fs/ocfs2/dlm/dlmast.c - kernel/msm-4.9 - Gitiles

 /* -*- mode: c; c-basic-offset: 8; -*-
  * vim: noexpandtab sw=8 ts=8 sts=0:
  *
  * dlmast.c
  *
  * AST and BAST functionality for local and remote nodes
  *
  * 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.
  *
  */


 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/highmem.h>
 #include <linux/utsname.h>
 #include <linux/init.h>
 #include <linux/sysctl.h>
 #include <linux/random.h>
 #include <linux/blkdev.h>
 #include <linux/socket.h>
 #include <linux/inet.h>
 #include <linux/spinlock.h>


 #include "cluster/heartbeat.h"
 #include "cluster/nodemanager.h"
 #include "cluster/tcp.h"
 #include "cluster/endian.h"

 #include "dlmapi.h"
 #include "dlmcommon.h"

 #define MLOG_MASK_PREFIX ML_DLM
 #include "cluster/masklog.h"

 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 			   struct dlm_lock *lock);
 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);

 /* Should be called as an ast gets queued to see if the new
  * lock level will obsolete a pending bast.
  * For example, if dlm_thread queued a bast for an EX lock that
  * was blocking another EX, but before sending the bast the
  * lock owner downconverted to NL, the bast is now obsolete.
  * Only the ast should be sent.
  * This is needed because the lock and convert paths can queue
  * asts out-of-band (not waiting for dlm_thread) in order to
  * allow for LKM_NOQUEUE to get immediate responses. */
 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
 	assert_spin_locked(&dlm->ast_lock);
 	assert_spin_locked(&lock->spinlock);

 	if (lock->ml.highest_blocked == LKM_IVMODE)
 		return 0;
 	BUG_ON(lock->ml.highest_blocked == LKM_NLMODE);

 	if (lock->bast_pending &&
 	    list_empty(&lock->bast_list))
 		/* old bast already sent, ok */
 		return 0;

 	if (lock->ml.type == LKM_EXMODE)
 		/* EX blocks anything left, any bast still valid */
 		return 0;
 	else if (lock->ml.type == LKM_NLMODE)
 		/* NL blocks nothing, no reason to send any bast, cancel it */
 		return 1;
 	else if (lock->ml.highest_blocked != LKM_EXMODE)
 		/* PR only blocks EX */
 		return 1;

 	return 0;
 }

 static void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
 	mlog_entry_void();

 	BUG_ON(!dlm);
 	BUG_ON(!lock);

 	assert_spin_locked(&dlm->ast_lock);
 	if (!list_empty(&lock->ast_list)) {
 		mlog(ML_ERROR, "ast list not empty!!  pending=%d, newlevel=%d\n",
 		     lock->ast_pending, lock->ml.type);
 		BUG();
 	}
 	BUG_ON(!list_empty(&lock->ast_list));
 	if (lock->ast_pending)
 		mlog(0, "lock has an ast getting flushed right now\n");

 	/* putting lock on list, add a ref */
 	dlm_lock_get(lock);
 	spin_lock(&lock->spinlock);

 	/* check to see if this ast obsoletes the bast */
 	if (dlm_should_cancel_bast(dlm, lock)) {
 		struct dlm_lock_resource *res = lock->lockres;
 		mlog(0, "%s: cancelling bast for %.*s\n",
 		     dlm->name, res->lockname.len, res->lockname.name);
 		lock->bast_pending = 0;
 		list_del_init(&lock->bast_list);
 		lock->ml.highest_blocked = LKM_IVMODE;
 		/* removing lock from list, remove a ref.  guaranteed
 		 * this won't be the last ref because of the get above,
 		 * so res->spinlock will not be taken here */
 		dlm_lock_put(lock);
 		/* free up the reserved bast that we are cancelling.
 		 * guaranteed that this will not be the last reserved
 		 * ast because *both* an ast and a bast were reserved
 		 * to get to this point.  the res->spinlock will not be
 		 * taken here */
 		dlm_lockres_release_ast(dlm, res);
 	}
 	list_add_tail(&lock->ast_list, &dlm->pending_asts);
 	lock->ast_pending = 1;
 	spin_unlock(&lock->spinlock);
 }

 void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
 	mlog_entry_void();

