lustre/ptlrpc/sec_gc.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see [sun.com URL with a
  20  * copy of GPLv2].
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  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 #ifndef EXPORT_SYMTAB
  42 # define EXPORT_SYMTAB
  43 #endif
  44 #define DEBUG_SUBSYSTEM S_SEC
  45
  46 #ifndef __KERNEL__
  47 #include <liblustre.h>
  48 #else
  49 #include <libcfs/libcfs.h>
  50 #endif
  51
  52 #include <obd_support.h>
  53 #include <obd_class.h>
  54 #include <lustre_net.h>
  55 #include <lustre_sec.h>
  56
  57 #define SEC_GC_INTERVAL (30 * 60)
  58
  59 #ifdef __KERNEL__
  60
  61 static DECLARE_MUTEX(sec_gc_mutex);
  62 static CFS_LIST_HEAD(sec_gc_list);
  63 static spinlock_t sec_gc_list_lock = SPIN_LOCK_UNLOCKED;
  64
  65 static CFS_LIST_HEAD(sec_gc_ctx_list);
  66 static spinlock_t sec_gc_ctx_list_lock = SPIN_LOCK_UNLOCKED;
  67
  68 static struct ptlrpc_thread sec_gc_thread;
  69 static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
  70
  71
  72 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
  73 {
  74         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
  75         LASSERT(sec->ps_gc_interval > 0);
  76         LASSERT(list_empty(&sec->ps_gc_list));
  77
  78         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
  79
  80         spin_lock(&sec_gc_list_lock);
  81         list_add_tail(&sec_gc_list, &sec->ps_gc_list);
  82         spin_unlock(&sec_gc_list_lock);
  83
  84         CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
  85 }
  86 EXPORT_SYMBOL(sptlrpc_gc_add_sec);
  87
  88 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
  89 {
  90         if (list_empty(&sec->ps_gc_list))
  91                 return;
  92
  93         might_sleep();
  94
  95         /* signal before list_del to make iteration in gc thread safe */
  96         atomic_inc(&sec_gc_wait_del);
  97
  98         spin_lock(&sec_gc_list_lock);
  99         list_del_init(&sec->ps_gc_list);
 100         spin_unlock(&sec_gc_list_lock);
 101
 102         /* barrier */
 103         mutex_down(&sec_gc_mutex);
 104         mutex_up(&sec_gc_mutex);
 105
 106         atomic_dec(&sec_gc_wait_del);
 107
 108         CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 109 }
 110 EXPORT_SYMBOL(sptlrpc_gc_del_sec);
 111
 112 void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
 113 {
 114         LASSERT(list_empty(&ctx->cc_gc_chain));
 115
 116         CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
 117                ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 118         spin_lock(&sec_gc_ctx_list_lock);
 119         list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
 120         spin_unlock(&sec_gc_ctx_list_lock);
 121
 122         sec_gc_thread.t_flags |= SVC_SIGNAL;
 123         cfs_waitq_signal(&sec_gc_thread.t_ctl_waitq);
 124 }
 125 EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
 126
 127 static void sec_process_ctx_list(void)
 128 {
 129         struct ptlrpc_cli_ctx *ctx;
 130
 131         spin_lock(&sec_gc_ctx_list_lock);
 132
 133         while (!list_empty(&sec_gc_ctx_list)) {
 134                 ctx = list_entry(sec_gc_ctx_list.next,
 135                                  struct ptlrpc_cli_ctx, cc_gc_chain);
 136                 list_del_init(&ctx->cc_gc_chain);
 137                 spin_unlock(&sec_gc_ctx_list_lock);
 138
 139                 LASSERT(ctx->cc_sec);
 140                 LASSERT(atomic_read(&ctx->cc_refcount) == 1);
 141                 CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
 142                        ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
 143                 sptlrpc_cli_ctx_put(ctx, 1);
 144
 145                 spin_lock(&sec_gc_ctx_list_lock);
 146         }
 147
 148         spin_unlock(&sec_gc_ctx_list_lock);
 149 }
 150
 151 static void sec_do_gc(struct ptlrpc_sec *sec)
 152 {
 153         LASSERT(sec->ps_policy->sp_cops->gc_ctx);
 154
 155         if (unlikely(sec->ps_gc_next == 0)) {
 156                 CWARN("sec %p(%s) has 0 gc time\n",
 157                       sec, sec->ps_policy->sp_name);
 158                 return;
 159         }
 160
 161         CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
 162
 163         if (cfs_time_after(sec->ps_gc_next, cfs_time_current_sec()))
 164                 return;
 165
 166         sec->ps_policy->sp_cops->gc_ctx(sec);
 167         sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
 168 }
 169
 170 static int sec_gc_main(void *arg)
 171 {
 172         struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
 173         struct l_wait_info    lwi;
 174
 175         cfs_daemonize("sptlrpc_gc");
 176
 177         /* Record that the thread is running */
 178         thread->t_flags = SVC_RUNNING;
 179         cfs_waitq_signal(&thread->t_ctl_waitq);
 180
 181         while (1) {
 182                 struct ptlrpc_sec *sec;
 183
 184                 thread->t_flags &= ~SVC_SIGNAL;
 185                 sec_process_ctx_list();
 186 again:
 187                 /* go through sec list do gc.
