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blktrace: fix memory leak when freeing struct blk_io_trace

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Impact: fix mixed ioctl and ftrace-plugin blktrace use memory leak

When mixing the use of ioctl-based blktrace and ftrace-based blktrace,
we can leak memory in this way:

  # btrace /dev/sda > /dev/null &
  # echo 0 > /sys/block/sda/sda1/trace/enable

now we leak bt->dropped_file, bt->msg_file, bt->rchan...

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 2009-03-27 10:20:24 +08:00 committed by Ingo Molnar
parent 17ba97e347
commit ad5dd5493a
1 changed files with 12 additions and 17 deletions
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29
kernel/trace/blktrace.c
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@ -247,7 +247,7 @@ record_it:
static struct dentry *blk_tree_root;
static DEFINE_MUTEX(blk_tree_mutex);
static void blk_trace_cleanup(struct blk_trace *bt)
static void blk_trace_free(struct blk_trace *bt)
{
debugfs_remove(bt->msg_file);
debugfs_remove(bt->dropped_file);
@ -255,6 +255,11 @@ static void blk_trace_cleanup(struct blk_trace *bt)
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
}
static void blk_trace_cleanup(struct blk_trace *bt)
{
blk_trace_free(bt);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
}
@ -410,11 +415,11 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
if (buts->name[i] == '/')
buts->name[i] = '_';
ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
goto err;
return -ENOMEM;
ret = -ENOMEM;
bt->sequence = alloc_percpu(unsigned long);
if (!bt->sequence)
goto err;
@ -483,17 +488,7 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
return 0;
err:
if (bt) {
if (bt->msg_file)
debugfs_remove(bt->msg_file);
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
}
blk_trace_free(bt);
return ret;
}
@ -1091,6 +1086,7 @@ static void blk_tracer_print_header(struct seq_file *m)
static void blk_tracer_start(struct trace_array *tr)
{
blk_tracer_enabled = true;
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
}
@ -1098,18 +1094,17 @@ static int blk_tracer_init(struct trace_array *tr)
{
blk_tr = tr;
blk_tracer_start(tr);
blk_tracer_enabled = true;
return 0;
}
static void blk_tracer_stop(struct trace_array *tr)
{
blk_tracer_enabled = false;
trace_flags |= TRACE_ITER_CONTEXT_INFO;
}
static void blk_tracer_reset(struct trace_array *tr)
{
blk_tracer_enabled = false;
blk_tracer_stop(tr);
}
@ -1250,7 +1245,7 @@ static int blk_trace_remove_queue(struct request_queue *q)
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
kfree(bt);
blk_trace_free(bt);
return 0;
}