Added in MESSAGE notes for blktraces
Allows messages to be inserted into blktrace streams.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index cfc3147..b7cd8f1 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -55,6 +55,7 @@
enum blktrace_notify {
__BLK_TN_PROCESS = 0, /* establish pid/name mapping */
__BLK_TN_TIMESTAMP, /* include system clock */
+ __BLK_TN_MESSAGE, /* Character string message */
};
@@ -79,6 +80,7 @@
#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
+#define BLK_TN_MESSAGE (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_IO_TRACE_MAGIC 0x65617400
#define BLK_IO_TRACE_VERSION 0x07
@@ -149,7 +151,28 @@
extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
extern int do_blk_trace_setup(struct request_queue *q,
char *name, dev_t dev, struct blk_user_trace_setup *buts);
+extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
+/**
+ * blk_add_trace_msg - Add a (simple) message to the blktrace stream
+ * @q: queue the io is for
+ * @fmt: format to print message in
+ * args... Variable argument list for format
+ *
+ * Description:
+ * Records a (simple) message onto the blktrace stream.
+ *
+ * NOTE: BLK_TN_MAX_MSG characters are output at most.
+ * NOTE: Can not use 'static inline' due to presence of var args...
+ *
+ **/
+#define blk_add_trace_msg(q, fmt, ...) \
+ do { \
+ struct blk_trace *bt = (q)->blk_trace; \
+ if (unlikely(bt)) \
+ __trace_note_message(bt, fmt, ##__VA_ARGS__); \
+ } while (0)
+#define BLK_TN_MAX_MSG 1024
/**
* blk_add_trace_rq - Add a trace for a request oriented action
@@ -299,6 +322,8 @@
#define blk_trace_setup(q, name, dev, arg) (-ENOTTY)
#define blk_trace_startstop(q, start) (-ENOTTY)
#define blk_trace_remove(q) (-ENOTTY)
+#define blk_add_trace_msg(q, fmt, ...) do { } while (0)
+
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#endif /* __KERNEL__ */
#endif