linux/fs/ocfs2/dlm/dlmlock.c
Kurt Hackel d74c9803a9 ocfs2: Added post handler callable function in o2net message handler
Currently o2net allows one handler function per message type. This
patch adds the ability to call another function to be called after
the handler has returned the message to the other node.

Handlers are now given the option of returning a context (in the form of a
void **) which will be passed back into the post message handler function.

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-02-07 12:06:56 -08:00

750 lines
19 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmlock.c
*
* underlying calls for lock creation
*
* 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 <linux/delay.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"
static DEFINE_SPINLOCK(dlm_cookie_lock);
static u64 dlm_next_cookie = 1;
static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags);
static void dlm_init_lock(struct dlm_lock *newlock, int type,
u8 node, u64 cookie);
static void dlm_lock_release(struct kref *kref);
static void dlm_lock_detach_lockres(struct dlm_lock *lock);
/* Tell us whether we can grant a new lock request.
* locking:
* caller needs: res->spinlock
* taken: none
* held on exit: none
* returns: 1 if the lock can be granted, 0 otherwise.
*/
static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
struct dlm_lock *lock)
{
struct list_head *iter;
struct dlm_lock *tmplock;
list_for_each(iter, &res->granted) {
tmplock = list_entry(iter, struct dlm_lock, list);
if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
return 0;
}
list_for_each(iter, &res->converting) {
tmplock = list_entry(iter, struct dlm_lock, list);
if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
return 0;
}
return 1;
}
/* performs lock creation at the lockres master site
* locking:
* caller needs: none
* taken: takes and drops res->spinlock
* held on exit: none
* returns: DLM_NORMAL, DLM_NOTQUEUED
*/
static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags)
{
int call_ast = 0, kick_thread = 0;
enum dlm_status status = DLM_NORMAL;
mlog_entry("type=%d\n", lock->ml.type);
spin_lock(&res->spinlock);
/* if called from dlm_create_lock_handler, need to
* ensure it will not sleep in dlm_wait_on_lockres */
status = __dlm_lockres_state_to_status(res);
if (status != DLM_NORMAL &&
lock->ml.node != dlm->node_num) {
/* erf. state changed after lock was dropped. */
spin_unlock(&res->spinlock);
dlm_error(status);
return status;
}
__dlm_wait_on_lockres(res);
__dlm_lockres_reserve_ast(res);
if (dlm_can_grant_new_lock(res, lock)) {
mlog(0, "I can grant this lock right away\n");
/* got it right away */
lock->lksb->status = DLM_NORMAL;
status = DLM_NORMAL;
dlm_lock_get(lock);
list_add_tail(&lock->list, &res->granted);
/* for the recovery lock, we can't allow the ast
* to be queued since the dlmthread is already
* frozen. but the recovery lock is always locked
* with LKM_NOQUEUE so we do not need the ast in
* this special case */
if (!dlm_is_recovery_lock(res->lockname.name,
res->lockname.len)) {
kick_thread = 1;
call_ast = 1;
} else {
mlog(0, "%s: returning DLM_NORMAL to "
"node %u for reco lock\n", dlm->name,
lock->ml.node);
}
} else {
/* for NOQUEUE request, unless we get the
* lock right away, return DLM_NOTQUEUED */
if (flags & LKM_NOQUEUE) {
status = DLM_NOTQUEUED;
if (dlm_is_recovery_lock(res->lockname.name,
res->lockname.len)) {
mlog(0, "%s: returning NOTQUEUED to "
"node %u for reco lock\n", dlm->name,
lock->ml.node);
}
} else {
dlm_lock_get(lock);
list_add_tail(&lock->list, &res->blocked);
kick_thread = 1;
}
}
/* reduce the inflight count, this may result in the lockres
* being purged below during calc_usage */
if (lock->ml.node == dlm->node_num)
dlm_lockres_drop_inflight_ref(dlm, res);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
/* either queue the ast or release it */
if (call_ast)
dlm_queue_ast(dlm, lock);
else
dlm_lockres_release_ast(dlm, res);
dlm_lockres_calc_usage(dlm, res);
if (kick_thread)
dlm_kick_thread(dlm, res);
return status;
}
void dlm_revert_pending_lock(struct dlm_lock_resource *res,
struct dlm_lock *lock)
{
/* remove from local queue if it failed */
list_del_init(&lock->list);
lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
}
/*
* locking:
* caller needs: none
* taken: takes and drops res->spinlock
* held on exit: none
* returns: DLM_DENIED, DLM_RECOVERING, or net status
*/
static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
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,
res->lockname.name, flags);
spin_lock(&res->spinlock);
/* will exit this call with spinlock held */
__dlm_wait_on_lockres(res);
res->state |= DLM_LOCK_RES_IN_PROGRESS;
/* add lock to local (secondary) queue */
dlm_lock_get(lock);
list_add_tail(&lock->list, &res->blocked);
lock->lock_pending = 1;
spin_unlock(&res->spinlock);
/* spec seems to say that you will get DLM_NORMAL when the lock
* has been queued, meaning we need to wait for a reply here. */
status = dlm_send_remote_lock_request(dlm, res, lock, flags);
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
lock->lock_pending = 0;
if (status != DLM_NORMAL) {
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,
res->lockname.len)) {
/* special case for the $RECOVERY lock.
