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 int ll_delete(struct dentry *de)
  43 {
  44         if (de->d_it != 0) {
  45                 CERROR("%s put dentry %p+%p with d_it %p\n", current->comm,
  46                        de, de->d_fsdata, de->d_it);
  47                 LBUG();
  48         }
  49         return 0;
  50 }
  51
  52 void ll_set_dd(struct dentry *de)
  53 {
  54         ENTRY;
  55         LASSERT(de != NULL);
  56
  57         lock_kernel();
  58
  59         if (de->d_fsdata == NULL) {
  60                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
  61                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
  62         }
  63
  64         unlock_kernel();
  65
  66         EXIT;
  67 }
  68
  69 void ll_intent_release(struct dentry *de, struct lookup_intent *it)
  70 {
  71         struct lustre_handle *handle;
  72         ENTRY;
  73
  74         if (it->it_lock_mode) {
  75                 handle = (struct lustre_handle *)it->it_lock_handle;
  76                 ldlm_lock_decref(handle, it->it_lock_mode);
  77
  78                 /* intent_release may be called multiple times, from
  79                    this thread and we don't want to double-decref this
  80                    lock (see bug 494) */
  81                 it->it_lock_mode = 0;
  82         }
  83
  84         if (!de->d_it || it->it_op == IT_RELEASED_MAGIC) {
  85                 EXIT;
  86                 return;
  87         }
  88
  89         if (de->d_it == it)
  90                 LL_GET_INTENT(de, it);
  91         else
  92                 CDEBUG(D_INODE, "STRANGE intent release: %p %p\n",
  93                        de->d_it, it);
  94
  95         EXIT;
  96 }
  97
  98 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  99
 100 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
 101                               struct inode *parent, struct dentry **de,
 102                               struct lookup_intent *it, int offset, obd_id ino)
 103 {
 104         struct ll_sb_info     *sbi = ll_i2sbi(parent);
 105         struct mds_body       *body;
 106         struct lov_stripe_md  *lsm = NULL;
 107         struct lov_mds_md     *lmm;
 108         int                    lmmsize;
 109         int                    rc = 0;
 110         ENTRY;
 111
 112         /* NB 1 request reference will be taken away by ll_intent_lock()
 113          * when I return */
 114
 115         if ((flag & LL_LOOKUP_NEGATIVE) != 0)
 116                 GOTO (out, rc = -ENOENT);
 117
 118         /* We only get called if the mdc_enqueue() called from
 119          * ll_intent_lock() was successful.  Therefore the mds_body is
 120          * present and correct, and the eadata is present (but still
 121          * opaque, so only obd_unpackmd() can check the size) */
 122         body = lustre_msg_buf(request->rq_repmsg, offset, sizeof (*body));
 123         LASSERT (body != NULL);
 124         LASSERT_REPSWABBED (request, offset);
 125
 126         if (body->valid & OBD_MD_FLEASIZE) {
 127                 /* Only bother with this if inodes's LSM not set? */
 128
 129                 if (body->eadatasize == 0) {
 130                         CERROR ("OBD_MD_FLEASIZE set, but eadatasize 0\n");
 131                         GOTO (out, rc = -EPROTO);
 132                 }
 133                 lmmsize = body->eadatasize;
 134                 lmm = lustre_msg_buf (request->rq_repmsg, offset + 1, lmmsize);
 135                 LASSERT (lmm != NULL);
 136                 LASSERT_REPSWABBED (request, offset + 1);
 137
 138                 rc = obd_unpackmd (&sbi->ll_osc_conn,
 139                                    &lsm, lmm, lmmsize);
 140                 if (rc < 0) {
 141                         CERROR ("Error %d unpacking eadata\n", rc);
 142                         LBUG();
 143                         /* XXX don't know if I should do this... */
 144                         GOTO (out, rc);
 145                         /* or skip the ll_update_inode but still do
 146                          * mdc_lock_set_inode() */
 147                 }
 148                 LASSERT (rc >= sizeof (*lsm));
 149                 rc = 0;
 150         }
 151
 152         ll_update_inode((*de)->d_inode, body, lsm);
 153
 154         if (lsm != NULL &&
 155             ll_i2info((*de)->d_inode)->lli_smd != lsm)
 156                 obd_free_memmd (&sbi->ll_osc_conn, &lsm);
 157
 158         ll_mdc_lock_set_inode((struct lustre_handle *)it->it_lock_handle,
 159                               (*de)->d_inode);
 160  out:
 161         RETURN(rc);
 162 }
 163
 164 int ll_have_md_lock(struct dentry *de)
 165 {
 166         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 167         struct lustre_handle lockh;
 168         struct ldlm_res_id res_id = { .name = {0} };
 169         struct obd_device *obddev;
 170         int flags;
 171         ENTRY;
 172
 173         if (!de->d_inode)
 174                RETURN(0);
 175
 176         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 177         res_id.name[0] = de->d_inode->i_ino;
 178         res_id.name[1] = de->d_inode->i_generation;
 179
 180         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id.name[0]);
 181
 182         flags = LDLM_FL_BLOCK_GRANTED | LDLM_FL_MATCH_DATA;
 183         if (ldlm_lock_match(obddev->obd_namespace, flags, &res_id, LDLM_PLAIN,
 184                             NULL, 0, LCK_PR, de->d_inode, &lockh)) {
 185                 ldlm_lock_decref(&lockh, LCK_PR);
 186                 RETURN(1);
 187         }
 188
 189         if (ldlm_lock_match(obddev->obd_namespace, flags, &res_id, LDLM_PLAIN,
 190                             NULL, 0, LCK_PW, de->d_inode, &lockh)) {
 191                 ldlm_lock_decref(&lockh, LCK_PW);
 192                 RETURN(1);
 193         }
 194         RETURN(0);
 195 }
 196
 197 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 198 {
 199         int rc;
 200         ENTRY;
 201         CDEBUG(D_VFSTRACE, "VFS Op:name=%s,intent=%s\n", de->d_name.name,
 202                LL_IT2STR(it));
 203
 204         /* We don't want to cache negative dentries, so return 0 immediately.
