The patch titled
Subject: ocfs2/dlm: do not get resource spinlock if lockres is new
has been added to the -mm tree. Its filename is
ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
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------------------------------------------------------
From: Joseph Qi <joseph.qi@xxxxxxxxxx>
Subject: ocfs2/dlm: do not get resource spinlock if lockres is new
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 <joseph.qi@xxxxxxxxxx>
Reviewed-by: joyce.xue <xuejiufei@xxxxxxxxxx>
Reported-by: Guozhonghua <guozhonghua@xxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/dlm/dlmmaster.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff -puN fs/ocfs2/dlm/dlmmaster.c~ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new fs/ocfs2/dlm/dlmmaster.c
--- a/fs/ocfs2/dlm/dlmmaster.c~ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new
+++ a/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 -mm which might be from joseph.qi@xxxxxxxxxx are
ocfs2-free-vol_lable-in-ocfs2_delete_osb.patch
ocfs2-dlm-do-not-get-resource-spinlock-if-lockres-is-new.patch
ocfs2-dlm-refactor-error-handling-in-dlm_alloc_ctxt.patch
ocfs2-fix-shift-left-operations-overflow.patch
ocfs2-call-o2quo_exit-if-malloc-failed-in-o2net_init.patch
ocfs2-dlm-fix-race-between-dispatched_work-and-dlm_lockres_grab_inflight_worker.patch
ocfs2-fix-deadlock-between-o2hb-thread-and-o2net_wq.patch
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