Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: (56 commits)
  [PATCH] fs/ocfs2/dlm/: cleanups
  ocfs2: fix compiler warnings in dlm_convert_lock_handler()
  ocfs2: dlm_print_one_mle() needs to be defined
  ocfs2: remove whitespace in dlmunlock.c
  ocfs2: move dlm work to a private work queue
  ocfs2: fix incorrect error returns
  ocfs2: tune down some noisy messages during dlm recovery
  ocfs2: display message before waiting for recovery to complete
  ocfs2: mlog in dlm_convert_lock_handler() should be ML_ERROR
  ocfs2: retry operations when a lock is marked in recovery
  ocfs2: use cond_resched() in dlm_thread()
  ocfs2: use GFP_NOFS in some dlm operations
  ocfs2: wait for recovery when starting lock mastery
  ocfs2: continue recovery when a dead node is encountered
  ocfs2: remove unneccesary spin_unlock() in dlm_remaster_locks()
  ocfs2: dlm_remaster_locks() should never exit without completing
  ocfs2: special case recovery lock in dlmlock_remote()
  ocfs2: pending mastery asserts and migrations should block each other
  ocfs2: temporarily disable automatic lock migration
  ocfs2: do not unconditionally purge the lockres in dlmlock_remote()
  ...

fs/ocfs2/dlm/dlmast.c

@@ -197,12 +197,14 @@ static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 				  lock->ml.node == dlm->node_num ? "master" :
 				  "remote");
 			memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
-		} else if (lksb->flags & DLM_LKSB_PUT_LVB) {
-			mlog(0, "setting lvb from lockres for %s node\n",
-				  lock->ml.node == dlm->node_num ? "master" :
-				  "remote");
-			memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN);
 		}
+		/* Do nothing for lvb put requests - they should be done in
+ 		 * place when the lock is downconverted - otherwise we risk
+ 		 * racing gets and puts which could result in old lvb data
+ 		 * being propagated. We leave the put flag set and clear it
+ 		 * here. In the future we might want to clear it at the time
+ 		 * the put is actually done.
+		 */
 		spin_unlock(&res->spinlock);
 	}
 

fs/ocfs2/dlm/dlmcommon.h

@@ -37,7 +37,17 @@
 #define DLM_THREAD_SHUFFLE_INTERVAL    5     // flush everything every 5 passes
 #define DLM_THREAD_MS                  200   // flush at least every 200 ms
 
-#define DLM_HASH_BUCKETS     (PAGE_SIZE / sizeof(struct hlist_head))
+#define DLM_HASH_SIZE_DEFAULT	(1 << 14)
+#if DLM_HASH_SIZE_DEFAULT < PAGE_SIZE
+# define DLM_HASH_PAGES		1
+#else
+# define DLM_HASH_PAGES		(DLM_HASH_SIZE_DEFAULT / PAGE_SIZE)
+#endif
+#define DLM_BUCKETS_PER_PAGE	(PAGE_SIZE / sizeof(struct hlist_head))
+#define DLM_HASH_BUCKETS	(DLM_HASH_PAGES * DLM_BUCKETS_PER_PAGE)
+
+/* Intended to make it easier for us to switch out hash functions */
+#define dlm_lockid_hash(_n, _l) full_name_hash(_n, _l)
 
 enum dlm_ast_type {
 	DLM_AST = 0,
@@ -61,7 +71,8 @@ static inline int dlm_is_recovery_lock(const char *lock_name, int name_len)
 	return 0;
 }
 
