1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * lustre/ptlrpc/sec_gc.c
37 *
38 * Author: Eric Mei <ericm@clusterfs.com>
39 */
40
41 #define DEBUG_SUBSYSTEM S_SEC
42
43 #include "../../include/linux/libcfs/libcfs.h"
44
45 #include "../include/obd_support.h"
46 #include "../include/obd_class.h"
47 #include "../include/lustre_net.h"
48 #include "../include/lustre_sec.h"
49
50 #include "ptlrpc_internal.h"
51
52 #define SEC_GC_INTERVAL (30 * 60)
53
54 static struct mutex sec_gc_mutex;
55 static LIST_HEAD(sec_gc_list);
56 static spinlock_t sec_gc_list_lock;
57
58 static LIST_HEAD(sec_gc_ctx_list);
59 static spinlock_t sec_gc_ctx_list_lock;
60
61 static struct ptlrpc_thread sec_gc_thread;
62 static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
63
sptlrpc_gc_add_sec(struct ptlrpc_sec * sec)64 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
65 {
66 LASSERT(sec->ps_policy->sp_cops->gc_ctx);
67 LASSERT(sec->ps_gc_interval > 0);
68 LASSERT(list_empty(&sec->ps_gc_list));
69
70 sec->ps_gc_next = ktime_get_real_seconds() + sec->ps_gc_interval;
71
72 spin_lock(&sec_gc_list_lock);
73 list_add_tail(&sec_gc_list, &sec->ps_gc_list);
74 spin_unlock(&sec_gc_list_lock);
75
76 CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
77 }
78 EXPORT_SYMBOL(sptlrpc_gc_add_sec);
79
sptlrpc_gc_del_sec(struct ptlrpc_sec * sec)80 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
81 {
82 if (list_empty(&sec->ps_gc_list))
83 return;
84
85 might_sleep();
86
87 /* signal before list_del to make iteration in gc thread safe */
88 atomic_inc(&sec_gc_wait_del);
89
90 spin_lock(&sec_gc_list_lock);
91 list_del_init(&sec->ps_gc_list);
92 spin_unlock(&sec_gc_list_lock);
93
94 /* barrier */
95 mutex_lock(&sec_gc_mutex);
96 mutex_unlock(&sec_gc_mutex);
97
98 atomic_dec(&sec_gc_wait_del);
99
100 CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
101 }
102 EXPORT_SYMBOL(sptlrpc_gc_del_sec);
103
sec_process_ctx_list(void)104 static void sec_process_ctx_list(void)
105 {
106 struct ptlrpc_cli_ctx *ctx;
107
108 spin_lock(&sec_gc_ctx_list_lock);
109
110 while (!list_empty(&sec_gc_ctx_list)) {
111 ctx = list_entry(sec_gc_ctx_list.next,
112 struct ptlrpc_cli_ctx, cc_gc_chain);
113 list_del_init(&ctx->cc_gc_chain);
114 spin_unlock(&sec_gc_ctx_list_lock);
115
116 LASSERT(ctx->cc_sec);
117 LASSERT(atomic_read(&ctx->cc_refcount) == 1);
118 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
119 ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
120 sptlrpc_cli_ctx_put(ctx, 1);
121
122 spin_lock(&sec_gc_ctx_list_lock);
123 }
124
125 spin_unlock(&sec_gc_ctx_list_lock);
126 }
127
sec_do_gc(struct ptlrpc_sec * sec)128 static void sec_do_gc(struct ptlrpc_sec *sec)
129 {
130 LASSERT(sec->ps_policy->sp_cops->gc_ctx);
131
132 if (unlikely(sec->ps_gc_next == 0)) {
133 CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
134 sec, sec->ps_policy->sp_name);
135 return;
136 }
137
138 CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
139
140 if (sec->ps_gc_next > ktime_get_real_seconds())
141 return;
142
143 sec->ps_policy->sp_cops->gc_ctx(sec);
144 sec->ps_gc_next = ktime_get_real_seconds() + sec->ps_gc_interval;
145 }
146
sec_gc_main(void * arg)147 static int sec_gc_main(void *arg)
148 {
149 struct ptlrpc_thread *thread = arg;
150 struct l_wait_info lwi;
151
152 unshare_fs_struct();
153
154 /* Record that the thread is running */
155 thread_set_flags(thread, SVC_RUNNING);
156 wake_up(&thread->t_ctl_waitq);
157
158 while (1) {
159 struct ptlrpc_sec *sec;
160
161 thread_clear_flags(thread, SVC_SIGNAL);
162 sec_process_ctx_list();
163 again:
164 /* go through sec list do gc.
165 * FIXME here we iterate through the whole list each time which
166 * is not optimal. we perhaps want to use balanced binary tree
167 * to trace each sec as order of expiry time.
168 * another issue here is we wakeup as fixed interval instead of
169 * according to each sec's expiry time */
170 mutex_lock(&sec_gc_mutex);
171 list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
172 /* if someone is waiting to be deleted, let it
173 * proceed as soon as possible. */
174 if (atomic_read(&sec_gc_wait_del)) {
175 CDEBUG(D_SEC, "deletion pending, start over\n");
176 mutex_unlock(&sec_gc_mutex);
177 goto again;
178 }
179
180 sec_do_gc(sec);
181 }
182 mutex_unlock(&sec_gc_mutex);
183
184 /* check ctx list again before sleep */
185 sec_process_ctx_list();
186
187 lwi = LWI_TIMEOUT(SEC_GC_INTERVAL * HZ, NULL, NULL);
188 l_wait_event(thread->t_ctl_waitq,
189 thread_is_stopping(thread) ||
190 thread_is_signal(thread),
191 &lwi);
192
193 if (thread_test_and_clear_flags(thread, SVC_STOPPING))
194 break;
195 }
196
197 thread_set_flags(thread, SVC_STOPPED);
198 wake_up(&thread->t_ctl_waitq);
199 return 0;
200 }
201
sptlrpc_gc_init(void)202 int sptlrpc_gc_init(void)
203 {
204 struct l_wait_info lwi = { 0 };
205 struct task_struct *task;
206
207 mutex_init(&sec_gc_mutex);
208 spin_lock_init(&sec_gc_list_lock);
209 spin_lock_init(&sec_gc_ctx_list_lock);
210
211 /* initialize thread control */
212 memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
213 init_waitqueue_head(&sec_gc_thread.t_ctl_waitq);
214
215 task = kthread_run(sec_gc_main, &sec_gc_thread, "sptlrpc_gc");
216 if (IS_ERR(task)) {
217 CERROR("can't start gc thread: %ld\n", PTR_ERR(task));
218 return PTR_ERR(task);
219 }
220
221 l_wait_event(sec_gc_thread.t_ctl_waitq,
222 thread_is_running(&sec_gc_thread), &lwi);
223 return 0;
224 }
225
sptlrpc_gc_fini(void)226 void sptlrpc_gc_fini(void)
227 {
228 struct l_wait_info lwi = { 0 };
229
230 thread_set_flags(&sec_gc_thread, SVC_STOPPING);
231 wake_up(&sec_gc_thread.t_ctl_waitq);
232
233 l_wait_event(sec_gc_thread.t_ctl_waitq,
234 thread_is_stopped(&sec_gc_thread), &lwi);
235 }
236