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         ino_t ino;
 458
 459         ENTRY;
 460
 461         /*
 462          * N.B. Several error exits in ext2_new_inode don't set err.
 463          */
 464         ino = iops(dir)->o_create(iid(dir), 0, &err);
 465         if ( err )
 466                 return err;
 467         err = -EIO;
 468         inode =  iget(dir->i_sb, ino);
 469         if (!inode || !list_empty(&inode->i_dentry)) {
 470                 CDEBUG(D_INODE, "No inode, ino %ld\n", ino);
 471                 EXIT;
 472                 return err;
 473         }
 474
 475         inode->i_op = &obdfs_file_inode_operations;
 476         inode->i_mode = mode;
 477         mark_inode_dirty(inode);
 478         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 479         if (!page) {
 480                 inode->i_nlink--;
 481                 mark_inode_dirty(inode);
 482                 iput (inode);
 483                 EXIT;
 484                 return err;
 485         }
 486         de->inode = cpu_to_le32(inode->i_ino);
 487         ext2_set_de_type(dir->i_sb, de, S_IFREG);
 488         dir->i_version = ++event;
 489         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 490         UnlockPage(page);
 491 #if 0
 492         if (IS_SYNC(dir)) {
 493                 ll_rw_block (WRITE, 1, &bh);
 494                 wait_on_buffer (bh);
 495         }
 496 #endif
 497         page_cache_release(page);
 498         d_instantiate(dentry, inode);
 499         EXIT;
 500         return 0;
 501 }
 502
 503 int obdfs_mknod (struct inode * dir, struct dentry *dentry, int mode, int rdev)
 504 {
 505         struct inode * inode;
 506         struct page *page;
 507         struct ext2_dir_entry_2 * de;
 508         int err = -EIO;
 509
 510         ino_t ino;
 511
 512         ENTRY;
 513
 514         /*
 515          * N.B. Several error exits in ext2_new_inode don't set err.
 516          */
 517         ino = iops(dir)->o_create(iid(dir), 0, &err);
 518         if ( ino == -1 )
 519                 return -1;
 520         inode =  iget(dir->i_sb, ino);
 521         if (!inode)
 522                 return err;
 523
 524         inode->i_uid = current->fsuid;
 525         init_special_inode(inode, mode, rdev);
 526         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 527         if (!page)
 528                 goto out_no_entry;
 529         de->inode = cpu_to_le32(inode->i_ino);
 530         dir->i_version = ++event;
 531         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 532         mark_inode_dirty(inode);
 533         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 534         UnlockPage(page);
 535
 536 #if 0
 537         if (IS_SYNC(dir)) {
 538                 ll_rw_block (WRITE, 1, &bh);
 539                 wait_on_buffer (bh);
 540         }
 541 #endif
 542         d_instantiate(dentry, inode);
 543         page_cache_release(page);
 544         err = 0;
 545 out:
 546         return err;
 547
 548 out_no_entry:
 549         inode->i_nlink--;
 550         mark_inode_dirty(inode);
 551         iput(inode);
 552         goto out;
 553 }
 554
 555 int obdfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 556 {
 557         struct inode * inode;
 558         struct page *page, *inode_page;
 559         struct ext2_dir_entry_2 * de;
 560         int err;
 561         ino_t ino;
 562
 563         ENTRY;
 564
 565         err = -EMLINK;
 566         if (dir->i_nlink >= EXT2_LINK_MAX)
 567                 goto out;
 568
 569         err = -EIO;
 570         ino = iops(dir)->o_create(iid(dir), 0, &err);
 571         if ( ino == -1 )
 572                 return -1;
 573         inode =  iget(dir->i_sb, ino);
 574         if (!inode)
 575                 return err;
 576
 577
 578         inode->i_op = &obdfs_dir_inode_operations;
 579         inode->i_blocks = 0;
 580         inode_page = obdfs_getpage(inode, 0, 1, LOCKED);
 581         if (!inode_page) {
 582                 inode->i_nlink--; /* is this nlink == 0? */
