lustre/obdfs/namei.c

   1 /*
   2  *  linux/fs/ext2/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/minix/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 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), page_address(page) +
 112                                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                                 CDEBUG(D_INODE, "Bad entry: at %p len %d\n",
 129                                        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 }
 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 }
 189
 190
 191 /*
 192  *      ext2_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 static struct page *obdfs_add_entry (struct inode * dir,
 204                                      const char * name, int namelen,
 205                                      struct ext2_dir_entry_2 ** res_dir,
 206                                      int *err)
 207 {
 208         unsigned long offset;
 209         unsigned short rec_len;
 210         struct page *page;
 211         struct ext2_dir_entry_2 * de, * de1;
 212         struct super_block * sb;
 213
 214         ENTRY;
 215         *err = -EINVAL;
 216         *res_dir = NULL;
 217         if (!dir || !dir->i_nlink) {
 218                 EXIT;
 219                 return NULL;
 220         }
 221         sb = dir->i_sb;
 222
 223         if (!namelen) {
 224                 EXIT;
 225                 return NULL;
 226         }
 227         /*
 228          * Is this a busy deleted directory?  Can't create new files if so
 229          */
 230         if (dir->i_size == 0)
 231         {
 232                 EXIT;
 233                 *err = -ENOENT;
 234                 return NULL;
 235         }
 236         page = obdfs_getpage(dir, 0, 0, LOCKED);
 237         if (!page) {
 238                 EXIT;
 239                 return NULL;
 240         }
 241         rec_len = EXT2_DIR_REC_LEN(namelen);
 242         CDEBUG(D_INODE, "reclen: %d\n", rec_len);
 243         offset = 0;
 244         de = (struct ext2_dir_entry_2 *) page_address(page);
 245         *err = -ENOSPC;
 246         while (1) {
 247                 CDEBUG(D_INODE, "Considering entry at %p, (page at %#lx - %#lx), offset %ld\n",
 248                        de, page_address(page), page_address(page) + PAGE_SIZE, offset);
 249                 if ((char *)de >= PAGE_SIZE + (char *)page_address(page)) {
 250                         UnlockPage(page);
 251                         page_cache_release(page);
 252                         page = obdfs_getpage(dir, offset, 1, LOCKED);
 253                         if (!page) {
 254                                 EXIT;
 255                                 return NULL;
 256                         }
 257                         if (dir->i_size <= offset) {
 258                                 if (dir->i_size == 0) {
 259                                         *err = -ENOENT;
 260                                         EXIT;
 261                                         return NULL;
 262                                 }
 263
 264                                 CDEBUG(D_INODE, "creating next block\n");
 265
 266                                 de = (struct ext2_dir_entry_2 *) page_address(page);
 267                                 de->inode = 0;
 268                                 de->rec_len = le16_to_cpu(PAGE_SIZE);
 269                                 dir->i_size = offset + PAGE_SIZE;
 270                                 dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 271                                 mark_inode_dirty(dir);
 272                         } else {
 273
 274                                 ext2_debug ("skipping to next block\n");
 275
 276                                 de = (struct ext2_dir_entry_2 *) page_address(page);
 277                         }
 278                 }
 279                 CDEBUG(D_INODE, "\n");
 280                 if (!obdfs_check_dir_entry ("ext2_add_entry", dir, de, page,
 281                                            offset)) {
 282                         *err = -ENOENT;
 283                         UnlockPage(page);
 284                         page_cache_release(page);
 285                         EXIT;
 286                         return NULL;
 287                 }
 288                 CDEBUG(D_INODE, "\n");
 289                 if (ext2_match (namelen, name, de)) {
 290                                 *err = -EEXIST;
 291                                 UnlockPage(page);
 292                                 page_cache_release(page);
 293                                 EXIT;
 294                                 return NULL;
 295                 }
 296                 CDEBUG(D_INODE, "Testing for enough space at de %p\n", de);
 297                 if ( (le32_to_cpu(de->inode) == 0 &&
 298                       le16_to_cpu(de->rec_len) >= rec_len) ||
 299                      (le16_to_cpu(de->rec_len) >=
 300                       EXT2_DIR_REC_LEN(de->name_len) + rec_len)) {
 301                         offset += le16_to_cpu(de->rec_len);
 302                         CDEBUG(D_INODE, "Found enough space de %p, offset %#lx\n", de, offset);
 303                         if (le32_to_cpu(de->inode)) {
 304                                 CDEBUG(D_INODE, "Inserting new in %p\n", de);
 305                                 de1 = (struct ext2_dir_entry_2 *) ((char *) de +
 306                                         EXT2_DIR_REC_LEN(de->name_len));
 307                                 CDEBUG(D_INODE, "-- de1 at %p\n", de1);
 308                                 de1->rec_len = cpu_to_le16(le16_to_cpu(de->rec_len) -
 309                                         EXT2_DIR_REC_LEN(de->name_len));
 310                                 de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
 311                                 de = de1;
 312                         }
 313                         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);
 314                         de->inode = 0;
 315                         de->name_len = namelen;
 316                         de->file_type = 0;
 317                         memcpy (de->name, name, namelen);
 318                         CDEBUG(D_INODE, "Copy done\n");
 319                         /*
 320                          * XXX shouldn't update any times until successful
 321                          * completion of syscall, but too many callers depend
 322                          * on this.
