lustre/obdfs/namei.c

   1 /*
   2  *  linux/fs/obdfs/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/ext2/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *
  20  *  Changes for use in OBDFS
  21  *  Copyright (c) 1999, Seagate Technology Inc.
  22  *
  23  */
  24
  25 #include <asm/uaccess.h>
  26
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/ext2_fs.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/sched.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/locks.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/iobuf.h>
  37
  38 #include <linux/obd_support.h>
  39 #include <linux/obdfs.h>
  40
  41 /*
  42  * define how far ahead to read directories while searching them.
  43  */
  44 #define NAMEI_RA_CHUNKS  2
  45 #define NAMEI_RA_BLOCKS  4
  46 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  47 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  48
  49 /*
  50  * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
  51  *
  52  * `len <= EXT2_NAME_LEN' is guaranteed by caller.
  53  * `de != NULL' is guaranteed by caller.
  54  */
  55 static inline int ext2_match (int len, const char * const name,
  56                        struct ext2_dir_entry_2 * de)
  57 {
  58         if (len != de->name_len)
  59                 return 0;
  60         if (!de->inode)
  61                 return 0;
  62         return !memcmp(name, de->name, len);
  63 }
  64
  65 /*
  66  *      ext2_find_entry()
  67  *
  68  * finds an entry in the specified directory with the wanted name. It
  69  * returns the cache buffer in which the entry was found, and the entry
  70  * itself (as a parameter - res_dir). It does NOT read the inode of the
  71  * entry - you'll have to do that yourself if you want to.
  72  */
  73 static struct page * obdfs_find_entry (struct inode * dir,
  74                                              const char * const name, int namelen,
  75                                              struct ext2_dir_entry_2 ** res_dir, int lock)
  76 {
  77         struct super_block * sb;
  78         unsigned long offset;
  79         struct page * page;
  80         ENTRY;
  81         CDEBUG(D_INODE, "find entry for %*s\n", namelen, name);
  82
  83         *res_dir = NULL;
  84         sb = dir->i_sb;
  85
  86         if (namelen > EXT2_NAME_LEN)
  87                 return NULL;
  88
  89         CDEBUG(D_INODE, "dirsize is %Ld\n", dir->i_size);
  90
  91         page = 0;
  92         offset = 0;
  93         while ( offset < dir->i_size ) {
  94                 struct ext2_dir_entry_2 * de;
  95                 char * dlimit;
  96
  97                 page = obdfs_getpage(dir, offset, 0, lock);
  98
  99                 if ( !page ) {
 100                         CDEBUG(D_INODE, "No page, offset %lx\n", offset);
 101                         return NULL;
 102                 }
 103
 104                 de = (struct ext2_dir_entry_2 *) page_address(page);
 105                 dlimit = (char *)page_address(page) + PAGE_SIZE;
 106                 while ((char *) de < dlimit) {
 107                         /* this code is executed quadratically often */
 108                         /* do minimal checking `by hand' */
 109                         int de_len;
 110                         /* CDEBUG(D_INODE, "Entry %p len %d, page at %#lx - %#lx , offset %lx\n",
 111                                de, le16_to_cpu(de->rec_len), page_address(page),
 112                                page_address(page) + PAGE_SIZE, offset); */
 113
 114                         if ((char *) de + namelen <= dlimit &&
 115                             ext2_match (namelen, name, de)) {
 116                                 /* found a match -
 117                                    just to be sure, do a full check */
 118                                 if (!obdfs_check_dir_entry("ext2_find_entry",
 119                                                           dir, de, page, offset))
 120                                         goto failure;
 121                                 *res_dir = de;
 122                                 EXIT;
 123                                 return page;
 124                         }
 125                         /* prevent looping on a bad block */
 126                         de_len = le16_to_cpu(de->rec_len);
 127                         if (de_len <= 0) {
 128                                 printk("Bad entry at %p len %d\n", de, de_len);
 129                                 goto failure;
 130                         }
 131                         offset += de_len;
 132                         de = (struct ext2_dir_entry_2 *)
 133                                 ((char *) de + de_len);
 134                         /* CDEBUG(D_INODE, "Next while %lx\n", offset); */
 135                 }
 136                 if ( lock )
 137                         UnlockPage(page);
 138                 page_cache_release(page);
 139                 page = NULL;
 140                 CDEBUG(D_INODE, "Next for %lx\n", offset);
 141         }
 142
 143 failure:
 144         CDEBUG(D_INODE, "Negative case, page %p, offset %ld\n", page, offset);
 145         if (page) {
 146                 if (lock)
 147                         UnlockPage(page);
 148                 page_cache_release(page);
 149         }
 150         EXIT;
 151         return NULL;
 152 }
 153
 154 struct dentry *obdfs_lookup(struct inode * dir, struct dentry *dentry)
 155 {
 156         struct inode * inode;
 157         struct ext2_dir_entry_2 * de;
 158         struct page * page;
 159         ENTRY;
 160
 161         if (dentry->d_name.len > EXT2_NAME_LEN)
 162                 return ERR_PTR(-ENAMETOOLONG);
 163
 164         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 165         inode = NULL;
 166         if ( !page )
 167                 CDEBUG(D_INODE, "No page - negative entry.\n");
 168         if ( page && !de ) {
 169                 CDEBUG(D_INODE, "Danger: PAGE but de.\n");
 170                 return ERR_PTR(-ENOENT);
 171         }
 172         if (page) {
 173                 unsigned long ino = le32_to_cpu(de->inode);
 174                 UnlockPage(page);
 175                 page_cache_release(page);
 176                 inode = iget(dir->i_sb, ino);
 177
 178                 if (!inode) {
 179                         CDEBUG(D_INODE, "No inode.\n");
 180                         EXIT;
 181                         return ERR_PTR(-EACCES);
 182                 }
 183         }
 184         d_add(dentry, inode);
 185         EXIT;
 186         return NULL;
 187 }
 188
 189
 190 /*
 191  *      ext2_add_entry()
 192  *
 193  * adds a file entry to the specified directory, using the same
 194  * semantics as ext2_find_entry(). It returns NULL if it failed.