 583                 mark_inode_dirty(inode);
 584                 iput (inode);
 585                 return err;
 586         }
 587
 588         /* create . and .. */
 589         de = (struct ext2_dir_entry_2 *) page_address(inode_page);
 590         de->inode = cpu_to_le32(inode->i_ino);
 591         de->name_len = 1;
 592         de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
 593         strcpy (de->name, ".");
 594         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 595
 596         de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 597         de->inode = cpu_to_le32(dir->i_ino);
 598         de->rec_len = cpu_to_le16(PAGE_SIZE - EXT2_DIR_REC_LEN(1));
 599         de->name_len = 2;
 600         strcpy (de->name, "..");
 601         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 602
 603         iops(dir)->o_brw(WRITE, iid(dir), inode, inode_page, 1);
 604         inode->i_blocks = PAGE_SIZE/inode->i_sb->s_blocksize;
 605         inode->i_size = PAGE_SIZE;
 606         UnlockPage(inode_page);
 607         page_cache_release(inode_page);
 608
 609         inode->i_nlink = 2;
 610         inode->i_mode = S_IFDIR | mode;
 611         if (dir->i_mode & S_ISGID)
 612                 inode->i_mode |= S_ISGID;
 613         mark_inode_dirty(inode);
 614
 615         /* now deal with the parent */
 616         page = obdfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 617         if (!page) {
 618                 goto out_no_entry;
 619         }
 620
 621         de->inode = cpu_to_le32(inode->i_ino);
 622         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 623         dir->i_version = ++event;
 624
 625 #if 0
 626         if (IS_SYNC(dir)) {
 627                 ll_rw_block (WRITE, 1, &bh);
 628                 wait_on_buffer (bh);
 629         }
 630 #endif
 631         dir->i_nlink++;
 632         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 633         mark_inode_dirty(dir);
 634         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 1);
 635         UnlockPage(page);
 636         page_cache_release(page);
 637         d_instantiate(dentry, inode);
 638         err = 0;
 639 out:
 640         EXIT;
 641         return err;
 642
 643 out_no_entry:
 644         inode->i_nlink = 0;
 645         mark_inode_dirty(inode);
 646         iput (inode);
 647         EXIT;
 648         goto out;
 649 }
 650
 651
 652 /*
 653  * routine to check that the specified directory is empty (for rmdir)
 654  */
 655 static int empty_dir (struct inode * inode)
 656 {
 657         unsigned long offset;
 658         struct page *page;
 659         struct ext2_dir_entry_2 * de, * de1;
 660         struct super_block * sb;
 661
 662         sb = inode->i_sb;
 663         if (inode->i_size < EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2) ||
 664             !(page = obdfs_getpage (inode, 0, 0, LOCKED))) {
 665                 ext2_warning (inode->i_sb, "empty_dir",
 666                               "bad directory (dir #%lu) - no data block",
 667                               inode->i_ino);
 668                 return 1;
 669         }
 670         de = (struct ext2_dir_entry_2 *) page_address(page);
 671         de1 = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 672         if (le32_to_cpu(de->inode) != inode->i_ino || !le32_to_cpu(de1->inode) ||
 673             strcmp (".", de->name) || strcmp ("..", de1->name)) {
 674                 ext2_warning (inode->i_sb, "empty_dir",
 675                               "bad directory (dir #%lu) - no `.' or `..'",
 676                               inode->i_ino);
 677                 page_cache_release(page);
 678                 return 1;
 679         }
 680         offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
 681         de = (struct ext2_dir_entry_2 *) ((char *) de1 + le16_to_cpu(de1->rec_len));
 682         while (offset < inode->i_size ) {
 683                 if (!page || (void *) de >= (void *) (page_address(page) + PAGE_SIZE)) {
 684                         if (page) {
