/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmconvert.c
*
* underlying calls for lock conversion
*
* 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"
#include "dlmconvert.h"
#define MLOG_MASK_PREFIX ML_DLM
#include "cluster/masklog.h"
/* NOTE: __dlmconvert_master is the only function in here that
* needs a spinlock held on entry (res->spinlock) and it is the
* only one that holds a lock on exit (res->spinlock).
* All other functions in here need no locks and drop all of
* the locks that they acquire. */
static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags,
int type, int *call_ast,
int *kick_thread);
static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags, int type);
/*
* this is only called directly by dlmlock(), and only when the
* local node is the owner of the lockres
* locking:
* caller needs: none
* taken: takes and drops res->spinlock
* held on exit: none
* returns: see __dlmconvert_master
*/
enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags, int type)
{
int call_ast = 0, kick_thread = 0;
enum dlm_status status;
spin_lock(&res->spinlock);
/* we are not in a network handler, this is fine */
__dlm_wait_on_lockres(res);
__dlm_lockres_reserve_ast(res);
res->state |= DLM_LOCK_RES_IN_PROGRESS;
status = __dlmconvert_master(dlm, res, lock, flags, type,
&call_ast, &kick_thread);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
spin_unlock(&res->spinlock);
wake_up(&res->wq);
if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
dlm_error(status);
/* either queue the ast or release it */
if (call_ast)
dlm_queue_ast(dlm, lock);
else
dlm_lockres_release_ast(dlm, res);
if (kick_thread)
dlm_kick_thread(dlm, res);
return status;
}
/* performs lock conversion at the lockres master site
* locking:
* caller needs: res->spinlock
* taken: takes and drops lock->spinlock
* held on exit: res->spinlock
* returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
* call_ast: whether ast should be called for this lock
* kick_thread: whether dlm_kick_thread should be called
*/
static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags,
int type, int *call_ast,
int *kick_thread)
{
enum dlm_status status = DLM_NORMAL;
struct list_head *iter;
struct dlm_lock *tmplock=NULL;
assert_spin_locked(&res->spinlock);
mlog_entry("type=%d, convert_type=%d, new convert_type=%d\n",
lock->ml.type, lock->ml.convert_type, type);
spin_lock(&lock->spinlock);
/* already converting? */
if (lock->ml.convert_type != LKM_IVMODE) {
mlog(ML_ERROR, "attempted to convert a lock with a lock "
"conversion pending\n");
status = DLM_DENIED;
goto unlock_exit;
}
/* must be on grant queue to convert */
if (!dlm_lock_on_list(&res->granted, lock)) {
mlog(ML_ERROR, "attempted to convert a lock not on grant "
"queue\n");
status = DLM_DENIED;
goto unlock_exit;
}
if (flags & LKM_VALBLK) {
switch (lock->ml.type) {
case LKM_EXMODE:
/* EX + LKM_VALBLK + convert == set lvb */
mlog(0, "will set lvb: converting %s->%s\n",
dlm_lock_mode_name(lock->ml.type),
dlm_lock_mode_name(type));
lock->lksb->flags |= DLM_LKSB_PUT_LVB;
break;
case LKM_PRMODE:
case LKM_NLMODE:
/* refetch if new level is not NL */
if (type > LKM_NLMODE) {
mlog(0, "will fetch new value into "
"lvb: converting %s->%s\n",
dlm_lock_mode_name(lock->ml.type),
dlm_lock_mode_name(type));
lock->lksb->flags |= DLM_LKSB_GET_LVB;
} else {
mlog(0, "will NOT fetch new value "
"into lvb: converting %s->%s\n",
dlm_lock_mode_name(lock->ml.type),
dlm_lock_mode_name(type));
flags &= ~(LKM_VALBLK);
}
