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 = 0;
  81         int rc;
  82         ENTRY;
  83
  84         valid |= OBD_MD_CAPA;
  85
  86         rc = md_getattr(md_exp, &lli->lli_id, valid, NULL, NULL, 0,
  87                         0, ocapa, &req);
  88         if (rc < 0)
  89                 CDEBUG(D_INFO, "md_getattr failed: rc = %d\n", rc);
  90         RETURN(rc);
  91 }
  92
  93 static int ll_capa_thread(void *arg)
  94 {
  95         struct thread_ctl *ctl = arg;
  96         unsigned long flags;
  97         ENTRY;
  98
  99         {
 100                 char name[sizeof(current->comm)];
 101                 snprintf(name, sizeof(name) - 1, "ll_capa");
 102                 kportal_daemonize(name);
 103         }
 104
 105         SIGNAL_MASK_LOCK(current, flags);
 106         sigfillset(&current->blocked);
 107         RECALC_SIGPENDING;
 108         SIGNAL_MASK_UNLOCK(current, flags);
 109
 110         /*
 111          * letting starting function know, that we are ready and control may be
 112          * returned.
 113          */
 114         capa_thread.t_flags = SVC_RUNNING;
 115         complete(&ctl->ctl_starting);
 116
 117         while (1) {
 118                 struct l_wait_info lwi = { 0 };
 119                 struct obd_capa *ocapa, *next = NULL;
 120                 unsigned long expiry, sleep = CAPA_PRE_EXPIRY;
 121
 122                 l_wait_event(capa_thread.t_ctl_waitq,
 123                              (have_expired_capa() || ll_capa_check_stop()),
 124                              &lwi);
 125
 126                 spin_lock(&capa_lock);
 127                 list_for_each_entry(ocapa, ll_capa_list, c_list) {
 128                         if (__capa_is_to_expire(ocapa)) {
 129                                 /* get capa in case it's deleted */
 130                                 __capa_get(ocapa);
 131
 132                                 spin_unlock(&capa_lock);
 133                                 ll_renew_capa(ocapa);
 134                                 capa_put(ocapa, CLIENT_CAPA);
 135                                 spin_lock(&capa_lock);
 136                         } else {
 137                                 next = ocapa;
 138                                 break;
 139                         }
 140                 }
 141                 if (next) {
 142                         expiry = expiry_to_jiffies(next->c_capa.lc_expiry);
 143                         mod_timer(&ll_capa_timer, expiry);
 144                         CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 145                         if (next->c_capa.lc_flags & CAPA_FL_NOROUND)
 146                                 sleep = CAPA_PRE_EXPIRY_NOROUND;
 147                 }
 148                 spin_unlock(&capa_lock);
 149
 150                 if (ll_capa_check_stop())
 151                         break;
 152
 153                 /* wait ll_renew_capa finish */
 154                 set_current_state(TASK_INTERRUPTIBLE);
 155                 schedule_timeout(sleep * HZ);
 156         }
 157
 158         capa_thread.t_flags = SVC_STOPPED;
 159
 160         /* this is SMP-safe way to finish thread. */
 161         complete_and_exit(&ctl->ctl_finishing, 0);
 162         EXIT;
 163 }
 164
 165 /* just wake up, others are handled by ll_capa_thread */
 166 void ll_capa_timer_callback(unsigned long unused)
 167 {
 168         ENTRY;
 169         wake_up(&capa_thread.t_ctl_waitq);
 170         EXIT;
 171 }
 172
 173 int ll_capa_thread_start(void)
 174 {
 175         int rc;
 176         ENTRY;
 177
 178         LASSERT(capa_thread.t_flags == 0);
 179         init_completion(&ll_capa_ctl.ctl_starting);
 180         init_completion(&ll_capa_ctl.ctl_finishing);
 181         init_waitqueue_head(&capa_thread.t_ctl_waitq);
 182
 183         rc = kernel_thread(ll_capa_thread, &ll_capa_ctl,
 184                            (CLONE_VM | CLONE_FILES));
 185         if (rc < 0) {
 186                 CERROR("cannot start expired capa thread, "
 187                        "err = %d\n", rc);
 188                 RETURN(rc);
 189         }
 190         wait_for_completion(&ll_capa_ctl.ctl_starting);
 191         LASSERT(capa_thread.t_flags == SVC_RUNNING);
 192         RETURN(0);
 193 }
 194
 195 void ll_capa_thread_stop(void)
 196 {
 197         ENTRY;
 198
 199         capa_thread.t_flags = SVC_STOPPING;
 200         wake_up(&capa_thread.t_ctl_waitq);
 201         wait_for_completion(&ll_capa_ctl.ctl_finishing);
 202         LASSERT(capa_thread.t_flags == SVC_STOPPED);
 203         capa_thread.t_flags = 0;
 204
 205         EXIT;
 206 }
 207
 208 int ll_set_och_capa(struct inode *inode, struct lookup_intent *it,
 209                     struct obd_client_handle *och)
 210 {
 211         struct ptlrpc_request *req = LUSTRE_IT(it)->it_data;
 212         struct ll_inode_info *lli = ll_i2info(inode);
 213         struct mds_body *body;
 214         struct lustre_capa *capa;
 215         __u64 mdsid = lli->lli_id.li_fid.lf_group;
 216         unsigned long ino = lli->lli_id.li_stc.u.e3s.l3s_ino;
 217         int capa_op = (it->it_flags & MAY_WRITE) ? MAY_WRITE : MAY_READ;
 218         unsigned long expiry;
 219         int rc = 0;
 220         ENTRY;
 221
 222         body = lustre_msg_buf(req->rq_repmsg, 1, sizeof (*body));
 223         LASSERT(body != NULL);          /* reply already checked out */
 224         LASSERT_REPSWABBED(req, 1);     /* and swabbed down */
 225
 226         capa = lustre_msg_buf(req->rq_repmsg, 7, sizeof (*capa));
 227         LASSERT(capa != NULL);          /* reply already checked out */
 228         LASSERT_REPSWABBED(req, 7);     /* and swabbed down */
 229
 230         och->och_capa = capa_get(current->uid, capa_op, mdsid, ino,
 231                                  CLIENT_CAPA, capa, inode, &body->handle);
 232         if (!och->och_capa)
 233                 rc = -ENOMEM;
 234
 235         expiry = expiry_to_jiffies(capa->lc_expiry - capa_pre_expiry(capa));
 236
 237         spin_lock(&capa_lock);
 238         if (time_before(expiry, ll_capa_timer.expires) ||
 239             !timer_pending(&ll_capa_timer)) {
 240                 mod_timer(&ll_capa_timer, expiry);
 241                 CDEBUG(D_INFO, "ll_capa_timer new expiry: %lu\n", expiry);
 242         }
 243         spin_unlock(&capa_lock);
 244
 245         RETURN(rc);
 246 }
 247