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, last_ra_blk = 0; 78 int i, 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 unsigned int ra_sectors = 16; 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_nolock; 99 } 100 101 offset = filp->f_pos & (sb->s_blocksize - 1); 102 103 while (!error && !stored && filp->f_pos < i_size_read(inode)) { 104 blk = (filp->f_pos) >> sb->s_blocksize_bits; 105 bh = ocfs2_bread(inode, blk, &err, 0); 106 if (!bh) { 107 mlog(ML_ERROR, 108 "directory #%llu contains a hole at offset %lld\n", 109 (unsigned long long)OCFS2_I(inode)->ip_blkno, 110 filp->f_pos); 111 filp->f_pos += sb->s_blocksize - offset; 112 continue; 113 } 114 115 /* The idea here is to begin with 8k read-ahead and to stay 116 * 4k ahead of our current position. 117 * 118 * TODO: Use the pagecache for this. We just need to 119 * make sure it's cluster-safe... */ 120 if (!last_ra_blk 121 || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) { 122 for (i = ra_sectors >> (sb->s_blocksize_bits - 9); 123 i > 0; i--) { 124 tmp = ocfs2_bread(inode, ++blk, &err, 1); 125 if (tmp) 126 brelse(tmp); 127 } 128 last_ra_blk = blk; 129 ra_sectors = 8; 130 } 131 132 revalidate: 133 /* If the dir block has changed since the last call to 134 * readdir(2), then we might be pointing to an invalid 135 * dirent right now. Scan from the start of the block 136 * to make sure. */ 137 if (filp->f_version != inode->i_version) { 138 for (i = 0; i < sb->s_blocksize && i < offset; ) { 139 de = (struct ocfs2_dir_entry *) (bh->b_data + i); 140 /* It's too expensive to do a full 141 * dirent test each time round this 142 * loop, but we do have to test at 143 * least that it is non-zero. A 144 * failure will be detected in the 145 * dirent test below. */ 146 if (le16_to_cpu(de->rec_len) < 147 OCFS2_DIR_REC_LEN(1)) 148 break; 149 i += le16_to_cpu(de->rec_len); 150 } 151 offset = i; 152 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) 153 | offset; 154 filp->f_version = inode->i_version; 155 } 156 157 while (!error && filp->f_pos < i_size_read(inode) 158 && offset < sb->s_blocksize) { 159 de = (struct ocfs2_dir_entry *) (bh->b_data + offset); 160 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 161 /* On error, skip the f_pos to the 162 next block. */ 163 filp->f_pos = (filp->f_pos | 164 (sb->s_blocksize - 1)) + 1; 165 brelse(bh); 166 goto bail; 167 } 168 offset += le16_to_cpu(de->rec_len); 169 if (le64_to_cpu(de->inode)) { 170 /* We might block in the next section 171 * if the data destination is 172 * currently swapped out. So, use a 173 * version stamp to detect whether or 174 * not the directory has been modified 175 * during the copy operation. 176 */ 177 unsigned long version = filp->f_version; 178 unsigned char d_type = DT_UNKNOWN; 179 180 if (de->file_type < OCFS2_FT_MAX) 181 d_type = ocfs2_filetype_table[de->file_type]; 182 error = filldir(dirent, de->name, 183 de->name_len, 184 filp->f_pos, 185 ino_from_blkno(sb, le64_to_cpu(de->inode)), 186 d_type); 187 if (error) 188 break; 189 if (version != filp->f_version) 190 goto revalidate; 191 stored ++; 192 } 193 filp->f_pos += le16_to_cpu(de->rec_len); 194 } 195 offset = 0; 196 brelse(bh); 197 } 198 199 stored = 0; 200 bail: 201 ocfs2_meta_unlock(inode, 0); 202 203 bail_nolock: 204 mlog_exit(stored); 205 206 return stored; 207 } 208 209 /* 210 * NOTE: this should always be called with parent dir i_mutex taken. 211 */ 212 int ocfs2_find_files_on_disk(const char *name, 213 int namelen, 214 u64 *blkno, 215 struct inode *inode, 216 struct buffer_head **dirent_bh, 217 struct ocfs2_dir_entry **dirent) 218 { 219 int status = -ENOENT; 220 221 mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n", 222 namelen, name, blkno, inode, dirent_bh, dirent); 223 224 *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent); 225 if (!*dirent_bh || !