 	BUG_ON(!dlm);
 	BUG_ON(!lock);

 	spin_lock(&dlm->ast_lock);
 	__dlm_queue_ast(dlm, lock);
 	spin_unlock(&dlm->ast_lock);
 }


 static void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
 	mlog_entry_void();

 	BUG_ON(!dlm);
 	BUG_ON(!lock);
 	assert_spin_locked(&dlm->ast_lock);

 	BUG_ON(!list_empty(&lock->bast_list));
 	if (lock->bast_pending)
 		mlog(0, "lock has a bast getting flushed right now\n");

 	/* putting lock on list, add a ref */
 	dlm_lock_get(lock);
 	spin_lock(&lock->spinlock);
 	list_add_tail(&lock->bast_list, &dlm->pending_basts);
 	lock->bast_pending = 1;
 	spin_unlock(&lock->spinlock);
 }

 void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
 	mlog_entry_void();

 	BUG_ON(!dlm);
 	BUG_ON(!lock);

 	spin_lock(&dlm->ast_lock);
 	__dlm_queue_bast(dlm, lock);
 	spin_unlock(&dlm->ast_lock);
 }

 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 			   struct dlm_lock *lock)
 {
 	struct dlm_lockstatus *lksb = lock->lksb;
 	BUG_ON(!lksb);

 	/* only updates if this node masters the lockres */
 	if (res->owner == dlm->node_num) {

 		spin_lock(&res->spinlock);
 		/* check the lksb flags for the direction */
 		if (lksb->flags & DLM_LKSB_GET_LVB) {
 			mlog(0, "getting lvb from lockres for %s node\n",
 				  lock->ml.node == dlm->node_num ? "master" :
 				  "remote");
 			memcpy(lksb->lvb, res->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);
 	}

 	/* reset any lvb flags on the lksb */
 	lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
 }

 void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 		      struct dlm_lock *lock)
 {
 	dlm_astlockfunc_t *fn;
 	struct dlm_lockstatus *lksb;

 	mlog_entry_void();

 	lksb = lock->lksb;
 	fn = lock->ast;
 	BUG_ON(lock->ml.node != dlm->node_num);

 	dlm_update_lvb(dlm, res, lock);
 	(*fn)(lock->astdata);
 }


 int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 		      struct dlm_lock *lock)
 {
 	int ret;
 	struct dlm_lockstatus *lksb;
 	int lksbflags;

 	mlog_entry_void();

 	lksb = lock->lksb;
 	BUG_ON(lock->ml.node == dlm->node_num);

 	lksbflags = lksb->flags;
 	dlm_update_lvb(dlm, res, lock);

 	/* lock request came from another node
 	 * go do the ast over there */
 	ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags);
 	return ret;
 }

 void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 		       struct dlm_lock *lock, int blocked_type)
 {
 	dlm_bastlockfunc_t *fn = lock->bast;

 	mlog_entry_void();
 	BUG_ON(lock->ml.node != dlm->node_num);

 	(*fn)(lock->astdata, blocked_type);
 }


 int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data)
 {
 	int ret;
 	unsigned int locklen;
 	struct dlm_ctxt *dlm = data;
 	struct dlm_lock_resource *res = NULL;
 	struct dlm_lock *lock = NULL;
 	struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf;
 	char *name;
 	struct list_head *iter, *head=NULL;
 	u64 cookie;
 	u32 flags;

 	if (!dlm_grab(dlm)) {
 		dlm_error(DLM_REJECTED);
 		return DLM_REJECTED;
 	}

 	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
 			"Domain %s not fully joined!\n", dlm->name);

 	name = past->name;
 	locklen = past->namelen;
 	cookie = be64_to_cpu(past->cookie);
 	flags = be32_to_cpu(past->flags);

 	if (locklen > DLM_LOCKID_NAME_MAX) {
 		ret = DLM_IVBUFLEN;
 		mlog(ML_ERROR, "Invalid name length in proxy ast handler!\n");
 		goto leave;
 	}

 	if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
 	     (LKM_PUT_LVB|LKM_GET_LVB)) {
 		mlog(ML_ERROR, "both PUT and GET lvb specified\n");
 		ret = DLM_BADARGS;
 		goto leave;
 	}

