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 ptlrpc_thread ll_capa_thread;
  36 static struct list_head *ll_capa_list = &capa_list[CLIENT_CAPA];
  37 static struct thread_ctl {
  38         struct completion ctl_starting;
  39         struct completion ctl_finishing;
  40 } ll_capa_ctl;
  41
  42 static inline int have_expired_capa(void)
  43 {
  44         struct obd_capa *ocapa;
  45         int expired = 0;
  46         unsigned long expiry;
  47         ENTRY;
  48
  49         spin_lock(&capa_lock);
  50         if (!list_empty(ll_capa_list)) {
  51                 ocapa = list_entry(ll_capa_list->next, struct obd_capa, c_list);
  52
  53                 expired = __capa_is_to_expire(ocapa);
  54                 if (!expired && !timer_pending(&ll_capa_timer)) {
  55                         /* the expired capa has been put, so set the timer to
  56                          * the expired of the next capa */
  57                         expiry = expiry_to_jiffies(ocapa->c_capa.lc_expiry);
  58                         mod_timer(&ll_capa_timer, expiry);
  59                         CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
  60                 }
  61         }
  62         spin_unlock(&capa_lock);
  63
  64         RETURN(expired);
  65 }
  66
  67 static int inline ll_capa_check_stop(void)
  68 {
  69         return (ll_capa_thread.t_flags & SVC_STOPPING) ? 1: 0;
  70 }
  71
  72 static int ll_renew_capa(struct obd_capa *ocapa)
  73 {
  74         struct ptlrpc_request *req = NULL;
  75         /* no need to lock, no one else will touch it */
  76         struct inode *inode = ocapa->c_inode;
  77         struct obd_export *md_exp = ll_i2mdexp(inode);
  78         struct ll_inode_info *lli = ll_i2info(inode);
  79         __u64 valid = 0;
  80         int rc;
  81         ENTRY;
  82
  83         valid |= OBD_MD_CAPA;
  84
  85         rc = md_getattr(md_exp, &lli->lli_id, valid, NULL, NULL, 0,
  86                         0, ocapa, &req);
  87         if (rc < 0)
  88                 CDEBUG(D_INFO, "md_getattr failed: rc = %d\n", rc);
  89         RETURN(rc);
  90 }
  91
  92 static int ll_capa_thread_main(void *arg)
  93 {
  94         struct thread_ctl *ctl = arg;
  95         unsigned long flags;
  96         ENTRY;
  97
  98         {
  99                 char name[sizeof(current->comm)];
 100                 snprintf(name, sizeof(name) - 1, "ll_capa");
 101                 kportal_daemonize(name);
 102         }
 103
 104         SIGNAL_MASK_LOCK(current, flags);
 105         sigfillset(&current->blocked);
 106         RECALC_SIGPENDING;
 107         SIGNAL_MASK_UNLOCK(current, flags);
 108
 109         /*
 110          * letting starting function know, that we are ready and control may be
 111          * returned.
 112          */
 113         ll_capa_thread.t_flags = SVC_RUNNING;
 114         complete(&ctl->ctl_starting);
 115
 116         while (1) {
 117                 struct l_wait_info lwi = { 0 };
 118                 struct obd_capa *ocapa, *next = NULL;
 119                 unsigned long expiry, sleep = CAPA_PRE_EXPIRY;
 120
 121                 l_wait_event(ll_capa_thread.t_ctl_waitq,
 122                              (have_expired_capa() || ll_capa_check_stop()),
 123                              &lwi);
 124
 125                 spin_lock(&capa_lock);
 126                 list_for_each_entry(ocapa, ll_capa_list, c_list) {
 127                         if (__capa_is_to_expire(ocapa)) {
 128                                 /* get capa in case it's deleted */
 129                                 __capa_get(ocapa);
 130
 131                                 spin_unlock(&capa_lock);
 132                                 ll_renew_capa(ocapa);
 133                                 capa_put(ocapa, CLIENT_CAPA);
 134                                 spin_lock(&capa_lock);
 135                         } else {
 136                                 next = ocapa;
 137                                 break;
 138                         }
 139                 }
 140                 if (next) {