 195  *
 196  * NOTE!! The inode part of 'de' is left at 0 - which means you
 197  * may not sleep between calling this and putting something into
 198  * the entry, as someone else might have used it while you slept.
 199
 200  * returns a locked and held page upon success
 201  */
 202 static struct page *obdfs_add_entry (struct inode * dir,
 203                                      const char * name, int namelen,
 204                                      struct ext2_dir_entry_2 ** res_dir,
 205                                      int *err)
 206 {
 207         unsigned long offset;
 208         unsigned short rec_len;
 209         struct page *page;
 210         struct ext2_dir_entry_2 * de, * de1;
 211         struct super_block * sb;
 212
 213         ENTRY;
 214         *err = -EINVAL;
 215         *res_dir = NULL;
 216         if (!dir || !dir->i_nlink) {
 217                 EXIT;
 218                 return NULL;
 219         }
 220         sb = dir->i_sb;
 221
 222         if (!namelen) {
 223                 EXIT;
 224                 return NULL;
 225         }
 226         /*
 227          * Is this a busy deleted directory?  Can't create new files if so
 228          */
 229         if (dir->i_size == 0)
 230         {
 231                 EXIT;
 232                 *err = -ENOENT;
 233                 return NULL;
 234         }
 235         page = obdfs_getpage(dir, 0, 0, LOCKED);
 236         if (!page) {
 237                 EXIT;
 238                 return NULL;
 239         }
 240         rec_len = EXT2_DIR_REC_LEN(namelen);
 241         CDEBUG(D_INODE, "reclen: %d\n", rec_len);
 242         offset = 0;
 243         de = (struct ext2_dir_entry_2 *) page_address(page);
 244         *err = -ENOSPC;
 245         while (1) {
 246                 CDEBUG(D_INODE, "Considering entry at %p, (page at %#lx - %#lx), offset %ld\n",
 247                        de, page_address(page), page_address(page) + PAGE_SIZE, offset);
 248                 if ((char *)de >= PAGE_SIZE + (char *)page_address(page)) {
 249                         UnlockPage(page);
 250                         page_cache_release(page);
 251                         page = obdfs_getpage(dir, offset, 1, LOCKED);
 252                         if (!page) {
 253                                 EXIT;
 254                                 return NULL;
 255                         }
 256                         if (dir->i_size <= offset) {
 257                                 if (dir->i_size == 0) {
 258                                         *err = -ENOENT;
 259                                         EXIT;
 260                                         return NULL;
 261                                 }
 262
 263                                 CDEBUG(D_INODE, "creating next block\n");
 264
 265                                 de = (struct ext2_dir_entry_2 *) page_address(page);
 266                                 de->inode = 0;
 267                                 de->rec_len = le16_to_cpu(PAGE_SIZE);
 268                                 dir->i_size = offset + PAGE_SIZE;
 269                                 dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 270                                 mark_inode_dirty(dir);
 271                         } else {
 272
 273                                 ext2_debug ("skipping to next block\n");
 274
 275                                 de = (struct ext2_dir_entry_2 *) page_address(page);
 276                         }
 277                 }
 278                 CDEBUG(D_INODE, "\n");
 279                 if (!obdfs_check_dir_entry ("ext2_add_entry", dir, de, page,
 280                                            offset)) {
 281                         *err = -ENOENT;
 282                         UnlockPage(page);
 283                         page_cache_release(page);
 284                         EXIT;
 285                         return NULL;
 286                 }
 287                 CDEBUG(D_INODE, "\n");
 288                 if (ext2_match (namelen, name, de)) {
 289                                 *err = -EEXIST;
 290                                 UnlockPage(page);
 291                                 page_cache_release(page);
 292                                 EXIT;
 293                                 return NULL;
 294                 }
 295                 CDEBUG(D_INODE, "Testing for enough space at de %p\n", de);
 296                 if ( (le32_to_cpu(de->inode) == 0 && le16_to_cpu(de->rec_len) >= rec_len) ||
 297                      (le16_to_cpu(de->rec_len) >= EXT2_DIR_REC_LEN(de->name_len) + rec_len)) {
 298                         offset += le16_to_cpu(de->rec_len);
 299                         CDEBUG(D_INODE, "Found enough space de %p, offset %#lx\n", de, offset);
 300                         if (le32_to_cpu(de->inode)) {
 301                                 CDEBUG(D_INODE, "Inserting new in %p\n", de);