 323                          *
 324                          * XXX similarly, too many callers depend on
 325                          * ext2_new_inode() setting the times, but error
 326                          * recovery deletes the inode, so the worst that can
 327                          * happen is that the times are slightly out of date
 328                          * and/or different from the directory change time.
 329                          */
 330                         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 331                         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 332                         mark_inode_dirty(dir);
 333                         dir->i_version = ++event;
 334                         *res_dir = de;
 335                         *err = 0;
 336                         PDEBUG(page, "addentry");
 337                         CDEBUG(D_INODE, "Regular exit from add_entry");
 338                         EXIT;
 339                         return page;
 340                 }
 341                 CDEBUG(D_INODE, "\n");
 342                 offset += le16_to_cpu(de->rec_len);
 343                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 344
 345         }
 346         CDEBUG(D_INODE, "\n");
 347
 348         UnlockPage(page);
 349         page_cache_release(page);
 350         PDEBUG(page, "addentry");
 351         EXIT;
 352         return NULL;
 353 }
 354
 355 /*
 356  * ext2_delete_entry deletes a directory entry by merging it with the
 357  * previous entry
 358  */
 359 static int obdfs_delete_entry (struct ext2_dir_entry_2 * dir,
 360                               struct page * page)
 361 {
 362         struct ext2_dir_entry_2 * de, * pde;
 363         int i;
 364
 365         i = 0;
 366         pde = NULL;
 367         de = (struct ext2_dir_entry_2 *) page_address(page);
 368         while (i < PAGE_SIZE) {
 369                 if (!obdfs_check_dir_entry ("ext2_delete_entry", NULL,
 370                                            de, page, i))
 371                         return -EIO;
 372                 if (de == dir)  {
 373                         if (pde)
 374                                 pde->rec_len =
 375                                         cpu_to_le16(le16_to_cpu(pde->rec_len) +
 376                                                     le16_to_cpu(dir->rec_len));
 377                         else
 378                                 dir->inode = 0;
 379                         return 0;
 380                 }
 381                 i += le16_to_cpu(de->rec_len);
 382                 pde = de;
 383                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 384         }
 385         return -ENOENT;
 386 }
 387
 388
 389 static inline void ext2_set_de_type(struct super_block *sb,
 390                                 struct ext2_dir_entry_2 *de,
 391                                 umode_t mode) {
 392         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
 393                 return;
 394         if (S_ISCHR(mode))
 395                 de->file_type = EXT2_FT_CHRDEV;
 396         else if (S_ISBLK(mode))
 397                 de->file_type = EXT2_FT_BLKDEV;
 398         else if (S_ISFIFO(mode))
 399                 de->file_type = EXT2_FT_FIFO;
 400         else if (S_ISLNK(mode))
 401                 de->file_type = EXT2_FT_SYMLINK;
 402         else if (S_ISREG(mode))
 403                 de->file_type = EXT2_FT_REG_FILE;
 404         else if (S_ISDIR(mode))
 405                 de->file_type = EXT2_FT_DIR;
 406 }
 407
 408
 409 /*
 410  * Display all dentries holding the specified inode.