-#define DLM_RECO_STATE_ACTIVE  0x0001
+#define DLM_RECO_STATE_ACTIVE    0x0001
+#define DLM_RECO_STATE_FINALIZE  0x0002
 
 struct dlm_recovery_ctxt
 {
@@ -85,7 +96,7 @@ enum dlm_ctxt_state {
 struct dlm_ctxt
 {
 	struct list_head list;
-	struct hlist_head *lockres_hash;
+	struct hlist_head **lockres_hash;
 	struct list_head dirty_list;
 	struct list_head purge_list;
 	struct list_head pending_asts;
@@ -120,6 +131,7 @@ struct dlm_ctxt
 	struct o2hb_callback_func dlm_hb_down;
 	struct task_struct *dlm_thread_task;
 	struct task_struct *dlm_reco_thread_task;
+	struct workqueue_struct *dlm_worker;
 	wait_queue_head_t dlm_thread_wq;
 	wait_queue_head_t dlm_reco_thread_wq;
 	wait_queue_head_t ast_wq;
@@ -132,6 +144,11 @@ struct dlm_ctxt
 	struct list_head	dlm_eviction_callbacks;
 };
 
+static inline struct hlist_head *dlm_lockres_hash(struct dlm_ctxt *dlm, unsigned i)
+{
+	return dlm->lockres_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] + (i % DLM_BUCKETS_PER_PAGE);
+}
+
 /* these keventd work queue items are for less-frequently
  * called functions that cannot be directly called from the
  * net message handlers for some reason, usually because
@@ -216,20 +233,29 @@ struct dlm_lock_resource
 	/* WARNING: Please see the comment in dlm_init_lockres before
 	 * adding fields here. */
 	struct hlist_node hash_node;
+	struct qstr lockname;
 	struct kref      refs;
 
-	/* please keep these next 3 in this order
-	 * some funcs want to iterate over all lists */
+	/*
+	 * Please keep granted, converting, and blocked in this order,
+	 * as some funcs want to iterate over all lists.
+	 *
+	 * All four lists are protected by the hash's reference.
+	 */
 	struct list_head granted;
 	struct list_head converting;
 	struct list_head blocked;
+	struct list_head purge;
 
+	/*
+	 * These two lists require you to hold an additional reference
+	 * while they are on the list.
+	 */
 	struct list_head dirty;
 	struct list_head recovering; // dlm_recovery_ctxt.resources list
 
 	/* unused lock resources have their last_used stamped and are
 	 * put on a list for the dlm thread to run. */
-	struct list_head purge;
 	unsigned long    last_used;
 
 	unsigned migration_pending:1;
@@ -238,7 +264,6 @@ struct dlm_lock_resource
 	wait_queue_head_t wq;
 	u8  owner;              //node which owns the lock resource, or unknown
 	u16 state;
-	struct qstr lockname;
 	char lvb[DLM_LVB_LEN];
 };
 
@@ -300,6 +325,15 @@ enum dlm_lockres_list {
 	DLM_BLOCKED_LIST
 };
 
+static inline int dlm_lvb_is_empty(char *lvb)
+{
+	int i;
+	for (i=0; i<DLM_LVB_LEN; i++)
+		if (lvb[i])
+			return 0;
+	return 1;
+}
+
 static inline struct list_head *
 dlm_list_idx_to_ptr(struct dlm_lock_resource *res, enum dlm_lockres_list idx)
 {
@@ -609,7 +643,8 @@ struct dlm_finalize_reco
 {
 	u8 node_idx;
 	u8 dead_node;
-	__be16 pad1;
+	u8 flags;
+	u8 pad1;
 	__be32 pad2;
 };
 
@@ -676,6 +711,7 @@ void dlm_wait_for_recovery(struct dlm_ctxt *dlm);
 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node);
 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout);
+int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout);
 
 void dlm_put(struct dlm_ctxt *dlm);
 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm);
@@ -687,14 +723,20 @@ void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
 			    struct dlm_lock_resource *res);
 void dlm_purge_lockres(struct dlm_ctxt *dlm,
 		       struct dlm_lock_resource *lockres);
-void dlm_lockres_get(struct dlm_lock_resource *res);
+static inline void dlm_lockres_get(struct dlm_lock_resource *res)
+{
+	/* This is called on every lookup, so it might be worth
+	 * inlining. */
+	kref_get(&res->refs);
+}
 void dlm_lockres_put(struct dlm_lock_resource *res);
 void __dlm_unhash_lockres(struct dlm_lock_resource *res);
 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
 			  struct dlm_lock_resource *res);
 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 						const char *name,
-						unsigned int len);
+						unsigned int len,
+						unsigned int hash);
 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 					      const char *name,
 					      unsigned int len);
@@ -819,6 +861,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm,
 			   u8 dead_node);
 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
 