break;
}
}
/* in-place downconvert? */
if (type <= lock->ml.type)
goto grant;
/* upconvert from here on */
status = DLM_NORMAL;
list_for_each(iter, &res->granted) {
tmplock = list_entry(iter, struct dlm_lock, list);
if (tmplock == lock)
continue;
if (!dlm_lock_compatible(tmplock->ml.type, type))
goto switch_queues;
}
list_for_each(iter, &res->converting) {
tmplock = list_entry(iter, struct dlm_lock, list);
if (!dlm_lock_compatible(tmplock->ml.type, type))
goto switch_queues;
/* existing conversion requests take precedence */
if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
goto switch_queues;
}
/* fall thru to grant */
grant:
mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
res->lockname.name, dlm_lock_mode_name(type));
/* immediately grant the new lock type */
lock->lksb->status = DLM_NORMAL;
if (lock->ml.node == dlm->node_num)
mlog(0, "doing in-place convert for nonlocal lock\n");
lock->ml.type = type;
status = DLM_NORMAL;
*call_ast = 1;
goto unlock_exit;
switch_queues:
if (flags & LKM_NOQUEUE) {
mlog(0, "failed to convert NOQUEUE lock %.*s from "
"%d to %d...\n", res->lockname.len, res->lockname.name,
lock->ml.type, type);
status = DLM_NOTQUEUED;
goto unlock_exit;
}
mlog(0, "res %.*s, queueing...\n", res->lockname.len,
res->lockname.name);
lock->ml.convert_type = type;
/* do not alter lock refcount. switching lists. */
list_del_init(&lock->list);
list_add_tail(&lock->list, &res->converting);
unlock_exit:
spin_unlock(&lock->spinlock);
if (status == DLM_DENIED) {
__dlm_print_one_lock_resource(res);
}
if (status == DLM_NORMAL)
*kick_thread = 1;
return status;
}
void dlm_revert_pending_convert(struct dlm_lock_resource *res,
struct dlm_lock *lock)
{
/* do not alter lock refcount. switching lists. */
list_del_init(&lock->list);
list_add_tail(&lock->list, &res->granted);
lock->ml.convert_type = LKM_IVMODE;
lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
}
/* messages the master site to do lock conversion
* locking:
* caller needs: none
* taken: takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
* held on exit: none
* returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
*/
enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags, int type)
{
enum dlm_status status;
mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
spin_lock(&res->spinlock);
if (res->state & DLM_LOCK_RES_RECOVERING) {
mlog(0, "bailing out early since res is RECOVERING "
"on secondary queue\n");
/* __dlm_print_one_lock_resource(res); */
status = DLM_RECOVERING;
goto bail;
}
/* will exit this call with spinlock held */
__dlm_wait_on_lockres(res);
if (lock->ml.convert_type != LKM_IVMODE) {
__dlm_print_one_lock_resource(res);
mlog(ML_ERROR, "converting a remote lock that is already "
"converting! (cookie=%u:%llu, conv=%d)\n",
dlm_get_lock_cookie_node(lock->ml.cookie),
dlm_get_lock_cookie_seq(lock->ml.cookie),
lock->ml.convert_type);
status = DLM_DENIED;
goto bail;
}
res->state |= DLM_LOCK_RES_IN_PROGRESS;
/* move lock to local convert queue */
/* do not alter lock refcount. switching lists. */
list_del_init(&lock->list);
list_add_tail(&lock->list, &res->converting);
lock->convert_pending = 1;
lock->ml.convert_type = type;
if (flags & LKM_VALBLK) {
if (lock->ml.type == LKM_EXMODE) {
flags |= LKM_PUT_LVB;
lock->lksb->flags |= DLM_LKSB_PUT_LVB;
} else {
if (lock->ml.convert_type == LKM_NLMODE)
flags &= ~LKM_VALBLK;
else {
flags |= LKM_GET_LVB;
lock->lksb->flags |= DLM_LKSB_GET_LVB;
}
}
}
spin_unlock(&res->spinlock);
/* no locks held here.