* there will never be an AST delivered to put
* this lock on the proper secondary queue
* (granted), so do it manually. */
mlog(0, "%s: $RECOVERY lock for this node (%u) is "
"mastered by %u; got lock, manually granting (no ast)\n",
dlm->name, dlm->node_num, res->owner);
list_move_tail(&lock->list, &res->granted);
}
spin_unlock(&res->spinlock);
if (lockres_changed)
dlm_lockres_calc_usage(dlm, res);
wake_up(&res->wq);
return status;
}
/* for remote lock creation.
* locking:
* caller needs: none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
* taken: none
* held on exit: none
* returns: DLM_NOLOCKMGR, or net status
*/
static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock, int flags)
{
struct dlm_create_lock create;
int tmpret, status = 0;
enum dlm_status ret;
mlog_entry_void();
memset(&create, 0, sizeof(create));
create.node_idx = dlm->node_num;
create.requested_type = lock->ml.type;
create.cookie = lock->ml.cookie;
create.namelen = res->lockname.len;
create.flags = cpu_to_be32(flags);
memcpy(create.name, res->lockname.name, create.namelen);
tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
sizeof(create), res->owner, &status);
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)) {
ret = DLM_RECOVERING;
mlog(0, "node %u died so returning DLM_RECOVERING "
"from lock message!\n", res->owner);
} else {
ret = dlm_err_to_dlm_status(tmpret);
}
}
return ret;
}
void dlm_lock_get(struct dlm_lock *lock)
{
kref_get(&lock->lock_refs);
}
void dlm_lock_put(struct dlm_lock *lock)
{
kref_put(&lock->lock_refs, dlm_lock_release);
}
static void dlm_lock_release(struct kref *kref)
{
struct dlm_lock *lock;
lock = container_of(kref, struct dlm_lock, lock_refs);
BUG_ON(!list_empty(&lock->list));
BUG_ON(!list_empty(&lock->ast_list));
BUG_ON(!list_empty(&lock->bast_list));
BUG_ON(lock->ast_pending);
BUG_ON(lock->bast_pending);
dlm_lock_detach_lockres(lock);
if (lock->lksb_kernel_allocated) {
mlog(0, "freeing kernel-allocated lksb\n");
kfree(lock->lksb);
}
kfree(lock);
}
/* associate a lock with it's lockres, getting a ref on the lockres */
void dlm_lock_attach_lockres(struct dlm_lock *lock,
struct dlm_lock_resource *res)
{
dlm_lockres_get(res);
lock->lockres = res;
}
/* drop ref on lockres, if there is still one associated with lock */
static void dlm_lock_detach_lockres(struct dlm_lock *lock)
{
struct dlm_lock_resource *res;
res = lock->lockres;
if (res) {
lock->lockres = NULL;
mlog(0, "removing lock's lockres reference\n");
dlm_lockres_put(res);
}
}
static void dlm_init_lock(struct dlm_lock *newlock, int type,
u8 node, u64 cookie)
{
INIT_LIST_HEAD(&newlock->list);
INIT_LIST_HEAD(&newlock->ast_list);
INIT_LIST_HEAD(&newlock->bast_list);
spin_lock_init(&newlock->spinlock);
newlock->ml.type = type;
newlock->ml.convert_type = LKM_IVMODE;
newlock->ml.highest_blocked = LKM_IVMODE;
newlock->ml.node = node;
newlock->ml.pad1 = 0;
newlock->ml.list = 0;
newlock->ml.flags = 0;
newlock->ast = NULL;
newlock->bast = NULL;
newlock->astdata = NULL;
