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 #include <linux/lustre_version.h>
  34
  35 #include "llite_internal.h"
  36
  37 /* should NOT be called with the dcache lock, see fs/dcache.c */
  38 static void ll_release(struct dentry *de)
  39 {
  40         struct ll_dentry_data *lld;
  41         ENTRY;
  42         LASSERT(de != NULL);
  43         lld = ll_d2d(de);
  44         LASSERT(lld != NULL);
  45         LASSERT(lld->lld_cwd_count == 0);
  46         LASSERT(lld->lld_mnt_count == 0);
  47         OBD_FREE(de->d_fsdata, sizeof(struct ll_dentry_data));
  48
  49         EXIT;
  50 }
  51
  52 /* should NOT be called with the dcache lock, see fs/dcache.c */
  53 static int ll_ddelete(struct dentry *de)
  54 {
  55         ENTRY;
  56         LASSERT(de);
  57         CDEBUG(D_DENTRY, "%s dentry %*s (%p, parent %p, inode %p) %s%s\n",
  58                (de->d_flags & DCACHE_LUSTRE_INVALID ? "keeping" : "deleting"),
  59                de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
  60                d_unhashed(de) ? "" : "hashed,",
  61                list_empty(&de->d_subdirs) ? "" : "subdirs");
  62         RETURN(0);
  63 }
  64
  65 void ll_set_dd(struct dentry *de)
  66 {
  67         ENTRY;
  68         LASSERT(de != NULL);
  69
  70         CDEBUG(D_DENTRY, "ldd on dentry %*s (%p) parent %p inode %p refc %d\n",
  71                de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
  72                atomic_read(&de->d_count));
  73         lock_kernel();
  74         if (de->d_fsdata == NULL) {
  75                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
  76         }
  77         unlock_kernel();
  78
  79         EXIT;
  80 }
  81
  82 void ll_intent_drop_lock(struct lookup_intent *it)
  83 {
  84         struct lustre_handle *handle;
  85
  86         if (it->it_op && it->d.lustre.it_lock_mode) {
  87                 handle = (struct lustre_handle *)&it->d.lustre.it_lock_handle;
  88                 CDEBUG(D_DLMTRACE, "releasing lock with cookie "LPX64
  89                        " from it %p\n", handle->cookie, it);
  90                 ldlm_lock_decref(handle, it->d.lustre.it_lock_mode);
  91
  92                 /* bug 494: intent_release may be called multiple times, from
  93                  * this thread and we don't want to double-decref this lock */
  94                 it->d.lustre.it_lock_mode = 0;
  95         }
  96 }
  97
  98 void ll_intent_release(struct lookup_intent *it)
  99 {
 100         ENTRY;
 101
 102         ll_intent_drop_lock(it);
 103         it->it_magic = 0;
 104         it->it_op_release = 0;
 105         it->d.lustre.it_disposition = 0;
 106         it->d.lustre.it_data = NULL;
 107         EXIT;
 108 }
 109
 110 void ll_unhash_aliases(struct inode *inode)
 111 {
 112         struct list_head *tmp, *head;
 113         struct ll_sb_info *sbi;
 114         ENTRY;
 115
 116         if (inode == NULL) {
 117                 CERROR("unexpected NULL inode, tell phil\n");
 118                 return;
 119         }
 120
 121         CDEBUG(D_INODE, "marking dentries for ino %lu/%u(%p) invalid\n",
 122                inode->i_ino, inode->i_generation, inode);
 123
 124         sbi = ll_i2sbi(inode);
 125         head = &inode->i_dentry;
 126 restart:
 127         spin_lock(&dcache_lock);
 128         tmp = head;
 129         while ((tmp = tmp->next) != head) {
 130                 struct dentry *dentry = list_entry(tmp, struct dentry, d_alias);
 131                 if (atomic_read(&dentry->d_count) == 0) {
 132                         CDEBUG(D_DENTRY, "deleting dentry %*s (%p) parent %p "
 133                                "inode %p\n", dentry->d_name.len,
 134                                dentry->d_name.name, dentry, dentry->d_parent,
 135                                dentry->d_inode);
 136                         dget_locked(dentry);
 137                         __d_drop(dentry);
 138                         spin_unlock(&dcache_lock);
 139                         dput(dentry);
 140                         goto restart;
 141                 } else if (!(dentry->d_flags & DCACHE_LUSTRE_INVALID)) {
 142                         CDEBUG(D_DENTRY, "unhashing dentry %*s (%p) parent %p "
 143                                "inode %p refc %d\n", dentry->d_name.len,
