1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * dir.c 5 * 6 * Creates, reads, walks and deletes directory-nodes 7 * 8 * Copyright (C) 2002, 2004 Oracle. All rights reserved. 9 * 10 * Portions of this code from linux/fs/ext3/dir.c 11 * 12 * Copyright (C) 1992, 1993, 1994, 1995 13 * Remy Card (card@masi.ibp.fr) 14 * Laboratoire MASI - Institut Blaise pascal 15 * Universite Pierre et Marie Curie (Paris VI) 16 * 17 * from 18 * 19 * linux/fs/minix/dir.c 20 * 21 * Copyright (C) 1991, 1992 Linux Torvalds 22 * 23 * This program is free software; you can redistribute it and/or 24 * modify it under the terms of the GNU General Public 25 * License as published by the Free Software Foundation; either 26 * version 2 of the License, or (at your option) any later version. 27 * 28 * This program is distributed in the hope that it will be useful, 29 * but WITHOUT ANY WARRANTY; without even the implied warranty of 30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 31 * General Public License for more details. 32 * 33 * You should have received a copy of the GNU General Public 34 * License along with this program; if not, write to the 35 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 36 * Boston, MA 021110-1307, USA. 37 */ 38 39 #include <linux/fs.h> 40 #include <linux/types.h> 41 #include <linux/slab.h> 42 #include <linux/highmem.h> 43 44 #define MLOG_MASK_PREFIX ML_NAMEI 45 #include <cluster/masklog.h> 46 47 #include "ocfs2.h" 48 49 #include "alloc.h" 50 #include "dir.h" 51 #include "dlmglue.h" 52 #include "extent_map.h" 53 #include "file.h" 54 #include "inode.h" 55 #include "journal.h" 56 #include "namei.h" 57 #include "suballoc.h" 58 #include "uptodate.h" 59 60 #include "buffer_head_io.h" 61 62 static unsigned char ocfs2_filetype_table[] = { 63 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 64 }; 65 66 static int ocfs2_extend_dir(struct ocfs2_super *osb, 67 struct inode *dir, 68 struct buffer_head *parent_fe_bh, 69 struct buffer_head **new_de_bh); 70 /* 71 * ocfs2_readdir() 72 * 73 */ 74 int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir) 75 { 76 int error = 0; 77 unsigned long offset, blk; 78 int i, num, stored; 79 struct buffer_head * bh, * tmp; 80 struct ocfs2_dir_entry * de; 81 int err; 82 struct inode *inode = filp->f_dentry->d_inode; 83 struct super_block * sb = inode->i_sb; 84 int have_disk_lock = 0; 85 86 mlog_entry("dirino=%llu\n", 87 (unsigned long long)OCFS2_I(inode)->ip_blkno); 88 89 stored = 0; 90 bh = NULL; 91 92 error = ocfs2_meta_lock(inode, NULL, NULL, 0); 93 if (error < 0) { 94 if (error != -ENOENT) 95 mlog_errno(error); 96 /* we haven't got any yet, so propagate the error. */ 97 stored = error; 98 goto bail; 99 } 100 have_disk_lock = 1; 101 102 offset = filp->f_pos & (sb->s_blocksize - 1); 103 104 while (!error && !stored && filp->f_pos < i_size_read(inode)) { 105 blk = (filp->f_pos) >> sb->s_blocksize_bits; 106 bh = ocfs2_bread(inode, blk, &err, 0); 107 if (!bh) { 108 mlog(ML_ERROR, 109 "directory #%llu contains a hole at offset %lld\n", 110 (unsigned long long)OCFS2_I(inode)->ip_blkno, 111 filp->f_pos); 112 filp->f_pos += sb->s_blocksize - offset; 113 continue; 114 } 115 116 /* 117 * Do the readahead (8k) 118 */ 119 if (!offset) { 120 for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0; 121 i > 0; i--) { 122 tmp = ocfs2_bread(inode, ++blk, &err, 1); 123 if (tmp) 124 brelse(tmp); 125 } 126 } 127 128 revalidate: 129 /* If the dir block has changed since the last call to 130 * readdir(2), then we might be pointing to an invalid 131 * dirent right now. Scan from the start of the block 132 * to make sure. */ 133 if (filp->f_version != inode->i_version) { 134 for (i = 0; i < sb->s_blocksize && i < offset; ) { 135 de = (struct ocfs2_dir_entry *) (bh->b_data + i); 136 /* It's too expensive to do a full 137 * dirent test each time round this 138 * loop, but we do have to test at 139 * least that it is non-zero. A 140 * failure will be detected in the 141 * dirent test below. */ 142 if (le16_to_cpu(de->rec_len) < 143 OCFS2_DIR_REC_LEN(1)) 144 