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         struct lustre_capa *capa;
  47         int expired = 0;
  48         unsigned long expiry;
  49         struct timeval tv;
  50
  51         ENTRY;
  52
  53         do_gettimeofday(&tv);
  54         spin_lock(&capa_lock);
  55         if (!list_empty(ll_capa_list)) {
  56                 ocapa = list_entry(ll_capa_list->next, struct obd_capa, c_list);
  57                 expired = __capa_is_to_expire(ocapa, &tv);
  58                 if (!expired) {
  59                         capa = &ocapa->c_capa;
  60                         expiry = expiry_to_jiffies(capa->lc_expiry -
  61                                                    capa_pre_expiry(capa));
  62                         if (time_before(expiry, ll_capa_timer.expires) ||
  63                             !timer_pending(&ll_capa_timer)) {
  64                                 mod_timer(&ll_capa_timer, expiry);
  65                                 CDEBUG(D_INFO,"ll_capa_timer new expiry: %lu\n",
  66                                        expiry);
  67                         }
  68                 }
  69         }
  70         spin_unlock(&capa_lock);
  71
  72         RETURN(expired);
  73 }
  74
  75 static int inline ll_capa_check_stop(void)
  76 {
  77         return (capa_thread.t_flags & SVC_STOPPING) ? 1: 0;
  78 }
  79
  80 static int ll_renew_capa(struct obd_capa *ocapa)
  81 {
  82         struct ptlrpc_request *req = NULL;
  83         /* no need to lock, no one else will touch it */
  84         struct inode *inode = ocapa->c_inode;
  85         struct obd_export *md_exp = ll_i2mdexp(inode);
  86         struct ll_inode_info *lli = ll_i2info(inode);
  87         __u64 valid = OBD_MD_CAPA;
  88         int rc;
  89         ENTRY;
  90
  91         if (capa_expired(&ocapa->c_capa))
  92                 RETURN(-ESTALE);
  93
  94         rc = md_getattr(md_exp, &lli->lli_id, valid, NULL, NULL, 0,
  95                         0, ocapa, &req);
  96         RETURN(rc);
  97 }
  98
  99 static int ll_capa_thread(void *arg)
 100 {
 101         struct thread_ctl *ctl = arg;
 102         unsigned long flags;
 103         int rc;
 104         ENTRY;
 105
 106         {
 107                 char name[sizeof(current->comm)];
 108                 snprintf(name, sizeof(name) - 1, "ll_capa");
 109                 kportal_daemonize(name);
 110         }
 111
 112         SIGNAL_MASK_LOCK(current, flags);
 113         sigfillset(&current->blocked);
 114         RECALC_SIGPENDING;
 115         SIGNAL_MASK_UNLOCK(current, flags);
 116
 117         /*
 118          * letting starting function know, that we are ready and control may be
 119          * returned.