 411  */
 412 static void show_dentry(struct list_head * dlist, int subdirs)
 413 {
 414         struct list_head *tmp = dlist;
 415
 416         while ((tmp = tmp->next) != dlist) {
 417                 struct dentry * dentry;
 418                 const char * unhashed = "";
 419
 420                 if ( subdirs )
 421                                 dentry  = list_entry(tmp, struct dentry, d_child);
 422                         else
 423                                 dentry  = list_entry(tmp, struct dentry, d_alias);
 424
 425                 if (list_empty(&dentry->d_hash))
 426                         unhashed = "(unhashed)";
 427
 428                 if ( dentry->d_inode )
 429                         printk("show_dentry: %s/%s, d_count=%d%s (ino %ld, dev %d, ct %d)\n",
 430                                dentry->d_parent->d_name.name,
 431                                dentry->d_name.name, dentry->d_count,
 432                                unhashed, dentry->d_inode->i_ino,
 433                                dentry->d_inode->i_dev,
 434                                dentry->d_inode->i_count);
 435                 else
 436                         printk("show_dentry: %s/%s, d_count=%d%s \n",
 437                                dentry->d_parent->d_name.name,
 438                                dentry->d_name.name, dentry->d_count,
 439                                unhashed);
 440         }
 441 }
 442
 443
 444 /*
 445  * By the time this is called, we already have created
 446  * the directory cache entry for the new file, but it
 447  * is so far negative - it has no inode.
 448  *
 449  * If the create succeeds, we fill in the inode information
 450  * with d_instantiate().
 451  */
 452 int obdfs_create (struct inode * dir, struct dentry * dentry, int mode)
 453 {
 454         struct inode * inode;
 455         struct page *page;
 456         struct ext2_dir_entry_2 * de;
 457         int err = -EIO;
 458         struct obdfs_sb_info *sbi;
 459         ino_t ino;
 460
 461         ENTRY;
 462
 463         sbi = dir->i_sb->u.generic_sbp;
 464         /*
 465          * N.B. Several error exits in ext2_new_inode don't set err.
 466          */
 467         ino = sbi->osi_ops->o_create(sbi->osi_conn_info.conn_id, 0, &err);
 468         if ( err )
 469                 return err;
 470         err = -EIO;
 471         inode =  iget(dir->i_sb, ino);
 472         if (!inode || !list_empty(&inode->i_dentry)) {
 473                 CDEBUG(D_INODE, "No inode, ino %ld\n", ino);
 474                 EXIT;
 475                 return err;
 476         }
 477
 478         inode->i_op = &obdfs_inode_ops;
 479         inode->i_mode = mode;
 480         mark_inode_dirty(inode);
 481         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 482         if (!page) {
 483                 inode->i_nlink--;
 484                 mark_inode_dirty(inode);
 485                 iput (inode);
 486                 EXIT;
 487                 return err;
 488         }
 489         de->inode = cpu_to_le32(inode->i_ino);
 490         ext2_set_de_type(dir->i_sb, de, S_IFREG);
 491         dir->i_version = ++event;
 492         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
 493                             dir, page, 0);
 494         UnlockPage(page);
 495 #if 0
 496         if (IS_SYNC(dir)) {
 497                 ll_rw_block (WRITE, 1, &bh);
 498                 wait_on_buffer (bh);
 499         }
 500 #endif
 501         page_cache_release(page);
 502         d_instantiate(dentry, inode);
 503         EXIT;
 504         return 0;
 505 }
 506
 507 int obdfs_mknod (struct inode * dir, struct dentry *dentry, int mode, int rdev)
 508 {
 509         struct inode * inode;
 510         struct page *page;
 511         struct ext2_dir_entry_2 * de;
 512         int err = -EIO;
 513         struct obdfs_sb_info *sbi;
 514
 515         ino_t ino;
 516
 517         ENTRY;
 518
 519         sbi = dir->i_sb->u.generic_sbp;
 520         /*
 521          * N.B. Several error exits in ext2_new_inode don't set err.