break; 145 i += le16_to_cpu(de->rec_len); 146 } 147 offset = i; 148 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) 149 | offset; 150 filp->f_version = inode->i_version; 151 } 152 153 while (!error && filp->f_pos < i_size_read(inode) 154 && offset < sb->s_blocksize) { 155 de = (struct ocfs2_dir_entry *) (bh->b_data + offset); 156 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 157 /* On error, skip the f_pos to the 158 next block. */ 159 filp->f_pos = (filp->f_pos | 160 (sb->s_blocksize - 1)) + 1; 161 brelse(bh); 162 goto bail; 163 } 164 offset += le16_to_cpu(de->rec_len); 165 if (le64_to_cpu(de->inode)) { 166 /* We might block in the next section 167 * if the data destination is 168 * currently swapped out. So, use a 169 * version stamp to detect whether or 170 * not the directory has been modified 171 * during the copy operation. 172 */ 173 unsigned long version = filp->f_version; 174 unsigned char d_type = DT_UNKNOWN; 175 176 if (de->file_type < OCFS2_FT_MAX) 177 d_type = ocfs2_filetype_table[de->file_type]; 178 error = filldir(dirent, de->name, 179 de->name_len, 180 filp->f_pos, 181 ino_from_blkno(sb, le64_to_cpu(de->inode)), 182 d_type); 183 if (error) 184 break; 185 if (version != filp->f_version) 186 goto revalidate; 187 stored ++; 188 } 189 filp->f_pos += le16_to_cpu(de->rec_len); 190 } 191 offset = 0; 192 brelse(bh); 193 } 194 195 stored = 0; 196 bail: 197 if (have_disk_lock) 198 ocfs2_meta_unlock(inode, 0); 199 200 mlog_exit(stored); 201 202 return stored; 203 } 204 205 /* 206 * NOTE: this should always be called with parent dir i_mutex taken. 207 */ 208 int ocfs2_find_files_on_disk(const char *name, 209 int namelen, 210 u64 *blkno, 211 struct inode *inode, 212 struct buffer_head **dirent_bh, 213 struct ocfs2_dir_entry **dirent) 214 { 215 int status = -ENOENT; 216 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); 217 218 mlog_entry("(osb=%p, parent=%llu, name='%.*s', blkno=%p, inode=%p)\n", 219 osb, (unsigned long long)OCFS2_I(inode)->ip_blkno, 220 namelen, name, blkno, inode); 221 222 *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent); 223 if (!*dirent_bh || !*dirent) { 224 status = -ENOENT; 225 goto leave; 226 } 227 228 *blkno = le64_to_cpu((*dirent)->inode); 229 230 status = 0; 231 leave: 232 if (status < 0) { 233 *dirent = NULL; 234 if (*dirent_bh) { 235 brelse(*dirent_bh); 236 *dirent_bh = NULL; 237 } 238 } 239 240 mlog_exit(status); 241 return status; 242 } 243 244 /* Check for a name within a directory. 245 * 246 * Return 0 if the name does not exist 247 * Return -EEXIST if the directory contains the name 248 * 249 * Callers should have i_mutex + a cluster lock on dir 250 */ 251 int ocfs2_check_dir_for_entry(struct inode *dir, 252 const char *name, 253 int namelen) 254 { 255 int ret; 256 struct buffer_head *dirent_bh = NULL; 257 struct ocfs2_dir_entry *dirent = NULL; 258 259 mlog_entry("dir %llu, name '%.*s'\n", 260 (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name); 261 262 ret = -EEXIST; 263 dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent); 264 if (dirent_bh) 265 goto bail; 266 267 ret = 0; 268 bail: 269 if (dirent_bh) 270 brelse(dirent_bh); 271 272 mlog_exit(ret); 273 return ret; 274 } 275 276 /* 277 * routine to check that the specified directory is empty (for rmdir) 278 */ 279 int ocfs2_empty_dir(struct inode *inode) 280 { 281 unsigned long offset; 282 struct buffer_head * bh; 283 struct ocfs2_dir_entry * de, * de1; 284 struct super_block * sb; 285 int err; 286 287 sb = inode->i_sb; 288 if ((i_size_read(inode) < 289 (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) || 290 !