[Patch updated] blktrace: remove debugfs entries on bad path

[Stefan Raspl <raspl@linux.vnet.ibm.com>]

debugfs directory entries for devices are not removed on some
of the failure pathes in do_blk_trace_setup().
One way to reproduce is to start blktrace on multiple devices
with insufficient Vmalloc space: Devices will fail with
a message like this:

	BLKTRACESETUP(2) /dev/sdu failed: 5/Input/output error

If so, the respective entries in debugfs
(e.g. /sys/kernel/debug/block/sdu) will remain and subsequent
attempts to start blktrace on the respective devices will not
succeed due to existing directories.



Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Stefan Raspl <stefan.raspl@linux.vnet.ibm.com>


---
 kernel/trace/blktrace.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -262,6 +262,7 @@ static void blk_trace_free(struct blk_tr
 {
 	debugfs_remove(bt->msg_file);
 	debugfs_remove(bt->dropped_file);
+	debugfs_remove(bt->dir);
 	relay_close(bt->rchan);
 	free_percpu(bt->sequence);
 	free_percpu(bt->msg_data);