 685                                 UnlockPage(page);
 686                                 page_cache_release(page);
 687                         }
 688                         page = obdfs_getpage(inode, offset, 0, LOCKED);
 689                         if (!page) {
 690 #if 0
 691                                 ext2_error (sb, "empty_dir",
 692                                             "directory #%lu contains a hole at offset %lu",
 693                                             inode->i_ino, offset);
 694 #endif
 695                                 offset += sb->s_blocksize;
 696                                 continue;
 697                         }
 698                         de = (struct ext2_dir_entry_2 *) page_address(page);
 699                 }
 700                 if (!obdfs_check_dir_entry ("empty_dir", inode, de, page,
 701                                            offset)) {
 702                         UnlockPage(page);
 703                         page_cache_release(page);
 704                         return 1;
 705                 }
 706                 if (le32_to_cpu(de->inode)) {
 707                         UnlockPage(page);
 708                         page_cache_release(page);
 709                         return 0;
 710                 }
 711                 offset += le16_to_cpu(de->rec_len);
 712                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 713         }
 714         UnlockPage(page);
 715         page_cache_release(page);
 716         return 1;
 717 }
 718
 719 int obdfs_rmdir (struct inode * dir, struct dentry *dentry)
 720 {
 721         int retval;
 722         struct inode * inode;
 723         struct page *page;
 724         struct ext2_dir_entry_2 * de;
 725
 726         ENTRY;
 727
 728         retval = -ENOENT;
 729         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 730         if (!page)
 731                 goto end_rmdir;
 732
 733         inode = dentry->d_inode;
 734         DQUOT_INIT(inode);
 735
 736         retval = -EIO;
 737         if (le32_to_cpu(de->inode) != inode->i_ino)
 738                 goto end_rmdir;
 739
 740         retval = -ENOTEMPTY;
 741         if (!empty_dir (inode))
 742                 goto end_rmdir;
 743
 744         retval = obdfs_delete_entry (de, page);
 745         dir->i_version = ++event;
 746         if (retval)
 747                 goto end_rmdir;
 748         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 749         UnlockPage(page);
 750 #if 0
 751         if (IS_SYNC(dir)) {
 752                 ll_rw_block (WRITE, 1, &bh);
 753                 wait_on_buffer (bh);
 754         }
 755 #endif
 756         if (inode->i_nlink != 2)
 757                 ext2_warning (inode->i_sb, "ext2_rmdir",
 758                               "empty directory has nlink!=2 (%d)",
 759                               inode->i_nlink);
 760         inode->i_version = ++event;
 761         inode->i_nlink = 0;
 762         inode->i_size = 0;
 763         mark_inode_dirty(inode);
 764         dir->i_nlink--;
 765         inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 766         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 767         mark_inode_dirty(dir);
 768         d_delete(dentry);
 769
 770 end_rmdir:
 771         if ( page )
 772                 page_cache_release(page);
 773         EXIT;
 774         return retval;
 775 }
 776
 777 int obdfs_unlink(struct inode * dir, struct dentry *dentry)
 778 {
 779         int retval;
 780         struct inode * inode;
 781         struct page *page;
 782         struct ext2_dir_entry_2 * de;
 783
 784         ENTRY;
 785
 786         retval = -ENOENT;
 787         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 788         if (!page)
 789                 goto end_unlink;
 790
 791         inode = dentry->d_inode;
 792         DQUOT_INIT(inode);
 793
 794         retval = -EIO;
 795         if (le32_to_cpu(de->inode) != inode->i_ino)
 796                 goto end_unlink;
 797
 798         if (!inode->i_nlink) {
 799                 ext2_warning (inode->i_sb, "ext2_unlink",