(bh = ocfs2_bread(inode, 0, &err, 0))) { 291 mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n", 292 (unsigned long long)OCFS2_I(inode)->ip_blkno); 293 return 1; 294 } 295 296 de = (struct ocfs2_dir_entry *) bh->b_data; 297 de1 = (struct ocfs2_dir_entry *) 298 ((char *)de + le16_to_cpu(de->rec_len)); 299 if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) || 300 !le64_to_cpu(de1->inode) || 301 strcmp(".", de->name) || 302 strcmp("..", de1->name)) { 303 mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n", 304 (unsigned long long)OCFS2_I(inode)->ip_blkno); 305 brelse(bh); 306 return 1; 307 } 308 offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len); 309 de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len)); 310 while (offset < i_size_read(inode) ) { 311 if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) { 312 brelse(bh); 313 bh = ocfs2_bread(inode, 314 offset >> sb->s_blocksize_bits, &err, 0); 315 if (!bh) { 316 mlog(ML_ERROR, "dir %llu has a hole at %lu\n", 317 (unsigned long long)OCFS2_I(inode)->ip_blkno, offset); 318 offset += sb->s_blocksize; 319 continue; 320 } 321 de = (struct ocfs2_dir_entry *) bh->b_data; 322 } 323 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 324 brelse(bh); 325 return 1; 326 } 327 if (le64_to_cpu(de->inode)) { 328 brelse(bh); 329 return 0; 330 } 331 offset += le16_to_cpu(de->rec_len); 332 de = (struct ocfs2_dir_entry *) 333 ((char *)de + le16_to_cpu(de->rec_len)); 334 } 335 brelse(bh); 336 return 1; 337 } 338 339 /* returns a bh of the 1st new block in the allocation. */ 340 int ocfs2_do_extend_dir(struct super_block *sb, 341 struct ocfs2_journal_handle *handle, 342 struct inode *dir, 343 struct buffer_head *parent_fe_bh, 344 struct ocfs2_alloc_context *data_ac, 345 struct ocfs2_alloc_context *meta_ac, 346 struct buffer_head **new_bh) 347 { 348 int status; 349 int extend; 350 u64 p_blkno; 351 352 spin_lock(&OCFS2_I(dir)->ip_lock); 353 extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)); 354 spin_unlock(&OCFS2_I(dir)->ip_lock); 355 356 if (extend) { 357 status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1, 358 parent_fe_bh, handle, 359 data_ac, meta_ac, NULL); 360 BUG_ON(status == -EAGAIN); 361 if (status < 0) { 362 mlog_errno(status); 363 goto bail; 364 } 365 } 366 367 status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >> 368 (sb->s_blocksize_bits - 9)), 369 1, &p_blkno, NULL); 370 if (status < 0) { 371 mlog_errno(status); 372 goto bail; 373 } 374 375 *new_bh = sb_getblk(sb, p_blkno); 376 if (!*new_bh) { 377 status = -EIO; 378 mlog_errno(status); 379 goto bail; 380 } 381 status = 0; 382 bail: 383 mlog_exit(status); 384 return status; 385 } 386 387 /* assumes you already have a cluster lock on the directory. */ 388 static int ocfs2_extend_dir(struct ocfs2_super *osb, 389 struct inode *dir, 390 struct buffer_head *parent_fe_bh, 391 struct buffer_head **new_de_bh) 392 { 393 int status = 0; 394 int credits, num_free_extents; 395 loff_t dir_i_size; 396 struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 397 struct ocfs2_alloc_context *data_ac = NULL; 398 struct ocfs2_alloc_context *meta_ac = NULL; 399 struct ocfs2_journal_handle *handle = NULL; 400 struct buffer_head *new_bh = NULL; 401 struct ocfs2_dir_entry * de; 402 struct super_block *sb = osb->sb; 403 404 mlog_entry_void(); 405 406 dir_i_size = i_size_read(dir); 407 mlog(0, "extending dir %llu (i_size = %lld)\n", 408 (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size); 409 410 handle = ocfs2_alloc_handle(osb); 411 if (handle == NULL) { 412 status = -ENOMEM; 413 mlog_errno(status); 414 goto bail; 415 } 416 417 /* dir->i_size is always block aligned. */ 418 spin_lock(&OCFS2_I(dir)->ip_lock); 419 if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) { 420 spin_unlock(&OCFS2_I(dir)->ip_lock); 421 num_free_extents = ocfs2_num_free_extents(osb, dir, fe); 422 if (num_free_extents < 0) { 423 status = num_free_extents; 424 mlog_errno(status); 425 goto bail; 426 } 427 428 if (!num_free_extents) { 429 status = ocfs2_reserve_new_metadata(osb, handle, 430 fe, &meta_ac); 431 if (status < 0) { 432 if (status != -ENOSPC) 433 mlog_errno(status); 434 goto bail; 435 } 436 } 437 438 status = ocfs2_reserve_clusters(osb, handle, 1, &data_ac); 439 if (status < 0) { 440 if (status != -ENOSPC) 441 mlog_errno(status); 442 goto bail; 443 } 444 445 credits = ocfs2_calc_extend_credits(sb, fe, 1); 446 } else { 447 spin_unlock(&OCFS2_I(dir)->ip_lock); 448 credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS; 449 } 450 451 handle = ocfs2_start_trans(osb, handle, credits); 452 if (IS_ERR(handle)) { 453 status = PTR_ERR(handle); 454 handle = NULL; 455 mlog_errno(status); 456 goto bail; 457 } 458 459 status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh, 460 data_ac, meta_ac, &new_bh); 461 if (status < 0) { 462 mlog_errno(status); 463 goto bail; 464 } 465 466 ocfs2_set_new_buffer_uptodate(dir, new_bh); 467 468 status = ocfs2_journal_access(handle, dir, new_bh, 469 OCFS2_JOURNAL_ACCESS_CREATE); 470 if (status < 0) { 471 mlog_errno(status); 472 goto bail; 473 } 474 memset(new_bh->b_data, 0, sb->s_blocksize); 475 de = (struct ocfs2_dir_entry *) new_bh->b_data; 476 de->inode = 0; 477 de->rec_len = cpu_to_le16(sb->s_blocksize); 478 status = ocfs2_journal_dirty(handle, new_bh); 479 if (status < 0) { 480 mlog_errno(status); 481 goto bail; 482 } 483 484 dir_i_size += dir->i_sb->s_blocksize; 485 i_size_write(dir, dir_i_size); 486 dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size); 487 status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh); 488 if (status < 0) { 489 mlog_errno(status); 490 goto bail; 491 } 492 493 *new_de_bh = new_bh; 494 get_bh(*new_de_bh); 495 bail: 496 if (handle) 497 ocfs2_commit_trans(handle); 498 499 if (data_ac) 500 ocfs2_free_alloc_context(data_ac); 501 if (meta_ac) 502 ocfs2_free_alloc_context(meta_ac); 503 504 if (new_bh) 505 brelse(new_bh); 506 507 mlog_exit(status); 508 return status; 509 } 510 511 /* 512 * Search the dir for a good spot, extending it if necessary. The 513 * block containing an appropriate record is returned in ret_de_bh. 514 */ 515 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb, 516 struct inode *dir, 517 struct buffer_head *parent_fe_bh, 518 const char *name, 519 int namelen, 520 struct buffer_head **ret_de_bh) 521 { 522 unsigned long offset; 523 struct buffer_head * bh = NULL; 524 unsigned short rec_len; 525 struct ocfs2_dinode *fe; 526 struct ocfs2_dir_entry *de; 527 struct super_block *sb; 528 int status; 529 530 mlog_entry_void(); 531 532 mlog(0, "getting ready to insert namelen %d into dir %llu\n", 533 namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno); 534 535 BUG_ON(!S_ISDIR(dir->i_mode)); 536 fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 537 BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir)); 538 539 sb = dir->i_sb; 540 541 if (!namelen) { 542 status = -EINVAL; 543 mlog_errno(status); 544 goto bail; 545 } 546 547 bh = ocfs2_bread(dir, 0, &status, 0); 548 if (!bh) { 549 mlog_errno(status); 550 goto bail; 551 } 552 553 rec_len = OCFS2_DIR_REC_LEN(namelen); 554 offset = 0; 555 de = (struct ocfs2_dir_entry *) bh->b_data; 556 while (1) { 557 if ((char *)de >= sb->s_blocksize + bh->b_data) { 558 brelse(bh); 559 bh = NULL; 560 561 if (i_size_read(dir) <= offset) { 562 status = ocfs2_extend_dir(osb, 563 dir, 564 parent_fe_bh, 565 &bh); 566 if (status < 0) { 567 mlog_errno(status); 568 goto bail; 569 } 570 BUG_ON(!bh); 571 *ret_de_bh = bh; 572 get_bh(*ret_de_bh); 573 goto bail; 574 } 575 bh = ocfs2_bread(dir, 576 offset >> sb->s_blocksize_bits, 577 &status, 578 0); 579 if (!bh) { 580 mlog_errno(status); 581 goto bail; 582 } 583 /* move to next block */ 584 de = (struct ocfs2_dir_entry *) bh->b_data; 585 } 586 if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { 587 status = -ENOENT; 588 goto bail; 589 } 590 if (ocfs2_match(namelen, name, de)) { 591 status = -EEXIST; 592 goto bail; 593 } 594 if (((le64_to_cpu(de->inode) == 0) && 595 (le16_to_cpu(de->rec_len) >= rec_len)) || 596 (le16_to_cpu(de->rec_len) >= 597 (OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) { 598 /* Ok, we found a spot. Return this bh and let 599 * the caller actually fill it in. */ 600 *ret_de_bh = bh; 601 get_bh(*ret_de_bh); 602 status = 0; 603 goto bail; 604 } 605 offset += le16_to_cpu(de->rec_len); 606 de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len)); 607 } 608 609 status = 0; 610 bail: 611 if (bh) 612 brelse(bh); 613 614 mlog_exit(status); 615 return status; 616 } 617