+int __dlm_lockres_unused(struct dlm_lock_resource *res);
 
 static inline const char * dlm_lock_mode_name(int mode)
 {

fs/ocfs2/dlm/dlmconvert.c

@@ -214,6 +214,9 @@ static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
 	if (lock->ml.node == dlm->node_num)
 		mlog(0, "doing in-place convert for nonlocal lock\n");
 	lock->ml.type = type;
+	if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
+		memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
+
 	status = DLM_NORMAL;
 	*call_ast = 1;
 	goto unlock_exit;
@@ -461,6 +464,12 @@ int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data)
 	}
 
 	spin_lock(&res->spinlock);
+	status = __dlm_lockres_state_to_status(res);
+	if (status != DLM_NORMAL) {
+		spin_unlock(&res->spinlock);
+		dlm_error(status);
+		goto leave;
+	}
 	list_for_each(iter, &res->granted) {
 		lock = list_entry(iter, struct dlm_lock, list);
 		if (lock->ml.cookie == cnv->cookie &&
@@ -470,6 +479,21 @@ int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data)
 		}
 		lock = NULL;
 	}
+	if (!lock) {
+		__dlm_print_one_lock_resource(res);
+		list_for_each(iter, &res->granted) {
+			lock = list_entry(iter, struct dlm_lock, list);
+			if (lock->ml.node == cnv->node_idx) {
+				mlog(ML_ERROR, "There is something here "
+				     "for node %u, lock->ml.cookie=%llu, "
+				     "cnv->cookie=%llu\n", cnv->node_idx,
+				     (unsigned long long)lock->ml.cookie,
+				     (unsigned long long)cnv->cookie);
+				break;
+			}
+		}
+		lock = NULL;
+	}
 	spin_unlock(&res->spinlock);
 	if (!lock) {
 		status = DLM_IVLOCKID;

fs/ocfs2/dlm/dlmdebug.c

@@ -37,10 +37,8 @@
 
 #include "dlmapi.h"
 #include "dlmcommon.h"
-#include "dlmdebug.h"
 
 #include "dlmdomain.h"
-#include "dlmdebug.h"
 
 #define MLOG_MASK_PREFIX ML_DLM
 #include "cluster/masklog.h"
@@ -120,6 +118,7 @@ void dlm_print_one_lock(struct dlm_lock *lockid)
 }
 EXPORT_SYMBOL_GPL(dlm_print_one_lock);
 
+#if 0
 void dlm_dump_lock_resources(struct dlm_ctxt *dlm)
 {
 	struct dlm_lock_resource *res;
@@ -136,12 +135,13 @@ void dlm_dump_lock_resources(struct dlm_ctxt *dlm)
 
 	spin_lock(&dlm->spinlock);
 	for (i=0; i<DLM_HASH_BUCKETS; i++) {
-		bucket = &(dlm->lockres_hash[i]);
+		bucket = dlm_lockres_hash(dlm, i);
 		hlist_for_each_entry(res, iter, bucket, hash_node)
 			dlm_print_one_lock_resource(res);
 	}
 	spin_unlock(&dlm->spinlock);
 }
+#endif  /*  0  */
 
 static const char *dlm_errnames[] = {
 	[DLM_NORMAL] =			"DLM_NORMAL",

fs/ocfs2/dlm/dlmdebug.h

-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * dlmdebug.h
- *
- * Copyright (C) 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- */
-
-#ifndef DLMDEBUG_H
-#define DLMDEBUG_H
-
-void dlm_dump_lock_resources(struct dlm_ctxt *dlm);
-
-#endif

fs/ocfs2/dlm/dlmdomain.c

@@ -41,7 +41,6 @@
 #include "dlmapi.h"
 #include "dlmcommon.h"
 
