Messages in this thread Patch in this message | | | Date | Fri, 20 Mar 2009 10:26:18 GMT | From | Li Zefan <> | Subject | [tip:tracing/blktrace] blktrace: don't increase blk_probes_ref if failed to setup blk trace |
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Commit-ID: 64ddedc03c9ecbe97b0700e85c5f11d2f5a4565c Gitweb: http://git.kernel.org/tip/64ddedc03c9ecbe97b0700e85c5f11d2f5a4565c Author: Li Zefan <lizf@cn.fujitsu.com> AuthorDate: Fri, 20 Mar 2009 09:48:47 +0800 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Fri, 20 Mar 2009 11:20:05 +0100
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> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <49C2F5FF.80002@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- kernel/trace/blktrace.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 223b92e..11e7c8d 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) {
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