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(size: 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(v: &ls->ls_requestqueue_cnt);
52 mutex_lock(&ls->ls_requestqueue_mutex);
53 list_add_tail(new: &e->list, head: &ls->ls_requestqueue);
54 mutex_unlock(lock: &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(head: &ls->ls_requestqueue)) {
78 mutex_unlock(lock: &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(lock: &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, ms: &e->request, saved_seq: e->recover_seq);
96
97 mutex_lock(&ls->ls_requestqueue_mutex);
98 list_del(entry: &e->list);
99 if (atomic_dec_and_test(v: &ls->ls_requestqueue_cnt))
100 wake_up(&ls->ls_requestqueue_wait);
101 kfree(objp: e);
102
103 if (dlm_locking_stopped(ls)) {
104 log_debug(ls, "process_requestqueue abort running");
105 mutex_unlock(lock: &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(v: &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, nodeid: e->nodeid)) {
166 list_del(entry: &e->list);
167 if (atomic_dec_and_test(v: &ls->ls_requestqueue_cnt))
168 wake_up(&ls->ls_requestqueue_wait);
169 kfree(objp: e);
170 }
171 }
172 mutex_unlock(lock: &ls->ls_requestqueue_mutex);
173}
174
175

source code of linux/fs/dlm/requestqueue.c