 522          */
 523         ino = sbi->osi_ops->o_create(sbi->osi_conn_info.conn_id, 0, &err);
 524         if ( ino == -1 )
 525                 return -1;
 526         inode =  iget(dir->i_sb, ino);
 527         if (!inode)
 528                 return err;
 529
 530         inode->i_uid = current->fsuid;
 531         init_special_inode(inode, mode, rdev);
 532         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 533         if (!page)
 534                 goto out_no_entry;
 535         de->inode = cpu_to_le32(inode->i_ino);
 536         dir->i_version = ++event;
 537         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 538         mark_inode_dirty(inode);
 539         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
 540                             dir, page, 0);
 541         UnlockPage(page);
 542
 543 #if 0
 544         if (IS_SYNC(dir)) {
 545                 ll_rw_block (WRITE, 1, &bh);
 546                 wait_on_buffer (bh);
 547         }
 548 #endif
 549         d_instantiate(dentry, inode);
 550         page_cache_release(page);
 551         err = 0;
 552 out:
 553         return err;
 554
 555 out_no_entry:
 556         inode->i_nlink--;
 557         mark_inode_dirty(inode);
 558         iput(inode);
 559         goto out;
 560 }
 561
 562 int obdfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 563 {
 564         struct inode * child;
 565         struct page *page, *child_page;
 566         struct ext2_dir_entry_2 * de;
 567         struct obdfs_sb_info *sbi;
 568         int err;
 569         ino_t ino;
 570
 571         ENTRY;
 572         sbi = dir->i_sb->u.generic_sbp;
 573
 574         err = -EMLINK;
 575         if (dir->i_nlink >= EXT2_LINK_MAX)
 576                 goto out;
 577
 578         err = -EIO;
 579         ino = iops(dir)->o_create(sbi->osi_conn_info.conn_id, 0, &err);
 580         if ( ino == -1 )
 581                 return -1;
 582         child =  iget(dir->i_sb, ino);
 583         if (!child)
 584                 return err;
 585
 586
 587         child->i_op = &obdfs_inode_ops;
 588         child->i_size = PAGE_SIZE;
 589         child->i_blocks = 0;
 590         child_page = obdfs_getpage(child, 0, 1, LOCKED);
 591         if (!child_page) {
 592                 child->i_nlink--; /* is this nlink == 0? */
 593                 mark_inode_dirty(child);
 594                 iput (child);
 595                 return err;
 596         }
 597         child->i_blocks = PAGE_SIZE/child->i_sb->s_blocksize;
 598
 599         /* create . and .. */
 600         de = (struct ext2_dir_entry_2 *) page_address(child_page);
 601         de->inode = cpu_to_le32(child->i_ino);
 602         de->name_len = 1;
 603         de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
 604         strcpy (de->name, ".");
 605         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 606
 607         de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 608         de->inode = cpu_to_le32(dir->i_ino);
 609         de->rec_len = cpu_to_le16(PAGE_SIZE - EXT2_DIR_REC_LEN(1));
 610         de->name_len = 2;
 611         strcpy (de->name, "..");
 612         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 613
 614         iops(dir)->o_brw(WRITE, sbi->osi_conn_info.conn_id, child, child_page, 1);
 615         UnlockPage(child_page);
 616         page_cache_release(child_page);
 617
 618         child->i_nlink = 2;
 619         child->i_mode = S_IFDIR | mode;
 620         if (dir->i_mode & S_ISGID)
 621                 child->i_mode |= S_ISGID;
 622         mark_inode_dirty(child);
 623
 624         /* now deal with the parent */
 625         page = obdfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 626         if (!page) {
 627                 goto out_no_entry;
 628         }
 629
 630         de->inode = cpu_to_le32(child->i_ino);
 631         ext2_set_de_type(dir->i_sb, de, S_IFDIR);
 632         dir->i_version = ++event;
 633
 634 #if 0
 635         if (IS_SYNC(dir)) {
 636                 ll_rw_block (WRITE, 1, &bh);
 637                 wait_on_buffer (bh);
 638         }
 639 #endif
 640         dir->i_nlink++;
 641         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 642         mark_inode_dirty(dir);
 643         iops(dir)->o_brw(WRITE, sbi->osi_conn_info.conn_id, dir, page, 1);
 644         UnlockPage(page);
 645         page_cache_release(page);