newlock->ml.cookie = cpu_to_be64(cookie);
newlock->ast_pending = 0;
newlock->bast_pending = 0;
newlock->convert_pending = 0;
newlock->lock_pending = 0;
newlock->unlock_pending = 0;
newlock->cancel_pending = 0;
newlock->lksb_kernel_allocated = 0;
kref_init(&newlock->lock_refs);
}
struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
struct dlm_lockstatus *lksb)
{
struct dlm_lock *lock;
int kernel_allocated = 0;
lock = kzalloc(sizeof(*lock), GFP_NOFS);
if (!lock)
return NULL;
if (!lksb) {
/* zero memory only if kernel-allocated */
lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
if (!lksb) {
kfree(lock);
return NULL;
}
kernel_allocated = 1;
}
dlm_init_lock(lock, type, node, cookie);
if (kernel_allocated)
lock->lksb_kernel_allocated = 1;
lock->lksb = lksb;
lksb->lockid = lock;
return lock;
}
/* handler for lock creation net message
* locking:
* caller needs: none
* taken: takes and drops res->spinlock
* held on exit: none
* returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
*/
int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
struct dlm_lock_resource *res = NULL;
struct dlm_lock *newlock = NULL;
struct dlm_lockstatus *lksb = NULL;
enum dlm_status status = DLM_NORMAL;
char *name;
unsigned int namelen;
BUG_ON(!dlm);
mlog_entry_void();
if (!dlm_grab(dlm))
return DLM_REJECTED;
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) {
dlm_error(status);
goto leave;
}
status = DLM_SYSERR;
newlock = dlm_new_lock(create->requested_type,
create->node_idx,
be64_to_cpu(create->cookie), NULL);
if (!newlock) {
dlm_error(status);
goto leave;
}
lksb = newlock->lksb;
if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
lksb->flags |= DLM_LKSB_GET_LVB;
mlog(0, "set DLM_LKSB_GET_LVB flag\n");
}
status = DLM_IVLOCKID;
res = dlm_lookup_lockres(dlm, name, namelen);
if (!res) {
dlm_error(status);
goto leave;
}
spin_lock(&res->spinlock);
status = __dlm_lockres_state_to_status(res);
spin_unlock(&res->spinlock);
if (status != DLM_NORMAL) {
mlog(0, "lockres recovering/migrating/in-progress\n");
goto leave;
}
dlm_lock_attach_lockres(newlock, res);
status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
leave:
if (status != DLM_NORMAL)
if (newlock)
dlm_lock_put(newlock);
if (res)
dlm_lockres_put(res);
dlm_put(dlm);
return status;
}
/* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
{
u64 tmpnode = node_num;
/* shift single byte of node num into top 8 bits */
tmpnode <<= 56;
spin_lock(&dlm_cookie_lock);
*cookie = (dlm_next_cookie | tmpnode);
if (++dlm_next_cookie & 0xff00000000000000ull) {
mlog(0, "This node's cookie will now wrap!\n");
dlm_next_cookie = 1;
}
spin_unlock(&dlm_cookie_lock);
}
enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
struct dlm_lockstatus *lksb, int flags,
const char *name, int namelen, dlm_astlockfunc_t *ast,
void *data, dlm_bastlockfunc_t *bast)
{
enum dlm_status status;
struct dlm_lock_resource *res = NULL;
struct dlm_lock *lock = NULL;
int convert = 0, recovery = 0;
/* yes this function is a mess.
