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linux/fs/ocfs2/dlm/dlmunlock.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

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmunlock.c
*
* underlying calls for unlocking locks
*
* 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"
#define MLOG_MASK_PREFIX ML_DLM
#include "cluster/masklog.h"
#define DLM_UNLOCK_FREE_LOCK 0x00000001
#define DLM_UNLOCK_CALL_AST 0x00000002
#define DLM_UNLOCK_REMOVE_LOCK 0x00000004
#define DLM_UNLOCK_REGRANT_LOCK 0x00000008
#define DLM_UNLOCK_CLEAR_CONVERT_TYPE 0x00000010
static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int *actions);
static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int *actions);
static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int flags,
u8 owner);
/*
* according to the spec:
* http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf
*
* flags & LKM_CANCEL != 0: must be converting or blocked
* flags & LKM_CANCEL == 0: must be granted
*
* So to unlock a converting lock, you must first cancel the
* convert (passing LKM_CANCEL in flags), then call the unlock
* again (with no LKM_CANCEL in flags).
*/
/*
* locking:
* caller needs: none
* taken: res->spinlock and lock->spinlock taken and dropped
* held on exit: none
* returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
* all callers should have taken an extra ref on lock coming in
*/
static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int flags, int *call_ast,
int master_node)
{
enum dlm_status status;
int actions = 0;
int in_use;
u8 owner;
mlog(0, "master_node = %d, valblk = %d\n", master_node,
flags & LKM_VALBLK);
if (master_node)
BUG_ON(res->owner != dlm->node_num);
else
BUG_ON(res->owner == dlm->node_num);
spin_lock(&dlm->spinlock);
/* We want to be sure that we're not freeing a lock
* that still has AST's pending... */
in_use = !list_empty(&lock->ast_list);
spin_unlock(&dlm->spinlock);
if (in_use) {
mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock "
"while waiting for an ast!", res->lockname.len,
res->lockname.name);
return DLM_BADPARAM;
}
spin_lock(&res->spinlock);
if (res->state & DLM_LOCK_RES_IN_PROGRESS) {
if (master_node) {
mlog(ML_ERROR, "lockres in progress!\n");
spin_unlock(&res->spinlock);
return DLM_FORWARD;
}
/* ok for this to sleep if not in a network handler */
__dlm_wait_on_lockres(res);
res->state |= DLM_LOCK_RES_IN_PROGRESS;
}
spin_lock(&lock->spinlock);
if (res->state & DLM_LOCK_RES_RECOVERING) {
status = DLM_RECOVERING;
goto leave;
}
if (res->state & DLM_LOCK_RES_MIGRATING) {
status = DLM_MIGRATING;
goto leave;
}
/* see above for what the spec says about
* LKM_CANCEL and the lock queue state */
if (flags & LKM_CANCEL)
status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions);
else
status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions);
if (status != DLM_NORMAL && (status != DLM_CANCELGRANT || !master_node))
goto leave;
/* By now this has been masked out of cancel requests. */
if (flags & LKM_VALBLK) {
/* make the final update to the lvb */
if (master_node)
memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN);
else
flags |= LKM_PUT_LVB; /* let the send function
* handle it. */
}
if (!master_node) {
owner = res->owner;
/* drop locks and send message */
if (flags & LKM_CANCEL)
lock->cancel_pending = 1;
else
lock->unlock_pending = 1;
spin_unlock(&lock->spinlock);
spin_unlock(&res->spinlock);
status = dlm_send_remote_unlock_request(dlm, res, lock, lksb,
flags, owner);
spin_lock(&res->spinlock);
spin_lock(&lock->spinlock);
/* if the master told us the lock was already granted,
* let the ast handle all of these actions */
