From ad5dd5493a55e462796e42e50a49e76df76fdb05 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 27 Mar 2009 10:20:24 +0800 Subject: [PATCH] blktrace: fix memory leak when freeing struct blk_io_trace 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 Acked-by: Jens Axboe Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/blktrace.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 8d6bd12aab1..2f21d776160 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -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; }