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.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2016, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/ptlrpc/sec_gc.c
  33  *
  34  * Author: Eric Mei <ericm@clusterfs.com>
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_SEC
  38
  39 #include <linux/kthread.h>
  40 #include <libcfs/libcfs.h>
  41
  42 #include <obd_support.h>
  43 #include <obd_class.h>
  44 #include <lustre_net.h>
  45 #include <lustre_sec.h>
  46
  47 #include "ptlrpc_internal.h"
  48
  49 #define SEC_GC_INTERVAL (30 * 60)
  50
  51
  52 static struct mutex sec_gc_mutex;
  53 static spinlock_t sec_gc_list_lock;
  54 static struct list_head sec_gc_list;
  55
  56 static spinlock_t sec_gc_ctx_list_lock;
  57 static struct list_head sec_gc_ctx_list;
  58
  59 static struct ptlrpc_thread sec_gc_thread;
  60 static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
  61
  62
  63 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
  64 {
  65         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
  66         LASSERT(sec->ps_gc_interval > 0);
  67         LASSERT(list_empty(&sec->ps_gc_list));
  68
  69         sec->ps_gc_next = ktime_get_real_seconds() + sec->ps_gc_interval;
  70
  71         spin_lock(&sec_gc_list_lock);
  72         list_add_tail(&sec->ps_gc_list, &sec_gc_list);
  73         spin_unlock(&sec_gc_list_lock);
  74
  75         CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
  76 }
  77
  78 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
  79 {
  80         if (list_empty(&sec->ps_gc_list))
  81                 return;
  82
  83         might_sleep();
  84
  85         /* signal before list_del to make iteration in gc thread safe */
  86         atomic_inc(&sec_gc_wait_del);
  87
  88         spin_lock(&sec_gc_list_lock);
  89         list_del_init(&sec->ps_gc_list);
  90         spin_unlock(&sec_gc_list_lock);
  91
  92         /* barrier */
  93         mutex_lock(&sec_gc_mutex);
  94         mutex_unlock(&sec_gc_mutex);
  95
  96         atomic_dec(&sec_gc_wait_del);
  97
  98         CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
  99 }
 100
 101 void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
 102 {
 103         LASSERT(list_empty(&ctx->cc_gc_chain));
 104
 105         CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
 106                ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 107         spin_lock(&sec_gc_ctx_list_lock);
 108         list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
 109         spin_unlock(&sec_gc_ctx_list_lock);
 110
 111         thread_add_flags(&sec_gc_thread, SVC_SIGNAL);
 112         wake_up(&sec_gc_thread.t_ctl_waitq);
 113 }
 114 EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
 115
 116 static void sec_process_ctx_list(void)
 117 {
 118         struct ptlrpc_cli_ctx *ctx;
 119
 120         spin_lock(&sec_gc_ctx_list_lock);
 121
 122         while (!list_empty(&sec_gc_ctx_list)) {
 123                 ctx = list_entry(sec_gc_ctx_list.next,
 124                                      struct ptlrpc_cli_ctx, cc_gc_chain);
 125                 list_del_init(&ctx->cc_gc_chain);
 126                 spin_unlock(&sec_gc_ctx_list_lock);
 127
 128                 LASSERT(ctx->cc_sec);
 129                 LASSERT(atomic_read(&ctx->cc_refcount) == 1);
 130                 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
 131                        ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 132                 sptlrpc_cli_ctx_put(ctx, 1);
 133
 134                 spin_lock(&sec_gc_ctx_list_lock);
 135         }
 136
 137         spin_unlock(&sec_gc_ctx_list_lock);
 138 }
 139
 140 static void sec_do_gc(struct ptlrpc_sec *sec)
 141 {
 142         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
 143
 144         if (unlikely(sec->ps_gc_next == 0)) {
 145                 CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
 146                       sec, sec->ps_policy->sp_name);
 147                 return;
 148         }
 149
 150         CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 151
 152         if (sec->ps_gc_next > ktime_get_real_seconds())
 153                 return;
 154
 155         sec->ps_policy->sp_cops->gc_ctx(sec);
 156         sec->ps_gc_next = ktime_get_real_seconds() + sec->ps_gc_interval;
 157 }
 158
 159 static int sec_gc_main(void *arg)
 160 {
 161         struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
 162         struct l_wait_info    lwi;
 163
 164         unshare_fs_struct();
 165
 166         /* Record that the thread is running */
 167         thread_set_flags(thread, SVC_RUNNING);
 168         wake_up(&thread->t_ctl_waitq);
 169
 170         while (1) {
 171                 struct ptlrpc_sec *sec;
 172
 173                 thread_clear_flags(thread, SVC_SIGNAL);
 174                 sec_process_ctx_list();
 175 again:
 176                 /* go through sec list do gc.