-#include "dlmdebug.h"
 #include "dlmdomain.h"
 
 #include "dlmver.h"
@@ -49,6 +48,33 @@
 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
 #include "cluster/masklog.h"
 
+static void dlm_free_pagevec(void **vec, int pages)
+{
+	while (pages--)
+		free_page((unsigned long)vec[pages]);
+	kfree(vec);
+}
+
+static void **dlm_alloc_pagevec(int pages)
+{
+	void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
+	int i;
+
+	if (!vec)
+		return NULL;
+
+	for (i = 0; i < pages; i++)
+		if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
+			goto out_free;
+
+	mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
+	     pages, DLM_HASH_PAGES, (unsigned long)DLM_BUCKETS_PER_PAGE);
+	return vec;
+out_free:
+	dlm_free_pagevec(vec, i);
+	return NULL;
+}
+
 /*
  *
  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
@@ -90,8 +116,7 @@ void __dlm_insert_lockres(struct dlm_ctxt *dlm,
 	assert_spin_locked(&dlm->spinlock);
 
 	q = &res->lockname;
-	q->hash = full_name_hash(q->name, q->len);
-	bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]);
+	bucket = dlm_lockres_hash(dlm, q->hash);
 
 	/* get a reference for our hashtable */
 	dlm_lockres_get(res);
@@ -100,34 +125,32 @@ void __dlm_insert_lockres(struct dlm_ctxt *dlm,
 }
 
 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
-					 const char *name,
-					 unsigned int len)
+						const char *name,
+						unsigned int len,
+						unsigned int hash)
 {
-	unsigned int hash;
-	struct hlist_node *iter;
-	struct dlm_lock_resource *tmpres=NULL;
 	struct hlist_head *bucket;
+	struct hlist_node *list;
 
 	mlog_entry("%.*s\n", len, name);
 
 	assert_spin_locked(&dlm->spinlock);
 
-	hash = full_name_hash(name, len);
-
-	bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
-
-	/* check for pre-existing lock */
-	hlist_for_each(iter, bucket) {
-		tmpres = hlist_entry(iter, struct dlm_lock_resource, hash_node);
-		if (tmpres->lockname.len == len &&
-		    memcmp(tmpres->lockname.name, name, len) == 0) {
-			dlm_lockres_get(tmpres);
-			break;
-		}
+	bucket = dlm_lockres_hash(dlm, hash);
 
-		tmpres = NULL;
+	hlist_for_each(list, bucket) {
+		struct dlm_lock_resource *res = hlist_entry(list,
+			struct dlm_lock_resource, hash_node);
+		if (res->lockname.name[0] != name[0])
+			continue;
+		if (unlikely(res->lockname.len != len))
+			continue;
+		if (memcmp(res->lockname.name + 1, name + 1, len - 1))
+			continue;
+		dlm_lockres_get(res);
+		return res;
 	}
-	return tmpres;
+	return NULL;
 }
 
 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
@@ -135,9 +158,10 @@ struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 				    unsigned int len)
 {
 	struct dlm_lock_resource *res;
+	unsigned int hash = dlm_lockid_hash(name, len);
 
 	spin_lock(&dlm->spinlock);
-	res = __dlm_lookup_lockres(dlm, name, len);
+	res = __dlm_lookup_lockres(dlm, name, len, hash);
 	spin_unlock(&dlm->spinlock);
 	return res;
 }
@@ -194,7 +218,7 @@ static int dlm_wait_on_domain_helper(const char *domain)
 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 {
 	if (dlm->lockres_hash)
-		free_page((unsigned long) dlm->lockres_hash);
+		dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 
 	if (dlm->name)
 		kfree(dlm->name);
@@ -278,11 +302,21 @@ int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 	return ret;
 }
 