 144                                dentry->d_name.name, dentry, dentry->d_parent,
 145                                dentry->d_inode, atomic_read(&dentry->d_count));
 146                         hlist_del_init(&dentry->d_hash);
 147                         dentry->d_flags |= DCACHE_LUSTRE_INVALID;
 148                         hlist_add_head(&dentry->d_hash,
 149                                        &sbi->ll_orphan_dentry_list);
 150                 }
 151         }
 152         spin_unlock(&dcache_lock);
 153         EXIT;
 154 }
 155
 156 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
 157
 158 static int revalidate_it_finish(struct ptlrpc_request *request,
 159                                 int offset, struct lookup_intent *it,
 160                                 struct dentry *de)
 161 {
 162         struct ll_sb_info *sbi;
 163         int rc = 0;
 164         ENTRY;
 165
 166         if (!request)
 167                 RETURN(0);
 168
 169         if (it_disposition(it, DISP_LOOKUP_NEG))
 170                 RETURN(-ENOENT);
 171
 172         sbi = ll_i2sbi(de->d_inode);
 173         rc = ll_prep_inode(sbi->ll_osc_exp, sbi->ll_mdc_exp,
 174                            &de->d_inode, request, offset, NULL);
 175
 176         RETURN(rc);
 177 }
 178
 179 void ll_lookup_finish_locks(struct lookup_intent *it, struct dentry *dentry)
 180 {
 181         LASSERT(it != NULL);
 182         LASSERT(dentry != NULL);
 183
 184         if (it->d.lustre.it_lock_mode && dentry->d_inode != NULL) {
 185                 struct inode *inode = dentry->d_inode;
 186                 CDEBUG(D_DLMTRACE, "setting l_data to inode %p (%lu/%u)\n",
 187                        inode, inode->i_ino, inode->i_generation);
 188                 mdc_set_lock_data(NULL, &it->d.lustre.it_lock_handle, inode);
 189         }
 190
 191         /* drop lookup or getattr locks immediately */
 192         if (it->it_op == IT_LOOKUP || it->it_op == IT_GETATTR) {
 193 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 194                 /* on 2.6 there are situation when several lookups and
 195                  * revalidations may be requested during single operation.
 196                  * therefore, we don't release intent here -bzzz */
 197                 ll_intent_drop_lock(it);
 198 #else
 199                 ll_intent_release(it);
 200 #endif
 201         }
 202 }
 203
 204 void ll_frob_intent(struct lookup_intent **itp, struct lookup_intent *deft)
 205 {
 206         struct lookup_intent *it = *itp;
 207 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 208         if (it && it->it_magic != INTENT_MAGIC) {
 209                 CERROR("WARNING: uninitialized intent\n");
 210                 LBUG();
 211         }
 212         if (it && (it->it_op == IT_GETATTR || it->it_op == 0))
 213                 it->it_op = IT_LOOKUP;
 214 #endif
 215
 216         if (!it || it->it_op == IT_GETXATTR)
 217                 it = *itp = deft;
 218
 219         it->it_op_release = ll_intent_release;
 220 }
 221
 222 int ll_revalidate_it(struct dentry *de, int flags, struct lookup_intent *it)
 223 {
 224         int rc;
 225         struct ll_fid pfid, cfid;
 226         struct it_cb_data icbd;
 227         struct ll_uctxt ctxt;
 228         struct ptlrpc_request *req = NULL;
 229         struct lookup_intent lookup_it = { .it_op = IT_LOOKUP };
 230         struct obd_export *exp;
 231
 232         ENTRY;
 233         CDEBUG(D_VFSTRACE, "VFS Op:name=%s,intent=%s\n", de->d_name.name,
 234                LL_IT2STR(it));
 235
 236         /* Cached negative dentries are unsafe for now - look them up again */
 237         if (de->d_inode == NULL)
 238                 RETURN(0);
 239
 240         CDEBUG(D_INODE, "revalidate 0x%p: %*s -> %lu/%lu\n",
 241                         de, de->d_name.len, de->d_name.name,
 242                         (unsigned long) de->d_inode->i_ino,
 243                         (unsigned long) de->d_inode->i_generation);
 244
 245         exp = ll_i2mdcexp(de->d_inode);
 246         ll_inode2fid(&pfid, de->d_parent->d_inode);
 247         ll_inode2fid(&cfid, de->d_inode);
 248         icbd.icbd_parent = de->d_parent->d_inode;
 249         icbd.icbd_childp = &de;
 250
 251         /* Never execute intents for mount points.
