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) 2001-2003 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 /* should NOT be called with the dcache lock, see fs/dcache.c */
  35 void ll_release(struct dentry *de)
  36 {
  37         ENTRY;
  38         OBD_FREE(de->d_fsdata, sizeof(struct ll_dentry_data));
  39         EXIT;
  40 }
  41
  42 void ll_set_dd(struct dentry *de)
  43 {
  44         ENTRY;
  45         LASSERT(de != NULL);
  46
  47         lock_kernel();
  48
  49         if (de->d_fsdata == NULL) {
  50                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
  51                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
  52         }
  53
  54         unlock_kernel();
  55
  56         EXIT;
  57 }
  58
  59 void ll_intent_release(struct dentry *de, struct lookup_intent *it)
  60 {
  61         struct lustre_handle *handle;
  62         ENTRY;
  63
  64         LASSERT(ll_d2d(de) != NULL);
  65         mdc_put_rpc_lock(&mdc_rpc_lock, it);
  66
  67         if (it->it_lock_mode) {
  68                 handle = (struct lustre_handle *)it->it_lock_handle;
  69                 if (it->it_op == IT_SETATTR)
  70                         ldlm_lock_decref_and_cancel(handle, it->it_lock_mode);
  71                 else
  72                         ldlm_lock_decref(handle, it->it_lock_mode);
  73
  74                 /* intent_release may be called multiple times, from
  75                    this thread and we don't want to double-decref this
  76                    lock (see bug 494) */
  77                 it->it_lock_mode = 0;
  78         }
  79
  80         if (!de->d_it || it->it_op == IT_RELEASED_MAGIC) {
  81                 EXIT;
  82                 return;
  83         }
  84
  85         if (de->d_it == it)
  86                 LL_GET_INTENT(de, it);
  87         else
  88                 CERROR("STRANGE intent release: %p %p\n", de->d_it, it);
  89
  90         EXIT;
  91 }
  92
  93 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  94
  95 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
  96                               struct dentry **de, struct lookup_intent *it,
  97                               int offset, obd_id ino)
  98 {
  99         struct mds_body *body;
 100         struct lov_mds_md *lmm = NULL;
 101         int rc = 0;
 102         ENTRY;
 103
 104         if (!(flag & LL_LOOKUP_NEGATIVE)) {
 105                 body = lustre_msg_buf(request->rq_repmsg, offset);
 106                 if (body->valid & OBD_MD_FLEASIZE)
 107                         lmm = lustre_msg_buf(request->rq_repmsg, offset + 1);
 108                 ll_update_inode((*de)->d_inode, body, lmm);
 109                 mdc_lock_set_inode((struct lustre_handle *)it->it_lock_handle,
 110                                    (*de)->d_inode);
 111         } else
 112                 rc = -ENOENT;
 113
 114         ptlrpc_req_finished(request);
 115         RETURN(rc);
 116 }
 117
 118 int ll_have_md_lock(struct dentry *de)
 119 {
 120         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 121         struct lustre_handle lockh;
 122         struct ldlm_res_id res_id = { .name = {0} };
 123         struct obd_device *obddev;
 124         ENTRY;
 125
 126         if (!de->d_inode)
 127                RETURN(0);
 128
 129         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 130         res_id.name[0] = de->d_inode->i_ino;
 131         res_id.name[1] = de->d_inode->i_generation;
 132
 133         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id.name[0]);
 134
 135         if (ldlm_lock_match(obddev->obd_namespace, LDLM_FL_BLOCK_GRANTED,
 136                             &res_id, LDLM_PLAIN, NULL, 0, LCK_PR, &lockh)) {
 137                 ldlm_lock_decref(&lockh, LCK_PR);
 138                 RETURN(1);
 139         }
 140
 141         if (ldlm_lock_match(obddev->obd_namespace, LDLM_FL_BLOCK_GRANTED,
 142                             &res_id, LDLM_PLAIN, NULL, 0, LCK_PW, &lockh)) {
 143                 ldlm_lock_decref(&lockh, LCK_PW);
 144                 RETURN(1);
 145         }
 146         RETURN(0);
 147 }
 148
 149 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 150 {
 151         int rc;
 152         ENTRY;
 153
 154         /* We don't want to cache negative dentries, so return 0 immediately.
 155          * We believe that this is safe, that negative dentries cannot be
 156          * pinned by someone else */
 157         if (de->d_inode == NULL) {
 158                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 159                 RETURN(0);
 160         }
 161
 162         if (it && it->it_op == IT_TRUNC)
 163                 it->it_op = IT_SETATTR;
 164
 165         if (it == NULL || it->it_op == IT_GETATTR) {
 166                 /* We could just return 1 immediately, but since we should only
 167                  * be called in revalidate2 if we already have a lock, let's
 168                  * verify that. */
 169                 struct inode *inode = de->d_inode;
 170                 struct ll_sb_info *sbi = ll_i2sbi(inode);
 171                 struct obd_device *obddev = class_conn2obd(&sbi->ll_mdc_conn);
 172                 struct ldlm_res_id res_id =
 173                         { .name = {inode->i_ino, (__u64)inode->i_generation} };
 174                 struct lustre_handle lockh;
 175                 rc = ldlm_lock_match(obddev->obd_namespace,
 176                                      LDLM_FL_BLOCK_GRANTED, &res_id,
 177                                      LDLM_PLAIN, NULL, 0, LCK_PR, &lockh);
 178                 if (rc) {
 179                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 180                         if (it && it->it_op == IT_GETATTR) {
 181                                 memcpy(it->it_lock_handle, &lockh,
 182                                        sizeof(lockh));
 183                                 it->it_lock_mode = LCK_PR;
 184                                 LL_SAVE_INTENT(de, it);
 185                         } else {
 186                                 ldlm_lock_decref(&lockh, LCK_PR);
 187                         }
 188                         RETURN(1);
 189                 }
 190                 rc = ldlm_lock_match(obddev->obd_namespace,
 191                                      LDLM_FL_BLOCK_GRANTED, &res_id,
 192                                      LDLM_PLAIN, NULL, 0, LCK_PW, &lockh);
 193                 if (rc) {
 194                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 195                         if (it && it->it_op == IT_GETATTR) {
 196                                 memcpy(it->it_lock_handle, &lockh,
 197                                        sizeof(lockh));
 198                                 it->it_lock_mode = LCK_PW;
 199                                 LL_SAVE_INTENT(de, it);
 200                         } else {
 201                                 ldlm_lock_decref(&lockh, LCK_PW);
 202                         }
 203                         RETURN(1);
 204                 }
 205                 if (S_ISDIR(de->d_inode->i_mode))
 206                         ll_invalidate_inode_pages(de->d_inode);
 207                 d_unhash_aliases(de->d_inode);
 208                 RETURN(0);
 209         }
 210
 211         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 212         if (rc == -ESTALE)
 213                 RETURN(0);
 214         if (rc < 0 && it->it_status) {
 215                 CERROR("ll_intent_lock: rc %d : it->it_status %d\n", rc,
 216                        it->it_status);
 217                 RETURN(0);
 218         }
 219         /* unfortunately ll_intent_lock may cause a callback and revoke our
 220            dentry */
 221         spin_lock(&dcache_lock);
 222         list_del_init(&de->d_hash);
 223         spin_unlock(&dcache_lock);
 224         d_rehash(de);
 225
 226         RETURN(1);
 227 }
 228
 229 struct dentry_operations ll_d_ops = {
 230         .d_revalidate2 = ll_revalidate2,
 231         .d_intent_release = ll_intent_release,
 232         .d_release = ll_release,
 233 };