+static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
+{
+	if (dlm->dlm_worker) {
+		flush_workqueue(dlm->dlm_worker);
+		destroy_workqueue(dlm->dlm_worker);
+		dlm->dlm_worker = NULL;
+	}
+}
+
 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 {
 	dlm_unregister_domain_handlers(dlm);
 	dlm_complete_thread(dlm);
 	dlm_complete_recovery_thread(dlm);
+	dlm_destroy_dlm_worker(dlm);
 
 	/* We've left the domain. Now we can take ourselves out of the
 	 * list and allow the kref stuff to help us free the
@@ -304,8 +338,8 @@ static void dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 restart:
 	spin_lock(&dlm->spinlock);
 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
-		while (!hlist_empty(&dlm->lockres_hash[i])) {
-			res = hlist_entry(dlm->lockres_hash[i].first,
+		while (!hlist_empty(dlm_lockres_hash(dlm, i))) {
+			res = hlist_entry(dlm_lockres_hash(dlm, i)->first,
 					  struct dlm_lock_resource, hash_node);
 			/* need reference when manually grabbing lockres */
 			dlm_lockres_get(res);
@@ -1126,6 +1160,13 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
 		goto bail;
 	}
 
+	dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
+	if (!dlm->dlm_worker) {
+		status = -ENOMEM;
+		mlog_errno(status);
+		goto bail;
+	}
+
 	do {
 		unsigned int backoff;
 		status = dlm_try_to_join_domain(dlm);
@@ -1166,6 +1207,7 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
 		dlm_unregister_domain_handlers(dlm);
 		dlm_complete_thread(dlm);
 		dlm_complete_recovery_thread(dlm);
+		dlm_destroy_dlm_worker(dlm);
 	}
 
 	return status;
@@ -1191,7 +1233,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 		goto leave;
 	}
 
-	dlm->lockres_hash = (struct hlist_head *) __get_free_page(GFP_KERNEL);
+	dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
 	if (!dlm->lockres_hash) {
 		mlog_errno(-ENOMEM);
 		kfree(dlm->name);
@@ -1200,8 +1242,8 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 		goto leave;
 	}
 
-	for (i=0; i<DLM_HASH_BUCKETS; i++)
-		INIT_HLIST_HEAD(&dlm->lockres_hash[i]);
+	for (i = 0; i < DLM_HASH_BUCKETS; i++)
+		INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
 
 	strcpy(dlm->name, domain);
 	dlm->key = key;
@@ -1231,6 +1273,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 
 	dlm->dlm_thread_task = NULL;
 	dlm->dlm_reco_thread_task = NULL;
+	dlm->dlm_worker = NULL;
 	init_waitqueue_head(&dlm->dlm_thread_wq);
 	init_waitqueue_head(&dlm->dlm_reco_thread_wq);
 	init_waitqueue_head(&dlm->reco.event);

fs/ocfs2/dlm/dlmfs.c

@@ -116,7 +116,7 @@ static int dlmfs_file_open(struct inode *inode,
 	 * doesn't make sense for LVB writes. */
 	file->f_flags &= ~O_APPEND;
 
-	fp = kmalloc(sizeof(*fp), GFP_KERNEL);
+	fp = kmalloc(sizeof(*fp), GFP_NOFS);
 	if (!fp) {
 		status = -ENOMEM;
 		goto bail;
@@ -196,7 +196,7 @@ static ssize_t dlmfs_file_read(struct file *filp,
 	else
 		readlen = count - *ppos;
 
-	lvb_buf = kmalloc(readlen, GFP_KERNEL);
+	lvb_buf = kmalloc(readlen, GFP_NOFS);
 	if (!lvb_buf)
 		return -ENOMEM;
 
@@ -240,7 +240,7 @@ static ssize_t dlmfs_file_write(struct file *filp,
 	else
 		writelen = count - *ppos;
 
