The patch titled Subject: ocfs2/dlm: fix race between convert and recovery has been added to the -mm tree. Its filename is ocfs2-dlm-fix-race-between-convert-and-recovery.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/ocfs2-dlm-fix-race-between-convert-and-recovery.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/ocfs2-dlm-fix-race-between-convert-and-recovery.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Joseph Qi <joseph.qi@xxxxxxxxxx> Subject: ocfs2/dlm: fix race between convert and recovery There is a race window between dlmconvert_remote and dlm_move_lockres_to_recovery_list, which will cause a lock with OCFS2_LOCK_BUSY in grant list, thus system hangs. dlmconvert_remote { spin_lock(&res->spinlock); list_move_tail(&lock->list, &res->converting); lock->convert_pending = 1; spin_unlock(&res->spinlock); status = dlm_send_remote_convert_request(); >>>>>> race window, master has queued ast and return DLM_NORMAL, and then down before sending ast. this node detects master down and call dlm_move_lockres_to_recovery_list, which will revert the lock to grant list. Then OCFS2_LOCK_BUSY won't be cleared as new master won't send ast any more because it thinks already be authorized. spin_lock(&res->spinlock); lock->convert_pending = 0; if (status != DLM_NORMAL) dlm_revert_pending_convert(res, lock); spin_unlock(&res->spinlock); } In this case, just leave it in convert list and new master will take care of it after recovery. And if convert request returns other than DLM_NORMAL, convert thread will do the revert itself. So remove the revert logic in dlm_move_lockres_to_recovery_list. Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxx> Reported-by: Yiwen Jiang <jiangyiwen@xxxxxxxxxx> Cc: Mark Fasheh <mfasheh@xxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/dlm/dlmrecovery.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff -puN fs/ocfs2/dlm/dlmrecovery.c~ocfs2-dlm-fix-race-between-convert-and-recovery fs/ocfs2/dlm/dlmrecovery.c --- a/fs/ocfs2/dlm/dlmrecovery.c~ocfs2-dlm-fix-race-between-convert-and-recovery +++ a/fs/ocfs2/dlm/dlmrecovery.c @@ -2058,15 +2058,7 @@ void dlm_move_lockres_to_recovery_list(s queue = dlm_list_idx_to_ptr(res, i); list_for_each_entry_safe(lock, next, queue, list) { dlm_lock_get(lock); - if (lock->convert_pending) { - /* move converting lock back to granted */ - BUG_ON(i != DLM_CONVERTING_LIST); - mlog(0, "node died with convert pending " - "on %.*s. move back to granted list.\n", - res->lockname.len, res->lockname.name); - dlm_revert_pending_convert(res, lock); - lock->convert_pending = 0; - } else if (lock->lock_pending) { + if (lock->lock_pending) { /* remove pending lock requests completely */ BUG_ON(i != DLM_BLOCKED_LIST); mlog(0, "node died with lock pending " _ Patches currently in -mm which might be from joseph.qi@xxxxxxxxxx are ocfs2-dlm-fix-race-between-convert-and-recovery.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