 646         d_instantiate(dentry, child);
 647         err = 0;
 648 out:
 649         EXIT;
 650         return err;
 651
 652 out_no_entry:
 653         child->i_nlink = 0;
 654         mark_inode_dirty(child);
 655         iput (child);
 656         EXIT;
 657         goto out;
 658 }
 659
 660
 661 /*
 662  * routine to check that the specified directory is empty (for rmdir)
 663  */
 664 static int empty_dir (struct inode * inode)
 665 {
 666         unsigned long offset;
 667         struct page *page;
 668         struct ext2_dir_entry_2 * de, * de1;
 669         struct super_block * sb;
 670
 671         sb = inode->i_sb;
 672         if (inode->i_size < EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2) ||
 673             !(page = obdfs_getpage (inode, 0, 0, LOCKED))) {
 674                 ext2_warning (inode->i_sb, "empty_dir",
 675                               "bad directory (dir #%lu) - no data block",
 676                               inode->i_ino);
 677                 return 1;
 678         }
 679         de = (struct ext2_dir_entry_2 *) page_address(page);
 680         de1 = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 681         if (le32_to_cpu(de->inode) != inode->i_ino || !le32_to_cpu(de1->inode) ||
 682             strcmp (".", de->name) || strcmp ("..", de1->name)) {
 683                 ext2_warning (inode->i_sb, "empty_dir",
 684                               "bad directory (dir #%lu) - no `.' or `..'",
 685                               inode->i_ino);
 686                 page_cache_release(page);
 687                 return 1;
 688         }
 689         offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
 690         de = (struct ext2_dir_entry_2 *) ((char *) de1 + le16_to_cpu(de1->rec_len));
 691         while (offset < inode->i_size ) {
 692                 if (!page || (void *) de >= (void *) (page_address(page) + PAGE_SIZE)) {
 693                         if (page) {
 694                                 UnlockPage(page);
 695                                 page_cache_release(page);
 696                         }
 697                         page = obdfs_getpage(inode, offset, 0, LOCKED);
 698                         if (!page) {
 699 #if 0
 700                                 ext2_error (sb, "empty_dir",
 701                                             "directory #%lu contains a hole at offset %lu",
 702                                             inode->i_ino, offset);
 703 #endif
 704                                 offset += sb->s_blocksize;
 705                                 continue;
 706                         }
 707                         de = (struct ext2_dir_entry_2 *) page_address(page);
 708                 }
 709                 if (!obdfs_check_dir_entry ("empty_dir", inode, de, page,
 710                                            offset)) {
 711                         UnlockPage(page);
 712                         page_cache_release(page);
 713                         return 1;
 714                 }
 715                 if (le32_to_cpu(de->inode)) {
 716                         UnlockPage(page);
 717                         page_cache_release(page);
 718                         return 0;
 719                 }
 720                 offset += le16_to_cpu(de->rec_len);
 721                 de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
 722         }
 723         UnlockPage(page);
 724         page_cache_release(page);
 725         return 1;
 726 }
 727
 728 int obdfs_rmdir (struct inode * dir, struct dentry *dentry)
 729 {
 730         int retval;
 731         struct inode * inode;
 732         struct page *page;
 733         struct ext2_dir_entry_2 * de;
 734         struct obdfs_sb_info *sbi;
 735
 736         ENTRY;
 737         sbi = dir->i_sb->u.generic_sbp;
 738
 739         retval = -ENOENT;
 740         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 741         if (!page)
 742                 goto end_rmdir;
 743
 744         inode = dentry->d_inode;
 745         DQUOT_INIT(inode);
 746
 747         retval = -EIO;
 748         if (le32_to_cpu(de->inode) != inode->i_ino)
 749                 goto end_rmdir;
 750
 751         retval = -ENOTEMPTY;
 752         if (!empty_dir (inode))
 753                 goto end_rmdir;
 754
 755         retval = obdfs_delete_entry (de, page);
 756         dir->i_version = ++event;
