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, 2014, 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 <linux/kthread.h>
  44 #include <libcfs/libcfs.h>
  45
  46 #include <obd_support.h>
  47 #include <obd_class.h>
  48 #include <lustre_net.h>
  49 #include <lustre_sec.h>
  50
  51 #include "ptlrpc_internal.h"
  52
  53 #define SEC_GC_INTERVAL (30 * 60)
  54
  55
  56 static struct mutex sec_gc_mutex;
  57 static spinlock_t sec_gc_list_lock;
  58 static struct list_head sec_gc_list;
  59
  60 static spinlock_t sec_gc_ctx_list_lock;
  61 static struct list_head sec_gc_ctx_list;
  62
  63 static struct ptlrpc_thread sec_gc_thread;
  64 static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
  65
  66
  67 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
  68 {
  69         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
  70         LASSERT(sec->ps_gc_interval > 0);
  71         LASSERT(list_empty(&sec->ps_gc_list));
  72
  73         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
  74
  75         spin_lock(&sec_gc_list_lock);
  76         list_add_tail(&sec->ps_gc_list, &sec_gc_list);
  77         spin_unlock(&sec_gc_list_lock);
  78
  79         CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
  80 }
  81
  82 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
  83 {
  84         if (list_empty(&sec->ps_gc_list))
  85                 return;
  86
  87         might_sleep();
  88
  89         /* signal before list_del to make iteration in gc thread safe */
  90         atomic_inc(&sec_gc_wait_del);
  91
  92         spin_lock(&sec_gc_list_lock);
  93         list_del_init(&sec->ps_gc_list);
  94         spin_unlock(&sec_gc_list_lock);
  95
  96         /* barrier */
  97         mutex_lock(&sec_gc_mutex);
  98         mutex_unlock(&sec_gc_mutex);
  99
 100         atomic_dec(&sec_gc_wait_del);
 101
 102         CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 103 }
 104
 105 void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
 106 {
 107         LASSERT(list_empty(&ctx->cc_gc_chain));
 108
 109         CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
 110                ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 111         spin_lock(&sec_gc_ctx_list_lock);
 112         list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
 113         spin_unlock(&sec_gc_ctx_list_lock);
 114
 115         thread_add_flags(&sec_gc_thread, SVC_SIGNAL);
 116         wake_up(&sec_gc_thread.t_ctl_waitq);
 117 }
 118 EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
 119
 120 static void sec_process_ctx_list(void)
 121 {
 122         struct ptlrpc_cli_ctx *ctx;
 123
 124         spin_lock(&sec_gc_ctx_list_lock);
 125
 126         while (!list_empty(&sec_gc_ctx_list)) {
 127                 ctx = list_entry(sec_gc_ctx_list.next,
 128                                      struct ptlrpc_cli_ctx, cc_gc_chain);
 129                 list_del_init(&ctx->cc_gc_chain);
 130                 spin_unlock(&sec_gc_ctx_list_lock);
 131
 132                 LASSERT(ctx->cc_sec);
 133                 LASSERT(atomic_read(&ctx->cc_refcount) == 1);
 134                 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
 135                        ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 136                 sptlrpc_cli_ctx_put(ctx, 1);
 137
 138                 spin_lock(&sec_gc_ctx_list_lock);
 139         }
 140
 141         spin_unlock(&sec_gc_ctx_list_lock);
 142 }
 143
 144 static void sec_do_gc(struct ptlrpc_sec *sec)
 145 {
 146         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
 147
 148         if (unlikely(sec->ps_gc_next == 0)) {
 149                 CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
 150                       sec, sec->ps_policy->sp_name);
 151                 return;
 152         }
 153
 154         CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 155
 156         if (cfs_time_after(sec->ps_gc_next, cfs_time_current_sec()))
 157                 return;
 158
 159         sec->ps_policy->sp_cops->gc_ctx(sec);
 160         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
 161 }
 162
 163 static int sec_gc_main(void *arg)
 164 {
 165         struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
 166         struct l_wait_info    lwi;
 167
 168         unshare_fs_struct();
 169
 170         /* Record that the thread is running */
 171         thread_set_flags(thread, SVC_RUNNING);
 172         wake_up(&thread->t_ctl_waitq);
 173
 174         while (1) {
 175                 struct ptlrpc_sec *sec;
 176
 177                 thread_clear_flags(thread, SVC_SIGNAL);
 178                 sec_process_ctx_list();
 179 again:
 180                 /* go through sec list do gc.
 181                  * FIXME here we iterate through the whole list each time which
 182                  * is not optimal. we perhaps want to use balanced binary tree
 183                  * to trace each sec as order of expiry time.
 184                  * another issue here is we wakeup as fixed interval instead of
 185                  * according to each sec's expiry time */
 186                 mutex_lock(&sec_gc_mutex);
 187                 list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
 188                         /* if someone is waiting to be deleted, let it
 189                          * proceed as soon as possible. */
 190                         if (atomic_read(&sec_gc_wait_del)) {
 191                                 CDEBUG(D_SEC, "deletion pending, start over\n");
 192                                 mutex_unlock(&sec_gc_mutex);
 193                                 goto again;
 194                         }
 195
 196                         sec_do_gc(sec);
 197                 }
 198                 mutex_unlock(&sec_gc_mutex);
 199
 200                 /* check ctx list again before sleep */
 201                 sec_process_ctx_list();
 202
 203                 lwi = LWI_TIMEOUT(msecs_to_jiffies(SEC_GC_INTERVAL *
 204                                                    MSEC_PER_SEC),
 205                                   NULL, NULL);
 206                 l_wait_event(thread->t_ctl_waitq,
 207                              thread_is_stopping(thread) ||
 208                              thread_is_signal(thread),
 209                              &lwi);
 210
 211                 if (thread_test_and_clear_flags(thread, SVC_STOPPING))
 212                         break;
 213         }
 214
 215         thread_set_flags(thread, SVC_STOPPED);
 216         wake_up(&thread->t_ctl_waitq);
 217         return 0;
 218 }
 219
 220 int sptlrpc_gc_init(void)
 221 {
 222         struct l_wait_info lwi = { 0 };
 223         struct task_struct *task;
 224
 225         mutex_init(&sec_gc_mutex);
 226         spin_lock_init(&sec_gc_list_lock);
 227         spin_lock_init(&sec_gc_ctx_list_lock);
 228
 229         INIT_LIST_HEAD(&sec_gc_list);
 230         INIT_LIST_HEAD(&sec_gc_ctx_list);
 231
 232         /* initialize thread control */
 233         memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
 234         init_waitqueue_head(&sec_gc_thread.t_ctl_waitq);
 235
 236         task = kthread_run(sec_gc_main, &sec_gc_thread, "sptlrpc_gc");
 237         if (IS_ERR(task)) {
 238                 CERROR("can't start gc thread: %ld\n", PTR_ERR(task));
 239                 return PTR_ERR(task);
 240         }
 241
 242         l_wait_event(sec_gc_thread.t_ctl_waitq,
 243                      thread_is_running(&sec_gc_thread), &lwi);
 244         return 0;
 245 }
 246
 247 void sptlrpc_gc_fini(void)
 248 {
 249         struct l_wait_info lwi = { 0 };
 250
 251         thread_set_flags(&sec_gc_thread, SVC_STOPPING);
 252         wake_up(&sec_gc_thread.t_ctl_waitq);
 253
 254         l_wait_event(sec_gc_thread.t_ctl_waitq,
 255                      thread_is_stopped(&sec_gc_thread), &lwi);
 256 }