 141                         expiry = expiry_to_jiffies(next->c_capa.lc_expiry);
 142                         mod_timer(&ll_capa_timer, expiry);
 143                         CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 144                         if (next->c_capa.lc_flags & CAPA_FL_NOROUND)
 145                                 sleep = CAPA_PRE_EXPIRY_NOROUND;
 146                 }
 147                 spin_unlock(&capa_lock);
 148
 149                 if (ll_capa_check_stop())
 150                         break;
 151
 152                 /* wait ll_renew_capa finish */
 153                 set_current_state(TASK_INTERRUPTIBLE);
 154                 schedule_timeout(sleep * HZ);
 155         }
 156
 157         ll_capa_thread.t_flags = SVC_STOPPED;
 158
 159         /* this is SMP-safe way to finish thread. */
 160         complete_and_exit(&ctl->ctl_finishing, 0);
 161         EXIT;
 162 }
 163
 164 /* just wake up, others are handled by ll_capa_thread */
 165 void ll_capa_timer_callback(unsigned long unused)
 166 {
 167         ENTRY;
 168         wake_up(&ll_capa_thread.t_ctl_waitq);
 169         EXIT;
 170 }
 171
 172 int ll_capa_start_thread(void)
 173 {
 174         int rc;
 175         ENTRY;
 176
 177         LASSERT(ll_capa_thread.t_flags == 0);
 178         init_completion(&ll_capa_ctl.ctl_starting);
 179         init_completion(&ll_capa_ctl.ctl_finishing);
 180         init_waitqueue_head(&ll_capa_thread.t_ctl_waitq);
 181
 182         rc = kernel_thread(ll_capa_thread_main, &ll_capa_ctl,
 183                            (CLONE_VM | CLONE_FILES));
 184         if (rc < 0) {
 185                 CERROR("cannot start expired capa thread, "
 186                        "err = %d\n", rc);
 187                 RETURN(rc);
 188         }
 189         wait_for_completion(&ll_capa_ctl.ctl_starting);
 190         LASSERT(ll_capa_thread.t_flags == SVC_RUNNING);
 191         RETURN(0);
 192 }
 193
 194 void ll_capa_stop_thread(void)
 195 {
 196         ENTRY;
 197
 198         ll_capa_thread.t_flags = SVC_STOPPING;
 199         wake_up(&ll_capa_thread.t_ctl_waitq);
 200         wait_for_completion(&ll_capa_ctl.ctl_finishing);
 201         LASSERT(ll_capa_thread.t_flags == SVC_STOPPED);
 202         ll_capa_thread.t_flags = 0;
 203
 204         EXIT;
 205 }
 206
 207 int ll_set_och_capa(struct inode *inode, struct lookup_intent *it,
 208                     struct obd_client_handle *och)
 209 {
 210         struct ptlrpc_request *req = LUSTRE_IT(it)->it_data;
 211         struct ll_inode_info *lli = ll_i2info(inode);
 212         struct mds_body *body;
 213         struct lustre_capa *capa;
 214         __u64 mdsid = lli->lli_id.li_fid.lf_group;
 215         unsigned long ino = lli->lli_id.li_stc.u.e3s.l3s_ino;
 216         int capa_op = (it->it_flags & MAY_WRITE) ? MAY_WRITE : MAY_READ;
 217         unsigned long expiry;
 218         int rc = 0;
 219         ENTRY;
 220
 221         body = lustre_msg_buf(req->rq_repmsg, 1, sizeof (*body));
 222         LASSERT(body != NULL);          /* reply already checked out */
 223         LASSERT_REPSWABBED(req, 1);     /* and swabbed down */
 224
 225         capa = lustre_msg_buf(req->rq_repmsg, 7, sizeof (*capa));
 226         LASSERT(capa != NULL);          /* reply already checked out */
 227         LASSERT_REPSWABBED(req, 7);     /* and swabbed down */
 228
 229         och->och_capa = capa_get(current->uid, capa_op, mdsid, ino,
 230                                  CLIENT_CAPA, capa, inode, &body->handle);
 231         if (!och->och_capa)
 232                 rc = -ENOMEM;
 233
 234         DEBUG_CAPA(D_INFO, capa, "ll_set_och_capa");
 235
 236         expiry = expiry_to_jiffies(capa->lc_expiry - capa_pre_expiry(capa));
 237
 238         spin_lock(&capa_lock);
 239         if (time_before(expiry, ll_capa_timer.expires) ||
 240             !timer_pending(&ll_capa_timer)) {
 241                 mod_timer(&ll_capa_timer, expiry);
 242                 CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 243         }
 244         spin_unlock(&capa_lock);
 245
 246         RETURN(rc);
 247 }
 248