diff options
| -rw-r--r-- | block/blktrace.c | 14 | ||||
| -rw-r--r-- | include/linux/blktrace_api.h | 25 |
2 files changed, 39 insertions, 0 deletions
diff --git a/block/blktrace.c b/block/blktrace.c index b2cbb4e5d76..20e11f354f1 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -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) { diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index cfc3147e5cf..b7cd8f1eedb 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -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 |