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                 /* intent_release may be called multiple times, and we don't
  72                  * want to double-decref this lock (see bug 494) */
  73                 it->it_lock_mode = 0;
  74         }
  75
  76         if (!de->d_it || it->it_op == IT_RELEASED_MAGIC) {
  77                 EXIT;
  78                 return;
  79         }
  80
  81         if (de->d_it == it)
  82                 LL_GET_INTENT(de, it);
  83
  84         EXIT;
  85 }
  86
  87 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  88
  89 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
  90                           struct dentry **de,
  91                           struct lookup_intent *it,
  92                           int offset, obd_id ino)
  93 {
  94         ldlm_lock_set_data((struct lustre_handle *)it->it_lock_handle,
  95                            (*de)->d_inode, sizeof(*((*de)->d_inode)));
  96         ptlrpc_req_finished(request);
  97         return 0;
  98 }
  99
 100 static int ll_have_lock(struct dentry *de)
 101 {
 102         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 103         struct lustre_handle lockh;
 104         __u64 res_id[RES_NAME_SIZE] = {0};
 105         struct obd_device *obddev;
 106         ENTRY;
 107
 108         if (!de->d_inode)
 109                RETURN(0);
 110
 111         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 112         res_id[0] = de->d_inode->i_ino;
 113         res_id[1] = de->d_inode->i_generation;
 114
 115         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id[0]);
 116
 117         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 118                             NULL, 0, LCK_PR, &lockh)) {
 119                 ldlm_lock_decref(&lockh, LCK_PR);
 120                 RETURN(1);
 121         }
 122
 123         if (ldlm_lock_match(obddev->obd_namespace, res_id, LDLM_PLAIN,
 124                             NULL, 0, LCK_PW, &lockh)) {
 125                 ldlm_lock_decref(&lockh, LCK_PW);
 126                 RETURN(1);
 127         }
 128         RETURN(0);
 129 }
 130
 131 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 132 {
 133         int rc;
 134         ENTRY;
 135
 136         /* We don't want to cache negative dentries, so return 0 immediately.
 137          * We believe that this is safe, that negative dentries cannot be
 138          * pinned by someone else */
 139         if (de->d_inode == NULL) {
 140                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 141                 RETURN(0);
 142         }
 143
 144 //        if (it == NULL && ll_have_lock(de))
 145 //                RETURN(1);
 146
 147         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 148         if (rc < 0) {
 149                 /* Something bad happened; overwrite it_status? */
 150                 CERROR("ll_intent_lock: %d\n", rc);
 151         }
 152         /* unfortunately ll_intent_lock may cause a callback and revoke our
 153            dentry */
 154         spin_lock(&dcache_lock);
 155         list_del_init(&de->d_hash);
 156         spin_unlock(&dcache_lock);
 157         d_rehash(de);
 158
 159         RETURN(1);
 160 }
 161
 162 int ll_set_dd(struct dentry *de)
 163 {
 164         ENTRY;
 165         LASSERT(de != NULL);
 166
 167         lock_kernel();
 168
 169         if (de->d_fsdata != NULL) {
 170                 CERROR("dentry %p already has d_fsdata set\n", de);
 171         } else {
 172                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
 173                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
 174         }
 175
 176         unlock_kernel();
 177
 178         RETURN(0);
 179 }
 180
 181 struct dentry_operations ll_d_ops = {
 182         .d_revalidate2 = ll_revalidate2,
 183         .d_intent_release = ll_intent_release,
 184         .d_release = ll_release,
 185 };