xref: /linux/fs/dlm/requestqueue.c (revision af1f459233d4edeef634f559539e7f4b64cb1d25)
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 
19 struct 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 
33 void 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 
68 int 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 
125 void 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 
131 static 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 
156 void 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