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blktrace: fix the original blktrace

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Currently the original blktrace, which is using relay and is used via
ioctl, is broken. You can use ftrace to see the output of blktrace,
but user-space blktrace is unusable.

It's broken by "blktrace: add ftrace plugin"
(c71a896154)

 -	if (unlikely(bt->trace_state != Blktrace_running))
 +	if (unlikely(bt->trace_state != Blktrace_running || !blk_tracer_enabled))
		return;

With this patch, both ioctl and ftrace can be used, but of course you
can't use both of them at the same time.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-03-25 17:21:26 +08:00 committed by Ingo Molnar
parent b5230b56ee
commit 5554720482
1 changed files with 5 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
kernel/trace/blktrace.c
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@ -110,7 +110,7 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
unsigned long flags;
char *buf;
if (blk_tr) {
if (blk_tracer_enabled) {
va_start(args, fmt);
ftrace_vprintk(fmt, args);
va_end(args);
@ -169,7 +169,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
pid_t pid;
int cpu, pc = 0;
if (unlikely(bt->trace_state != Blktrace_running ||
if (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
return;
@ -185,7 +185,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
return;
cpu = raw_smp_processor_id();
if (blk_tr) {
if (blk_tracer_enabled) {
tracing_record_cmdline(current);
pc = preempt_count();
@ -235,7 +235,7 @@ record_it:
if (pdu_len)
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
if (blk_tr) {
if (blk_tracer_enabled) {
trace_buffer_unlock_commit(blk_tr, event, 0, pc);
return;
}
@ -267,8 +267,7 @@ int blk_trace_remove(struct request_queue *q)
if (!bt)
return -EINVAL;
if (bt->trace_state == Blktrace_setup ||
bt->trace_state == Blktrace_stopped)
if (bt->trace_state != Blktrace_running)
blk_trace_cleanup(bt);
return 0;
@ -1273,7 +1272,6 @@ static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
bt->dev = dev;
bt->act_mask = (u16)-1;
bt->end_lba = -1ULL;
bt->trace_state = Blktrace_running;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt != NULL) {