 	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
 		  (flags & LKM_GET_LVB ? "get lvb" : "none"));

 	mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type);

 	if (past->type != DLM_AST &&
 	    past->type != DLM_BAST) {
 		mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu"
 		     "name=%.*s\n", past->type,
 		     dlm_get_lock_cookie_node(cookie),
 		     dlm_get_lock_cookie_seq(cookie),
 		     locklen, name);
 		ret = DLM_IVLOCKID;
 		goto leave;
 	}

 	res = dlm_lookup_lockres(dlm, name, locklen);
 	if (!res) {
 		mlog(0, "got %sast for unknown lockres! "
 		     "cookie=%u:%llu, name=%.*s, namelen=%u\n",
 		     past->type == DLM_AST ? "" : "b",
 		     dlm_get_lock_cookie_node(cookie),
 		     dlm_get_lock_cookie_seq(cookie),
 		     locklen, name, locklen);
 		ret = DLM_IVLOCKID;
 		goto leave;
 	}

 	/* cannot get a proxy ast message if this node owns it */
 	BUG_ON(res->owner == dlm->node_num);

 	mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name);

 	spin_lock(&res->spinlock);
 	if (res->state & DLM_LOCK_RES_RECOVERING) {
 		mlog(0, "responding with DLM_RECOVERING!\n");
 		ret = DLM_RECOVERING;
 		goto unlock_out;
 	}
 	if (res->state & DLM_LOCK_RES_MIGRATING) {
 		mlog(0, "responding with DLM_MIGRATING!\n");
 		ret = DLM_MIGRATING;
 		goto unlock_out;
 	}
 	/* try convert queue for both ast/bast */
 	head = &res->converting;
 	lock = NULL;
 	list_for_each(iter, head) {
 		lock = list_entry (iter, struct dlm_lock, list);
 		if (be64_to_cpu(lock->ml.cookie) == cookie)
 			goto do_ast;
 	}

 	/* if not on convert, try blocked for ast, granted for bast */
 	if (past->type == DLM_AST)
 		head = &res->blocked;
 	else
 		head = &res->granted;

 	list_for_each(iter, head) {
 		lock = list_entry (iter, struct dlm_lock, list);
 		if (be64_to_cpu(lock->ml.cookie) == cookie)
 			goto do_ast;
 	}

 	mlog(0, "got %sast for unknown lock!  cookie=%u:%llu, "
 	     "name=%.*s, namelen=%u\n", past->type == DLM_AST ? "" : "b",
 	     dlm_get_lock_cookie_node(cookie), dlm_get_lock_cookie_seq(cookie),
 	     locklen, name, locklen);

 	ret = DLM_NORMAL;
 unlock_out:
 	spin_unlock(&res->spinlock);
 	goto leave;

 do_ast:
 	ret = DLM_NORMAL;
 	if (past->type == DLM_AST) {
 		/* do not alter lock refcount.  switching lists. */
 		list_move_tail(&lock->list, &res->granted);
 		mlog(0, "ast: adding to granted list... type=%d, "
 			  "convert_type=%d\n", lock->ml.type, lock->ml.convert_type);
 		if (lock->ml.convert_type != LKM_IVMODE) {
 			lock->ml.type = lock->ml.convert_type;
 			lock->ml.convert_type = LKM_IVMODE;
 		} else {
 			// should already be there....
 		}

 		lock->lksb->status = DLM_NORMAL;

