dlmunlock.c

linux2.6.16版本

			mlog(0, "master was in-progress.  retry\n");
			ret = DLM_FORWARD;
		} else
			ret = status;
		lksb->status = 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);
		}
		lksb->status = ret;
	}

	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)
{
	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;
	/* 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=%"MLFu64"\n",
		     unlock->cookie);
	else {
		/* send the lksb->status back to the other node */
		status = lksb->status;
		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 */
		lksb->status = DLM_NORMAL;
		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 */
		lksb->status = DLM_NORMAL;
		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.  DLM_CANCELGRANT */
		lksb->status = DLM_CANCELGRANT;
		status = DLM_NORMAL;
		*actions = DLM_UNLOCK_CALL_AST;
	} else {
		mlog(ML_ERROR, "lock to cancel is not on any list!\n");
		lksb->status = DLM_IVLOCKID;
		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)) {
		lksb->status = DLM_DENIED;
		status = DLM_DENIED;
		dlm_error(status);
		*actions = 0;
	} else {
		/* unlock granted lock */
		lksb->status = DLM_NORMAL;
		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);
	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, lksb->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, lksb->status);
	}

	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);