 800                               "Deleting nonexistent file (%lu), %d",
 801                               inode->i_ino, inode->i_nlink);
 802                 inode->i_nlink = 1;
 803         }
 804         retval = obdfs_delete_entry (de, page);
 805         if (retval)
 806                 goto end_unlink;
 807         dir->i_version = ++event;
 808         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 809         UnlockPage(page);
 810 #if 0
 811         if (IS_SYNC(dir)) {
 812                 ll_rw_block (WRITE, 1, &bh);
 813                 wait_on_buffer (bh);
 814         }
 815 #endif
 816         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 817         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 818         mark_inode_dirty(dir);
 819         inode->i_nlink--;
 820         mark_inode_dirty(inode);
 821         inode->i_ctime = dir->i_ctime;
 822         retval = 0;
 823         d_delete(dentry);       /* This also frees the inode */
 824
 825 end_unlink:
 826         if (page)
 827                 page_cache_release(page);
 828         EXIT;
 829         return retval;
 830 }
 831
 832 int obdfs_symlink (struct inode * dir, struct dentry *dentry, const char * symname)
 833 {
 834         struct ext2_dir_entry_2 * de;
 835         struct inode * inode;
 836         struct page* page = NULL, * name_page = NULL;
 837         char * link;
 838         int i, l, err = -EIO;
 839         char c;
 840         ino_t ino;
 841
 842         ENTRY;
 843         /*
 844          * N.B. Several error exits in ext2_new_inode don't set err.
 845          */
 846         ino = iops(dir)->o_create(iid(dir), 0, &err);
 847         if ( ino == -1 )  {
 848                 EXIT;
 849                 return -1;
 850         }
 851         inode =  iget(dir->i_sb, ino);
 852         if (!inode) {
 853                 EXIT;
 854                 return err;
 855         }
 856         inode->i_mode = S_IFLNK | S_IRWXUGO;
 857         inode->i_op = &obdfs_symlink_inode_operations;
 858         for (l = 0; l < inode->i_sb->s_blocksize - 1 &&
 859              symname [l]; l++)
 860                 ;
 861
 862         if (l >= sizeof (inode->u.ext2_i.i_data)) {
 863                 CDEBUG(D_INODE, "l=%d, normal symlink\n", l);
 864
 865                 name_page = obdfs_getpage(inode, 0, 1, LOCKED);
 866                 if (!name_page) {
 867                         inode->i_nlink--;
 868                         mark_inode_dirty(inode);
 869                         iput (inode);
 870                         EXIT;
 871                         return err;
 872                 }
 873                 link = (char *)page_address(name_page);
 874         } else {
 875                 link = (char *) inode->u.ext2_i.i_data;
 876
 877                 CDEBUG(D_INODE, "l=%d, fast symlink\n", l);
 878
 879         }
 880         i = 0;
 881         while (i < inode->i_sb->s_blocksize - 1 && (c = *(symname++)))
 882                 link[i++] = c;
 883         link[i] = 0;
 884         if (name_page) {
 885                 iops(inode)->o_brw(WRITE, iid(inode), inode, name_page, 1);
 886                 PDEBUG(name_page, "symlink");
 887                 UnlockPage(name_page);
 888                 page_cache_release(name_page);
 889         }
 890         inode->i_size = i;
 891         mark_inode_dirty(inode);
 892
 893         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 894         if (!page)
 895                 goto out_no_entry;
 896         de->inode = cpu_to_le32(inode->i_ino);
 897         ext2_set_de_type(dir->i_sb, de, S_IFLNK);
 898         dir->i_version = ++event;
 899         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 1);
 900         UnlockPage(page);
 901 #if 0
 902         if (IS_SYNC(dir)) {
 903                 ll_rw_block (WRITE, 1, &bh);
 904                 wait_on_buffer (bh);
 905         }
 906 #endif
 907         d_instantiate(dentry, inode);
 908         err = 0;
 909 out:
 910         EXIT;
 911         return err;
 912
