lustre/llite/dcache.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2001, 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/fs.h>
  23 #include <linux/sched.h>
  24 #include <linux/smp_lock.h>
  25 #include <linux/quotaops.h>
  26
  27 #define DEBUG_SUBSYSTEM S_LLITE
  28
  29 #include <linux/obd_support.h>
  30 #include <linux/lustre_lite.h>
  31 #include <linux/lustre_dlm.h>
  32
  33 extern struct address_space_operations ll_aops;
  34
  35 void ll_release(struct dentry *de)
  36 {
  37         ENTRY;
  38
  39         OBD_FREE(de->d_fsdata, sizeof(struct ll_dentry_data));
  40         EXIT;
  41 }
  42
  43 void ll_intent_release(struct dentry *de, struct lookup_intent *it)
  44 {
  45         struct lustre_handle *handle;
  46         ENTRY;
  47
  48         if (it == NULL) {
  49                 EXIT;
  50                 return;
  51         }
  52
  53         LASSERT(ll_d2d(de) != NULL);
  54
  55         if (it->it_lock_mode) {
  56                 handle = (struct lustre_handle *)it->it_lock_handle;
  57                 if (it->it_op == IT_SETATTR) {
  58                         int rc;
  59                         ldlm_lock_decref(handle, it->it_lock_mode);
  60                         rc = ldlm_cli_cancel(handle);
  61                         if (rc < 0)
  62                                 CERROR("ldlm_cli_cancel: %d\n", rc);
  63                 } else
  64                         ldlm_lock_decref(handle, it->it_lock_mode);
  65         }
  66
  67         if (it->it_op != IT_RELEASED_MAGIC) {
  68                 up(&ll_d2d(de)->lld_it_sem);
  69                 it->it_op = IT_RELEASED_MAGIC;
  70         }
  71         EXIT;
  72 }
  73
  74 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
  75 {
  76         int rc;
  77         ENTRY;
  78
  79         /* We don't want to cache negative dentries, so return 0 immediately.
  80          * We believe that this is safe, that negative dentries cannot be
  81          * pinned by someone else */
  82         if (de->d_inode == NULL) {
  83                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
  84                 RETURN(0);
  85         }
  86
  87         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, NULL);
  88         if (rc < 0) {
  89                 /* Something bad happened; overwrite it_status? */
  90                 CERROR("ll_intent_lock: %d\n", rc);
  91         }
  92
  93         if (it != NULL && it->it_status == 0) {
  94                 LL_SAVE_INTENT(de, it);
  95         } else if (it != NULL) {
  96                 de->d_it = NULL;
  97                 CDEBUG(D_DENTRY,
  98                        "D_IT dentry %p fsdata %p intent: %s status %d\n",
  99                        de, ll_d2d(de), ldlm_it2str(it->it_op), it->it_status);
 100         }
 101
 102         RETURN(1);
 103 #if 0
 104         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 105         struct lustre_handle lockh;
 106         __u64 res_id[RES_NAME_SIZE] = {0};
 107         struct obd_device *obddev;
 108         int rc = 0;
 109         ENTRY;
 110
 111         if (it) {
 112                 CDEBUG(D_INFO, "name: %*s, intent: %s\n", de->d_name.len,
 113                        de->d_name.name, ldlm_it2str(it->it_op));
 114                 if (it->it_op == IT_RENAME)
 115                         it->it_data = de;
 116         }
 117
 118         if (!de->d_inode)
 119                 GOTO(out, rc = 0);
 120
 121         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 122         res_id[0] = de->d_inode->i_ino;
 123
 124         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id[0]);
 125
 126         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_MDSINTENT,
 127                             NULL, 0, LCK_PR, &lockh)) {
 128                 ldlm_lock_decref(&lockh, LCK_PR);
 129                 GOTO(out, rc = 1);
 130         }
 131
 132         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_MDSINTENT,
 133                             NULL, 0, LCK_PW, &lockh)) {
 134                 ldlm_lock_decref(&lockh, LCK_PW);
 135                 GOTO(out, rc = 1);
 136         }
 137
 138         /* If the dentry is busy, we won't get called in lookup2 if we
 139          * return 0, so return 1.
 140          *
 141          * This is a temporary fix for bug 224, but is one of the causes of
 142          * 225. */
 143         CDEBUG(D_INFO, "d_count: %d\n", atomic_read(&de->d_count));
 144         if (it && atomic_read(&de->d_count) > 1) {
 145                 CDEBUG(D_INFO, "returning 1 for %*s during %s because d_count "
 146                        "is %d\n", de->d_name.len, de->d_name.name,
 147                        ldlm_it2str(it->it_op), atomic_read(&de->d_count));
 148                 GOTO(out, rc = 1);
 149         }
 150
 151  out:
 152         if (ll_d2d(de) == NULL) {
 153                 CERROR("allocating fsdata\n");
 154                 ll_set_dd(de);
 155         }
 156         //down(&ll_d2d(de)->lld_it_sem);
 157         de->d_it = it;
 158
 159         RETURN(rc);
 160 #endif
 161 }
 162
 163 int ll_set_dd(struct dentry *de)
 164 {
 165         ENTRY;
 166         LASSERT(de != NULL);
 167
 168         lock_kernel();
 169
 170         if (de->d_fsdata != NULL) {
 171                 CERROR("dentry %p already has d_fsdata set\n", de);
 172         } else {
 173                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
 174                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
 175         }
 176
 177         unlock_kernel();
 178
 179         RETURN(0);
 180 }
 181
 182 struct dentry_operations ll_d_ops = {
 183         .d_revalidate2 = ll_revalidate2,
 184         .d_intent_release = ll_intent_release,
 185         .d_release = ll_release,
 186 };