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