 302                                 de1 = (struct ext2_dir_entry_2 *) ((char *) de +
 303                                         EXT2_DIR_REC_LEN(de->name_len));
 304                                 CDEBUG(D_INODE, "-- de1 at %p\n", de1);
 305                                 de1->rec_len = cpu_to_le16(le16_to_cpu(de->rec_len) -
 306                                         EXT2_DIR_REC_LEN(de->name_len));
 307                                 de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
 308                                 de = de1;
 309                         }
 310                         CDEBUG(D_INODE, "Reclen adjusted; copy %d bytes to %p, page at %#lx EOP at %#lx\n", namelen, de->name, page_address(page), page_address(page) + PAGE_SIZE);
 311                         de->inode = 0;
 312                         de->name_len = namelen;
 313                         de->file_type = 0;
 314                         memcpy (de->name, name, namelen);
 315                         CDEBUG(D_INODE, "Copy done\n");
 316                         /*
 317                          * XXX shouldn't update any times until successful
 318                          * completion of syscall, but too many callers depend
 319                          * on this.
 320                          *
 321                          * XXX similarly, too many callers depend on
 322                          * ext2_new_inode() setting the times, but error
 323                          * recovery deletes the inode, so the worst that can
 324                          * happen is that the times are slightly out of date
 325                          * and/or different from the directory change time.
 326                          */
 327                         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 328                         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 329                         mark_inode_dirty(dir);
 330                         dir->i_version = ++event;
 331                         *res_dir = de;
 332                         *err = 0;
 333                         PDEBUG(page, "addentry");
 334                         CDEBUG(D_INODE, "Regular exit from add_entry");
 335                         EXIT;
 336                         return page;
 337                 }
 338                 CDEBUG(D_INODE, "\n");
 339                 offset += le16_to_cpu(de->rec_len);
 340                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 341
 342         }
 343         CDEBUG(D_INODE, "\n");
 344
 345         UnlockPage(page);
 346         page_cache_release(page);
 347         PDEBUG(page, "addentry");
 348         EXIT;
 349         return NULL;
 350 }
 351
 352 /*
 353  * ext2_delete_entry deletes a directory entry by merging it with the
 354  * previous entry
 355  */
 356 static int obdfs_delete_entry (struct ext2_dir_entry_2 * dir,
 357                               struct page * page)
 358 {
 359         struct ext2_dir_entry_2 * de, * pde;
 360         int i;
 361
 362         i = 0;
 363         pde = NULL;
 364         de = (struct ext2_dir_entry_2 *) page_address(page);
 365         while (i < PAGE_SIZE) {
 366                 if (!obdfs_check_dir_entry ("ext2_delete_entry", NULL,
 367                                            de, page, i))
 368                         return -EIO;
 369                 if (de == dir)  {
 370                         if (pde)
 371                                 pde->rec_len =
 372                                         cpu_to_le16(le16_to_cpu(pde->rec_len) +
 373                                                     le16_to_cpu(dir->rec_len));
 374                         else
 375                                 dir->inode = 0;
 376                         return 0;
 377                 }
 378                 i += le16_to_cpu(de->rec_len);
 379                 pde = de;
 380                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 381         }
 382         return -ENOENT;
 383 }
 384
 385
 386 static inline void ext2_set_de_type(struct super_block *sb,
 387                                 struct ext2_dir_entry_2 *de,
 388                                 umode_t mode) {
 389         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
 390                 return;
 391         if (S_ISCHR(mode))
 392                 de->file_type = EXT2_FT_CHRDEV;
 393         else if (S_ISBLK(mode))
 394                 de->file_type = EXT2_FT_BLKDEV;
 395         else if (S_ISFIFO(mode))
 396                 de->file_type = EXT2_FT_FIFO;
 397         else if (S_ISLNK(mode))
 398                 de->file_type = EXT2_FT_SYMLINK;
 399         else if (S_ISREG(mode))
 400                 de->file_type = EXT2_FT_REG_FILE;
 401         else if (S_ISDIR(mode))
 402                 de->file_type = EXT2_FT_DIR;
 403 }
 404
 405
 406 /*
 407  * Display all dentries holding the specified inode.