 120          */
 121         capa_thread.t_flags = SVC_RUNNING;
 122         complete(&ctl->ctl_starting);
 123
 124         while (1) {
 125                 struct l_wait_info lwi = { 0 };
 126                 struct obd_capa *ocapa, tcapa, *tmp, *next = NULL;
 127                 unsigned long expiry, sleep = CAPA_PRE_EXPIRY;
 128                 struct inode *inode;
 129                 struct timeval tv;
 130
 131                 l_wait_event(capa_thread.t_ctl_waitq,
 132                              (have_expired_capa() || ll_capa_check_stop()),
 133                              &lwi);
 134
 135                 if (ll_capa_check_stop())
 136                         break;
 137
 138                 do_gettimeofday(&tv);
 139                 spin_lock(&capa_lock);
 140                 list_for_each_entry_safe(ocapa, tmp, ll_capa_list, c_list) {
 141                         if (ocapa->c_capa.lc_flags & CAPA_FL_SHORT)
 142                                 sleep = CAPA_PRE_EXPIRY_SHORT;
 143
 144                         if (ocapa->c_capa.lc_op == CAPA_TRUNC)
 145                                 continue;
 146
 147                         if (__capa_is_to_expire(ocapa, &tv)) {
 148                                 inode = igrab(ocapa->c_inode);
 149                                 if (inode == NULL)
 150                                         continue;
 151
 152                                 tcapa = *ocapa;
 153                                 spin_unlock(&capa_lock);
 154
 155                                 rc = ll_renew_capa(&tcapa);
 156                                 iput(inode);
 157
 158                                 if (rc)
 159                                         capa_put(ocapa);
 160
 161                                 spin_lock(&capa_lock);
 162                         } else {
 163                                 next = ocapa;
 164                                 break;
 165                         }
 166                 }
 167
 168                 if (next) {
 169                         struct lustre_capa *capa = &next->c_capa;
 170
 171                         expiry = expiry_to_jiffies(capa->lc_expiry -
 172                                                    capa_pre_expiry(capa));
 173                         if (time_before(expiry, ll_capa_timer.expires) ||
 174                             !timer_pending(&ll_capa_timer)) {
 175                                 mod_timer(&ll_capa_timer, expiry);
 176                                 CDEBUG(D_INFO,"ll_capa_timer new expiry: %lu\n",
 177                                        expiry);
 178                         }
 179                 }
 180                 spin_unlock(&capa_lock);
 181
 182                 /* wait ll_renew_capa finish */
 183                 set_current_state(TASK_INTERRUPTIBLE);
 184                 schedule_timeout(sleep * HZ);
 185         }
 186
 187         capa_thread.t_flags = SVC_STOPPED;
 188
 189         /* this is SMP-safe way to finish thread. */
 190         complete_and_exit(&ctl->ctl_finishing, 0);
 191         EXIT;
 192 }
 193
 194 /* just wake up, others are handled by ll_capa_thread */
 195 void ll_capa_timer_callback(unsigned long unused)
 196 {
 197         ENTRY;
 198         wake_up(&capa_thread.t_ctl_waitq);
 199         EXIT;
 200 }
 201
 202 int ll_capa_thread_start(void)
 203 {
 204         int rc;
 205         ENTRY;
 206
 207         LASSERT(capa_thread.t_flags == 0);
 208         init_completion(&ll_capa_ctl.ctl_starting);
 209         init_completion(&ll_capa_ctl.ctl_finishing);
 210         init_waitqueue_head(&capa_thread.t_ctl_waitq);
 211
 212         rc = kernel_thread(ll_capa_thread, &ll_capa_ctl,
 213                            (CLONE_VM | CLONE_FILES));
 214         if (rc < 0) {
 215                 CERROR("cannot start expired capa thread, "
 216                        "err = %d\n", rc);
 217                 RETURN(rc);
 218         }
 219         wait_for_completion(&ll_capa_ctl.ctl_starting);
 220         LASSERT(capa_thread.t_flags == SVC_RUNNING);
 221         RETURN(0);
 222 }
 223
 224 void ll_capa_thread_stop(void)
 225 {
 226         ENTRY;
 227
 228         capa_thread.t_flags = SVC_STOPPING;