-	lvb_buf = kmalloc(writelen, GFP_KERNEL);
+	lvb_buf = kmalloc(writelen, GFP_NOFS);
 	if (!lvb_buf)
 		return -ENOMEM;
 

fs/ocfs2/dlm/dlmlock.c

@@ -201,6 +201,7 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 				      struct dlm_lock *lock, int flags)
 {
 	enum dlm_status status = DLM_DENIED;
+	int lockres_changed = 1;
 
 	mlog_entry("type=%d\n", lock->ml.type);
 	mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
@@ -226,8 +227,25 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
 	lock->lock_pending = 0;
 	if (status != DLM_NORMAL) {
-		if (status != DLM_NOTQUEUED)
+		if (status == DLM_RECOVERING &&
+		    dlm_is_recovery_lock(res->lockname.name,
+					 res->lockname.len)) {
+			/* recovery lock was mastered by dead node.
+			 * we need to have calc_usage shoot down this
+			 * lockres and completely remaster it. */
+			mlog(0, "%s: recovery lock was owned by "
+			     "dead node %u, remaster it now.\n",
+			     dlm->name, res->owner);
+		} else if (status != DLM_NOTQUEUED) {
+			/*
+			 * DO NOT call calc_usage, as this would unhash
+			 * the remote lockres before we ever get to use
+			 * it.  treat as if we never made any change to
+			 * the lockres.
+			 */
+			lockres_changed = 0;
 			dlm_error(status);
+		}
 		dlm_revert_pending_lock(res, lock);
 		dlm_lock_put(lock);
 	} else if (dlm_is_recovery_lock(res->lockname.name, 
@@ -243,7 +261,8 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
 	}
 	spin_unlock(&res->spinlock);
 
-	dlm_lockres_calc_usage(dlm, res);
+	if (lockres_changed)
+		dlm_lockres_calc_usage(dlm, res);
 
 	wake_up(&res->wq);
 	return status;
@@ -280,6 +299,14 @@ static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
 	if (tmpret >= 0) {
 		// successfully sent and received
 		ret = status;  // this is already a dlm_status
+		if (ret == DLM_REJECTED) {
+			mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
+			     "no longer owned by %u.  that node is coming back "
+			     "up currently.\n", dlm->name, create.namelen,
+			     create.name, res->owner);
+			dlm_print_one_lock_resource(res);
+			BUG();
+		}
 	} else {
 		mlog_errno(tmpret);
 		if (dlm_is_host_down(tmpret)) {
@@ -381,13 +408,13 @@ struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 	struct dlm_lock *lock;
 	int kernel_allocated = 0;
 
-	lock = kcalloc(1, sizeof(*lock), GFP_KERNEL);
+	lock = kcalloc(1, sizeof(*lock), GFP_NOFS);
 	if (!lock)
 		return NULL;
 
 	if (!lksb) {
 		/* zero memory only if kernel-allocated */
-		lksb = kcalloc(1, sizeof(*lksb), GFP_KERNEL);
+		lksb = kcalloc(1, sizeof(*lksb), GFP_NOFS);
 		if (!lksb) {
 			kfree(lock);
 			return NULL;
@@ -428,11 +455,16 @@ int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data)
 	if (!dlm_grab(dlm))
 		return DLM_REJECTED;
 
-	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
-			"Domain %s not fully joined!\n", dlm->name);
-
 	name = create->name;
 	namelen = create->namelen;
+	status = DLM_REJECTED;
+	if (!dlm_domain_fully_joined(dlm)) {
+		mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
+		     "sending a create_lock message for lock %.*s!\n",
+		     dlm->name, create->node_idx, namelen, name);
+		dlm_error(status);
+		goto leave;
+	}
 
