diff options
| -rw-r--r-- | kernel/trace/blktrace.c | 27 |
1 files changed, 5 insertions, 22 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 73845b7..223b92e 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -47,10 +47,9 @@ static struct tracer_flags blk_tracer_flags = { }; /* Global reference count of probes */ -static DEFINE_MUTEX(blk_probe_mutex); static atomic_t blk_probes_ref = ATOMIC_INIT(0); -static int blk_register_tracepoints(void); +static void blk_register_tracepoints(void); static void blk_unregister_tracepoints(void); /* @@ -256,10 +255,8 @@ static void blk_trace_cleanup(struct blk_trace *bt) free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt); - mutex_lock(&blk_probe_mutex); if (atomic_dec_and_test(&blk_probes_ref)) blk_unregister_tracepoints(); - mutex_unlock(&blk_probe_mutex); } int blk_trace_remove(struct request_queue *q) @@ -471,13 +468,8 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, bt->pid = buts->pid; bt->trace_state = Blktrace_setup; - mutex_lock(&blk_probe_mutex); - if (atomic_add_return(1, &blk_probes_ref) == 1) { - ret = blk_register_tracepoints(); - if (ret) - goto probe_err; - } - mutex_unlock(&blk_probe_mutex); + if (atomic_add_return(1, &blk_probes_ref) == 1) + blk_register_tracepoints(); ret = -EBUSY; old_bt = xchg(&q->blk_trace, bt); @@ -487,9 +479,6 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, } return 0; -probe_err: - atomic_dec(&blk_probes_ref); - mutex_unlock(&blk_probe_mutex); err: if (bt) { if (bt->msg_file) @@ -863,7 +852,7 @@ void blk_add_driver_data(struct request_queue *q, } EXPORT_SYMBOL_GPL(blk_add_driver_data); -static int blk_register_tracepoints(void) +static void blk_register_tracepoints(void) { int ret; @@ -901,7 +890,6 @@ static int blk_register_tracepoints(void) WARN_ON(ret); ret = register_trace_block_remap(blk_add_trace_remap); WARN_ON(ret); - return 0; } static void blk_unregister_tracepoints(void) @@ -1099,11 +1087,8 @@ static void blk_tracer_print_header(struct seq_file *m) static void blk_tracer_start(struct trace_array *tr) { - mutex_lock(&blk_probe_mutex); if (atomic_add_return(1, &blk_probes_ref) == 1) - if (blk_register_tracepoints()) - atomic_dec(&blk_probes_ref); - mutex_unlock(&blk_probe_mutex); + blk_register_tracepoints(); trace_flags &= ~TRACE_ITER_CONTEXT_INFO; } @@ -1118,10 +1103,8 @@ static int blk_tracer_init(struct trace_array *tr) static void blk_tracer_stop(struct trace_array *tr) { trace_flags |= TRACE_ITER_CONTEXT_INFO; - mutex_lock(&blk_probe_mutex); if (atomic_dec_and_test(&blk_probes_ref)) blk_unregister_tracepoints(); - mutex_unlock(&blk_probe_mutex); } static void blk_tracer_reset(struct trace_array *tr) |
