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 3.10-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-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 Mon Sep 17 00:00:00 2001 From: Joseph Qi <joseph.qi@xxxxxxxxxx> Date: Thu, 25 Sep 2014 16:05:16 -0700 Subject: ocfs2/dlm: do not get resource spinlock if lockres is new From: Joseph Qi <joseph.qi@xxxxxxxxxx> 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 <joseph.qi@xxxxxxxxxx> Reviewed-by: joyce.xue <xuejiufei@xxxxxxxxxx> Reported-by: Guozhonghua <guozhonghua@xxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Mark Fasheh <mfasheh@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -653,12 +653,9 @@ 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, @@ -666,6 +663,13 @@ 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) { @@ -855,10 +859,8 @@ 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 joseph.qi@xxxxxxxxxx are queue-3.10/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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html