 757         if (retval)
 758                 goto end_rmdir;
 759         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id, dir, page, 0);
 760         UnlockPage(page);
 761 #if 0
 762         if (IS_SYNC(dir)) {
 763                 ll_rw_block (WRITE, 1, &bh);
 764                 wait_on_buffer (bh);
 765         }
 766 #endif
 767         if (inode->i_nlink != 2)
 768                 ext2_warning (inode->i_sb, "ext2_rmdir",
 769                               "empty directory has nlink!=2 (%d)",
 770                               inode->i_nlink);
 771         inode->i_version = ++event;
 772         inode->i_nlink = 0;
 773         inode->i_size = 0;
 774         mark_inode_dirty(inode);
 775         dir->i_nlink--;
 776         inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 777         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 778         mark_inode_dirty(dir);
 779         d_delete(dentry);
 780
 781 end_rmdir:
 782         if ( page )
 783                 page_cache_release(page);
 784         EXIT;
 785         return retval;
 786 }
 787
 788 int obdfs_unlink(struct inode * dir, struct dentry *dentry)
 789 {
 790         int retval;
 791         struct inode * inode;
 792         struct page *page;
 793         struct ext2_dir_entry_2 * de;
 794         struct obdfs_sb_info *sbi;
 795
 796         ENTRY;
 797         sbi = dir->i_sb->u.generic_sbp;
 798
 799         retval = -ENOENT;
 800         page = obdfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, LOCKED);
 801         if (!page)
 802                 goto end_unlink;
 803
 804         inode = dentry->d_inode;
 805         DQUOT_INIT(inode);
 806
 807         retval = -EIO;
 808         if (le32_to_cpu(de->inode) != inode->i_ino)
 809                 goto end_unlink;
 810
 811         if (!inode->i_nlink) {
 812                 ext2_warning (inode->i_sb, "ext2_unlink",
 813                               "Deleting nonexistent file (%lu), %d",
 814                               inode->i_ino, inode->i_nlink);
 815                 inode->i_nlink = 1;
 816         }
 817         retval = obdfs_delete_entry (de, page);
 818         if (retval)
 819                 goto end_unlink;
 820         dir->i_version = ++event;
 821         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id, dir, page, 0);
 822         UnlockPage(page);
 823 #if 0
 824         if (IS_SYNC(dir)) {
 825                 ll_rw_block (WRITE, 1, &bh);
 826                 wait_on_buffer (bh);
 827         }
 828 #endif
 829         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 830         dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
 831         mark_inode_dirty(dir);
 832         inode->i_nlink--;
 833         mark_inode_dirty(inode);
 834         inode->i_ctime = dir->i_ctime;
 835         retval = 0;
 836         d_delete(dentry);       /* This also frees the inode */
 837
 838 end_unlink:
 839         if (page)
 840                 page_cache_release(page);
 841         EXIT;
 842         return retval;
 843 }
 844
 845 int obdfs_symlink (struct inode * dir, struct dentry *dentry, const char * symname)
 846 {
 847         struct ext2_dir_entry_2 * de;
 848         struct inode * inode;
 849         struct page* page = NULL, * name_page = NULL;
 850         char * link;
 851         int i, l, err = -EIO;
 852         char c;
 853         struct obdfs_sb_info *sbi;
 854         ino_t ino;
 855
 856         ENTRY;
 857
 858         sbi = dir->i_sb->u.generic_sbp;
 859         /*
 860          * N.B. Several error exits in ext2_new_inode don't set err.
 861          */
 862         ino = sbi->osi_ops->o_create(sbi->osi_conn_info.conn_id, 0, &err);
 863         if ( ino == -1 )
 864                 return -1;
 865         inode =  iget(dir->i_sb, ino);
 866         if (!inode)
 867                 return err;
 868
 869         inode->i_mode = S_IFLNK | S_IRWXUGO;
 870         inode->i_op = &obdfs_inode_ops;
 871         for (l = 0; l < inode->i_sb->s_blocksize - 1 &&
 872              symname [l]; l++)
 873                 ;
 874         if (l >= sizeof (inode->u.ext2_i.i_data)) {
 875
 876                 CDEBUG(D_INODE, "l=%d, normal symlink\n", l);
 877
 878                 name_page = obdfs_getpage(inode, 0, 1, LOCKED);
 879                 if (!name_page) {
 880                         inode->i_nlink--;
