From fd51d251e4cdb21f68e9dbc4336514d64a105a79 Mon Sep 17 00:00:00 2001
From: Stefan Raspl <raspl@linux.vnet.ibm.com>
Date: Tue, 19 May 2009 09:59:08 +0200
Subject: [PATCH] blktrace: remove debugfs entries on bad path

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.

[ Impact: fix /debug/tracing file cleanup corner case ]

Signed-off-by: Stefan Raspl <stefan.raspl@linux.vnet.ibm.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
LKML-Reference: <4A1266CC.5040801@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/blktrace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 05b4747fd8732..e3abf55bc8e57 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -262,6 +262,7 @@ static void blk_trace_free(struct blk_trace *bt)
 {
 	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);
-- 
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