[PATCH 3/3] iowatcher: Handle cgroup information

[Jan Kara <jack@xxxxxxx>]

Since Linux kernel commit 35fe6d763229 "block: use standard blktrace API
to output cgroup info for debug notes" the kernel can pass
__BLK_TA_CGROUP flag in the action field of generated events. Teach
iowatcher to ignore this information.

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 iowatcher/blkparse.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/iowatcher/blkparse.c b/iowatcher/blkparse.c
index 982de9459826..6203854bd49c 100644
--- a/iowatcher/blkparse.c
+++ b/iowatcher/blkparse.c
@@ -51,7 +51,7 @@ extern int plot_io_action;
 extern int io_per_process;
 
 #define BLK_DATADIR(a) (((a) >> BLK_TC_SHIFT) & (BLK_TC_READ | BLK_TC_WRITE))
-#define BLK_TA_MASK ((1 << BLK_TC_SHIFT) - 1)
+#define BLK_TA_MASK (((1 << BLK_TC_SHIFT) - 1) & ~__BLK_TA_CGROUP)
 
 struct pending_io {
 	/* sector offset of this IO */
@@ -260,18 +260,23 @@ static void handle_notify(struct trace *trace)
 {
 	struct blk_io_trace *io = trace->io;
 	void *payload = (char *)io + sizeof(*io);
+	int pdu_len = io->pdu_len;
 	u32 two32[2];
 
-	if (io->action == BLK_TN_PROCESS) {
+	if (io->action & __BLK_TN_CGROUP) {
+		payload += sizeof(struct blk_io_cgroup_payload);
+		pdu_len -= sizeof(struct blk_io_cgroup_payload);
+	}
+	if ((io->action & ~__BLK_TN_CGROUP) == BLK_TN_PROCESS) {
 		if (io_per_process)
 			process_hash_insert(io->pid, payload);
 		return;
 	}
 
-	if (io->action != BLK_TN_TIMESTAMP)
+	if ((io->action & ~__BLK_TN_CGROUP) != BLK_TN_TIMESTAMP)
 		return;
 
-	if (io->pdu_len != sizeof(two32))
+	if (pdu_len != sizeof(two32))
 		return;
 
 	memcpy(two32, payload, sizeof(two32));
@@ -309,11 +314,16 @@ static int is_io_event(struct blk_io_trace *test)
 	char *message;
 	if (!(test->action & BLK_TC_ACT(BLK_TC_NOTIFY)))
 		return 1;
-	if (test->action == BLK_TN_MESSAGE) {
+	if ((test->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
 		int len = test->pdu_len;
+
+		message = (char *)(test + 1);
+		if (test->action & __BLK_TN_CGROUP) {
+			len -= sizeof(struct blk_io_cgroup_payload);
+			message += sizeof(struct blk_io_cgroup_payload);
+		}
 		if (len < 3)
 			return 0;
-		message = (char *)(test + 1);
 		if (strncmp(message, "fio ", 4) == 0) {
 			return 1;
 		}
@@ -372,13 +382,17 @@ static int parse_fio_bank_message(struct trace *trace, u64 *bank_ret, u64 *offse
 
 	if (!(test->action & BLK_TC_ACT(BLK_TC_NOTIFY)))
 		return -1;
-	if (test->action != BLK_TN_MESSAGE)
+	if ((test->action & ~__BLK_TN_CGROUP) != BLK_TN_MESSAGE)
 		return -1;
 
+	message = (char *)(test + 1);
+	if (test->action & __BLK_TN_CGROUP) {
+		len -= sizeof(struct blk_io_cgroup_payload);
+		message += sizeof(struct blk_io_cgroup_payload);
+	}
 	/* the message is fio rw bank offset num_banks */
 	if (len < 3)
 		return -1;
-	message = (char *)(test + 1);
 	if (strncmp(message, "fio r ", 6) != 0)
 		return -1;
 
-- 
2.16.4