 913 out_no_entry:
 914         inode->i_nlink--;
 915         mark_inode_dirty(inode);
 916         iput (inode);
 917         goto out;
 918 }
 919
 920 int obdfs_link (struct dentry * old_dentry,
 921                 struct inode * dir, struct dentry *dentry)
 922 {
 923         struct inode *inode = old_dentry->d_inode;
 924         struct ext2_dir_entry_2 * de;
 925         struct page *page;
 926         int err;
 927
 928         ENTRY;
 929
 930         if (S_ISDIR(inode->i_mode))
 931                 return -EPERM;
 932
 933         if (inode->i_nlink >= EXT2_LINK_MAX)
 934                 return -EMLINK;
 935
 936         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 937         if (!page)
 938                 return err;
 939
 940         de->inode = cpu_to_le32(inode->i_ino);
 941         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 942         dir->i_version = ++event;
 943         iops(dir)->o_brw(WRITE, iid(dir), dir, page, 0);
 944         UnlockPage(page);
 945
 946 #if 0
 947         if (IS_SYNC(dir)) {
 948                 ll_rw_block (WRITE, 1, &bh);
 949                 wait_on_buffer (bh);
 950         }
 951 #endif
 952         page_cache_release(page);
 953         inode->i_nlink++;
 954         inode->i_ctime = CURRENT_TIME;
 955         mark_inode_dirty(inode);
 956         inode->i_count++;
 957         d_instantiate(dentry, inode);
 958         return 0;
 959 }
 960
 961 #define PARENT_INO(buffer) \
 962         ((struct ext2_dir_entry_2 *) ((char *) buffer + \
 963         le16_to_cpu(((struct ext2_dir_entry_2 *) buffer)->rec_len)))->inode
 964
 965 /*
 966  * Anybody can rename anything with this: the permission checks are left to the
 967  * higher-level routines.
 968  */
 969 int obdfs_rename (struct inode * old_dir, struct dentry *old_dentry,
 970                            struct inode * new_dir, struct dentry *new_dentry)
 971 {
 972         struct inode * old_inode, * new_inode;
 973         struct page * old_page, * new_page, * dir_page;
 974         struct ext2_dir_entry_2 * old_de, * new_de;
 975         int retval;
 976
 977         ENTRY;
 978
 979         new_page = dir_page = NULL;
 980
 981         /* does the old entry exist? - if not get out */
 982         old_page = obdfs_find_entry (old_dir, old_dentry->d_name.name, old_dentry->d_name.len, &old_de, NOLOCK);
 983         PDEBUG(old_page, "rename - old page");
 984         /*
 985          *  Check for inode number is _not_ due to possible IO errors.
 986          *  We might rmdir the source, keep it as pwd of some process
 987          *  and merrily kill the link to whatever was created under the
 988          *  same name. Goodbye sticky bit ;-<
 989          */
 990         old_inode = old_dentry->d_inode;
 991         retval = -ENOENT;
 992         if (!old_page || le32_to_cpu(old_de->inode) != old_inode->i_ino)
 993                 goto end_rename;
 994
 995         /* find new inode */
 996         new_inode = new_dentry->d_inode;
 997         new_page = obdfs_find_entry (new_dir, new_dentry->d_name.name,
 998                                 new_dentry->d_name.len, &new_de, NOLOCK);
 999         PDEBUG(new_page, "rename - new page ");
1000         if (new_page) {
1001                 if (!new_inode) {
1002                         page_cache_release(new_page);
1003                         new_page = NULL;
1004                 } else {
1005                         DQUOT_INIT(new_inode);
1006                 }
1007         }
1008         /* in this case we to check more ... */
1009         if (S_ISDIR(old_inode->i_mode)) {
1010                 /* can only rename into empty new directory */
1011                 if (new_inode) {
1012                         retval = -ENOTEMPTY;
1013                         if (!empty_dir (new_inode))
1014                                 goto end_rename;
1015                 }
1016                 retval = -EIO;
1017                 dir_page= obdfs_getpage (old_inode, 0, 0, LOCKED);
1018                 PDEBUG(dir_page, "rename dir page");
1019
