ocfs2/dlm: do not get resource spinlock if lockres is new (5760a97c) · Commits · 戴 / test

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 ("ocfs2/dlm: Clean up refmap helpers"). Since lockres is new, it doesn't not require the &res->spinlock. So remove it. Fixes: ("ocfs2/dlm: Clean up refmap helpers") Signed-off-by:

Joseph Qi <joseph.qi@huawei.com> Reviewed-by:

joyce.xue <xuejiufei@huawei.com> Reported-by:

Guozhonghua <guozhonghua@h3c.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dlm/dlmmaster.c

+10 −8

Original line number	Diff line number	Diff line
		@@ -655,12 +655,9 @@ void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
		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(struct dlm_ctxt *dlm,
		__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

Admin message