* TODO: clean this up. lots of common code in the
* lock and convert paths, especially in the retry blocks */
if (!lksb) {
dlm_error(DLM_BADARGS);
return DLM_BADARGS;
}
status = DLM_BADPARAM;
if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
dlm_error(status);
goto error;
}
if (flags & ~LKM_VALID_FLAGS) {
dlm_error(status);
goto error;
}
convert = (flags & LKM_CONVERT);
recovery = (flags & LKM_RECOVERY);
if (recovery &&
(!dlm_is_recovery_lock(name, namelen) || convert) ) {
dlm_error(status);
goto error;
}
if (convert && (flags & LKM_LOCAL)) {
mlog(ML_ERROR, "strange LOCAL convert request!\n");
goto error;
}
if (convert) {
/* CONVERT request */
/* if converting, must pass in a valid dlm_lock */
lock = lksb->lockid;
if (!lock) {
mlog(ML_ERROR, "NULL lock pointer in convert "
"request\n");
goto error;
}
res = lock->lockres;
if (!res) {
mlog(ML_ERROR, "NULL lockres pointer in convert "
"request\n");
goto error;
}
dlm_lockres_get(res);
/* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
* static after the original lock call. convert requests will
* ensure that everything is the same, or return DLM_BADARGS.
* this means that DLM_DENIED_NOASTS will never be returned.
*/
if (lock->lksb != lksb || lock->ast != ast ||
lock->bast != bast || lock->astdata != data) {
status = DLM_BADARGS;
mlog(ML_ERROR, "new args: lksb=%p, ast=%p, bast=%p, "
"astdata=%p\n", lksb, ast, bast, data);
mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
"astdata=%p\n", lock->lksb, lock->ast,
lock->bast, lock->astdata);
goto error;
}
retry_convert:
dlm_wait_for_recovery(dlm);
if (res->owner == dlm->node_num)
status = dlmconvert_master(dlm, res, lock, flags, mode);
else
status = dlmconvert_remote(dlm, res, lock, flags, mode);
if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
status == DLM_FORWARD) {
/* for now, see how this works without sleeping
* and just retry right away. I suspect the reco
* or migration will complete fast enough that
* no waiting will be necessary */
mlog(0, "retrying convert with migration/recovery/"
"in-progress\n");
msleep(100);
goto retry_convert;
}
} else {
u64 tmpcookie;
/* LOCK request */
status = DLM_BADARGS;
if (!name) {
dlm_error(status);
goto error;
}
status = DLM_IVBUFLEN;
if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
dlm_error(status);
goto error;
}
dlm_get_next_cookie(dlm->node_num, &tmpcookie);
lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
if (!lock) {
dlm_error(status);
goto error;
}
if (!recovery)
dlm_wait_for_recovery(dlm);
/* find or create the lock resource */
res = dlm_get_lock_resource(dlm, name, namelen, flags);
if (!res) {
status = DLM_IVLOCKID;
dlm_error(status);
goto error;
}
mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
dlm_lock_attach_lockres(lock, res);
lock->ast = ast;
lock->bast = bast;
lock->astdata = data;
retry_lock:
if (flags & LKM_VALBLK) {
mlog(0, "LKM_VALBLK passed by caller\n");
/* LVB requests for non PR, PW or EX locks are
* ignored. */
if (mode < LKM_PRMODE)
flags &= ~LKM_VALBLK;
else {
flags |= LKM_GET_LVB;
lock->lksb->flags |= DLM_LKSB_GET_LVB;
}
}
if (res->owner == dlm->node_num)
status = dlmlock_master(dlm, res, lock, flags);
else
status = dlmlock_remote(dlm, res, lock, flags);
if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
status == DLM_FORWARD) {
mlog(0, "retrying lock with migration/"
"recovery/in progress\n");
msleep(100);
/* no waiting for dlm_reco_thread */
if (recovery) {
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;
}
}
if (status != DLM_NORMAL) {
lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
if (status != DLM_NOTQUEUED)
dlm_error(status);
goto error;
}
}
error:
if (status != DLM_NORMAL) {
if (lock && !convert)
dlm_lock_put(lock);
// this is kind of unnecessary
lksb->status = status;
}
/* put lockres ref from the convert path
* or from dlm_get_lock_resource */
if (res)
dlm_lockres_put(res);
return status;
}
EXPORT_SYMBOL_GPL(dlmlock);