* need to wait for a reply as to whether it got queued or not. */
status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
lock->convert_pending = 0;
/* if it failed, move it back to granted queue */
if (status != DLM_NORMAL) {
if (status != DLM_NOTQUEUED)
dlm_error(status);
dlm_revert_pending_convert(res, lock);
}
bail:
spin_unlock(&res->spinlock);
/* TODO: should this be a wake_one? */
/* wake up any IN_PROGRESS waiters */
wake_up(&res->wq);
return status;
}
/* sends DLM_CONVERT_LOCK_MSG to master site
* locking:
* caller needs: none
* taken: none
* held on exit: none
* returns: DLM_NOLOCKMGR, status from remote node
*/
static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags, int type)
{
struct dlm_convert_lock convert;
int tmpret;
enum dlm_status ret;
int status = 0;
struct kvec vec[2];
size_t veclen = 1;
mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
memset(&convert, 0, sizeof(struct dlm_convert_lock));
convert.node_idx = dlm->node_num;
convert.requested_type = type;
convert.cookie = lock->ml.cookie;
convert.namelen = res->lockname.len;
convert.flags = cpu_to_be32(flags);
memcpy(convert.name, res->lockname.name, convert.namelen);
vec[0].iov_len = sizeof(struct dlm_convert_lock);
vec[0].iov_base = &convert;
if (flags & LKM_PUT_LVB) {
/* extra data to send if we are updating lvb */
vec[1].iov_len = DLM_LVB_LEN;
vec[1].iov_base = lock->lksb->lvb;
veclen++;
}
tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
vec, veclen, res->owner, &status);
if (tmpret >= 0) {
// successfully sent and received
ret = status; // this is already a dlm_status
if (ret == DLM_RECOVERING) {
mlog(0, "node %u returned DLM_RECOVERING from convert "
"message!\n", res->owner);
} else if (ret == DLM_MIGRATING) {
mlog(0, "node %u returned DLM_MIGRATING from convert "
"message!\n", res->owner);
} else if (ret == DLM_FORWARD) {
mlog(0, "node %u returned DLM_FORWARD from convert "
"message!\n", res->owner);
} else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
dlm_error(ret);
} else {
mlog_errno(tmpret);
if (dlm_is_host_down(tmpret)) {
/* instead of logging the same network error over
* and over, sleep here and wait for the heartbeat
* to notice the node is dead. times out after 5s. */
dlm_wait_for_node_death(dlm, res->owner,
DLM_NODE_DEATH_WAIT_MAX);
ret = DLM_RECOVERING;
mlog(0, "node %u died so returning DLM_RECOVERING "
"from convert message!\n", res->owner);
} else {
ret = dlm_err_to_dlm_status(tmpret);
}
}
return ret;
}
/* handler for DLM_CONVERT_LOCK_MSG on master site
* locking:
* caller needs: none
* taken: takes and drop res->spinlock
* held on exit: none
* returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
* status from __dlmconvert_master
*/
int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data)
{
struct dlm_ctxt *dlm = data;
struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
struct dlm_lock_resource *res = NULL;
struct list_head *iter;
struct dlm_lock *lock = NULL;
struct dlm_lockstatus *lksb;
enum dlm_status status = DLM_NORMAL;
u32 flags;
int call_ast = 0, kick_thread = 0, ast_reserved = 0;
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);
if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
status = DLM_IVBUFLEN;
dlm_error(status);
goto leave;
}
flags = be32_to_cpu(cnv->flags);
if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
(LKM_PUT_LVB|LKM_GET_LVB)) {
mlog(ML_ERROR, "both PUT and GET lvb specified\n");
status = DLM_BADARGS;
goto leave;
}
mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
(flags & LKM_GET_LVB ? "get lvb" : "none"));
status = DLM_IVLOCKID;
res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
if (!res) {
dlm_error(status);
goto leave;
}
spin_lock(&res->spinlock);
list_for_each(iter, &res->granted) {
lock = list_entry(iter, struct dlm_lock, list);
if (lock->ml.cookie == cnv->cookie &&
lock->ml.node == cnv->node_idx) {
dlm_lock_get(lock);
break;
}
lock = NULL;
}
spin_unlock(&res->spinlock);
if (!lock) {
status = DLM_IVLOCKID;
dlm_error(status);
goto leave;
}
/* found the lock */
lksb = lock->lksb;
/* see if caller needed to get/put lvb */
if (flags & LKM_PUT_LVB) {
BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
lksb->flags |= DLM_LKSB_PUT_LVB;
memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
} else if (flags & LKM_GET_LVB) {
BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
lksb->flags |= DLM_LKSB_GET_LVB;
}
spin_lock(&res->spinlock);
status = __dlm_lockres_state_to_status(res);
if (status == DLM_NORMAL) {
__dlm_lockres_reserve_ast(res);
ast_reserved = 1;
res->state |= DLM_LOCK_RES_IN_PROGRESS;
status = __dlmconvert_master(dlm, res, lock, flags,
cnv->requested_type,
&call_ast, &kick_thread);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
}
spin_unlock(&res->spinlock);
if (status != DLM_NORMAL) {
if (status != DLM_NOTQUEUED)
dlm_error(status);
lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
}
leave:
if (!lock)
mlog(ML_ERROR, "did not find lock to convert on grant queue! "
"cookie=%u:%llu\n",
dlm_get_lock_cookie_node(cnv->cookie),
dlm_get_lock_cookie_seq(cnv->cookie));
else
dlm_lock_put(lock);
/* either queue the ast or release it, if reserved */
if (call_ast)
dlm_queue_ast(dlm, lock);
else if (ast_reserved)
dlm_lockres_release_ast(dlm, res);
if (kick_thread)
dlm_kick_thread(dlm, res);
if (res)
dlm_lockres_put(res);
dlm_put(dlm);
return status;
}
