Commit 9d5f09a4 authored by Alan D. Brunelle's avatar Alan D. Brunelle Committed by Jens Axboe

Added in MESSAGE notes for blktraces

Allows messages to be inserted into blktrace streams.
Signed-off-by: default avatarAlan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent be754d2c
......@@ -75,6 +75,20 @@ static void trace_note_time(struct blk_trace *bt)
local_irq_restore(flags);
}
void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
{
int n;
va_list args;
static char bt_msg_buf[BLK_TN_MAX_MSG];
va_start(args, fmt);
n = vscnprintf(bt_msg_buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);
trace_note(bt, 0, BLK_TN_MESSAGE, bt_msg_buf, n);
}
EXPORT_SYMBOL_GPL(__trace_note_message);
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
......
......@@ -55,6 +55,7 @@ enum blktrace_act {
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 @@ enum blktrace_notify {
#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_trace_shutdown(struct request_queue *);
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 @@ extern int blk_trace_remove(struct request_queue *q);
#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
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