 205          * We believe that this is safe, that negative dentries cannot be
 206          * pinned by someone else */
 207         if (de->d_inode == NULL) {
 208                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 209                 RETURN(0);
 210         }
 211
 212         if (it == NULL || it->it_op == IT_GETATTR) {
 213                 /* We could just return 1 immediately, but since we should only
 214                  * be called in revalidate2 if we already have a lock, let's
 215                  * verify that. */
 216                 struct inode *inode = de->d_inode;
 217                 struct ll_sb_info *sbi = ll_i2sbi(inode);
 218                 struct obd_device *obddev = class_conn2obd(&sbi->ll_mdc_conn);
 219                 struct ldlm_res_id res_id =
 220                         { .name = {inode->i_ino, (__u64)inode->i_generation} };
 221                 struct lustre_handle lockh;
 222                 int flags;
 223                 flags = LDLM_FL_BLOCK_GRANTED | LDLM_FL_MATCH_DATA;
 224                 rc = ldlm_lock_match(obddev->obd_namespace, flags, &res_id,
 225                                      LDLM_PLAIN, NULL, 0, LCK_PR, inode,
 226                                      &lockh);
 227                 if (rc) {
 228                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 229                         if (it && it->it_op == IT_GETATTR) {
 230                                 memcpy(it->it_lock_handle, &lockh,
 231                                        sizeof(lockh));
 232                                 it->it_lock_mode = LCK_PR;
 233                                 LL_SAVE_INTENT(de, it);
 234                         } else {
 235                                 ldlm_lock_decref(&lockh, LCK_PR);
 236                         }
 237                         RETURN(1);
 238                 }
 239                 rc = ldlm_lock_match(obddev->obd_namespace, flags, &res_id,
 240                                      LDLM_PLAIN, NULL, 0, LCK_PW, inode,
 241                                      &lockh);
 242                 if (rc) {
 243                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 244                         if (it && it->it_op == IT_GETATTR) {
 245                                 memcpy(it->it_lock_handle, &lockh,
 246                                        sizeof(lockh));
 247                                 it->it_lock_mode = LCK_PW;
 248                                 LL_SAVE_INTENT(de, it);
 249                         } else {
 250                                 ldlm_lock_decref(&lockh, LCK_PW);
 251                         }
 252                         RETURN(1);
 253                 }
 254                 if (S_ISDIR(de->d_inode->i_mode))
 255                         ll_invalidate_inode_pages(de->d_inode);
 256                 d_unhash_aliases(de->d_inode);
 257                 RETURN(0);
 258         }
 259
 260         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 261         if (rc < 0) {
 262                 CERROR("ll_intent_lock: rc %d : it->it_status %d\n", rc,
 263                        it->it_status);
 264                 RETURN(0);
 265         }
 266         /* unfortunately ll_intent_lock may cause a callback and revoke our
 267            dentry */
 268         spin_lock(&dcache_lock);
 269         list_del_init(&de->d_hash);
 270         spin_unlock(&dcache_lock);
 271         d_rehash(de);
 272
 273         RETURN(1);
 274 }
 275
 276 struct dentry_operations ll_d_ops = {
 277         .d_revalidate2 = ll_revalidate2,
 278         .d_intent_release = ll_intent_release,
 279         .d_release = ll_release,
 280         .d_delete = ll_delete,
 281 };