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