 		/* if we requested the lvb, fetch it into our lksb now */
 		if (flags & LKM_GET_LVB) {
 			BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB));
 			memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN);
 		}
 	}
 	spin_unlock(&res->spinlock);

 	if (past->type == DLM_AST)
 		dlm_do_local_ast(dlm, res, lock);
 	else
 		dlm_do_local_bast(dlm, res, lock, past->blocked_type);

 leave:

 	if (res)
 		dlm_lockres_put(res);

 	dlm_put(dlm);
 	return ret;
 }


 int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 			   struct dlm_lock *lock, int msg_type,
 			   int blocked_type, int flags)
 {
 	int ret = 0;
 	struct dlm_proxy_ast past;
 	struct kvec vec[2];
 	size_t veclen = 1;
 	int status;

 	mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n",
 		   res->lockname.len, res->lockname.name, lock->ml.node,
 		   msg_type, blocked_type);

 	memset(&past, 0, sizeof(struct dlm_proxy_ast));
 	past.node_idx = dlm->node_num;
 	past.type = msg_type;
 	past.blocked_type = blocked_type;
 	past.namelen = res->lockname.len;
 	memcpy(past.name, res->lockname.name, past.namelen);
 	past.cookie = lock->ml.cookie;

 	vec[0].iov_len = sizeof(struct dlm_proxy_ast);
 	vec[0].iov_base = &past;
 	if (flags & DLM_LKSB_GET_LVB) {
 		mlog(0, "returning requested LVB data\n");
 		be32_add_cpu(&past.flags, LKM_GET_LVB);
 		vec[1].iov_len = DLM_LVB_LEN;
 		vec[1].iov_base = lock->lksb->lvb;
 		veclen++;
 	}

 	ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
 				     lock->ml.node, &status);
 	if (ret < 0)
 		mlog_errno(ret);
 	else {
 		if (status == DLM_RECOVERING) {
 			mlog(ML_ERROR, "sent AST to node %u, it thinks this "
 			     "node is dead!\n", lock->ml.node);
 			BUG();
 		} else if (status == DLM_MIGRATING) {
 			mlog(ML_ERROR, "sent AST to node %u, it returned "
 			     "DLM_MIGRATING!\n", lock->ml.node);
 			BUG();
 		} else if (status != DLM_NORMAL && status != DLM_IVLOCKID) {
 			mlog(ML_ERROR, "AST to node %u returned %d!\n",
 			     lock->ml.node, status);
 			/* ignore it */
 		}
 		ret = 0;
 	}
 	return ret;
 }
	/* -- mode: c; c-basic-offset: 8; --
	* vim: noexpandtab sw=8 ts=8 sts=0:
	*
	* dlmast.c
	*
	* AST and BAST functionality for local and remote nodes
	*
	* 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.
	*
	*/


	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/highmem.h>
	#include <linux/utsname.h>
	#include <linux/init.h>
	#include <linux/sysctl.h>
	#include <linux/random.h>
	#include <linux/blkdev.h>
	#include <linux/socket.h>
	#include <linux/inet.h>
	#include <linux/spinlock.h>


	#include "cluster/heartbeat.h"
	#include "cluster/nodemanager.h"
	#include "cluster/tcp.h"
	#include "cluster/endian.h"

	#include "dlmapi.h"
	#include "dlmcommon.h"

	#define MLOG_MASK_PREFIX ML_DLM
	#include "cluster/masklog.h"

	static void dlm_update_lvb(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock);
	static int dlm_should_cancel_bast(struct dlm_ctxt dlm, struct dlm_lock lock);

	/* Should be called as an ast gets queued to see if the new
	* lock level will obsolete a pending bast.
	* For example, if dlm_thread queued a bast for an EX lock that
	* was blocking another EX, but before sending the bast the
	* lock owner downconverted to NL, the bast is now obsolete.
	* Only the ast should be sent.
	* This is needed because the lock and convert paths can queue
	* asts out-of-band (not waiting for dlm_thread) in order to
	* allow for LKM_NOQUEUE to get immediate responses. */
	static int dlm_should_cancel_bast(struct dlm_ctxt dlm, struct dlm_lock lock)
	{
	assert_spin_locked(&dlm->ast_lock);
	assert_spin_locked(&lock->spinlock);

	if (lock->ml.highest_blocked == LKM_IVMODE)
	return 0;
	BUG_ON(lock->ml.highest_blocked == LKM_NLMODE);

