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authorLi Zefan <lizf@cn.fujitsu.com>2009-03-20 09:48:47 +0800
committerIngo Molnar <mingo@elte.hu>2009-03-21 16:16:37 +0100
commitcbe28296eb1ac441b35cf45804d0ae808add7dd1 (patch)
treec387d2697ea153cadb629e3d664960bf12b8bc84 /kernel/trace/blktrace.c
parent3c289ba7c320560ee74979a8895141c829046a2d (diff)
blktrace: don't increase blk_probes_ref if failed to setup blk trace
do_blk_trace_setup() may return EBUSY, but the current code doesn't decrease blk_probes_ref in this case. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <49C2F5FF.80002@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/blktrace.c')
-rw-r--r--kernel/trace/blktrace.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 223b92e77b3..11e7c8d9d22 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -468,9 +468,6 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
- if (atomic_add_return(1, &blk_probes_ref) == 1)
- blk_register_tracepoints();
-
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
@@ -478,6 +475,9 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
goto err;
}
+ if (atomic_add_return(1, &blk_probes_ref) == 1)
+ blk_register_tracepoints();
+
return 0;
err:
if (bt) {