GFS2: Merge lock_dlm module into GFS2

This is the big patch that I've been working on for some time
now. There are many reasons for wanting to make this change
such as:
 o Reducing overhead by eliminating duplicated fields between structures
 o Simplifcation of the code (reduces the code size by a fair bit)
 o The locking interface is now the DLM interface itself as proposed
   some time ago.
 o Fewer lookups of glocks when processing replies from the DLM
 o Fewer memory allocations/deallocations for each glock
 o Scope to do further optimisations in the future (but this patch is
   more than big enough for now!)

Please note that (a) this patch relates to the lock_dlm module and
not the DLM itself, that is still a separate module; and (b) that
we retain the ability to build GFS2 as a standalone single node
filesystem with out requiring the DLM.

This patch needs a lot of testing, hence my keeping it I restarted
my -git tree after the last merge window. That way, this has the maximum
exposure before its merged. This is (modulo a few minor bug fixes) the
same patch that I've been posting on and off the the last three months
and its passed a number of different tests so far.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 0 insertions, 68 deletions

diff --git a/fs/gfs2/locking/dlm/thread.c b/fs/gfs2/locking/dlm/thread.c
deleted file mode 100644
index 38823ef..0000000
--- a/fs/gfs2/locking/dlm/thread.c
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
- * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
- * of the GNU General Public License version 2.
- */
-
-#include "lock_dlm.h"
-
-static inline int no_work(struct gdlm_ls *ls)
-{
-	int ret;
-
-	spin_lock(&ls->async_lock);
-	ret = list_empty(&ls->submit);
-	spin_unlock(&ls->async_lock);
-
-	return ret;
-}
-
-static int gdlm_thread(void *data)
-{
-	struct gdlm_ls *ls = (struct gdlm_ls *) data;
-	struct gdlm_lock *lp = NULL;
-
-	while (!kthread_should_stop()) {
-		wait_event_interruptible(ls->thread_wait,
-				!no_work(ls) || kthread_should_stop());
-
-		spin_lock(&ls->async_lock);
-
-		if (!list_empty(&ls->submit)) {
-			lp = list_entry(ls->submit.next, struct gdlm_lock,
-					delay_list);
-			list_del_init(&lp->delay_list);
-			spin_unlock(&ls->async_lock);
-			gdlm_do_lock(lp);
-			spin_lock(&ls->async_lock);
-		}
-		spin_unlock(&ls->async_lock);
-	}
-
-	return 0;
-}
-
-int gdlm_init_threads(struct gdlm_ls *ls)
-{
-	struct task_struct *p;
-	int error;
-
-	p = kthread_run(gdlm_thread, ls, "lock_dlm");
-	error = IS_ERR(p);
-	if (error) {
-		log_error("can't start lock_dlm thread %d", error);
-		return error;
-	}
-	ls->thread = p;
-
-	return 0;
-}
-
-void gdlm_release_threads(struct gdlm_ls *ls)
-{
-	kthread_stop(ls->thread);
-}
-