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;
 124                 unsigned long expiry, sleep = CAPA_PRE_EXPIRY;
 125                 struct inode *inode;
 126
 127                 l_wait_event(capa_thread.t_ctl_waitq,
 128                              (have_expired_capa() || ll_capa_check_stop()),
 129                              &lwi);
 130
 131                 if (ll_capa_check_stop())
 132                         break;
 133
 134                 spin_lock(&capa_lock);
 135                 list_for_each_entry_safe(ocapa, tmp, ll_capa_list, c_list) {
 136                         if (ocapa->c_capa.lc_flags & CAPA_FL_SHORT)
 137                                 sleep = CAPA_PRE_EXPIRY_SHORT;
 138
 139                         if (ocapa->c_capa.lc_op == CAPA_TRUNC)
 140                                 continue;
 141
 142                         if (__capa_is_to_expire(ocapa)) {
 143                                 inode = igrab(ocapa->c_inode);
 144                                 if (inode == NULL)
 145                                         continue;
 146                                 spin_unlock(&capa_lock);
 147
 148                                 rc = ll_renew_capa(ocapa);
 149                                 iput(inode);
 150
 151                                 if (rc)
 152                                         capa_put(ocapa);
 153
 154                                 spin_lock(&capa_lock);
 155                         } else {
 156                                 next = ocapa;
 157                                 break;
 158                         }
 159                 }
 160
 161                 if (next) {
 162                         struct lustre_capa *capa = &next->c_capa;
 163
 164                         expiry = expiry_to_jiffies(capa->lc_expiry -
 165                                                    capa_pre_expiry(capa));
 166                         if (time_before(expiry, ll_capa_timer.expires) ||
 167                             !timer_pending(&ll_capa_timer)) {
 168                                 mod_timer(&ll_capa_timer, expiry);
 169                                 CDEBUG(D_INFO,"ll_capa_timer new expiry: %lu\n",
 170                                        expiry);
 171                         }
 172                 }
 173                 spin_unlock(&capa_lock);
 174
 175                 /* wait ll_renew_capa finish */
 176                 set_current_state(TASK_INTERRUPTIBLE);
 177                 schedule_timeout(sleep * HZ);
 178         }
 179
 180         capa_thread.t_flags = SVC_STOPPED;
 181
 182         /* this is SMP-safe way to finish thread. */
 183         complete_and_exit(&ctl->ctl_finishing, 0);
 184         EXIT;
 185 }
 186
 187 /* just wake up, others are handled by ll_capa_thread */
 188 void ll_capa_timer_callback(unsigned long unused)
 189 {
 190         ENTRY;
 191         wake_up(&capa_thread.t_ctl_waitq);
 192         EXIT;
 193 }
 194
 195 int ll_capa_thread_start(void)
 196 {
 197         int rc;
 198         ENTRY;
 199
 200         LASSERT(capa_thread.t_flags == 0);
 201         init_completion(&ll_capa_ctl.ctl_starting);
 202         init_completion(&ll_capa_ctl.ctl_finishing);
 203         init_waitqueue_head(&capa_thread.t_ctl_waitq);
 204
 205         rc = kernel_thread(ll_capa_thread, &ll_capa_ctl,
 206                            (CLONE_VM | CLONE_FILES));
 207         if (rc < 0) {
 208                 CERROR("cannot start expired capa thread, "
 209                        "err = %d\n", rc);
 210                 RETURN(rc);
 211         }
 212         wait_for_completion(&ll_capa_ctl.ctl_starting);
 213         LASSERT(capa_thread.t_flags == SVC_RUNNING);
 214         RETURN(0);
 215 }
 216
 217 void ll_capa_thread_stop(void)
 218 {
 219         ENTRY;
 220
 221         capa_thread.t_flags = SVC_STOPPING;
 222         wake_up(&capa_thread.t_ctl_waitq);
 223         wait_for_completion(&ll_capa_ctl.ctl_finishing);