 	status = DLM_IVBUFLEN;
 	if (namelen > DLM_LOCKID_NAME_MAX) {
@@ -668,18 +700,22 @@ enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
 			msleep(100);
 			/* no waiting for dlm_reco_thread */
 			if (recovery) {
-				if (status == DLM_RECOVERING) {
-					mlog(0, "%s: got RECOVERING "
-					     "for $REOCVERY lock, master "
-					     "was %u\n", dlm->name, 
-					     res->owner);
-					dlm_wait_for_node_death(dlm, res->owner, 
-							DLM_NODE_DEATH_WAIT_MAX);
-				}
+				if (status != DLM_RECOVERING)
+					goto retry_lock;
+
+				mlog(0, "%s: got RECOVERING "
+				     "for $RECOVERY lock, master "
+				     "was %u\n", dlm->name,
+				     res->owner);
+				/* wait to see the node go down, then
+				 * drop down and allow the lockres to
+				 * get cleaned up.  need to remaster. */
+				dlm_wait_for_node_death(dlm, res->owner,
+						DLM_NODE_DEATH_WAIT_MAX);
 			} else {
 				dlm_wait_for_recovery(dlm);
+				goto retry_lock;
 			}
-			goto retry_lock;
 		}
 
 		if (status != DLM_NORMAL) {

fs/ocfs2/dlm/dlmthread.c

@@ -39,6 +39,7 @@
 #include <linux/inet.h>
 #include <linux/timer.h>
 #include <linux/kthread.h>
+#include <linux/delay.h>
 
 
 #include "cluster/heartbeat.h"
@@ -53,6 +54,8 @@
 #include "cluster/masklog.h"
 
 static int dlm_thread(void *data);
+static void dlm_purge_lockres_now(struct dlm_ctxt *dlm,
+				  struct dlm_lock_resource *lockres);
 
 static void dlm_flush_asts(struct dlm_ctxt *dlm);
 
@@ -80,7 +83,7 @@ void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags)
 }
 
 
-static int __dlm_lockres_unused(struct dlm_lock_resource *res)
+int __dlm_lockres_unused(struct dlm_lock_resource *res)
 {
 	if (list_empty(&res->granted) &&
 	    list_empty(&res->converting) &&
@@ -103,6 +106,20 @@ void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
 	assert_spin_locked(&res->spinlock);
 
 	if (__dlm_lockres_unused(res)){
+		/* For now, just keep any resource we master */
+		if (res->owner == dlm->node_num)
+		{
+			if (!list_empty(&res->purge)) {
+				mlog(0, "we master %s:%.*s, but it is on "
+				     "the purge list.  Removing\n",
+				     dlm->name, res->lockname.len,
+				     res->lockname.name);
+				list_del_init(&res->purge);
+				dlm->purge_count--;
+			}
+			return;
+		}
+
 		if (list_empty(&res->purge)) {
 			mlog(0, "putting lockres %.*s from purge list\n",
 			     res->lockname.len, res->lockname.name);
@@ -110,10 +127,23 @@ void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
 			res->last_used = jiffies;
 			list_add_tail(&res->purge, &dlm->purge_list);
 			dlm->purge_count++;
+
+			/* if this node is not the owner, there is
+			 * no way to keep track of who the owner could be.
+			 * unhash it to avoid serious problems. */
+			if (res->owner != dlm->node_num) {
+				mlog(0, "%s:%.*s: doing immediate "
+				     "purge of lockres owned by %u\n",
+				     dlm->name, res->lockname.len,
+				     res->lockname.name, res->owner);
+
+				dlm_purge_lockres_now(dlm, res);
+			}
 		}
 	} else if (!list_empty(&res->purge)) {
-		mlog(0, "removing lockres %.*s from purge list\n",
-		     res->lockname.len, res->lockname.name);
+		mlog(0, "removing lockres %.*s from purge list, "
+		     "owner=%u\n", res->lockname.len, res->lockname.name,
+		     res->owner);
 
 		list_del_init(&res->purge);
 		dlm->purge_count--;
@@ -165,6 +195,7 @@ void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *lockres)
 	} else if (ret < 0) {
 		mlog(ML_NOTICE, "lockres %.*s: migrate failed, retrying\n",
 		     lockres->lockname.len, lockres->lockname.name);
+		msleep(100);
 		goto again;
 	}
 
@@ -178,6 +209,24 @@ void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *lockres)
 	__dlm_unhash_lockres(lockres);
 }
 
