blktrace: fix a race when creating blk_tree_root in debugfs
t1 t2 ------ ------ do_blk_trace_setup() do_blk_trace_setup() if (!blk_tree_root) { if (!blk_tree_root) blk_tree_root = create_dir() blk_tree_root = create_dir(); (now blk_tree_root == NULL) ... dir = create_dir(name, blk_tree_root); Due to this race, t1 will create 'dir' in /debugfs but not /debugfs/block. 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:
Родитель
6c051ce030
Коммит
b5230b56ee
|
@ -426,11 +426,15 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
|
|||
|
||||
ret = -ENOENT;
|
||||
|
||||
mutex_lock(&blk_tree_mutex);
|
||||
if (!blk_tree_root) {
|
||||
blk_tree_root = debugfs_create_dir("block", NULL);
|
||||
if (!blk_tree_root)
|
||||
if (!blk_tree_root) {
|
||||
mutex_unlock(&blk_tree_mutex);
|
||||
goto err;
|
||||
}
|
||||
}
|
||||
mutex_unlock(&blk_tree_mutex);
|
||||
|
||||
dir = debugfs_create_dir(buts->name, blk_tree_root);
|
||||
|
||||
|
|
Загрузка…
Ссылка в новой задаче