Messages in this thread Patch in this message | | | From | Denis Efremov <> | Subject | [PATCH] md/linear: rcu_dereference outside read-lock section | Date | Tue, 14 Aug 2012 01:08:12 +0400 |
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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
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