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 (it->it_op == IT_RELEASED_MAGIC) {
  73                 EXIT;
  74                 return;
  75         }
  76
  77         if (de->d_it && de->d_it == it) {
  78                 de->d_it = NULL;
  79                 up(&ll_d2d(de)->lld_it_sem);
  80                 it->it_op = IT_RELEASED_MAGIC;
  81         }
  82
  83         EXIT;
  84 }
  85
  86 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  87
  88 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
  89                           struct dentry **de,
  90                           struct lookup_intent *it,
  91                           int offset, obd_id ino)
  92 {
  93         ldlm_lock_set_data((struct lustre_handle *)it->it_lock_handle,
  94                            (*de)->d_inode, sizeof(*((*de)->d_inode)));
  95         ptlrpc_req_finished(request);
  96         return 0;
  97 }
  98
  99 static int ll_have_lock(struct dentry *de)
 100 {
 101        struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 102         struct lustre_handle lockh;
 103         __u64 res_id[RES_NAME_SIZE] = {0};
 104         struct obd_device *obddev;
 105         ENTRY;
 106
 107        if (!de->d_inode)
 108                RETURN(0);
 109
 110         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 111         res_id[0] = de->d_inode->i_ino;
 112
 113         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id[0]);
 114
 115         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 116                             NULL, 0, LCK_PR, &lockh)) {
 117                 ldlm_lock_decref(&lockh, LCK_PR);
 118                 RETURN(1);
 119         }
 120
 121         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 122                             NULL, 0, LCK_PW, &lockh)) {
 123                 ldlm_lock_decref(&lockh, LCK_PW);
 124                 RETURN(1);
 125         }
 126         RETURN(0);
 127 }
 128
 129 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 130 {
 131         int rc;
 132         ENTRY;
 133
 134         /* We don't want to cache negative dentries, so return 0 immediately.
 135          * We believe that this is safe, that negative dentries cannot be
 136          * pinned by someone else */
 137         if (de->d_inode == NULL) {
 138                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 139                 RETURN(0);
 140         }
 141
 142         if (ll_have_lock(de))
 143                 GOTO(out, rc = 0);
 144
 145         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 146         if (rc < 0) {
 147                 /* Something bad happened; overwrite it_status? */
 148                 CERROR("ll_intent_lock: %d\n", rc);
 149         }
 150         /* unfortunately ll_intent_lock may cause a callback and revoke our
 151            dentry */
 152         spin_lock(&dcache_lock);
 153         list_del_init(&de->d_hash);
 154         spin_unlock(&dcache_lock);
 155         d_rehash(de);
 156
 157  out:
 158         if (!it)
 159                 de->d_it = NULL;
 160
 161         RETURN(1);
 162 }
 163
 164 int ll_set_dd(struct dentry *de)
 165 {
 166         ENTRY;
 167         LASSERT(de != NULL);
 168
 169         lock_kernel();
 170
 171         if (de->d_fsdata != NULL) {
 172                 CERROR("dentry %p already has d_fsdata set\n", de);
 173         } else {
 174                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
 175                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
 176         }
 177
 178         unlock_kernel();
 179
 180         RETURN(0);
 181 }
 182
 183 struct dentry_operations ll_d_ops = {
 184         .d_revalidate2 = ll_revalidate2,
 185         .d_intent_release = ll_intent_release,
 186         .d_release = ll_release,
 187 };