 408  */
 409 #if 0
 410 static void show_dentry(struct list_head * dlist, int subdirs)
 411 {
 412         struct list_head *tmp = dlist;
 413
 414         while ((tmp = tmp->next) != dlist) {
 415                 struct dentry * dentry;
 416                 const char * unhashed = "";
 417
 418                 if ( subdirs )
 419                         dentry  = list_entry(tmp, struct dentry, d_child);
 420                 else
 421                         dentry  = list_entry(tmp, struct dentry, d_alias);
 422
 423                 if (list_empty(&dentry->d_hash))
 424                         unhashed = "(unhashed)";
 425
 426                 if ( dentry->d_inode )
 427                         printk("show_dentry: %s/%s, d_count=%d%s (ino %ld, dev %d, ct %d)\n",
 428                                dentry->d_parent->d_name.name,
 429                                dentry->d_name.name, dentry->d_count,
 430                                unhashed, dentry->d_inode->i_ino,
 431                                dentry->d_inode->i_dev,
 432                                dentry->d_inode->i_count);
 433                 else
 434                         printk("show_dentry: %s/%s, d_count=%d%s \n",
 435                                dentry->d_parent->d_name.name,
 436                                dentry->d_name.name, dentry->d_count,
 437                                unhashed);
 438         }
 439 }
 440 #endif
 441
 442
 443 /*
 444  * By the time this is called, we already have created
 445  * the directory cache entry for the new file, but it
 446  * is so far negative - it has no inode.
 447  *
 448  * If the create succeeds, we fill in the inode information
 449  * with d_instantiate().
 450  */
 451 int obdfs_create (struct inode * dir, struct dentry * dentry, int mode)
 452 {
 453         struct inode * inode;
 454         struct page *page;
 455         struct ext2_dir_entry_2 * de;
 456         int err = -EIO;
 457         objid id;
 458
 459         ENTRY;
 460
 461         /*
 462          * N.B. Several error exits in ext2_new_inode don't set err.
 463          */
 464         err = iops(dir)->o_create(iid(dir), 0, &id);
 465         if ( err )
 466                 return err;
 467         inode =  iget(dir->i_sb, (ino_t)id);
 468         if (!inode || !list_empty(&inode->i_dentry)) {
 469                 CDEBUG(D_INODE, "No inode, ino %ld\n", id);
 470                 EXIT;
 471                 return -EIO;
 472         }
 473
 474         inode->i_op = &obdfs_file_inode_operations;
 475         inode->i_mode = mode;
 476         mark_inode_dirty(inode);
 477         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 478         if (!page) {
 479                 inode->i_nlink--;
 480                 mark_inode_dirty(inode);
 481                 iput (inode);
 482                 EXIT;
 483                 return err;
 484         }
 485         de->inode = cpu_to_le32(inode->i_ino);
 486         ext2_set_de_type(dir->i_sb, de, S_IFREG);
 487         dir->i_version = ++event;
 488         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 489         UnlockPage(page);
 490 #if 0
 491         if (IS_SYNC(dir)) {
 492                 ll_rw_block (WRITE, 1, &bh);
 493                 wait_on_buffer (bh);
 494         }
 495 #endif
 496         page_cache_release(page);
 497         d_instantiate(dentry, inode);
 498         EXIT;
 499         return 0;
 500 }
 501
 502 int obdfs_mknod (struct inode * dir, struct dentry *dentry, int mode, int rdev)
 503 {
 504         struct inode * inode;
 505         struct page *page;
 506         struct ext2_dir_entry_2 * de;
 507         int err;
 508
 509         objid id;
 510
 511         ENTRY;
 512
 513         /*
 514          * N.B. Several error exits in ext2_new_inode don't set err.
