparse_fmt.c b/blkparse_fmt.c
index 364f27c..83a8504 100644
--- a/blkparse_fmt.c
+++ b/blkparse_fmt.c
@@ -57,9 +57,12 @@ static inline void fill_rwbs(char *rwbs, struct blk_io_trace *t)
 	int b = t->action & BLK_TC_ACT(BLK_TC_BARRIER);
 	int s = t->action & BLK_TC_ACT(BLK_TC_SYNC);
 	int m = t->action & BLK_TC_ACT(BLK_TC_META);
+	int d = t->action & BLK_TC_ACT(BLK_TC_DISCARD);
 	int i = 0;
 
-	if (w)
+	if (d)
+		rwbs[i++] = 'D';
+	else if (w)
 		rwbs[i++] = 'W';
 	else if (t->bytes)
 		rwbs[i++] = 'R';
diff --git a/blkrawverify.c b/blkrawverify.c
index 82a435e..984dbff 100644
--- a/blkrawverify.c
+++ b/blkrawverify.c
@@ -49,6 +49,7 @@ static struct trace_info traces[] = {
 	TRACE_TO_STRING( BLK_TC_PC ),
 	TRACE_TO_STRING( BLK_TC_AHEAD ),
 	TRACE_TO_STRING( BLK_TC_META ),
+	TRACE_TO_STRING( BLK_TC_DISCARD ),
 };
 #define N_TRACES (sizeof(traces) / sizeof(struct trace_info))
 
diff --git a/blktrace_api.h b/blktrace_api.h
index 67720de..992850c 100644
--- a/blktrace_api.h
+++ b/blktrace_api.h
@@ -20,6 +20,7 @@ enum {
 	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
 	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
 	BLK_TC_META	= 1 << 12,	/* metadata */
+	BLK_TC_DISCARD	= 1 << 13,	/* discard requests */
 
 	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
 };

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@intel.com                              Intel Corporation