2013-08-19 20:57:00

by Richard Weinberger

Subject: [PATCH] xfs: Register hotcpu notifier after initialization

Currently the code initializizes mp->m_icsb_mutex and other things
_after_ register_hotcpu_notifier().
As the notifier takes mp->m_icsb_mutex it can happen
that it takes the lock before it's initialization.

Signed-off-by: Richard Weinberger <[email protected]>
---
fs/xfs/xfs_mount.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 2b0ba35..986f9cf 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -2260,12 +2260,6 @@ xfs_icsb_init_counters(
if (mp->m_sb_cnts == NULL)
return -ENOMEM;

-#ifdef CONFIG_HOTPLUG_CPU
- mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
- mp->m_icsb_notifier.priority = 0;
- register_hotcpu_notifier(&mp->m_icsb_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
-
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
@@ -2278,6 +2272,13 @@ xfs_icsb_init_counters(
* initial balance kicks us off correctly
*/
mp->m_icsb_counters = -1;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
+ mp->m_icsb_notifier.priority = 0;
+ register_hotcpu_notifier(&mp->m_icsb_notifier);
+#endif /* CONFIG_HOTPLUG_CPU */
+
return 0;
}

--
1.8.3.1

2013-08-19 22:21:31

by Ben Myers

Subject: Re: [PATCH] xfs: Register hotcpu notifier after initialization

On Mon, Aug 19, 2013 at 10:56:44PM +0200, Richard Weinberger wrote:
> Currently the code initializizes mp->m_icsb_mutex and other things
> _after_ register_hotcpu_notifier().
> As the notifier takes mp->m_icsb_mutex it can happen
> that it takes the lock before it's initialization.
>
> Signed-off-by: Richard Weinberger <[email protected]>

Looks good. Thanks Richard.

Reviewed-by: Ben Myers <[email protected]>

2013-08-22 19:11:23

by Ben Myers

Subject: Re: [PATCH] xfs: Register hotcpu notifier after initialization

On Mon, Aug 19, 2013 at 05:21:29PM -0500, Ben Myers wrote:
> On Mon, Aug 19, 2013 at 10:56:44PM +0200, Richard Weinberger wrote:
> > Currently the code initializizes mp->m_icsb_mutex and other things
> > _after_ register_hotcpu_notifier().
> > As the notifier takes mp->m_icsb_mutex it can happen
> > that it takes the lock before it's initialization.
> >
> > Signed-off-by: Richard Weinberger <[email protected]>
>
> Looks good. Thanks Richard.
>
> Reviewed-by: Ben Myers <[email protected]>

Applied. Thanks Richard.