 515          */
 516         err = iops(dir)->o_create(iid(dir), 0, &id);
 517         if ( err )
 518                 return err;
 519         inode =  iget(dir->i_sb, (ino_t)id);
 520         if (!inode)
 521                 return -EIO;
 522
 523         inode->i_uid = current->fsuid;
 524         init_special_inode(inode, mode, rdev);
 525         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 526         if (!page)
 527                 goto out_no_entry;
 528         de->inode = cpu_to_le32(inode->i_ino);
 529         dir->i_version = ++event;
 530         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 531         mark_inode_dirty(inode);
 532         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 533         UnlockPage(page);
 534
 535 #if 0
 536         if (IS_SYNC(dir)) {
 537                 ll_rw_block (WRITE, 1, &bh);
 538                 wait_on_buffer (bh);
 539         }
 540 #endif
 541         d_instantiate(dentry, inode);
 542         page_cache_release(page);
 543         err = 0;
 544 out:
 545         return err;
 546
 547 out_no_entry:
 548         inode->i_nlink--;
 549         mark_inode_dirty(inode);
 550         iput(inode);
 551         goto out;
 552 }
 553
 554 int obdfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 555 {
 556         struct inode * inode;
 557         struct page *page, *inode_page;
 558         struct ext2_dir_entry_2 * de;
 559         int err;
 560         objid id;
 561
 562         ENTRY;
 563
 564         err = -EMLINK;
 565         if (dir->i_nlink >= EXT2_LINK_MAX)
 566                 goto out;
 567
 568         err = iops(dir)->o_create(iid(dir), 0, &id);
 569         if ( err )
 570                 return err;
 571         inode =  iget(dir->i_sb, (ino_t)id);
 572         if (!inode)
 573                 return -EIO;
 574
 575
 576         inode->i_op = &obdfs_dir_inode_operations;
 577         inode->i_blocks = 0;
 578         inode_page = obdfs_getpage(inode, 0, 1, LOCKED);
 579         if (!inode_page) {
 580                 inode->i_nlink--; /* is this nlink == 0? */
 581                 mark_inode_dirty(inode);
 582                 iput (inode);
 583                 return err;
 584         }
 585
 586         /* create . and .. */
 587         de = (struct ext2_dir_entry_2 *) page_address(inode_page);
 588         de->inode = cpu_to_le32(inode->i_ino);
 589         de->name_len = 1;
 590         de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
 591         strcpy (de->name, ".");
 592         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 593
 594         de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 595         de->inode = cpu_to_le32(dir->i_ino);
 596         de->rec_len = cpu_to_le16(PAGE_SIZE - EXT2_DIR_REC_LEN(1));
 597         de->name_len = 2;
 598         strcpy (de->name, "..");
 599         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 600
 601         iops(dir)->o_brw(WRITE, iid(dir), inode, inode_page, 1);
 602         inode->i_blocks = PAGE_SIZE/inode->i_sb->s_blocksize;
 603         inode->i_size = PAGE_SIZE;
 604         UnlockPage(inode_page);
 605         page_cache_release(inode_page);
 606
 607         inode->i_nlink = 2;
 608         inode->i_mode = S_IFDIR | mode;
 609         if (dir->i_mode & S_ISGID)
 610                 inode->i_mode |= S_ISGID;
 611         mark_inode_dirty(inode);
 612
 613         /* now deal with the parent */
 614         page = obdfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 615         if (!page) {
 616                 goto out_no_entry;
 617         }
 618
 619         de->inode = cpu_to_le32(inode->i_ino);
 620         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 621         dir->i_version = ++event;
 622
 623 #if 0
 624         if (IS_SYNC(dir)) {
 625                 ll_rw_block (WRITE, 1, &bh);
 626                 wait_on_buffer (bh);
 627         }
 628 #endif
 629         dir->i_nlink++;
 630         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 631         mark_inode_dirty(dir);
 632         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 1);
 633         UnlockPage(page);
 634         page_cache_release(page);
 635         d_instantiate(dentry, inode);
 636         err = 0;
 637 out:
 638         EXIT;
 639         return err;
 640
 641 out_no_entry:
 642         inode->i_nlink = 0;
 643         mark_inode_dirty(inode);
 644         iput (inode);
 645         EXIT;
 646         goto out;
 647 }
 648
 649
 650 /*
 651  * routine to check that the specified directory is empty (for rmdir)
 652  */
 653 static int empty_dir (struct inode * inode)
 654 {
 655         unsigned long offset;
 656         struct page *page;
 657         struct ext2_dir_entry_2 * de, * de1;
 658         struct super_block * sb;
 659
 660         sb = inode->i_sb;
 661         if (inode->i_size < EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2) ||
 662             !(page = obdfs_getpage (inode, 0, 0, LOCKED))) {
 663                 ext2_warning (inode->i_sb, "empty_dir",
 664                               "bad directory (dir #%lu) - no data block",
 665                               inode->i_ino);
 666                 return 1;
 667         }
 668         de = (struct ext2_dir_entry_2 *) page_address(page);
 669         de1 = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 670         if (le32_to_cpu(de->inode) != inode->i_ino || !le32_to_cpu(de1->inode) ||
 671             strcmp (".", de->name) || strcmp ("..", de1->name)) {
 672                 ext2_warning (inode->i_sb, "empty_dir",
 673                               "bad directory (dir #%lu) - no `.' or `..'",
 674                               inode->i_ino);
 675                 page_cache_release(page);
 676                 return 1;
 677         }
 678         offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
 679         de = (struct ext2_dir_entry_2 *) ((char *) de1 + le16_to_cpu(de1->rec_len));
