/*****************************************************************************************************************************************************************  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.****  This copyrighted material is made available to anyone wishing to use,**  modify, copy, or redistribute it subject to the terms and conditions**  of the GNU General Public License v.2.***************************************************************************************************************************************************************/ #include "dlm_internal.h"#include "member.h"#include "lock.h"#include "dir.h"#include "config.h"#include "requestqueue.h" struct rq_entry {	struct list_head list;	int nodeid;	char request[1];}; /* * Requests received while the lockspace is in recovery get added to the * request queue and processed when recovery is complete.  This happens when * the lockspace is suspended on some nodes before it is on others, or the * lockspace is enabled on some while still suspended on others. */ int dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_header *hd){	struct rq_entry *e;	int length = hd->h_length;	int rv = 0; 	e = kmalloc(sizeof(struct rq_entry) + length, GFP_KERNEL);	if (!e) {		log_print("dlm_add_requestqueue: out of memory\n");		return 0;	} 	e->nodeid = nodeid;	memcpy(e->request, hd, length); 	/* We need to check dlm_locking_stopped() after taking the mutex to	   avoid a race where dlm_recoverd enables locking and runs	   process_requestqueue between our earlier dlm_locking_stopped check	   and this addition to the requestqueue. */ 	mutex_lock(&ls->ls_requestqueue_mutex);	if (dlm_locking_stopped(ls))		list_add_tail(&e->list, &ls->ls_requestqueue);	else {		log_debug(ls, "dlm_add_requestqueue skip from %d", nodeid);		kfree(e);		rv = -EAGAIN;	}	mutex_unlock(&ls->ls_requestqueue_mutex);	return rv;} int dlm_process_requestqueue(struct dlm_ls *ls){	struct rq_entry *e;	struct dlm_header *hd;	int error = 0; 	mutex_lock(&ls->ls_requestqueue_mutex); 	for (;;) {		if (list_empty(&ls->ls_requestqueue)) {			mutex_unlock(&ls->ls_requestqueue_mutex);			error = 0;			break;		}		e = list_entry(ls->ls_requestqueue.next, struct rq_entry, list);		mutex_unlock(&ls->ls_requestqueue_mutex); 		hd = (struct dlm_header *) e->request;		error = dlm_receive_message(hd, e->nodeid, 1); 		if (error == -EINTR) {			/* entry is left on requestqueue */			log_debug(ls, "process_requestqueue abort eintr");			break;		} 		mutex_lock(&ls->ls_requestqueue_mutex);		list_del(&e->list);		kfree(e); 		if (dlm_locking_stopped(ls)) {			log_debug(ls, "process_requestqueue abort running");			mutex_unlock(&ls->ls_requestqueue_mutex);			error = -EINTR;			break;		}		schedule();	} 	return error;} /* * After recovery is done, locking is resumed and dlm_recoverd takes all the * saved requests and processes them as they would have been by dlm_recvd.  At * the same time, dlm_recvd will start receiving new requests from remote * nodes.  We want to delay dlm_recvd processing new requests until * dlm_recoverd has finished processing the old saved requests. */ void dlm_wait_requestqueue(struct dlm_ls *ls){	for (;;) {		mutex_lock(&ls->ls_requestqueue_mutex);		if (list_empty(&ls->ls_requestqueue))			break;		if (dlm_locking_stopped(ls))			break;		mutex_unlock(&ls->ls_requestqueue_mutex);		schedule();	}	mutex_unlock(&ls->ls_requestqueue_mutex);} static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid){	uint32_t type = ms->m_type; 	/* the ls is being cleaned up and freed by release_lockspace */	if (!ls->ls_count)		return 1; 	if (dlm_is_removed(ls, nodeid))		return 1; 	/* directory operations are always purged because the directory is	   always rebuilt during recovery and the lookups resent */ 	if (type == DLM_MSG_REMOVE ||	    type == DLM_MSG_LOOKUP ||	    type == DLM_MSG_LOOKUP_REPLY)		return 1; 	if (!dlm_no_directory(ls))		return 0; 	/* with no directory, the master is likely to change as a part of	   recovery; requests to/from the defunct master need to be purged */ 	switch (type) {	case DLM_MSG_REQUEST:	case DLM_MSG_CONVERT:	case DLM_MSG_UNLOCK:	case DLM_MSG_CANCEL:		/* we're no longer the master of this resource, the sender		   will resend to the new master (see waiter_needs_recovery) */ 		if (dlm_hash2nodeid(ls, ms->m_hash) != dlm_our_nodeid())			return 1;		break; 	case DLM_MSG_REQUEST_REPLY:	case DLM_MSG_CONVERT_REPLY:	case DLM_MSG_UNLOCK_REPLY:	case DLM_MSG_CANCEL_REPLY:	case DLM_MSG_GRANT:		/* this reply is from the former master of the resource,		   we'll resend to the new master if needed */ 		if (dlm_hash2nodeid(ls, ms->m_hash) != nodeid)			return 1;		break;	} 	return 0;} void dlm_purge_requestqueue(struct dlm_ls *ls){	struct dlm_message *ms;	struct rq_entry *e, *safe; 	mutex_lock(&ls->ls_requestqueue_mutex);	list_for_each_entry_safe(e, safe, &ls->ls_requestqueue, list) {		ms = (struct dlm_message *) e->request; 		if (purge_request(ls, ms, e->nodeid)) {			list_del(&e->list);			kfree(e);		}	}	mutex_unlock(&ls->ls_requestqueue_mutex);}