lustre/ptlrpc/sec_gc.c

   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) 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 <libcfs/libcfs.h>
  44
  45 #include <obd_support.h>
  46 #include <obd_class.h>
  47 #include <lustre_net.h>
  48 #include <lustre_sec.h>
  49
  50 #define SEC_GC_INTERVAL (30 * 60)
  51
  52
  53 static struct mutex sec_gc_mutex;
  54 static spinlock_t sec_gc_list_lock;
  55 static struct list_head sec_gc_list;
  56
  57 static spinlock_t sec_gc_ctx_list_lock;
  58 static struct list_head sec_gc_ctx_list;
  59
  60 static struct ptlrpc_thread sec_gc_thread;
  61 static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
  62
  63
  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 = cfs_time_current_sec() + 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
  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
 104 void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
 105 {
 106         LASSERT(list_empty(&ctx->cc_gc_chain));
 107
 108         CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
 109                ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 110         spin_lock(&sec_gc_ctx_list_lock);
 111         list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
 112         spin_unlock(&sec_gc_ctx_list_lock);
 113
 114         thread_add_flags(&sec_gc_thread, SVC_SIGNAL);
 115         wake_up(&sec_gc_thread.t_ctl_waitq);
 116 }
 117 EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
 118
 119 static void sec_process_ctx_list(void)
 120 {
 121         struct ptlrpc_cli_ctx *ctx;
 122
 123         spin_lock(&sec_gc_ctx_list_lock);
 124
 125         while (!list_empty(&sec_gc_ctx_list)) {
 126                 ctx = list_entry(sec_gc_ctx_list.next,
 127                                      struct ptlrpc_cli_ctx, cc_gc_chain);
 128                 list_del_init(&ctx->cc_gc_chain);
 129                 spin_unlock(&sec_gc_ctx_list_lock);
 130
 131                 LASSERT(ctx->cc_sec);
 132                 LASSERT(atomic_read(&ctx->cc_refcount) == 1);
 133                 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
 134                        ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 135                 sptlrpc_cli_ctx_put(ctx, 1);
 136
 137                 spin_lock(&sec_gc_ctx_list_lock);
 138         }
 139
 140         spin_unlock(&sec_gc_ctx_list_lock);
 141 }
 142
 143 static void sec_do_gc(struct ptlrpc_sec *sec)
 144 {
 145         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
 146
 147         if (unlikely(sec->ps_gc_next == 0)) {
 148                 CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
 149                       sec, sec->ps_policy->sp_name);
 150                 return;
 151         }
 152
 153         CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 154
 155         if (cfs_time_after(sec->ps_gc_next, cfs_time_current_sec()))
 156                 return;
 157
 158         sec->ps_policy->sp_cops->gc_ctx(sec);
 159         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
 160 }
 161
 162 static int sec_gc_main(void *arg)
 163 {
 164         struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
 165         struct l_wait_info    lwi;
 166
 167         unshare_fs_struct();
 168
 169         /* Record that the thread is running */
 170         thread_set_flags(thread, SVC_RUNNING);
 171         wake_up(&thread->t_ctl_waitq);
 172
 173         while (1) {
 174                 struct ptlrpc_sec *sec;
 175
 176                 thread_clear_flags(thread, SVC_SIGNAL);
 177                 sec_process_ctx_list();
 178 again:
 179                 /* go through sec list do gc.
 180                  * FIXME here we iterate through the whole list each time which
 181                  * is not optimal. we perhaps want to use balanced binary tree
 182                  * to trace each sec as order of expiry time.
 183                  * another issue here is we wakeup as fixed interval instead of
 184                  * according to each sec's expiry time */
 185                 mutex_lock(&sec_gc_mutex);
 186                 list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
 187                         /* if someone is waiting to be deleted, let it
 188                          * proceed as soon as possible. */
 189                         if (atomic_read(&sec_gc_wait_del)) {
 190                                 CDEBUG(D_SEC, "deletion pending, start over\n");
 191                                 mutex_unlock(&sec_gc_mutex);
 192                                 goto again;
 193                         }
 194
 195                         sec_do_gc(sec);
 196                 }
 197                 mutex_unlock(&sec_gc_mutex);
 198
 199                 /* check ctx list again before sleep */
 200                 sec_process_ctx_list();
 201
 202                 lwi = LWI_TIMEOUT(msecs_to_jiffies(SEC_GC_INTERVAL *
 203                                                    MSEC_PER_SEC),
 204                                   NULL, NULL);
 205                 l_wait_event(thread->t_ctl_waitq,
 206                              thread_is_stopping(thread) ||
 207                              thread_is_signal(thread),
 208                              &lwi);
 209
 210                 if (thread_test_and_clear_flags(thread, SVC_STOPPING))
 211                         break;
 212         }
 213
 214         thread_set_flags(thread, SVC_STOPPED);
 215         wake_up(&thread->t_ctl_waitq);
 216         return 0;
 217 }
 218
 219 int sptlrpc_gc_init(void)
 220 {
 221         struct l_wait_info lwi = { 0 };
 222         struct task_struct *task;
 223
 224         mutex_init(&sec_gc_mutex);
 225         spin_lock_init(&sec_gc_list_lock);
 226         spin_lock_init(&sec_gc_ctx_list_lock);
 227
 228         INIT_LIST_HEAD(&sec_gc_list);
 229         INIT_LIST_HEAD(&sec_gc_ctx_list);
 230
 231         /* initialize thread control */
 232         memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
 233         init_waitqueue_head(&sec_gc_thread.t_ctl_waitq);
 234
 235         task = kthread_run(sec_gc_main, &sec_gc_thread, "sptlrpc_gc");
 236         if (IS_ERR(task)) {
 237                 CERROR("can't start gc thread: %ld\n", PTR_ERR(task));
 238                 return PTR_ERR(task);
 239         }
 240
 241         l_wait_event(sec_gc_thread.t_ctl_waitq,
 242                      thread_is_running(&sec_gc_thread), &lwi);
 243         return 0;
 244 }
 245
 246 void sptlrpc_gc_fini(void)
 247 {
 248         struct l_wait_info lwi = { 0 };
 249
 250         thread_set_flags(&sec_gc_thread, SVC_STOPPING);
 251         wake_up(&sec_gc_thread.t_ctl_waitq);
 252
 253         l_wait_event(sec_gc_thread.t_ctl_waitq,
 254                      thread_is_stopped(&sec_gc_thread), &lwi);
 255 }
 256