 881                         mark_inode_dirty(inode);
 882                         iput (inode);
 883                         return err;
 884                 }
 885                 link = (char *)page_address(name_page);
 886         } else {
 887                 link = (char *) inode->u.ext2_i.i_data;
 888
 889                 CDEBUG(D_INODE, "l=%d, fast symlink\n", l);
 890
 891         }
 892         i = 0;
 893         while (i < inode->i_sb->s_blocksize - 1 && (c = *(symname++)))
 894                 link[i++] = c;
 895         link[i] = 0;
 896         if (name_page) {
 897                 sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
 898                                     inode, name_page, 1);
 899                 PDEBUG(name_page, "symlink");
 900                 UnlockPage(name_page);
 901                 page_cache_release(name_page);
 902         }
 903         inode->i_size = i;
 904         mark_inode_dirty(inode);
 905
 906         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 907         if (!page)
 908                 goto out_no_entry;
 909         de->inode = cpu_to_le32(inode->i_ino);
 910         ext2_set_de_type(dir->i_sb, de, S_IFLNK);
 911         dir->i_version = ++event;
 912         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
 913                             dir, page, 1);
 914         UnlockPage(page);
 915 #if 0
 916         if (IS_SYNC(dir)) {
 917                 ll_rw_block (WRITE, 1, &bh);
 918                 wait_on_buffer (bh);
 919         }
 920 #endif
 921         d_instantiate(dentry, inode);
 922         err = 0;
 923 out:
 924         return err;
 925
 926 out_no_entry:
 927         inode->i_nlink--;
 928         mark_inode_dirty(inode);
 929         iput (inode);
 930         goto out;
 931 }
 932
 933 int obdfs_link (struct dentry * old_dentry,
 934                 struct inode * dir, struct dentry *dentry)
 935 {
 936         struct inode *inode = old_dentry->d_inode;
 937         struct ext2_dir_entry_2 * de;
 938         struct page *page;
 939         int err;
 940         struct obdfs_sb_info *sbi;
 941
 942         ENTRY;
 943         sbi = dir->i_sb->u.generic_sbp;
 944
 945         if (S_ISDIR(inode->i_mode))
 946                 return -EPERM;
 947
 948         if (inode->i_nlink >= EXT2_LINK_MAX)
 949                 return -EMLINK;
 950
 951         page = obdfs_add_entry (dir, dentry->d_name.name, dentry->d_name.len, &de, &err);
 952         if (!page)
 953                 return err;
 954
 955         de->inode = cpu_to_le32(inode->i_ino);
 956         ext2_set_de_type(dir->i_sb, de, inode->i_mode);
 957         dir->i_version = ++event;
 958         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
 959                             dir, page, 0);
 960         UnlockPage(page);
 961
 962 #if 0
 963         if (IS_SYNC(dir)) {
 964                 ll_rw_block (WRITE, 1, &bh);
 965                 wait_on_buffer (bh);
 966         }
 967 #endif
 968         page_cache_release(page);
 969         inode->i_nlink++;
 970         inode->i_ctime = CURRENT_TIME;
 971         mark_inode_dirty(inode);
 972         inode->i_count++;
 973         d_instantiate(dentry, inode);
 974         return 0;
 975 }
 976
 977 #define PARENT_INO(buffer) \
 978         ((struct ext2_dir_entry_2 *) ((char *) buffer + \
 979         le16_to_cpu(((struct ext2_dir_entry_2 *) buffer)->rec_len)))->inode
 980
 981 /*
 982  * Anybody can rename anything with this: the permission checks are left to the
 983  * higher-level routines.
 984  */
 985 int obdfs_rename (struct inode * old_dir, struct dentry *old_dentry,
 986                            struct inode * new_dir, struct dentry *new_dentry)
 987 {
 988         struct inode * old_inode, * new_inode;
 989         struct page * old_page, * new_page, * dir_page;
 990         struct ext2_dir_entry_2 * old_de, * new_de;
 991         int retval;
 992         struct obdfs_sb_info *sbi;
 993
 994         ENTRY;
 995         sbi = old_dir->i_sb->u.generic_sbp;
 996
 997         new_page = dir_page = NULL;
 998
 999         /* does the old entry exist? - if not get out */
1000         old_page = obdfs_find_entry (old_dir, old_dentry->d_name.name, old_dentry->d_name.len, &old_de, NOLOCK);
1001         PDEBUG(old_page, "rename - old page");
1002         /*
1003          *  Check for inode number is _not_ due to possible IO errors.