	if (lock->bast_pending &&
	list_empty(&lock->bast_list))
	/* old bast already sent, ok */
	return 0;

	if (lock->ml.type == LKM_EXMODE)
	/* EX blocks anything left, any bast still valid */
	return 0;
	else if (lock->ml.type == LKM_NLMODE)
	/* NL blocks nothing, no reason to send any bast, cancel it */
	return 1;
	else if (lock->ml.highest_blocked != LKM_EXMODE)
	/* PR only blocks EX */
	return 1;

	return 0;
	}

	static void __dlm_queue_ast(struct dlm_ctxt dlm, struct dlm_lock lock)
	{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	assert_spin_locked(&dlm->ast_lock);
	if (!list_empty(&lock->ast_list)) {
	mlog(ML_ERROR, "ast list not empty!! pending=%d, newlevel=%d\n",
	lock->ast_pending, lock->ml.type);
	BUG();
	}
	BUG_ON(!list_empty(&lock->ast_list));
	if (lock->ast_pending)
	mlog(0, "lock has an ast getting flushed right now\n");

	/* putting lock on list, add a ref */
	dlm_lock_get(lock);
	spin_lock(&lock->spinlock);

	/* check to see if this ast obsoletes the bast */
	if (dlm_should_cancel_bast(dlm, lock)) {
	struct dlm_lock_resource *res = lock->lockres;
	mlog(0, "%s: cancelling bast for %.*s\n",
	dlm->name, res->lockname.len, res->lockname.name);
	lock->bast_pending = 0;
	list_del_init(&lock->bast_list);
	lock->ml.highest_blocked = LKM_IVMODE;
	/* removing lock from list, remove a ref. guaranteed
	* this won't be the last ref because of the get above,
	* so res->spinlock will not be taken here */
	dlm_lock_put(lock);
	/* free up the reserved bast that we are cancelling.
	* guaranteed that this will not be the last reserved
	* ast because both an ast and a bast were reserved
	* to get to this point. the res->spinlock will not be
	* taken here */
	dlm_lockres_release_ast(dlm, res);
	}
	list_add_tail(&lock->ast_list, &dlm->pending_asts);
	lock->ast_pending = 1;
	spin_unlock(&lock->spinlock);
	}

	void dlm_queue_ast(struct dlm_ctxt dlm, struct dlm_lock lock)
	{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	spin_lock(&dlm->ast_lock);
	__dlm_queue_ast(dlm, lock);
	spin_unlock(&dlm->ast_lock);
	}


	static void __dlm_queue_bast(struct dlm_ctxt dlm, struct dlm_lock lock)
	{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);
	assert_spin_locked(&dlm->ast_lock);

	BUG_ON(!list_empty(&lock->bast_list));
	if (lock->bast_pending)
	mlog(0, "lock has a bast getting flushed right now\n");

	/* putting lock on list, add a ref */
	dlm_lock_get(lock);
	spin_lock(&lock->spinlock);
	list_add_tail(&lock->bast_list, &dlm->pending_basts);
	lock->bast_pending = 1;
	spin_unlock(&lock->spinlock);
	}

	void dlm_queue_bast(struct dlm_ctxt dlm, struct dlm_lock lock)
	{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	spin_lock(&dlm->ast_lock);
	__dlm_queue_bast(dlm, lock);
	spin_unlock(&dlm->ast_lock);
	}

	static void dlm_update_lvb(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock)
	{
	struct dlm_lockstatus *lksb = lock->lksb;
	BUG_ON(!lksb);

	/* only updates if this node masters the lockres */
	if (res->owner == dlm->node_num) {

	spin_lock(&res->spinlock);
	/* check the lksb flags for the direction */
	if (lksb->flags & DLM_LKSB_GET_LVB) {
	mlog(0, "getting lvb from lockres for %s node\n",
	lock->ml.node == dlm->node_num ? "master" :
	"remote");
	memcpy(lksb->lvb, res->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);
	}