 680         while (offset < inode->i_size ) {
 681                 if (!page || (void *) de >= (void *) (page_address(page) + PAGE_SIZE)) {
 682                         if (page) {
 683                                 UnlockPage(page);
 684                                 page_cache_release(page);
 685                         }
 686                         page = obdfs_getpage(inode, offset, 0, LOCKED);
 687                         if (!page) {
 688 #if 0
 689                                 ext2_error (sb, "empty_dir",
 690                                             "directory #%lu contains a hole at offset %lu",
 691                                             inode->i_ino, offset);
 692 #endif
 693                                 offset += sb->s_blocksize;
 694                                 continue;
 695                         }
 696                         de = (struct ext2_dir_entry_2 *) page_address(page);
 697                 }
 698                 if (!obdfs_check_dir_entry ("empty_dir", inode, de, page,
 699                                            offset)) {
 700                         UnlockPage(page);
 701                         page_cache_release(page);
 702                         return 1;
 703                 }
 704                 if (le32_to_cpu(de->inode)) {
 705                         UnlockPage(page);
 706                         page_cache_release(page);
 707                         return 0;
 708                 }
 709                 offset += le16_to_cpu(de->rec_len);
 710                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 711         }
 712         UnlockPage(page);
 713         page_cache_release(page);
 714         return 1;
 715 }
 716
 717 int obdfs_rmdir (struct inode * dir, struct dentry *dentry)
 718 {
 719         int retval;
 720         struct inode * inode;
 721         struct page *page;
 722         struct ext2_dir_entry_2 * de;
 723
 724         ENTRY;
 725
 726         retval = -ENOENT;
 727         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 728         if (!page)
 729                 goto end_rmdir;
 730
 731         inode = dentry->d_inode;
 732         DQUOT_INIT(inode);
 733
 734         retval = -EIO;
 735         if (le32_to_cpu(de->inode) != inode->i_ino)
 736                 goto end_rmdir;
 737
 738         retval = -ENOTEMPTY;
 739         if (!empty_dir (inode))
 740                 goto end_rmdir;
 741
 742         retval = obdfs_delete_entry (de, page);
 743         dir->i_version = ++event;
 744         if (retval)
 745                 goto end_rmdir;
 746         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 747         UnlockPage(page);
 748 #if 0
 749         if (IS_SYNC(dir)) {
 750                 ll_rw_block (WRITE, 1, &bh);
 751                 wait_on_buffer (bh);
 752         }
 753 #endif
 754         if (inode->i_nlink != 2)
 755                 ext2_warning (inode->i_sb, "ext2_rmdir",
 756                               "empty directory has nlink!=2 (%d)",
 757                               inode->i_nlink);
 758         inode->i_version = ++event;
 759         inode->i_nlink = 0;
 760         inode->i_size = 0;
 761         mark_inode_dirty(inode);
 762         dir->i_nlink--;
 763         inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 764         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 765         mark_inode_dirty(dir);
 766         d_delete(dentry);
 767
 768 end_rmdir:
 769         if ( page )
 770                 page_cache_release(page);
 771         EXIT;
 772         return retval;
 773 }
 774
 775 int obdfs_unlink(struct inode * dir, struct dentry *dentry)
 776 {
 777         int retval;
 778         struct inode * inode;
 779         struct page *page;
 780         struct ext2_dir_entry_2 * de;
 781
 782         ENTRY;
 783
 784         retval = -ENOENT;
 785         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 786         if (!page)
 787                 goto end_unlink;
 788
 789         inode = dentry->d_inode;
 790         DQUOT_INIT(inode);
 791
 792         retval = -EIO;
 793         if (le32_to_cpu(de->inode) != inode->i_ino)
 794                 goto end_unlink;
 795
 796         if (!inode->i_nlink) {
 797                 ext2_warning (inode->i_sb, "ext2_unlink",
 798                               "Deleting nonexistent file (%lu), %d",
 799                               inode->i_ino, inode->i_nlink);
 800                 inode->i_nlink = 1;
 801         }
 802         retval = obdfs_delete_entry (de, page);
 803         if (retval)
 804                 goto end_unlink;
 805         dir->i_version = ++event;
 806         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 807         UnlockPage(page);
 808 #if 0
 809         if (IS_SYNC(dir)) {
 810                 ll_rw_block (WRITE, 1, &bh);
 811                 wait_on_buffer (bh);
 812         }
 813 #endif
 814         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 815         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 816         mark_inode_dirty(dir);
 817         inode->i_nlink--;
 818         mark_inode_dirty(inode);
 819         inode->i_ctime = dir->i_ctime;
 820         retval = 0;
 821         d_delete(dentry);       /* This also frees the inode */
 822
 823 end_unlink:
 824         if (page)
 825                 page_cache_release(page);
 826         EXIT;
 827         return retval;
 828 }
 829
 830 int obdfs_symlink (struct inode * dir, struct dentry *dentry, const char * symname)
 831 {
 832         struct ext2_dir_entry_2 * de;
 833         struct inode * inode;
 834         struct page* page = NULL, * name_page = NULL;
 835         char * link;
 836         int i, l, err = -EIO;
 837         char c;
 838         objid id;
 839
 840         ENTRY;
 841         /*
 842          * N.B. Several error exits in ext2_new_inode don't set err.
