lustre/llite/llite_capa.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2004, 2005 Cluster File Systems, Inc.
   5  *
   6  * Author: Lai Siyao <lsy@clusterfs.com>
   7  *
   8  *   This file is part of Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #define DEBUG_SUBSYSTEM S_LLITE
  25
  26 #include <linux/fs.h>
  27 #include <linux/version.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/file.h>
  30 #include <linux/kmod.h>
  31
  32 #include <linux/lustre_lite.h>
  33 #include "llite_internal.h"
  34
  35 static struct list_head *ll_capa_list = &capa_list[CLIENT_CAPA];
  36 static struct ptlrpc_thread capa_thread;
  37
  38 static struct thread_ctl {
  39         struct completion ctl_starting;
  40         struct completion ctl_finishing;
  41 } ll_capa_ctl;
  42
  43 static inline int have_expired_capa(void)
  44 {
  45         struct obd_capa *ocapa;
  46         int expired = 0;
  47         unsigned long expiry;
  48         ENTRY;
  49
  50         spin_lock(&capa_lock);
  51         if (!list_empty(ll_capa_list)) {
  52                 ocapa = list_entry(ll_capa_list->next, struct obd_capa, c_list);
  53
  54                 expired = __capa_is_to_expire(ocapa);
  55                 if (!expired && !timer_pending(&ll_capa_timer)) {
  56                         /* the expired capa has been put, so set the timer to
  57                          * the expired of the next capa */
  58                         expiry = expiry_to_jiffies(ocapa->c_capa.lc_expiry);
  59                         mod_timer(&ll_capa_timer, expiry);
  60                         CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
  61                 }
  62         }
  63         spin_unlock(&capa_lock);
  64
  65         RETURN(expired);
  66 }
  67
  68 static int inline ll_capa_check_stop(void)
  69 {
  70         return (capa_thread.t_flags & SVC_STOPPING) ? 1: 0;
  71 }
  72
  73 static int ll_renew_capa(struct obd_capa *ocapa)
  74 {
  75         struct ptlrpc_request *req = NULL;
  76         /* no need to lock, no one else will touch it */
  77         struct inode *inode = ocapa->c_inode;
  78         struct obd_export *md_exp = ll_i2mdexp(inode);
  79         struct ll_inode_info *lli = ll_i2info(inode);
  80         __u64 valid = OBD_MD_CAPA;
  81         int rc;
  82         ENTRY;
  83
  84         if (capa_expired(&ocapa->c_capa)) {
  85                 /* this is the second time try to renew since the last
  86                  * renewal failed, it means on one is openning it and
  87                  * should be put now. */
  88                 capa_put(ocapa);
  89                 RETURN(0);
  90         }
  91
  92         rc = md_getattr(md_exp, &lli->lli_id, valid, NULL, NULL, 0,
  93                         0, ocapa, &req);
  94         RETURN(rc);
  95 }
  96
  97 static int ll_capa_thread(void *arg)
  98 {
  99         struct thread_ctl *ctl = arg;
 100         unsigned long flags;
 101         ENTRY;
 102
 103         {
 104                 char name[sizeof(current->comm)];
 105                 snprintf(name, sizeof(name) - 1, "ll_capa");
 106                 kportal_daemonize(name);
 107         }
 108
 109         SIGNAL_MASK_LOCK(current, flags);
 110         sigfillset(&current->blocked);
 111         RECALC_SIGPENDING;
 112         SIGNAL_MASK_UNLOCK(current, flags);
 113
 114         /*
 115          * letting starting function know, that we are ready and control may be
 116          * returned.
 117          */
 118         capa_thread.t_flags = SVC_RUNNING;
 119         complete(&ctl->ctl_starting);
 120
 121         while (1) {
 122                 struct l_wait_info lwi = { 0 };
 123                 struct obd_capa *ocapa, *next = NULL, tcapa;
 124                 unsigned long expiry, sleep = CAPA_PRE_EXPIRY;
 125
 126                 l_wait_event(capa_thread.t_ctl_waitq,
 127                              (have_expired_capa() || ll_capa_check_stop()),
 128                              &lwi);
 129
 130                 if (ll_capa_check_stop())
 131                         break;
 132
 133                 spin_lock(&capa_lock);
 134                 list_for_each_entry(ocapa, ll_capa_list, c_list) {
 135                         if (ocapa->c_capa.lc_op == CAPA_TRUNC)
 136                                 continue;
 137
 138                         if (__capa_is_to_expire(ocapa)) {
 139                                 /* copy capa in case it's deleted */
 140                                 tcapa = *ocapa;
 141                                 spin_unlock(&capa_lock);
 142
 143                                 ll_renew_capa(&tcapa);
 144
 145                                 spin_lock(&capa_lock);
 146                         } else {
 147                                 next = ocapa;
 148                                 break;
 149                         }
 150                 }
 151                 if (next) {
 152                         expiry = expiry_to_jiffies(next->c_capa.lc_expiry);
 153                         mod_timer(&ll_capa_timer, expiry);
 154                         CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 155                         if (next->c_capa.lc_flags & CAPA_FL_NOROUND)
 156                                 sleep = CAPA_PRE_EXPIRY_NOROUND;
 157                 }
 158                 spin_unlock(&capa_lock);
 159
 160                 /* wait ll_renew_capa finish */
