lkml.org 
[lkml]   [2012]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] md/linear: rcu_dereference outside read-lock section
Date
According to the comment in linear_stop function
rcu_dereference in linear_start and linear_stop functions
occurs under reconfig_mutex. The patch represents this
agreement in code and prevents lockdep complaint.

Found by Linux Driver Verification project (linuxtesting.org)

Signed-off-by: Denis Efremov <yefremov.denis@gmail.com>
---
drivers/md/linear.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index fa211d8..093f3e4 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -244,7 +244,8 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
if (!newconf)
return -ENOMEM;

- oldconf = rcu_dereference(mddev->private);
+ oldconf = rcu_dereference_protected(mddev->private,
+ lockdep_is_held(&mddev->reconfig_mutex));
mddev->raid_disks++;
rcu_assign_pointer(mddev->private, newconf);
md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
@@ -256,7 +257,9 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)

static int linear_stop (struct mddev *mddev)
{
- struct linear_conf *conf = mddev->private;
+ struct linear_conf *conf =
+ rcu_dereference_protected(mddev->private,
+ lockdep_is_held(&mddev->reconfig_mutex));

/*
* We do not require rcu protection here since
--
1.7.7


\
 
 \ /
  Last update: 2012-08-13 23:42    [W:0.030 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site