+/* make an unused lockres go away immediately.
+ * as soon as the dlm spinlock is dropped, this lockres
+ * will not be found. kfree still happens on last put. */
+static void dlm_purge_lockres_now(struct dlm_ctxt *dlm,
+				  struct dlm_lock_resource *lockres)
+{
+	assert_spin_locked(&dlm->spinlock);
+	assert_spin_locked(&lockres->spinlock);
+
+	BUG_ON(!__dlm_lockres_unused(lockres));
+
+	if (!list_empty(&lockres->purge)) {
+		list_del_init(&lockres->purge);
+		dlm->purge_count--;
+	}
+	__dlm_unhash_lockres(lockres);
+}
+
 static void dlm_run_purge_list(struct dlm_ctxt *dlm,
 			       int purge_now)
 {
@@ -420,6 +469,8 @@ void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 	/* don't shuffle secondary queues */
 	if ((res->owner == dlm->node_num) &&
 	    !(res->state & DLM_LOCK_RES_DIRTY)) {
+		/* ref for dirty_list */
+		dlm_lockres_get(res);
 		list_add_tail(&res->dirty, &dlm->dirty_list);
 		res->state |= DLM_LOCK_RES_DIRTY;
 	}
@@ -604,6 +655,8 @@ static int dlm_thread(void *data)
 			list_del_init(&res->dirty);
 			spin_unlock(&res->spinlock);
 			spin_unlock(&dlm->spinlock);
+			/* Drop dirty_list ref */
+			dlm_lockres_put(res);
 
 		 	/* lockres can be re-dirtied/re-added to the
 			 * dirty_list in this gap, but that is ok */
@@ -640,8 +693,9 @@ static int dlm_thread(void *data)
 			 * spinlock and do NOT have the dlm lock.
 			 * safe to reserve/queue asts and run the lists. */
 
-			mlog(0, "calling dlm_shuffle_lists with dlm=%p, "
-			     "res=%p\n", dlm, res);
+			mlog(0, "calling dlm_shuffle_lists with dlm=%s, "
+			     "res=%.*s\n", dlm->name,
+			     res->lockname.len, res->lockname.name);
 
 			/* called while holding lockres lock */
 			dlm_shuffle_lists(dlm, res);
@@ -655,6 +709,8 @@ static int dlm_thread(void *data)
 			/* if the lock was in-progress, stick
 			 * it on the back of the list */
 			if (delay) {
+				/* ref for dirty_list */
+				dlm_lockres_get(res);
 				spin_lock(&res->spinlock);
 				list_add_tail(&res->dirty, &dlm->dirty_list);
 				res->state |= DLM_LOCK_RES_DIRTY;
@@ -675,7 +731,7 @@ static int dlm_thread(void *data)
 
 		/* yield and continue right away if there is more work to do */
 		if (!n) {
-			yield();
+			cond_resched();
 			continue;
 		}
 

fs/ocfs2/dlm/dlmunlock.c

@@ -318,6 +318,16 @@ static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
 
 	mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
 
+	if (owner == dlm->node_num) {
+		/* ended up trying to contact ourself.  this means
+		 * that the lockres had been remote but became local
+		 * via a migration.  just retry it, now as local */
+		mlog(0, "%s:%.*s: this node became the master due to a "
+		     "migration, re-evaluate now\n", dlm->name,
+		     res->lockname.len, res->lockname.name);
+		return DLM_FORWARD;
+	}
+
 	memset(&unlock, 0, sizeof(unlock));
 	unlock.node_idx = dlm->node_num;
 	unlock.flags = cpu_to_be32(flags);

fs/ocfs2/dlm/userdlm.c

@@ -672,7 +672,7 @@ struct dlm_ctxt *user_dlm_register_context(struct qstr *name)
 	u32 dlm_key;
 	char *domain;
 
-	domain = kmalloc(name->len + 1, GFP_KERNEL);
+	domain = kmalloc(name->len + 1, GFP_NOFS);
 	if (!domain) {
 		mlog_errno(-ENOMEM);
 		return ERR_PTR(-ENOMEM);