 188                  * FIXME here we iterate through the whole list each time which
 189                  * is not optimal. we perhaps want to use balanced binary tree
 190                  * to trace each sec as order of expiry time.
 191                  * another issue here is we wakeup as fixed interval instead of
 192                  * according to each sec's expiry time */
 193                 mutex_down(&sec_gc_mutex);
 194                 list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
 195                         /* if someone is waiting to be deleted, let it
 196                          * proceed as soon as possible. */
 197                         if (atomic_read(&sec_gc_wait_del)) {
 198                                 CWARN("deletion pending, start over\n");
 199                                 mutex_up(&sec_gc_mutex);
 200                                 goto again;
 201                         }
 202
 203                         sec_do_gc(sec);
 204                 }
 205                 mutex_up(&sec_gc_mutex);
 206
 207                 /* check ctx list again before sleep */
 208                 sec_process_ctx_list();
 209
 210                 lwi = LWI_TIMEOUT(SEC_GC_INTERVAL * HZ, NULL, NULL);
 211                 l_wait_event(thread->t_ctl_waitq,
 212                              thread->t_flags & (SVC_STOPPING | SVC_SIGNAL),
 213                              &lwi);
 214
 215                 if (thread->t_flags & SVC_STOPPING) {
 216                         thread->t_flags &= ~SVC_STOPPING;
 217                         break;
 218                 }
 219         }
 220
 221         thread->t_flags = SVC_STOPPED;
 222         cfs_waitq_signal(&thread->t_ctl_waitq);
 223         return 0;
 224 }
 225
 226 int sptlrpc_gc_start_thread(void)
 227 {
 228         struct l_wait_info lwi = { 0 };
 229         int                rc;
 230
 231         /* initialize thread control */
 232         memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
 233         cfs_waitq_init(&sec_gc_thread.t_ctl_waitq);
 234
 235         rc = cfs_kernel_thread(sec_gc_main, &sec_gc_thread,
 236                                CLONE_VM | CLONE_FILES);
 237         if (rc < 0) {
 238                 CERROR("can't start gc thread: %d\n", rc);
 239                 return rc;
 240         }
 241
 242         l_wait_event(sec_gc_thread.t_ctl_waitq,
 243                      sec_gc_thread.t_flags & SVC_RUNNING, &lwi);
 244         return 0;
 245 }
 246
 247 void sptlrpc_gc_stop_thread(void)
 248 {
 249         struct l_wait_info lwi = { 0 };
 250
 251         sec_gc_thread.t_flags = SVC_STOPPING;
 252         cfs_waitq_signal(&sec_gc_thread.t_ctl_waitq);
 253
 254         l_wait_event(sec_gc_thread.t_ctl_waitq,
 255                      sec_gc_thread.t_flags & SVC_STOPPED, &lwi);
 256 }
 257
 258 #else /* !__KERNEL__ */
 259
 260 void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
 261 {
 262 }
 263 void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
 264 {
 265 }
 266 int sptlrpc_gc_start_thread(void)
 267 {
 268         return 0;
 269 }
 270 void sptlrpc_gc_stop_thread(void)
 271 {
 272 }
 273
 274 #endif /* __KERNEL__ */