 224         LASSERT(capa_thread.t_flags == SVC_STOPPED);
 225         capa_thread.t_flags = 0;
 226
 227         EXIT;
 228 }
 229
 230 int ll_set_capa(struct inode *inode, struct lookup_intent *it,
 231                 struct obd_client_handle *och)
 232 {
 233         struct ptlrpc_request *req = LUSTRE_IT(it)->it_data;
 234         struct mds_body *body;
 235         struct lustre_capa *capa;
 236         struct obd_capa *ocapa;
 237         struct ll_inode_info *lli = ll_i2info(inode);
 238         unsigned long expiry;
 239
 240         if (!S_ISREG(inode->i_mode))
 241                 return 0;
 242
 243         /* GNS code path will have no req */
 244         if (!req)
 245                 return 0;
 246
 247         body = lustre_msg_buf(req->rq_repmsg, 1, sizeof (*body));
 248         LASSERT(body != NULL);          /* reply already checked out */
 249         LASSERT_REPSWABBED(req, 1);     /* and swabbed down */
 250
 251         if (!(body->valid & OBD_MD_CAPA))
 252                 return 0;
 253
 254         ENTRY;
 255
 256         capa = lustre_msg_buf(req->rq_repmsg, 7, sizeof (*capa));
 257         LASSERT(capa != NULL);          /* reply already checked out */
 258         LASSERT_REPSWABBED(req, 7);     /* and swabbed down */
 259
 260         ocapa = capa_renew(capa, CLIENT_CAPA);
 261         if (!ocapa)
 262                 RETURN(-ENOMEM);
 263
 264         spin_lock(&capa_lock);
 265         ocapa->c_inode = inode;
 266         ocapa->c_handle = och->och_fh;
 267         spin_unlock(&capa_lock);
 268
 269         spin_lock(&lli->lli_lock);
 270         /* in case it was linked to lli_capas already */
 271         if (list_empty(&ocapa->c_lli_list))
 272                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 273         spin_unlock(&lli->lli_lock);
 274
 275         expiry = expiry_to_jiffies(capa->lc_expiry - capa_pre_expiry(capa));
 276
 277         spin_lock(&capa_lock);
 278         if (time_before(expiry, ll_capa_timer.expires) ||
 279             !timer_pending(&ll_capa_timer)) {
 280                 mod_timer(&ll_capa_timer, expiry);
 281                 CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 282         }
 283         spin_unlock(&capa_lock);
 284
 285         RETURN(0);
 286 }
 287
 288 int ll_set_trunc_capa(struct ptlrpc_request *req, int offset, struct inode *inode)
 289 {
 290         struct mds_body *body;
 291         struct obd_capa *ocapa;
 292         struct lustre_capa *capa;
 293         struct ll_inode_info *lli = ll_i2info(inode);
 294
 295         body = lustre_msg_buf(req->rq_repmsg, offset, sizeof(*body));
 296         if (!body)
 297                 return -ENOMEM;
 298
 299         if (!(body->valid & OBD_MD_CAPA))
 300                 return 0;
 301
 302         ENTRY;
 303         capa = (struct lustre_capa *)lustre_swab_repbuf(req, offset + 1,
 304                                         sizeof(*capa), lustre_swab_lustre_capa);
 305         if (!capa)
 306                 RETURN(-ENOMEM);
 307
 308         ocapa = capa_renew(capa, CLIENT_CAPA);
 309         if (!ocapa)
 310                 RETURN(-ENOMEM);
 311
 312         spin_lock(&lli->lli_lock);
 313         /* in case it was linked to lli_capas already */
 314         if (list_empty(&ocapa->c_lli_list))
 315                 list_add(&ocapa->c_lli_list, &lli->lli_capas);
 316         spin_unlock(&lli->lli_lock);
 317
 318         RETURN(0);
 319 }
 320
 321 struct obd_capa *ll_get_capa(struct inode *inode, uid_t uid, int op)
 322 {
 323         struct ll_inode_info *lli = ll_i2info(inode);
 324         struct obd_capa *ocapa, *tmp;
 325         ENTRY;
 326
 327         list_for_each_entry_safe(ocapa, tmp, &lli->lli_capas, c_lli_list) {
 328                 if (ocapa->c_capa.lc_ruid != uid)
 329                         continue;
 330                 if (ocapa->c_capa.lc_op != op)
 331                         continue;
 332
 333                 RETURN(ocapa);
 334         }
 335
 336         RETURN(NULL);
 337 }