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DEFINITIONS
This source file includes following definitions.
- dlm_should_cancel_bast
- __dlm_queue_ast
- dlm_queue_ast
- __dlm_queue_bast
- dlm_queue_bast
- dlm_update_lvb
- dlm_do_local_ast
- dlm_do_remote_ast
- dlm_do_local_bast
- dlm_proxy_ast_handler
- dlm_send_proxy_ast_msg
/* -*- 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 "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,
void **ret_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;
}