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