	/* reset any lvb flags on the lksb */
	lksb->flags &= ~(DLM_LKSB_PUT_LVB\|DLM_LKSB_GET_LVB);
	}

	void dlm_do_local_ast(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock)
	{
	dlm_astlockfunc_t *fn;
	struct dlm_lockstatus *lksb;

	mlog_entry_void();

	lksb = lock->lksb;
	fn = lock->ast;
	BUG_ON(lock->ml.node != dlm->node_num);

	dlm_update_lvb(dlm, res, lock);
	(*fn)(lock->astdata);
	}


	int dlm_do_remote_ast(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock)
	{
	int ret;
	struct dlm_lockstatus *lksb;
	int lksbflags;

	mlog_entry_void();

	lksb = lock->lksb;
	BUG_ON(lock->ml.node == dlm->node_num);

	lksbflags = lksb->flags;
	dlm_update_lvb(dlm, res, lock);

	/* lock request came from another node
	* go do the ast over there */
	ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags);
	return ret;
	}

	void dlm_do_local_bast(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock, int blocked_type)
	{
	dlm_bastlockfunc_t *fn = lock->bast;

	mlog_entry_void();
	BUG_ON(lock->ml.node != dlm->node_num);

	(*fn)(lock->astdata, blocked_type);
	}



	int dlm_proxy_ast_handler(struct o2net_msg msg, u32 len, void data)
	{
	int ret;
	unsigned int locklen;
	struct dlm_ctxt *dlm = data;
	struct dlm_lock_resource *res = NULL;
	struct dlm_lock *lock = NULL;
	struct dlm_proxy_ast past = (struct dlm_proxy_ast ) msg->buf;
	char *name;
	struct list_head iter, head=NULL;
	u64 cookie;
	u32 flags;

	if (!dlm_grab(dlm)) {
	dlm_error(DLM_REJECTED);
	return DLM_REJECTED;
	}

	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
	"Domain %s not fully joined!\n", dlm->name);

	name = past->name;
	locklen = past->namelen;
	cookie = be64_to_cpu(past->cookie);
	flags = be32_to_cpu(past->flags);

	if (locklen > DLM_LOCKID_NAME_MAX) {
	ret = DLM_IVBUFLEN;
	mlog(ML_ERROR, "Invalid name length in proxy ast handler!\n");
	goto leave;
	}

	if ((flags & (LKM_PUT_LVB\|LKM_GET_LVB)) ==
	(LKM_PUT_LVB\|LKM_GET_LVB)) {
	mlog(ML_ERROR, "both PUT and GET lvb specified\n");
	ret = DLM_BADARGS;
	goto leave;
	}

	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
	(flags & LKM_GET_LVB ? "get lvb" : "none"));

	mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type);

	if (past->type != DLM_AST &&
	past->type != DLM_BAST) {
	mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu"
	"name=%.*s\n", past->type,
	dlm_get_lock_cookie_node(cookie),
	dlm_get_lock_cookie_seq(cookie),
	locklen, name);
	ret = DLM_IVLOCKID;
	goto leave;
	}

	res = dlm_lookup_lockres(dlm, name, locklen);
	if (!res) {
	mlog(0, "got %sast for unknown lockres! "
	"cookie=%u:%llu, name=%.*s, namelen=%u\n",
	past->type == DLM_AST ? "" : "b",
	dlm_get_lock_cookie_node(cookie),
	dlm_get_lock_cookie_seq(cookie),
	locklen, name, locklen);
	ret = DLM_IVLOCKID;
	goto leave;
	}

	/* cannot get a proxy ast message if this node owns it */
	BUG_ON(res->owner == dlm->node_num);

	mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name);

	spin_lock(&res->spinlock);
	if (res->state & DLM_LOCK_RES_RECOVERING) {
	mlog(0, "responding with DLM_RECOVERING!\n");
	ret = DLM_RECOVERING;
	goto unlock_out;
	}
	if (res->state & DLM_LOCK_RES_MIGRATING) {
	mlog(0, "responding with DLM_MIGRATING!\n");
	ret = DLM_MIGRATING;
	goto unlock_out;
	}
	/* try convert queue for both ast/bast */
	head = &res->converting;
	lock = NULL;
	list_for_each(iter, head) {
	lock = list_entry (iter, struct dlm_lock, list);
	if (be64_to_cpu(lock->ml.cookie) == cookie)
	goto do_ast;
	}