 843          */
 844         err = iops(dir)->o_create(iid(dir), 0, &id);
 845         if ( err )  {
 846                 EXIT;
 847                 return err;
 848         }
 849         inode =  iget(dir->i_sb, (ino_t)id);
 850         if (!inode) {
 851                 EXIT;
 852                 return err;
 853         }
 854         inode->i_mode = S_IFLNK | S_IRWXUGO;
 855         inode->i_op = &obdfs_symlink_inode_operations;
 856         for (l = 0; l < inode->i_sb->s_blocksize - 1 &&
 857              symname [l]; l++)
 858                 ;
 859
 860         if (l >= sizeof (inode->u.ext2_i.i_data)) {
 861                 CDEBUG(D_INODE, "l=%d, normal symlink\n", l);
 862
 863                 name_page = obdfs_getpage(inode, 0, 1, LOCKED);
 864                 if (!name_page) {
 865                         inode->i_nlink--;
 866                         mark_inode_dirty(inode);
 867                         iput (inode);
 868                         EXIT;
 869                         return err;
 870                 }
 871                 link = (char *)page_address(name_page);
 872         } else {
 873                 link = (char *) inode->u.ext2_i.i_data;
 874
 875                 CDEBUG(D_INODE, "l=%d, fast symlink\n", l);
 876
 877         }
 878         i = 0;
 879         while (i < inode->i_sb->s_blocksize - 1 && (c = *(symname++)))
 880                 link[i++] = c;
 881         link[i] = 0;
 882         if (name_page) {
 883                 iops(inode)->o_brw(WRITE, iid(inode), inode, name_page, 1);
 884                 PDEBUG(name_page, "symlink");
 885                 UnlockPage(name_page);
 886                 page_cache_release(name_page);
 887         }
 888         inode->i_size = i;
 889         mark_inode_dirty(inode);
 890
 891         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 892         if (!page)
 893                 goto out_no_entry;
 894         de->inode = cpu_to_le32(inode->i_ino);
 895         ext2_set_de_type(dir->i_sb, de, S_IFLNK);
 896         dir->i_version = ++event;
 897         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 1);
 898         UnlockPage(page);
 899 #if 0
 900         if (IS_SYNC(dir)) {
 901                 ll_rw_block (WRITE, 1, &bh);
 902                 wait_on_buffer (bh);
 903         }
 904 #endif
 905         d_instantiate(dentry, inode);
 906         err = 0;
 907 out:
 908         EXIT;
 909         return err;
 910
 911 out_no_entry:
 912         inode->i_nlink--;
 913         mark_inode_dirty(inode);
 914         iput (inode);
 915         goto out;
 916 }
 917
 918 int obdfs_link (struct dentry * old_dentry,
 919                 struct inode * dir, struct dentry *dentry)
 920 {
 921         struct inode *inode = old_dentry->d_inode;
 922         struct ext2_dir_entry_2 * de;
 923         struct page *page;
 924         int err;
 925
 926         ENTRY;
 927
 928         if (S_ISDIR(inode->i_mode))
 929                 return -EPERM;
 930
 931         if (inode->i_nlink >= EXT2_LINK_MAX)
 932                 return -EMLINK;
 933
 934         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 935         if (!page)
 936                 return err;
 937
 938         de->inode = cpu_to_le32(inode->i_ino);
 939         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 940         dir->i_version = ++event;
 941         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 942         UnlockPage(page);
 943
 944 #if 0
 945         if (IS_SYNC(dir)) {
 946                 ll_rw_block (WRITE, 1, &bh);
 947                 wait_on_buffer (bh);
 948         }
 949 #endif
 950         page_cache_release(page);
 951         inode->i_nlink++;
 952         inode->i_ctime = CURRENT_TIME;
 953         mark_inode_dirty(inode);
 954         inode->i_count++;
 955         d_instantiate(dentry, inode);
 956         return 0;
 957 }
 958
 959 #define PARENT_INO(buffer) \
 960         ((struct ext2_dir_entry_2 *) ((char *) buffer + \
 961         le16_to_cpu(((struct ext2_dir_entry_2 *) buffer)->rec_len)))->inode
 962
 963 /*
 964  * Anybody can rename anything with this: the permission checks are left to the
 965  * higher-level routines.
 966  */
 967 int obdfs_rename (struct inode * old_dir, struct dentry *old_dentry,
 968                            struct inode * new_dir, struct dentry *new_dentry)
 969 {
 970         struct inode * old_inode, * new_inode;
 971         struct page * old_page, * new_page, * dir_page;
 972         struct ext2_dir_entry_2 * old_de, * new_de;
 973         int retval;
 974
 975         ENTRY;
 976
 977         new_page = dir_page = NULL;
 978
 979         /* does the old entry exist? - if not get out */
 980         old_page = obdfs_find_entry (old_dir, old_dentry->d_name.name, old_dentry->d_name.len, &old_de, NOLOCK);
 981         PDEBUG(old_page, "rename - old page");
 982         /*
 983          *  Check for inode number is _not_ due to possible IO errors.
