1// SPDX-License-Identifier: GPL-2.0-only
2/******************************************************************************
3*******************************************************************************
4**
5**  Copyright (C) 2005-2007 Red Hat, Inc.  All rights reserved.
6**
7**
8*******************************************************************************
9******************************************************************************/
10
11#include "dlm_internal.h"
12#include "member.h"
13#include "lock.h"
14#include "dir.h"
15#include "config.h"
16#include "requestqueue.h"
17#include "util.h"
18
19struct rq_entry {
20	struct list_head list;
21	uint32_t recover_seq;
22	int nodeid;
23	struct dlm_message request;
24};
25
26/*
27 * Requests received while the lockspace is in recovery get added to the
28 * request queue and processed when recovery is complete.  This happens when
29 * the lockspace is suspended on some nodes before it is on others, or the
30 * lockspace is enabled on some while still suspended on others.
31 */
32
33void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid,
34			  const struct dlm_message *ms)
35{
36	struct rq_entry *e;
37	int length = le16_to_cpu(ms->m_header.h_length) -
38		sizeof(struct dlm_message);
39
40	e = kmalloc(sizeof(struct rq_entry) + length, GFP_NOFS);
41	if (!e) {
42		log_print("dlm_add_requestqueue: out of memory len %d", length);
43		return;
44	}
45
46	e->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF;
47	e->nodeid = nodeid;
48	memcpy(&e->request, ms, sizeof(*ms));
49	memcpy(&e->request.m_extra, ms->m_extra, length);
50
51	atomic_inc(&ls->ls_requestqueue_cnt);
52	mutex_lock(&ls->ls_requestqueue_mutex);
53	list_add_tail(&e->list, &ls->ls_requestqueue);
54	mutex_unlock(&ls->ls_requestqueue_mutex);
55}
56
57/*
58 * Called by dlm_recoverd to process normal messages saved while recovery was
59 * happening.  Normal locking has been enabled before this is called.  dlm_recv
60 * upon receiving a message, will wait for all saved messages to be drained
61 * here before processing the message it got.  If a new dlm_ls_stop() arrives
62 * while we're processing these saved messages, it may block trying to suspend
63 * dlm_recv if dlm_recv is waiting for us in dlm_wait_requestqueue.  In that
64 * case, we don't abort since locking_stopped is still 0.  If dlm_recv is not
65 * waiting for us, then this processing may be aborted due to locking_stopped.
66 */
67
68int dlm_process_requestqueue(struct dlm_ls *ls)
69{
70	struct rq_entry *e;
71	struct dlm_message *ms;
72	int error = 0;
73
74	mutex_lock(&ls->ls_requestqueue_mutex);
75
76	for (;;) {
77		if (list_empty(&ls->ls_requestqueue)) {
78			mutex_unlock(&ls->ls_requestqueue_mutex);
79			error = 0;
80			break;
81		}
82		e = list_entry(ls->ls_requestqueue.next, struct rq_entry, list);
83		mutex_unlock(&ls->ls_requestqueue_mutex);
84
85		ms = &e->request;
86
87		log_limit(ls, "dlm_process_requestqueue msg %d from %d "
88			  "lkid %x remid %x result %d seq %u",
89			  le32_to_cpu(ms->m_type),
90			  le32_to_cpu(ms->m_header.h_nodeid),
91			  le32_to_cpu(ms->m_lkid), le32_to_cpu(ms->m_remid),
92			  from_dlm_errno(le32_to_cpu(ms->m_result)),
93			  e->recover_seq);
94
95		dlm_receive_message_saved(ls, &e->request, e->recover_seq);
96
97		mutex_lock(&ls->ls_requestqueue_mutex);
98		list_del(&e->list);
99		if (atomic_dec_and_test(&ls->ls_requestqueue_cnt))
100			wake_up(&ls->ls_requestqueue_wait);
101		kfree(e);
102
103		if (dlm_locking_stopped(ls)) {
104			log_debug(ls, "process_requestqueue abort running");
105			mutex_unlock(&ls->ls_requestqueue_mutex);
106			error = -EINTR;
107			break;
108		}
109		schedule();
110	}
111
112	return error;
113}
114
115/*
116 * After recovery is done, locking is resumed and dlm_recoverd takes all the
117 * saved requests and processes them as they would have been by dlm_recv.  At
118 * the same time, dlm_recv will start receiving new requests from remote nodes.
119 * We want to delay dlm_recv processing new requests until dlm_recoverd has
120 * finished processing the old saved requests.  We don't check for locking
121 * stopped here because dlm_ls_stop won't stop locking until it's suspended us
122 * (dlm_recv).
123 */
124
125void dlm_wait_requestqueue(struct dlm_ls *ls)
126{
127	wait_event(ls->ls_requestqueue_wait,
128		   atomic_read(&ls->ls_requestqueue_cnt) == 0);
129}
130
131static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid)
132{
133	__le32 type = ms->m_type;
134
135	/* the ls is being cleaned up and freed by release_lockspace */
136	if (!atomic_read(&ls->ls_count))
137		return 1;
138
139	if (dlm_is_removed(ls, nodeid))
140		return 1;
141
142	/* directory operations are always purged because the directory is
143	   always rebuilt during recovery and the lookups resent */
144
145	if (type == cpu_to_le32(DLM_MSG_REMOVE) ||
146	    type == cpu_to_le32(DLM_MSG_LOOKUP) ||
147	    type == cpu_to_le32(DLM_MSG_LOOKUP_REPLY))
148		return 1;
149
150	if (!dlm_no_directory(ls))
151		return 0;
152
153	return 1;
154}
155
156void dlm_purge_requestqueue(struct dlm_ls *ls)
157{
158	struct dlm_message *ms;
159	struct rq_entry *e, *safe;
160
161	mutex_lock(&ls->ls_requestqueue_mutex);
162	list_for_each_entry_safe(e, safe, &ls->ls_requestqueue, list) {
163		ms =  &e->request;
164
165		if (purge_request(ls, ms, e->nodeid)) {
166			list_del(&e->list);
167			if (atomic_dec_and_test(&ls->ls_requestqueue_cnt))
168				wake_up(&ls->ls_requestqueue_wait);
169			kfree(e);
170		}
171	}
172	mutex_unlock(&ls->ls_requestqueue_mutex);
173}
174
175