1020                 if (!dir_page)
1021                         goto end_rename;
1022                 if (le32_to_cpu(PARENT_INO(page_address(dir_page))) != old_dir->i_ino)
1023                         goto end_rename;
1024                 retval = -EMLINK;
1025                 if (!new_inode && new_dir!=old_dir &&
1026                                 new_dir->i_nlink >= EXT2_LINK_MAX)
1027                         goto end_rename;
1028         }
1029         /* create the target dir entry */
1030         if (!new_page) {
1031                 new_page = obdfs_add_entry (new_dir, new_dentry->d_name.name,
1032                                         new_dentry->d_name.len, &new_de,
1033                                         &retval);
1034                 PDEBUG(new_page, "rename new page");
1035                 if (!new_page)
1036                         goto end_rename;
1037         }
1038         new_dir->i_version = ++event;
1039
1040         /*
1041          * remove the old entry
1042          */
1043         new_de->inode = le32_to_cpu(old_inode->i_ino);
1044         if (EXT2_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
1045                                       EXT2_FEATURE_INCOMPAT_FILETYPE))
1046                 new_de->file_type = old_de->file_type;
1047
1048         obdfs_delete_entry (old_de, old_page);
1049
1050         old_dir->i_version = ++event;
1051         if (new_inode) {
1052                 new_inode->i_nlink--;
1053                 new_inode->i_ctime = CURRENT_TIME;
1054                 mark_inode_dirty(new_inode);
1055         }
1056         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
1057         old_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1058         mark_inode_dirty(old_dir);
1059         if (dir_page) {
1060                 PARENT_INO(page_address(dir_page)) = le32_to_cpu(new_dir->i_ino);
1061                 iops(old_inode)->o_brw(WRITE, iid(old_inode), old_inode, dir_page, 0);
1062                 old_dir->i_nlink--;
1063                 mark_inode_dirty(old_dir);
1064                 if (new_inode) {
1065                         new_inode->i_nlink--;
1066                         mark_inode_dirty(new_inode);
1067                 } else {
1068                         new_dir->i_nlink++;
1069                         new_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1070                         mark_inode_dirty(new_dir);
1071                 }
1072         }
1073         if ( old_page != new_page ) {
1074                 unsigned long index = old_page->index;
1075                 /* lock the old_page and release unlocked copy */
1076                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1077                 page_cache_release(old_page);
1078                 old_page = obdfs_getpage(old_dir, index >> PAGE_SHIFT, 0, LOCKED);
1079                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1080                 iops(old_dir)->o_brw(WRITE, iid(old_dir), old_dir, old_page,0);
1081         }
1082 #if 0
1083         if (IS_SYNC(old_dir)) {
1084                 ll_rw_block (WRITE, 1, &old_bh);
1085                 wait_on_buffer (old_bh);
1086         }
1087 #endif
1088         iops(new_dir)->o_brw(WRITE, iid(new_dir), new_dir, new_page, 0);
1089 #if 0
1090         if (IS_SYNC(new_dir)) {
1091                 ll_rw_block (WRITE, 1, &new_bh);
1092                 wait_on_buffer (new_bh);
1093         }
1094 #endif
1095
1096         retval = 0;
1097
1098 end_rename:
1099         if (old_page && PageLocked(old_page) )
1100                 UnlockPage(old_page);
1101         if (old_page)
1102                 page_cache_release(old_page);
1103         if (new_page && PageLocked(new_page) )
1104                 UnlockPage(new_page);
1105         if (new_page)
1106                 page_cache_release(new_page);
1107         if (dir_page && PageLocked(dir_page) )
1108                 UnlockPage(dir_page);
1109         if (dir_page)
1110                 page_cache_release(dir_page);
1111
1112
1113         return retval;
1114 }