 984          *  We might rmdir the source, keep it as pwd of some process
 985          *  and merrily kill the link to whatever was created under the
 986          *  same name. Goodbye sticky bit ;-<
 987          */
 988         old_inode = old_dentry->d_inode;
 989         retval = -ENOENT;
 990         if (!old_page || le32_to_cpu(old_de->inode) != old_inode->i_ino)
 991                 goto end_rename;
 992
 993         /* find new inode */
 994         new_inode = new_dentry->d_inode;
 995         new_page = obdfs_find_entry (new_dir, new_dentry->d_name.name,
 996                                 new_dentry->d_name.len, &new_de, NOLOCK);
 997         PDEBUG(new_page, "rename - new page ");
 998         if (new_page) {
 999                 if (!new_inode) {
1000                         page_cache_release(new_page);
1001                         new_page = NULL;
1002                 } else {
1003                         DQUOT_INIT(new_inode);
1004                 }
1005         }
1006         /* in this case we to check more ... */
1007         if (S_ISDIR(old_inode->i_mode)) {
1008                 /* can only rename into empty new directory */
1009                 if (new_inode) {
1010                         retval = -ENOTEMPTY;
1011                         if (!empty_dir (new_inode))
1012                                 goto end_rename;
1013                 }
1014                 retval = -EIO;
1015                 dir_page= obdfs_getpage (old_inode, 0, 0, LOCKED);
1016                 PDEBUG(dir_page, "rename dir page");
1017
1018                 if (!dir_page)
1019                         goto end_rename;
1020                 if (le32_to_cpu(PARENT_INO(page_address(dir_page))) != old_dir->i_ino)
1021                         goto end_rename;
1022                 retval = -EMLINK;
1023                 if (!new_inode && new_dir!=old_dir &&
1024                                 new_dir->i_nlink >= EXT2_LINK_MAX)
1025                         goto end_rename;
1026         }
1027         /* create the target dir entry */
1028         if (!new_page) {
1029                 new_page = obdfs_add_entry (new_dir, new_dentry->d_name.name,
1030                                         new_dentry->d_name.len, &new_de,
1031                                         &retval);
1032                 PDEBUG(new_page, "rename new page");
1033                 if (!new_page)
1034                         goto end_rename;
1035         }
1036         new_dir->i_version = ++event;
1037
1038         /*
1039          * remove the old entry
1040          */
1041         new_de->inode = le32_to_cpu(old_inode->i_ino);
1042         if (EXT2_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
1043                                       EXT2_FEATURE_INCOMPAT_FILETYPE))
1044                 new_de->file_type = old_de->file_type;
1045
1046         obdfs_delete_entry (old_de, old_page);
1047
1048         old_dir->i_version = ++event;
1049         if (new_inode) {
1050                 new_inode->i_nlink--;
1051                 new_inode->i_ctime = CURRENT_TIME;
1052                 mark_inode_dirty(new_inode);
1053         }
1054         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
1055         old_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1056         mark_inode_dirty(old_dir);
1057         if (dir_page) {
1058                 PARENT_INO(page_address(dir_page)) = le32_to_cpu(new_dir->i_ino);
1059                 iops(old_inode)->o_brw(WRITE, iid(old_inode), old_inode, dir_page, 0);
1060                 old_dir->i_nlink--;
1061                 mark_inode_dirty(old_dir);
1062                 if (new_inode) {
1063                         new_inode->i_nlink--;
1064                         mark_inode_dirty(new_inode);
1065                 } else {
1066                         new_dir->i_nlink++;
1067                         new_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1068                         mark_inode_dirty(new_dir);
1069                 }
1070         }
1071         if ( old_page != new_page ) {
1072                 unsigned long index = old_page->index;
1073                 /* lock the old_page and release unlocked copy */
1074                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1075                 page_cache_release(old_page);
1076                 old_page = obdfs_getpage(old_dir, index >> PAGE_SHIFT, 0, LOCKED);
1077                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1078                 iops(old_dir)->o_brw(WRITE, iid(old_dir), old_dir, old_page,0);
1079         }
1080 #if 0
1081         if (IS_SYNC(old_dir)) {
1082                 ll_rw_block (WRITE, 1, &old_bh);
1083                 wait_on_buffer (old_bh);
1084         }
1085 #endif
1086         iops(new_dir)->o_brw(WRITE, iid(new_dir), new_dir, new_page, 0);
1087 #if 0
1088         if (IS_SYNC(new_dir)) {
1089                 ll_rw_block (WRITE, 1, &new_bh);
1090                 wait_on_buffer (new_bh);
1091         }
1092 #endif
1093
1094         retval = 0;
1095
1096 end_rename:
1097         if (old_page && PageLocked(old_page) )
1098                 UnlockPage(old_page);
1099         if (old_page)
1100                 page_cache_release(old_page);
1101         if (new_page && PageLocked(new_page) )
1102                 UnlockPage(new_page);
1103         if (new_page)
1104                 page_cache_release(new_page);
1105         if (dir_page && PageLocked(dir_page) )
1106                 UnlockPage(dir_page);
1107         if (dir_page)
1108                 page_cache_release(dir_page);
1109
1110
1111         return retval;
1112 }