	/* if not on convert, try blocked for ast, granted for bast */
	if (past->type == DLM_AST)
	head = &res->blocked;
	else
	head = &res->granted;

	list_for_each(iter, head) {
	lock = list_entry (iter, struct dlm_lock, list);
	if (be64_to_cpu(lock->ml.cookie) == cookie)
	goto do_ast;
	}

	mlog(0, "got %sast for unknown lock! cookie=%u:%llu, "
	"name=%.*s, namelen=%u\n", past->type == DLM_AST ? "" : "b",
	dlm_get_lock_cookie_node(cookie), dlm_get_lock_cookie_seq(cookie),
	locklen, name, locklen);

	ret = DLM_NORMAL;
	unlock_out:
	spin_unlock(&res->spinlock);
	goto leave;

	do_ast:
	ret = DLM_NORMAL;
	if (past->type == DLM_AST) {
	/* do not alter lock refcount. switching lists. */
	list_move_tail(&lock->list, &res->granted);
	mlog(0, "ast: adding to granted list... type=%d, "
	"convert_type=%d\n", lock->ml.type, lock->ml.convert_type);
	if (lock->ml.convert_type != LKM_IVMODE) {
	lock->ml.type = lock->ml.convert_type;
	lock->ml.convert_type = LKM_IVMODE;
	} else {
	// should already be there....
	}

	lock->lksb->status = DLM_NORMAL;

	/* if we requested the lvb, fetch it into our lksb now */
	if (flags & LKM_GET_LVB) {
	BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB));
	memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN);
	}
	}
	spin_unlock(&res->spinlock);

	if (past->type == DLM_AST)
	dlm_do_local_ast(dlm, res, lock);
	else
	dlm_do_local_bast(dlm, res, lock, past->blocked_type);

	leave:

	if (res)
	dlm_lockres_put(res);

	dlm_put(dlm);
	return ret;
	}



	int dlm_send_proxy_ast_msg(struct dlm_ctxt dlm, struct dlm_lock_resource res,
	struct dlm_lock *lock, int msg_type,
	int blocked_type, int flags)
	{
	int ret = 0;
	struct dlm_proxy_ast past;
	struct kvec vec[2];
	size_t veclen = 1;
	int status;

	mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n",
	res->lockname.len, res->lockname.name, lock->ml.node,
	msg_type, blocked_type);

	memset(&past, 0, sizeof(struct dlm_proxy_ast));
	past.node_idx = dlm->node_num;
	past.type = msg_type;
	past.blocked_type = blocked_type;
	past.namelen = res->lockname.len;
	memcpy(past.name, res->lockname.name, past.namelen);
	past.cookie = lock->ml.cookie;

	vec[0].iov_len = sizeof(struct dlm_proxy_ast);
	vec[0].iov_base = &past;
	if (flags & DLM_LKSB_GET_LVB) {
	mlog(0, "returning requested LVB data\n");
	be32_add_cpu(&past.flags, LKM_GET_LVB);
	vec[1].iov_len = DLM_LVB_LEN;
	vec[1].iov_base = lock->lksb->lvb;
	veclen++;
	}

	ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
	lock->ml.node, &status);
	if (ret < 0)
	mlog_errno(ret);
	else {
	if (status == DLM_RECOVERING) {
	mlog(ML_ERROR, "sent AST to node %u, it thinks this "
	"node is dead!\n", lock->ml.node);
	BUG();
	} else if (status == DLM_MIGRATING) {
	mlog(ML_ERROR, "sent AST to node %u, it returned "
	"DLM_MIGRATING!\n", lock->ml.node);
	BUG();
	} else if (status != DLM_NORMAL && status != DLM_IVLOCKID) {
	mlog(ML_ERROR, "AST to node %u returned %d!\n",
	lock->ml.node, status);
	/* ignore it */
	}
	ret = 0;
	}
	return ret;
	}