 252          * Attributes will be fixed up in ll_inode_revalidate_it */
 253         if (d_mountpoint(de))
 254                 RETURN(1);
 255
 256         ll_frob_intent(&it, &lookup_it);
 257         LASSERT(it);
 258
 259         ll_i2uctxt(&ctxt, de->d_parent->d_inode, de->d_inode);
 260
 261         if (it->it_op == IT_GETATTR) { /* We need to check for LOOKUP lock
 262                                           as well */
 263                 rc = md_intent_lock(exp, &ctxt, &pfid, de->d_name.name,
 264                                     de->d_name.len, NULL, 0, &cfid, &lookup_it,
 265                                     flags, &req, ll_mdc_blocking_ast);
 266                 /* If there was no lookup lock, no point in even checking for
 267                    UPDATE lock */
 268                 if (!rc) {
 269                         it = &lookup_it;
 270                         GOTO(out, rc);
 271                 }
 272                 if (it_disposition(&lookup_it, DISP_LOOKUP_NEG)) {
 273                         ll_intent_release(&lookup_it);
 274                         it = &lookup_it;
 275                         GOTO(out, rc = 0);
 276                 }
 277
 278                 if (req)
 279                         ptlrpc_req_finished(req);
 280                 req = NULL;
 281                 ll_lookup_finish_locks(&lookup_it, de);
 282         }
 283
 284         rc = md_intent_lock(exp, &ctxt, &pfid, de->d_name.name, de->d_name.len,
 285                             NULL, 0, &cfid, it, flags, &req,
 286                             ll_mdc_blocking_ast);
 287         /* If req is NULL, then mdc_intent_lock only tried to do a lock match;
 288          * if all was well, it will return 1 if it found locks, 0 otherwise. */
 289         if (req == NULL && rc >= 0)
 290                 GOTO(out, rc);
 291
 292         if (rc < 0) {
 293                 if (rc != -ESTALE) {
 294                         CDEBUG(D_INFO, "ll_intent_lock: rc %d : it->it_status "
 295                                "%d\n", rc, it->d.lustre.it_status);
 296                 }
 297                 GOTO(out, rc = 0);
 298         }
 299
 300         rc = revalidate_it_finish(req, 1, it, de);
 301         if (rc != 0) {
 302                 ll_intent_release(it);
 303                 GOTO(out, rc = 0);
 304         }
 305         rc = 1;
 306
 307         /* unfortunately ll_intent_lock may cause a callback and revoke our
 308            dentry */
 309         spin_lock(&dcache_lock);
 310         hlist_del_init(&de->d_hash);
 311         __d_rehash(de, 0);
 312         spin_unlock(&dcache_lock);
 313
 314  out:
 315         if (req != NULL && rc == 1)
 316                 ptlrpc_req_finished(req);
 317         if (rc == 0) {
 318                 ll_unhash_aliases(de->d_inode);
 319                 /* done in ll_unhash_aliases()
 320                 de->d_flags |= DCACHE_LUSTRE_INVALID; */
 321         } else {
 322                 CDEBUG(D_DENTRY, "revalidated dentry %*s (%p) parent %p "
 323                                "inode %p refc %d\n", de->d_name.len,
 324                                de->d_name.name, de, de->d_parent, de->d_inode,
 325                                atomic_read(&de->d_count));
 326                 ll_lookup_finish_locks(it, de);
 327                 de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 328         }
 329         RETURN(rc);
 330 }
 331
 332 /*static*/ void ll_pin(struct dentry *de, struct vfsmount *mnt, int flag)
 333 {
 334         struct inode *inode= de->d_inode;
 335         struct ll_sb_info *sbi = ll_i2sbi(inode);
 336         struct ll_dentry_data *ldd = ll_d2d(de);
 337         struct obd_client_handle *handle;
 338         int rc = 0;
 339         ENTRY;
 340         LASSERT(ldd);
 341
 342         lock_kernel();
 343         /* Strictly speaking this introduces an additional race: the
 344          * increments should wait until the rpc has returned.