 229         wake_up(&capa_thread.t_ctl_waitq);
 230         wait_for_completion(&ll_capa_ctl.ctl_finishing);
 231         LASSERT(capa_thread.t_flags == SVC_STOPPED);
 232         capa_thread.t_flags = 0;
 233
 234         EXIT;
 235 }
 236
 237 int ll_set_capa(struct inode *inode, struct lookup_intent *it,
 238                 struct obd_client_handle *och)
 239 {
 240         struct ptlrpc_request *req = LUSTRE_IT(it)->it_data;
 241         struct mds_body *body;
 242         struct lustre_capa *capa;
 243         struct obd_capa *ocapa;
 244         struct ll_inode_info *lli = ll_i2info(inode);
 245         unsigned long expiry;
 246
 247         if (!S_ISREG(inode->i_mode))
 248                 return 0;
 249
 250         /* GNS code path will have no req */
 251         if (!req)
 252                 return 0;
 253
 254         body = lustre_msg_buf(req->rq_repmsg, 1, sizeof (*body));
 255         LASSERT(body != NULL);          /* reply already checked out */
 256         LASSERT_REPSWABBED(req, 1);     /* and swabbed down */
 257
 258         if (!(body->valid & OBD_MD_CAPA))
 259                 return 0;
 260
 261         ENTRY;
 262
 263         capa = lustre_msg_buf(req->rq_repmsg, 7, sizeof (*capa));
 264         LASSERT(capa != NULL);          /* reply already checked out */
 265         LASSERT_REPSWABBED(req, 7);     /* and swabbed down */
 266
 267         ocapa = capa_renew(capa, CLIENT_CAPA);
 268         if (!ocapa)
 269                 RETURN(-ENOMEM);
 270
 271         spin_lock(&capa_lock);
 272         ocapa->c_inode = inode;
 273         ocapa->c_handle = och->och_fh;
 274         spin_unlock(&capa_lock);
 275
 276         spin_lock(&lli->lli_lock);
 277         /* in case it was linked to lli_capas already */
 278         if (list_empty(&ocapa->c_lli_list))
 279                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 280         spin_unlock(&lli->lli_lock);
 281
 282         capa_put(ocapa);
 283
 284         expiry = expiry_to_jiffies(capa->lc_expiry - capa_pre_expiry(capa));
 285
 286         spin_lock(&capa_lock);
 287         if (time_before(expiry, ll_capa_timer.expires) ||
 288             !timer_pending(&ll_capa_timer)) {
 289                 mod_timer(&ll_capa_timer, expiry);
 290                 CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 291         }
 292         spin_unlock(&capa_lock);
 293
 294         RETURN(0);
 295 }
 296
 297 int ll_set_trunc_capa(struct ptlrpc_request *req, int offset, struct inode *inode)
 298 {
 299         struct mds_body *body;
 300         struct obd_capa *ocapa;
 301         struct lustre_capa *capa;
 302         struct ll_inode_info *lli = ll_i2info(inode);
 303
 304         body = lustre_msg_buf(req->rq_repmsg, offset, sizeof(*body));
 305         if (!body)
 306                 return -ENOMEM;
 307
 308         if (!(body->valid & OBD_MD_CAPA))
 309                 return 0;
 310
 311         ENTRY;
 312         capa = (struct lustre_capa *)lustre_swab_repbuf(req, offset + 1,
 313                                         sizeof(*capa), lustre_swab_lustre_capa);
 314         if (!capa)
 315                 RETURN(-ENOMEM);
 316
 317         ocapa = capa_renew(capa, CLIENT_CAPA);
 318         if (!ocapa)
 319                 RETURN(-ENOMEM);
 320
 321         spin_lock(&lli->lli_lock);
 322         /* in case it was linked to lli_capas already */
 323         if (list_empty(&ocapa->c_lli_list))
 324                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 325         spin_unlock(&lli->lli_lock);
 326
 327         RETURN(0);
 328 }
 329
 330 struct obd_capa *ll_get_capa(struct inode *inode, uid_t uid, int op)
 331 {
 332         struct ll_inode_info *lli = ll_i2info(inode);
 333         struct obd_capa *ocapa, *tmp;
 334         ENTRY;
 335
 336         list_for_each_entry_safe(ocapa, tmp, &lli->lli_capas, c_lli_list) {
 337                 if (ocapa->c_capa.lc_ruid != uid)
 338                         continue;
 339                 if (ocapa->c_capa.lc_op != op)
 340                         continue;
 341
 342                 RETURN(ocapa);
 343         }
 344
 345         RETURN(NULL);
 346 }