if (status == DLM_CANCELGRANT) {
actions &= ~(DLM_UNLOCK_REMOVE_LOCK|
DLM_UNLOCK_REGRANT_LOCK|
DLM_UNLOCK_CLEAR_CONVERT_TYPE);
} else if (status == DLM_RECOVERING ||
status == DLM_MIGRATING ||
status == DLM_FORWARD) {
/* must clear the actions because this unlock
* is about to be retried. cannot free or do
* any list manipulation. */
mlog(0, "%s:%.*s: clearing actions, %s\n",
dlm->name, res->lockname.len,
res->lockname.name,
status==DLM_RECOVERING?"recovering":
(status==DLM_MIGRATING?"migrating":
"forward"));
actions = 0;
}
if (flags & LKM_CANCEL)
lock->cancel_pending = 0;
else
lock->unlock_pending = 0;
}
/* get an extra ref on lock. if we are just switching
* lists here, we dont want the lock to go away. */
dlm_lock_get(lock);
if (actions & DLM_UNLOCK_REMOVE_LOCK) {
list_del_init(&lock->list);
dlm_lock_put(lock);
}
if (actions & DLM_UNLOCK_REGRANT_LOCK) {
dlm_lock_get(lock);
list_add_tail(&lock->list, &res->granted);
}
if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) {
mlog(0, "clearing convert_type at %smaster node\n",
master_node ? "" : "non-");
lock->ml.convert_type = LKM_IVMODE;
}
/* remove the extra ref on lock */
dlm_lock_put(lock);
leave:
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
if (!dlm_lock_on_list(&res->converting, lock))
BUG_ON(lock->ml.convert_type != LKM_IVMODE);
else
BUG_ON(lock->ml.convert_type == LKM_IVMODE);
spin_unlock(&lock->spinlock);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
/* let the caller's final dlm_lock_put handle the actual kfree */
if (actions & DLM_UNLOCK_FREE_LOCK) {
/* this should always be coupled with list removal */
BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK));
mlog(0, "lock %u:%llu should be gone now! refs=%d\n",
dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
atomic_read(&lock->lock_refs.refcount)-1);
dlm_lock_put(lock);
}
if (actions & DLM_UNLOCK_CALL_AST)
*call_ast = 1;
/* if cancel or unlock succeeded, lvb work is done */
if (status == DLM_NORMAL)
lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
return status;
}
void dlm_commit_pending_unlock(struct dlm_lock_resource *res,
struct dlm_lock *lock)
{
/* leave DLM_LKSB_PUT_LVB on the lksb so any final
* update of the lvb will be sent to the new master */
list_del_init(&lock->list);
}
void dlm_commit_pending_cancel(struct dlm_lock_resource *res,
struct dlm_lock *lock)
{
list_move_tail(&lock->list, &res->granted);
lock->ml.convert_type = LKM_IVMODE;
}
static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int flags,
int *call_ast)
{
return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1);
}
static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int flags, int *call_ast)
{
return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0);
}
/*
* locking:
* caller needs: none
* taken: none
* held on exit: none
* returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
*/
static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int flags,
u8 owner)
{
struct dlm_unlock_lock unlock;
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);
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);
unlock.cookie = lock->ml.cookie;
unlock.namelen = res->lockname.len;
memcpy(unlock.name, res->lockname.name, unlock.namelen);
vec[0].iov_len = sizeof(struct dlm_unlock_lock);
vec[0].iov_base = &unlock;
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_UNLOCK_LOCK_MSG, dlm->key,
vec, veclen, owner, &status);
if (tmpret >= 0) {
// successfully sent and received
if (status == DLM_FORWARD)
mlog(0, "master was in-progress. retry\n");
ret = status;
} else {
mlog_errno(tmpret);
if (dlm_is_host_down(tmpret)) {
/* NOTE: this seems strange, but it is what we want.
