blktrace: perform cleanup after setup error

Currently even if BLKTRACESETUP ioctl has failed user must call
BLKTRACETEARDOWN to be shure what all staff was cleaned, which
is contr-intuitive.
Let's setup ioctl make necessery cleanup by it self.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index d9d6206..07f945a 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -540,9 +540,10 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
        if (ret)
                return ret;
 
-       if (copy_to_user(arg, &buts, sizeof(buts)))
+       if (copy_to_user(arg, &buts, sizeof(buts))) {
+               blk_trace_remove(q);
                return -EFAULT;
-
+       }
        return 0;
 }
 EXPORT_SYMBOL_GPL(blk_trace_setup);