1004          *  We might rmdir the source, keep it as pwd of some process
1005          *  and merrily kill the link to whatever was created under the
1006          *  same name. Goodbye sticky bit ;-<
1007          */
1008         old_inode = old_dentry->d_inode;
1009         retval = -ENOENT;
1010         if (!old_page || le32_to_cpu(old_de->inode) != old_inode->i_ino)
1011                 goto end_rename;
1012
1013         /* find new inode */
1014         new_inode = new_dentry->d_inode;
1015         new_page = obdfs_find_entry (new_dir, new_dentry->d_name.name,
1016                                 new_dentry->d_name.len, &new_de, NOLOCK);
1017         PDEBUG(new_page, "rename - new page ");
1018         if (new_page) {
1019                 if (!new_inode) {
1020                         page_cache_release(new_page);
1021                         new_page = NULL;
1022                 } else {
1023                         DQUOT_INIT(new_inode);
1024                 }
1025         }
1026         /* in this case we to check more ... */
1027         if (S_ISDIR(old_inode->i_mode)) {
1028                 /* can only rename into empty new directory */
1029                 if (new_inode) {
1030                         retval = -ENOTEMPTY;
1031                         if (!empty_dir (new_inode))
1032                                 goto end_rename;
1033                 }
1034                 retval = -EIO;
1035                 dir_page= obdfs_getpage (old_inode, 0, 0, LOCKED);
1036                 PDEBUG(dir_page, "rename dir page");
1037
1038                 if (!dir_page)
1039                         goto end_rename;
1040                 if (le32_to_cpu(PARENT_INO(page_address(dir_page))) != old_dir->i_ino)
1041                         goto end_rename;
1042                 retval = -EMLINK;
1043                 if (!new_inode && new_dir!=old_dir &&
1044                                 new_dir->i_nlink >= EXT2_LINK_MAX)
1045                         goto end_rename;
1046         }
1047         /* create the target dir entry */
1048         if (!new_page) {
1049                 new_page = obdfs_add_entry (new_dir, new_dentry->d_name.name,
1050                                         new_dentry->d_name.len, &new_de,
1051                                         &retval);
1052                 PDEBUG(new_page, "rename new page");
1053                 if (!new_page)
1054                         goto end_rename;
1055         }
1056         new_dir->i_version = ++event;
1057
1058         /*
1059          * remove the old entry
1060          */
1061         new_de->inode = le32_to_cpu(old_inode->i_ino);
1062         if (EXT2_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
1063                                       EXT2_FEATURE_INCOMPAT_FILETYPE))
1064                 new_de->file_type = old_de->file_type;
1065
1066         obdfs_delete_entry (old_de, old_page);
1067
1068         old_dir->i_version = ++event;
1069         if (new_inode) {
1070                 new_inode->i_nlink--;
1071                 new_inode->i_ctime = CURRENT_TIME;
1072                 mark_inode_dirty(new_inode);
1073         }
1074         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
1075         old_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1076         mark_inode_dirty(old_dir);
1077         if (dir_page) {
1078                 PARENT_INO(page_address(dir_page)) = le32_to_cpu(new_dir->i_ino);
1079                 sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
1080                             old_inode, dir_page, 0);
1081                 old_dir->i_nlink--;
1082                 mark_inode_dirty(old_dir);
1083                 if (new_inode) {
1084                         new_inode->i_nlink--;
1085                         mark_inode_dirty(new_inode);
1086                 } else {
1087                         new_dir->i_nlink++;
1088                         new_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
1089                         mark_inode_dirty(new_dir);
1090                 }
1091         }
1092         if ( old_page != new_page ) {
1093                 unsigned long offset = old_page->offset;
1094                 /* lock the old_page and release unlocked copy */
1095                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1096                 page_cache_release(old_page);
1097                 old_page = obdfs_getpage(old_dir, offset, 0, LOCKED);
1098                 CDEBUG(D_INODE, "old_page at %p\n", old_page);
1099                 sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
1100                                     old_dir, old_page, 0);
1101         }
1102 #if 0
1103         if (IS_SYNC(old_dir)) {
1104                 ll_rw_block (WRITE, 1, &old_bh);
1105                 wait_on_buffer (old_bh);
1106         }
1107 #endif
1108         sbi->osi_ops->o_brw(WRITE, sbi->osi_conn_info.conn_id,
1109                             new_dir, new_page, 0);
1110 #if 0
1111         if (IS_SYNC(new_dir)) {
1112                 ll_rw_block (WRITE, 1, &new_bh);
1113                 wait_on_buffer (new_bh);
1114         }
1115 #endif
1116
1117         retval = 0;
1118
1119 end_rename:
1120         if (old_page && PageLocked(old_page) )
1121                 UnlockPage(old_page);
1122         if (old_page)
1123                 page_cache_release(old_page);
1124         if (new_page && PageLocked(new_page) )
1125                 UnlockPage(new_page);
1126         if (new_page)
1127                 page_cache_release(new_page);
1128         if (dir_page && PageLocked(dir_page) )
1129                 UnlockPage(dir_page);
1130         if (dir_page)
1131                 page_cache_release(dir_page);
1132
1133
1134         return retval;
1135 }