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 #ifndef __KERNEL__
  44 #include <liblustre.h>
  45 #else
  46 #include <libcfs/libcfs.h>
  47 #endif
  48
  49 #include <obd_support.h>
  50 #include <obd_class.h>
  51 #include <lustre_net.h>
  52 #include <lustre_sec.h>
  53
  54 #define SEC_GC_INTERVAL (30 * 60)
  55
  56 #ifdef __KERNEL__
  57
  58 static struct mutex sec_gc_mutex;
  59 static CFS_LIST_HEAD(sec_gc_list);
  60 static spinlock_t sec_gc_list_lock;
  61
  62 static CFS_LIST_HEAD(sec_gc_ctx_list);
  63 static spinlock_t sec_gc_ctx_list_lock;
  64
  65 static struct ptlrpc_thread sec_gc_thread;
  66 static cfs_atomic_t sec_gc_wait_del = CFS_ATOMIC_INIT(0);
  67
  68
  69 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
  70 {
  71         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
  72         LASSERT(sec->ps_gc_interval > 0);
  73         LASSERT(cfs_list_empty(&sec->ps_gc_list));
  74
  75         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
  76
  77         spin_lock(&sec_gc_list_lock);
  78         cfs_list_add_tail(&sec_gc_list, &sec->ps_gc_list);
  79         spin_unlock(&sec_gc_list_lock);
  80
  81         CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
  82 }
  83 EXPORT_SYMBOL(sptlrpc_gc_add_sec);
  84
  85 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
  86 {
  87         if (cfs_list_empty(&sec->ps_gc_list))
  88                 return;
  89
  90         cfs_might_sleep();
  91
  92         /* signal before list_del to make iteration in gc thread safe */
  93         cfs_atomic_inc(&sec_gc_wait_del);
  94
  95         spin_lock(&sec_gc_list_lock);
  96         cfs_list_del_init(&sec->ps_gc_list);
  97         spin_unlock(&sec_gc_list_lock);
  98
  99         /* barrier */
 100         mutex_lock(&sec_gc_mutex);
 101         mutex_unlock(&sec_gc_mutex);
 102
 103         cfs_atomic_dec(&sec_gc_wait_del);
 104
 105         CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 106 }
 107 EXPORT_SYMBOL(sptlrpc_gc_del_sec);
 108
 109 void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
 110 {
 111         LASSERT(cfs_list_empty(&ctx->cc_gc_chain));
 112
 113         CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
 114                ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 115         spin_lock(&sec_gc_ctx_list_lock);
 116         cfs_list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
 117         spin_unlock(&sec_gc_ctx_list_lock);
 118
 119         thread_add_flags(&sec_gc_thread, SVC_SIGNAL);
 120         wake_up(&sec_gc_thread.t_ctl_waitq);
 121 }
 122 EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
 123
 124 static void sec_process_ctx_list(void)
 125 {
 126         struct ptlrpc_cli_ctx *ctx;
 127
 128         spin_lock(&sec_gc_ctx_list_lock);
 129
 130         while (!cfs_list_empty(&sec_gc_ctx_list)) {
 131                 ctx = cfs_list_entry(sec_gc_ctx_list.next,
 132                                      struct ptlrpc_cli_ctx, cc_gc_chain);
 133                 cfs_list_del_init(&ctx->cc_gc_chain);
 134                 spin_unlock(&sec_gc_ctx_list_lock);
 135
 136                 LASSERT(ctx->cc_sec);
 137                 LASSERT(cfs_atomic_read(&ctx->cc_refcount) == 1);
 138                 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
 139                        ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 140                 sptlrpc_cli_ctx_put(ctx, 1);
 141
 142                 spin_lock(&sec_gc_ctx_list_lock);
 143         }
 144
 145         spin_unlock(&sec_gc_ctx_list_lock);
 146 }
 147
 148 static void sec_do_gc(struct ptlrpc_sec *sec)
 149 {
 150         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
 151
 152         if (unlikely(sec->ps_gc_next == 0)) {
 153                 CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
 154                       sec, sec->ps_policy->sp_name);
 155                 return;
 156         }
 157
 158         CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 159
 160         if (cfs_time_after(sec->ps_gc_next, cfs_time_current_sec()))
 161                 return;
 162
 163         sec->ps_policy->sp_cops->gc_ctx(sec);
 164         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
 165 }
 166
 167 static int sec_gc_main(void *arg)
 168 {
 169         struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
 170         struct l_wait_info    lwi;
 171
 172         unshare_fs_struct();
 173
 174         /* Record that the thread is running */
 175         thread_set_flags(thread, SVC_RUNNING);
 176         wake_up(&thread->t_ctl_waitq);
 177
 178         while (1) {
 179                 struct ptlrpc_sec *sec;
 180
 181                 thread_clear_flags(thread, SVC_SIGNAL);
 182                 sec_process_ctx_list();
 183 again:
 184                 /* go through sec list do gc.
 185                  * FIXME here we iterate through the whole list each time which
 186                  * is not optimal. we perhaps want to use balanced binary tree
 187                  * to trace each sec as order of expiry time.
 188                  * another issue here is we wakeup as fixed interval instead of
 189                  * according to each sec's expiry time */
 190                 mutex_lock(&sec_gc_mutex);
 191                 cfs_list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
 192                         /* if someone is waiting to be deleted, let it
 193                          * proceed as soon as possible. */
 194                         if (cfs_atomic_read(&sec_gc_wait_del)) {
 195                                 CDEBUG(D_SEC, "deletion pending, start over\n");
 196                                 mutex_unlock(&sec_gc_mutex);
 197                                 goto again;
 198                         }
 199
 200                         sec_do_gc(sec);
 201                 }
 202                 mutex_unlock(&sec_gc_mutex);
 203
 204                 /* check ctx list again before sleep */
 205                 sec_process_ctx_list();
 206
 207                 lwi = LWI_TIMEOUT(SEC_GC_INTERVAL * HZ, NULL, NULL);
 208                 l_wait_event(thread->t_ctl_waitq,
 209                              thread_is_stopping(thread) ||
 210                              thread_is_signal(thread),
 211                              &lwi);
 212
 213                 if (thread_test_and_clear_flags(thread, SVC_STOPPING))
 214                         break;
 215         }
 216
 217         thread_set_flags(thread, SVC_STOPPED);
 218         wake_up(&thread->t_ctl_waitq);
 219         return 0;
 220 }
 221
 222 int sptlrpc_gc_init(void)
 223 {
 224         struct l_wait_info lwi = { 0 };
 225         struct task_struct *task;
 226
 227         mutex_init(&sec_gc_mutex);
 228         spin_lock_init(&sec_gc_list_lock);
 229         spin_lock_init(&sec_gc_ctx_list_lock);
 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
 257 #else /* !__KERNEL__ */
 258
 259 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
 260 {
 261 }
 262 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
 263 {
 264 }
 265 int sptlrpc_gc_init(void)
 266 {
 267         return 0;
 268 }
 269 void sptlrpc_gc_fini(void)
 270 {
 271 }
 272
 273 #endif /* __KERNEL__ */