 345          * However, given that at present the function is void, this
 346          * issue is moot. */
 347         if (flag == 1 && (++ldd->lld_mnt_count) > 1) {
 348                 unlock_kernel();
 349                 EXIT;
 350                 return;
 351         }
 352
 353         if (flag == 0 && (++ldd->lld_cwd_count) > 1) {
 354                 unlock_kernel();
 355                 EXIT;
 356                 return;
 357         }
 358         unlock_kernel();
 359
 360         handle = (flag) ? &ldd->lld_mnt_och : &ldd->lld_cwd_och;
 361         rc = obd_pin(sbi->ll_mdc_exp, inode->i_ino, inode->i_generation,
 362                      inode->i_mode & S_IFMT, handle, flag);
 363
 364         if (rc) {
 365                 lock_kernel();
 366                 memset(handle, 0, sizeof(*handle));
 367                 if (flag == 0)
 368                         ldd->lld_cwd_count--;
 369                 else
 370                         ldd->lld_mnt_count--;
 371                 unlock_kernel();
 372         }
 373
 374         EXIT;
 375         return;
 376 }
 377
 378 /*static*/ void ll_unpin(struct dentry *de, struct vfsmount *mnt, int flag)
 379 {
 380         struct ll_sb_info *sbi = ll_i2sbi(de->d_inode);
 381         struct ll_dentry_data *ldd = ll_d2d(de);
 382         struct obd_client_handle handle;
 383         int count, rc = 0;
 384         ENTRY;
 385         LASSERT(ldd);
 386
 387         lock_kernel();
 388         /* Strictly speaking this introduces an additional race: the
 389          * increments should wait until the rpc has returned.
 390          * However, given that at present the function is void, this
 391          * issue is moot. */
 392         handle = (flag) ? ldd->lld_mnt_och : ldd->lld_cwd_och;
 393         if (handle.och_magic != OBD_CLIENT_HANDLE_MAGIC) {
 394                 /* the "pin" failed */
 395                 unlock_kernel();
 396                 EXIT;
 397                 return;
 398         }
 399
 400         if (flag)
 401                 count = --ldd->lld_mnt_count;
 402         else
 403                 count = --ldd->lld_cwd_count;
 404         unlock_kernel();
 405
 406         if (count != 0) {
 407                 EXIT;
 408                 return;
 409         }
 410
 411         rc = obd_unpin(sbi->ll_mdc_exp, &handle, flag);
 412         EXIT;
 413         return;
 414 }
 415
 416 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 417 static int ll_revalidate_nd(struct dentry *dentry, struct nameidata *nd)
 418 {
 419         int rc;
 420         ENTRY;
 421
 422         if (nd && nd->flags & LOOKUP_LAST && !(nd->flags & LOOKUP_LINK_NOTLAST))
 423                 rc = ll_revalidate_it(dentry, nd->flags, &nd->intent);
 424         else
 425                 rc = ll_revalidate_it(dentry, 0, NULL);
 426
 427         RETURN(rc);
 428 }
 429 #endif
 430
 431 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
 432 static void ll_dentry_iput(struct dentry *dentry, struct inode *inode)
 433 {
 434         struct ll_sb_info *sbi = ll_i2sbi(inode);
 435         struct ll_fid parent, child;
 436
 437         LASSERT(dentry->d_parent && dentry->d_parent->d_inode);
 438         ll_inode2fid(&parent, dentry->d_parent->d_inode);
 439         ll_inode2fid(&child, inode);
 440         md_change_cbdata_name(sbi->ll_mdc_exp, &parent,
 441                               (char *)dentry->d_name.name,
 442                               dentry->d_name.len, &child,
 443                               null_if_equal, inode);
 444         iput(inode);
 445 }
 446 #else
 447 #error "implement ->d_iput() for 2.6"
 448 #endif
 449
 450 struct dentry_operations ll_d_ops = {
 451 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 452         .d_revalidate = ll_revalidate_nd,
 453 #else
 454         .d_revalidate_it = ll_revalidate_it,
 455 #endif
 456         .d_release = ll_release,
 457         .d_iput = ll_dentry_iput,
 458         .d_delete = ll_ddelete,
 459 #if 0
 460         .d_pin = ll_pin,
 461         .d_unpin = ll_unpin,
 462 #endif
 463 };