* when the master goes down during a cancel or
* unlock, the recovery code completes the operation
* as if the master had not died, then passes the
* updated state to the recovery master. this thread
* just needs to finish out the operation and call
* the unlockast. */
ret = DLM_NORMAL;
} else {
/* something bad. this will BUG in ocfs2 */
ret = dlm_err_to_dlm_status(tmpret);
}
}
return ret;
}
/*
* locking:
* caller needs: none
* taken: takes and drops res->spinlock
* held on exit: none
* returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID,
* return value from dlmunlock_master
*/
int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf;
struct dlm_lock_resource *res = NULL;
struct list_head *iter;
struct dlm_lock *lock = NULL;
enum dlm_status status = DLM_NORMAL;
int found = 0, i;
struct dlm_lockstatus *lksb = NULL;
int ignore;
u32 flags;
struct list_head *queue;
flags = be32_to_cpu(unlock->flags);
if (flags & LKM_GET_LVB) {
mlog(ML_ERROR, "bad args! GET_LVB specified on unlock!\n");
return DLM_BADARGS;
}
if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) {
mlog(ML_ERROR, "bad args! cannot modify lvb on a CANCEL "
"request!\n");
return DLM_BADARGS;
}
if (unlock->namelen > DLM_LOCKID_NAME_MAX) {
mlog(ML_ERROR, "Invalid name length in unlock handler!\n");
return DLM_IVBUFLEN;
}
if (!dlm_grab(dlm))
return DLM_REJECTED;
mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
"Domain %s not fully joined!\n", dlm->name);
mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none");
res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen);
if (!res) {
/* We assume here that a no lock resource simply means
* it was migrated away and destroyed before the other
* node could detect it. */
mlog(0, "returning DLM_FORWARD -- res no longer exists\n");
status = DLM_FORWARD;
goto not_found;
}
queue=&res->granted;
found = 0;
spin_lock(&res->spinlock);
if (res->state & DLM_LOCK_RES_RECOVERING) {
spin_unlock(&res->spinlock);
mlog(0, "returning DLM_RECOVERING\n");
status = DLM_RECOVERING;
goto leave;
}
if (res->state & DLM_LOCK_RES_MIGRATING) {
spin_unlock(&res->spinlock);
mlog(0, "returning DLM_MIGRATING\n");
status = DLM_MIGRATING;
goto leave;
}
if (res->owner != dlm->node_num) {
spin_unlock(&res->spinlock);
mlog(0, "returning DLM_FORWARD -- not master\n");
status = DLM_FORWARD;
goto leave;
}
for (i=0; i<3; i++) {
list_for_each(iter, queue) {
lock = list_entry(iter, struct dlm_lock, list);
if (lock->ml.cookie == unlock->cookie &&
lock->ml.node == unlock->node_idx) {
dlm_lock_get(lock);
found = 1;
break;
}
}
if (found)
break;
/* scan granted -> converting -> blocked queues */
queue++;
}
spin_unlock(&res->spinlock);
if (!found) {
status = DLM_IVLOCKID;
goto not_found;
}
/* lock was found on queue */
lksb = lock->lksb;
if (flags & (LKM_VALBLK|LKM_PUT_LVB) &&
lock->ml.type != LKM_EXMODE)
flags &= ~(LKM_VALBLK|LKM_PUT_LVB);
/* unlockast only called on originating node */
if (flags & LKM_PUT_LVB) {
lksb->flags |= DLM_LKSB_PUT_LVB;
memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN);
}
/* if this is in-progress, propagate the DLM_FORWARD
* all the way back out */
status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore);
if (status == DLM_FORWARD)
mlog(0, "lockres is in progress\n");
if (flags & LKM_PUT_LVB)
lksb->flags &= ~DLM_LKSB_PUT_LVB;
dlm_lockres_calc_usage(dlm, res);
dlm_kick_thread(dlm, res);
not_found:
if (!found)
mlog(ML_ERROR, "failed to find lock to unlock! "
"cookie=%u:%llu\n",
dlm_get_lock_cookie_node(be64_to_cpu(unlock->cookie)),
dlm_get_lock_cookie_seq(be64_to_cpu(unlock->cookie)));
else
dlm_lock_put(lock);
leave:
if (res)
dlm_lockres_put(res);
dlm_put(dlm);
return status;
}
static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int *actions)
{
enum dlm_status status;
if (dlm_lock_on_list(&res->blocked, lock)) {
/* cancel this outright */
status = DLM_NORMAL;
*actions = (DLM_UNLOCK_CALL_AST |
