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