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_idl.h>
  32 #include <linux/lustre_dlm.h>
  33
  34 extern struct address_space_operations ll_aops;
  35
  36 void ll_release(struct dentry *de)
  37 {
  38         ENTRY;
  39
  40         OBD_FREE(de->d_fsdata, sizeof(struct ll_dentry_data));
  41         EXIT;
  42 }
  43
  44 extern void d_delete_aliases(struct inode *);
  45 void ll_intent_release(struct dentry *de, struct lookup_intent *it)
  46 {
  47         struct lustre_handle *handle;
  48         ENTRY;
  49
  50         /* XXX the check for RENAME2 is a workaround for old kernels
  51            which call intent_release twice in rename
  52         */
  53         if (it == NULL || it->it_op == IT_RENAME2) {
  54                 EXIT;
  55                 return;
  56         }
  57
  58         LASSERT(ll_d2d(de) != NULL);
  59
  60         if (it->it_lock_mode) {
  61                 handle = (struct lustre_handle *)it->it_lock_handle;
  62                 if (it->it_op == IT_SETATTR) {
  63                         int rc;
  64                         ldlm_lock_decref(handle, it->it_lock_mode);
  65                         rc = ldlm_cli_cancel(handle);
  66                         if (rc < 0)
  67                                 CERROR("ldlm_cli_cancel: %d\n", rc);
  68                 } else
  69                         ldlm_lock_decref(handle, it->it_lock_mode);
  70         }
  71
  72         if (!de->d_it || it->it_op == IT_RELEASED_MAGIC) {
  73                 EXIT;
  74                 return;
  75         }
  76
  77         if (de->d_it == it)
  78                 LL_GET_INTENT(de, it);
  79
  80         EXIT;
  81 }
  82
  83 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  84
  85 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
  86                           struct dentry **de,
  87                           struct lookup_intent *it,
  88                           int offset, obd_id ino)
  89 {
  90         ldlm_lock_set_data((struct lustre_handle *)it->it_lock_handle,
  91                            (*de)->d_inode, sizeof(*((*de)->d_inode)));
  92         ptlrpc_req_finished(request);
  93         return 0;
  94 }
  95
  96 static int ll_have_lock(struct dentry *de)
  97 {
  98         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
  99         struct lustre_handle lockh;
 100         __u64 res_id[RES_NAME_SIZE] = {0};
 101         struct obd_device *obddev;
 102         ENTRY;
 103
 104         if (!de->d_inode)
 105                RETURN(0);
 106
 107         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 108         res_id[0] = de->d_inode->i_ino;
 109         res_id[1] = de->d_inode->i_generation;
 110
 111         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id[0]);
 112
 113         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 114                             NULL, 0, LCK_PR, &lockh)) {
 115                 ldlm_lock_decref(&lockh, LCK_PR);
 116                 RETURN(1);
 117         }
 118
 119         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 120                             NULL, 0, LCK_PW, &lockh)) {
 121                 ldlm_lock_decref(&lockh, LCK_PW);
 122                 RETURN(1);
 123         }
 124         RETURN(0);
 125 }
 126
 127 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 128 {
 129         int rc;
 130         ENTRY;
 131
 132         /* We don't want to cache negative dentries, so return 0 immediately.
 133          * We believe that this is safe, that negative dentries cannot be
 134          * pinned by someone else */
 135         if (de->d_inode == NULL) {
 136                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 137                 RETURN(0);
 138         }
 139
 140         if (it == NULL && ll_have_lock(de))
 141                 RETURN(1);
 142
 143         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 144         if (rc < 0) {
 145                 /* Something bad happened; overwrite it_status? */
 146                 CERROR("ll_intent_lock: %d\n", rc);
 147         }
 148         /* unfortunately ll_intent_lock may cause a callback and revoke our
 149            dentry */
 150         spin_lock(&dcache_lock);
 151         list_del_init(&de->d_hash);
 152         spin_unlock(&dcache_lock);
 153         d_rehash(de);
 154
 155         RETURN(1);
 156 }
 157
 158 int ll_set_dd(struct dentry *de)
 159 {
 160         ENTRY;
 161         LASSERT(de != NULL);
 162
 163         lock_kernel();
 164
 165         if (de->d_fsdata != NULL) {
 166                 CERROR("dentry %p already has d_fsdata set\n", de);
 167         } else {
 168                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
 169                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
 170         }
 171
 172         unlock_kernel();
 173
 174         RETURN(0);
 175 }
 176
 177 struct dentry_operations ll_d_ops = {
 178         .d_revalidate2 = ll_revalidate2,
 179         .d_intent_release = ll_intent_release,
 180         .d_release = ll_release,
 181 };