DLM_UNLOCK_REMOVE_LOCK);
} else if (dlm_lock_on_list(&res->converting, lock)) {
/* cancel the request, put back on granted */
status = DLM_NORMAL;
*actions = (DLM_UNLOCK_CALL_AST |
DLM_UNLOCK_REMOVE_LOCK |
DLM_UNLOCK_REGRANT_LOCK |
DLM_UNLOCK_CLEAR_CONVERT_TYPE);
} else if (dlm_lock_on_list(&res->granted, lock)) {
/* too late, already granted. */
status = DLM_CANCELGRANT;
*actions = DLM_UNLOCK_CALL_AST;
} else {
mlog(ML_ERROR, "lock to cancel is not on any list!\n");
status = DLM_IVLOCKID;
*actions = 0;
}
return status;
}
static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_lock *lock,
struct dlm_lockstatus *lksb,
int *actions)
{
enum dlm_status status;
/* unlock request */
if (!dlm_lock_on_list(&res->granted, lock)) {
status = DLM_DENIED;
dlm_error(status);
*actions = 0;
} else {
/* unlock granted lock */
status = DLM_NORMAL;
*actions = (DLM_UNLOCK_FREE_LOCK |
DLM_UNLOCK_CALL_AST |
DLM_UNLOCK_REMOVE_LOCK);
}
return status;
}
/* there seems to be no point in doing this async
* since (even for the remote case) there is really
* no work to queue up... so just do it and fire the
* unlockast by hand when done... */
enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb,
int flags, dlm_astunlockfunc_t *unlockast, void *data)
{
enum dlm_status status;
struct dlm_lock_resource *res;
struct dlm_lock *lock = NULL;
int call_ast, is_master;
mlog_entry_void();
if (!lksb) {
dlm_error(DLM_BADARGS);
return DLM_BADARGS;
}
if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) {
dlm_error(DLM_BADPARAM);
return DLM_BADPARAM;
}
if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) {
mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n");
flags &= ~LKM_VALBLK;
}
if (!lksb->lockid || !lksb->lockid->lockres) {
dlm_error(DLM_BADPARAM);
return DLM_BADPARAM;
}
lock = lksb->lockid;
BUG_ON(!lock);
dlm_lock_get(lock);
res = lock->lockres;
BUG_ON(!res);
dlm_lockres_get(res);
retry:
call_ast = 0;
/* need to retry up here because owner may have changed */
mlog(0, "lock=%p res=%p\n", lock, res);
spin_lock(&res->spinlock);
is_master = (res->owner == dlm->node_num);
if (flags & LKM_VALBLK && lock->ml.type != LKM_EXMODE)
flags &= ~LKM_VALBLK;
spin_unlock(&res->spinlock);
if (is_master) {
status = dlmunlock_master(dlm, res, lock, lksb, flags,
&call_ast);
mlog(0, "done calling dlmunlock_master: returned %d, "
"call_ast is %d\n", status, call_ast);
} else {
status = dlmunlock_remote(dlm, res, lock, lksb, flags,
&call_ast);
mlog(0, "done calling dlmunlock_remote: returned %d, "
"call_ast is %d\n", status, call_ast);
}
if (status == DLM_RECOVERING ||
status == DLM_MIGRATING ||
status == DLM_FORWARD) {
/* We want to go away for a tiny bit to allow recovery
* / migration to complete on this resource. I don't
* know of any wait queue we could sleep on as this
* may be happening on another node. Perhaps the
* proper solution is to queue up requests on the
* other end? */
/* do we want to yield(); ?? */
msleep(50);
mlog(0, "retrying unlock due to pending recovery/"
"migration/in-progress\n");
goto retry;
}
if (call_ast) {
mlog(0, "calling unlockast(%p, %d)\n", data, status);
if (is_master) {
/* it is possible that there is one last bast
* pending. make sure it is flushed, then
* call the unlockast.
* not an issue if this is a mastered remotely,
* since this lock has been removed from the
* lockres queues and cannot be found. */
dlm_kick_thread(dlm, NULL);
wait_event(dlm->ast_wq,
dlm_lock_basts_flushed(dlm, lock));
}
(*unlockast)(data, status);
}
if (status == DLM_CANCELGRANT)
status = DLM_NORMAL;
if (status == DLM_NORMAL) {
mlog(0, "kicking the thread\n");
dlm_kick_thread(dlm, res);
} else
dlm_error(status);
dlm_lockres_calc_usage(dlm, res);
dlm_lockres_put(res);
dlm_lock_put(lock);
mlog(0, "returning status=%d!\n", status);
return status;
}
EXPORT_SYMBOL_GPL(dlmunlock);
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