This is a note to let you know that I've just added the patch titled
ocfs2/dlm: do not get resource spinlock if lockres is new
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 Mon Sep 17 00:00:00 2001
From: Joseph Qi <[email protected]>
Date: Thu, 25 Sep 2014 16:05:16 -0700
Subject: ocfs2/dlm: do not get resource spinlock if lockres is new
From: Joseph Qi <[email protected]>
commit 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 upstream.
There is a deadlock case which reported by Guozhonghua:
https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html
This case is caused by &res->spinlock and &dlm->master_lock
misordering in different threads.
It was introduced by commit 8d400b81cc83 ("ocfs2/dlm: Clean up refmap
helpers"). Since lockres is new, it doesn't not require the
&res->spinlock. So remove it.
Fixes: 8d400b81cc83 ("ocfs2/dlm: Clean up refmap helpers")
Signed-off-by: Joseph Qi <[email protected]>
Reviewed-by: joyce.xue <[email protected]>
Reported-by: Guozhonghua <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Mark Fasheh <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/ocfs2/dlm/dlmmaster.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -655,12 +655,9 @@ void dlm_lockres_clear_refmap_bit(struct
clear_bit(bit, res->refmap);
}
-
-void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
+static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res)
{
- assert_spin_locked(&res->spinlock);
-
res->inflight_locks++;
mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
@@ -668,6 +665,13 @@ void dlm_lockres_grab_inflight_ref(struc
__builtin_return_address(0));
}
+void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ assert_spin_locked(&res->spinlock);
+ __dlm_lockres_grab_inflight_ref(dlm, res);
+}
+
void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res)
{
@@ -894,10 +898,8 @@ lookup:
/* finally add the lockres to its hash bucket */
__dlm_insert_lockres(dlm, res);
- /* Grab inflight ref to pin the resource */
- spin_lock(&res->spinlock);
- dlm_lockres_grab_inflight_ref(dlm, res);
- spin_unlock(&res->spinlock);
+ /* since this lockres is new it doesn't not require the spinlock */
+ __dlm_lockres_grab_inflight_ref(dlm, res);
/* get an extra ref on the mle in case this is a BLOCK
* if so, the creator of the BLOCK may try to put the last
Patches currently in stable-queue which might be from [email protected] are
queue-3.16/ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