 161                 set_current_state(TASK_INTERRUPTIBLE);
 162                 schedule_timeout(sleep * HZ);
 163         }
 164
 165         capa_thread.t_flags = SVC_STOPPED;
 166
 167         /* this is SMP-safe way to finish thread. */
 168         complete_and_exit(&ctl->ctl_finishing, 0);
 169         EXIT;
 170 }
 171
 172 /* just wake up, others are handled by ll_capa_thread */
 173 void ll_capa_timer_callback(unsigned long unused)
 174 {
 175         ENTRY;
 176         wake_up(&capa_thread.t_ctl_waitq);
 177         EXIT;
 178 }
 179
 180 int ll_capa_thread_start(void)
 181 {
 182         int rc;
 183         ENTRY;
 184
 185         LASSERT(capa_thread.t_flags == 0);
 186         init_completion(&ll_capa_ctl.ctl_starting);
 187         init_completion(&ll_capa_ctl.ctl_finishing);
 188         init_waitqueue_head(&capa_thread.t_ctl_waitq);
 189
 190         rc = kernel_thread(ll_capa_thread, &ll_capa_ctl,
 191                            (CLONE_VM | CLONE_FILES));
 192         if (rc < 0) {
 193                 CERROR("cannot start expired capa thread, "
 194                        "err = %d\n", rc);
 195                 RETURN(rc);
 196         }
 197         wait_for_completion(&ll_capa_ctl.ctl_starting);
 198         LASSERT(capa_thread.t_flags == SVC_RUNNING);
 199         RETURN(0);
 200 }
 201
 202 void ll_capa_thread_stop(void)
 203 {
 204         ENTRY;
 205
 206         capa_thread.t_flags = SVC_STOPPING;
 207         wake_up(&capa_thread.t_ctl_waitq);
 208         wait_for_completion(&ll_capa_ctl.ctl_finishing);
 209         LASSERT(capa_thread.t_flags == SVC_STOPPED);
 210         capa_thread.t_flags = 0;
 211
 212         EXIT;
 213 }
 214
 215 int ll_set_capa(struct inode *inode, struct lookup_intent *it)
 216 {
 217         struct ptlrpc_request *req = LUSTRE_IT(it)->it_data;
 218         struct mds_body *body;
 219         struct lustre_capa *capa;
 220         struct obd_capa *ocapa;
 221         struct ll_inode_info *lli = ll_i2info(inode);
 222         unsigned long expiry;
 223
 224         if (!S_ISREG(inode->i_mode))
 225                 return 0;
 226
 227         body = lustre_msg_buf(req->rq_repmsg, 1, sizeof (*body));
 228         LASSERT(body != NULL);          /* reply already checked out */
 229         LASSERT_REPSWABBED(req, 1);     /* and swabbed down */
 230
 231         if (!(body->valid & OBD_MD_CAPA))
 232                 return 0;
 233
 234         ENTRY;
 235
 236         capa = lustre_msg_buf(req->rq_repmsg, 7, sizeof (*capa));
 237         LASSERT(capa != NULL);          /* reply already checked out */
 238         LASSERT_REPSWABBED(req, 7);     /* and swabbed down */
 239
 240         ocapa = capa_renew(capa, CLIENT_CAPA);
 241         if (!ocapa)
 242                 RETURN(-ENOMEM);
 243
 244         spin_lock(&capa_lock);
 245         ocapa->c_inode = inode;
 246         ocapa->c_handle = body->handle;
 247         spin_unlock(&capa_lock);
 248
 249         spin_lock(&lli->lli_lock);
 250         /* in case it was linked to lli_capas already */
 251         if (list_empty(&ocapa->c_lli_list))
 252                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 253         spin_unlock(&lli->lli_lock);
 254
 255         expiry = expiry_to_jiffies(capa->lc_expiry - capa_pre_expiry(capa));
 256
 257         spin_lock(&capa_lock);
 258         if (time_before(expiry, ll_capa_timer.expires) ||
 259             !timer_pending(&ll_capa_timer)) {
 260                 mod_timer(&ll_capa_timer, expiry);
 261                 CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 262         }
 263         spin_unlock(&capa_lock);
 264
 265         RETURN(0);
 266 }
 267
 268 int ll_set_trunc_capa(struct ptlrpc_request *req, int offset, struct inode *inode)
 269 {
 270         struct mds_body *body;
 271         struct obd_capa *ocapa;
 272         struct lustre_capa *capa;
 273         struct ll_inode_info *lli = ll_i2info(inode);
 274
 275         body = lustre_msg_buf(req->rq_repmsg, offset, sizeof(*body));
 276         if (!body)
 277                 return -ENOMEM;
 278
 279         if (!(body->valid & OBD_MD_CAPA))
 280                 return 0;
 281
 282         ENTRY;
 283         capa = (struct lustre_capa *)lustre_swab_repbuf(req, offset + 1,
 284                                         sizeof(*capa), lustre_swab_lustre_capa);
 285         if (!capa)
 286                 RETURN(-ENOMEM);
 287
 288         ocapa = capa_renew(capa, CLIENT_CAPA);
 289         if (!ocapa)
 290                 RETURN(-ENOMEM);
 291
 292         spin_lock(&lli->lli_lock);
 293         /* in case it was linked to lli_capas already */
 294         if (list_empty(&ocapa->c_lli_list))
 295                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 296         spin_unlock(&lli->lli_lock);
 297
 298         RETURN(0);
 299 }
 300
 301 struct obd_capa *ll_get_capa(struct inode *inode, uid_t uid, int op)
 302 {
 303         struct ll_inode_info *lli = ll_i2info(inode);
 304         struct obd_capa *ocapa, *tmp;
 305         ENTRY;
 306
 307         list_for_each_entry_safe(ocapa, tmp, &lli->lli_capas, c_lli_list) {
 308                 if (ocapa->c_capa.lc_ruid != uid)
 309                         continue;
 310                 if (ocapa->c_capa.lc_op != op)
 311                         continue;
 312
 313                 RETURN(ocapa);
 314         }
 315
 316         RETURN(NULL);
 317 }