 177                  * FIXME here we iterate through the whole list each time which
 178                  * is not optimal. we perhaps want to use balanced binary tree
 179                  * to trace each sec as order of expiry time.
 180                  * another issue here is we wakeup as fixed interval instead of
 181                  * according to each sec's expiry time */
 182                 mutex_lock(&sec_gc_mutex);
 183                 list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
 184                         /* if someone is waiting to be deleted, let it
 185                          * proceed as soon as possible. */
 186                         if (atomic_read(&sec_gc_wait_del)) {
 187                                 CDEBUG(D_SEC, "deletion pending, start over\n");
 188                                 mutex_unlock(&sec_gc_mutex);
 189                                 goto again;
 190                         }
 191
 192                         sec_do_gc(sec);
 193                 }
 194                 mutex_unlock(&sec_gc_mutex);
 195
 196                 /* check ctx list again before sleep */
 197                 sec_process_ctx_list();
 198
 199                 lwi = LWI_TIMEOUT(msecs_to_jiffies(SEC_GC_INTERVAL *
 200                                                    MSEC_PER_SEC),
 201                                   NULL, NULL);
 202                 l_wait_event(thread->t_ctl_waitq,
 203                              thread_is_stopping(thread) ||
 204                              thread_is_signal(thread),
 205                              &lwi);
 206
 207                 if (thread_test_and_clear_flags(thread, SVC_STOPPING))
 208                         break;
 209         }
 210
 211         thread_set_flags(thread, SVC_STOPPED);
 212         wake_up(&thread->t_ctl_waitq);
 213         return 0;
 214 }
 215
 216 int sptlrpc_gc_init(void)
 217 {
 218         struct l_wait_info lwi = { 0 };
 219         struct task_struct *task;
 220
 221         mutex_init(&sec_gc_mutex);
 222         spin_lock_init(&sec_gc_list_lock);
 223         spin_lock_init(&sec_gc_ctx_list_lock);
 224
 225         INIT_LIST_HEAD(&sec_gc_list);
 226         INIT_LIST_HEAD(&sec_gc_ctx_list);
 227
 228         /* initialize thread control */
 229         memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
 230         init_waitqueue_head(&sec_gc_thread.t_ctl_waitq);
 231
 232         task = kthread_run(sec_gc_main, &sec_gc_thread, "sptlrpc_gc");
 233         if (IS_ERR(task)) {
 234                 CERROR("can't start gc thread: %ld\n", PTR_ERR(task));
 235                 return PTR_ERR(task);
 236         }
 237
 238         l_wait_event(sec_gc_thread.t_ctl_waitq,
 239                      thread_is_running(&sec_gc_thread), &lwi);
 240         return 0;
 241 }
 242
 243 void sptlrpc_gc_fini(void)
 244 {
 245         struct l_wait_info lwi = { 0 };
 246
 247         thread_set_flags(&sec_gc_thread, SVC_STOPPING);
 248         wake_up(&sec_gc_thread.t_ctl_waitq);
 249
 250         l_wait_event(sec_gc_thread.t_ctl_waitq,
 251                      thread_is_stopped(&sec_gc_thread), &lwi);
 252 }