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