*dirent) { 226 status = -ENOENT; 227 goto leave; 228 } 229 230 *blkno = le64_to_cpu((*dirent)->inode); 231 232 status = 0; 233 leave: 234 if (status < 0) { 235 *dirent = NULL; 236 if (*dirent_bh) { 237 brelse(*dirent_bh); 238 *dirent_bh = NULL; 239 } 240 } 241 242 mlog_exit(status); 243 return status; 244 } 245 246 /* Check for a name within a directory. 247 * 248 * Return 0 if the name does not exist 249 * Return -EEXIST if the directory contains the name 250 * 251 * Callers should have i_mutex + a cluster lock on dir 252 */ 253 int ocfs2_check_dir_for_entry(struct inode *dir, 254 const char *name, 255 int namelen) 256 { 257 int ret; 258 struct buffer_head *dirent_bh = NULL; 259 struct ocfs2_dir_entry *dirent = NULL; 260 261 mlog_entry("dir %llu, name '%.*s'\n", 262 (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name); 263 264 ret = -EEXIST; 265 dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent); 266 if (dirent_bh) 267 goto bail; 268 269 ret = 0; 270 bail: 271 if (dirent_bh) 272 brelse(dirent_bh); 273 274 mlog_exit(ret); 275 return ret; 276 } 277 278 /* 279 * routine to check that the specified directory is empty (for rmdir) 280 */ 281 int ocfs2_empty_dir(struct inode *inode) 282 { 283 unsigned long offset; 284 struct buffer_head * bh; 285 struct ocfs2_dir_entry * de, * de1; 286 struct super_block * sb; 287 int err; 288 289 sb = inode->i_sb; 290 if ((i_size_read(inode) < 291 (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) || 292 !(bh = ocfs2_bread(inode, 0, &err, 0))) { 293 mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n", 294 (unsigned long long)OCFS2_I(inode)->ip_blkno); 295 return 1; 296 } 297 298 de = (struct ocfs2_dir_entry *) bh->b_data; 299 de1 = (struct ocfs2_dir_entry *) 300 ((char *)de + le16_to_cpu(de->rec_len)); 301 if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) || 302 !le64_to_cpu(de1->inode) || 303 strcmp(".", de->name) || 304 strcmp("..", de1->name)) { 305 mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n", 306 (unsigned long long)OCFS2_I(inode)->ip_blkno); 307 brelse(bh); 308 return 1; 309 } 310 offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len); 311 de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len)); 312 while (offset < i_size_read(inode) ) { 313 if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) { 314 brelse(bh); 315 bh = ocfs2_bread(inode, 316 offset >> sb->s_blocksize_bits, &err, 0); 317 if (!bh) { 318 mlog(ML_ERROR, "dir %llu has a hole at %lu\n", 319 (unsigned long long)OCFS2_I(inode)->ip_blkno, offset); 320 offset += sb->s_blocksize; 321 continue; 322 } 323 de = (struct ocfs2_dir_entry *) bh->b_data; 324 } 325 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 326 brelse(bh); 327 return 1; 328 } 329 if (le64_to_cpu(de->inode)) { 330 brelse(bh); 331 return 0; 332 } 333 offset += le16_to_cpu(de->rec_len); 334 de = (struct ocfs2_dir_entry *) 335 ((char *)de + le16_to_cpu(de->rec_len)); 336 } 337 brelse(bh); 338 return 1; 339 } 340 341 /* returns a bh of the 1st new block in the allocation. */ 342 int ocfs2_do_extend_dir(struct super_block *sb, 343 struct ocfs2_journal_handle *handle, 344 struct inode *dir, 345 struct buffer_head *parent_fe_bh, 346 struct ocfs2_alloc_context *data_ac, 347 struct ocfs2_alloc_context *meta_ac, 348 struct buffer_head **new_bh) 349 { 350 int status; 351 int extend; 352 u64 p_blkno; 353 354 spin_lock(&OCFS2_I(dir)->ip_lock); 355 extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)); 356 spin_unlock(&OCFS2_I(dir)->ip_lock); 357 358 if (extend) { 359 status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1, 360 parent_fe_bh, handle, 361 data_ac, meta_ac, NULL); 362 BUG_ON(status == -EAGAIN); 363 if (status < 0) { 364 mlog_errno(status); 365 goto bail; 366 } 367 } 368 369 status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >> 370 (sb->s_blocksize_bits - 9)), 371 1, &p_blkno, NULL); 372 if (status < 0) { 373 mlog_errno(status); 374 goto bail; 375 } 376 377 *new_bh = sb_getblk(sb, p_blkno); 378 if (!*new_bh) { 379 status = -EIO; 380 mlog_errno(status); 381 goto bail; 382 } 383 status = 0; 384 bail: 385 mlog_exit(status); 386 return status; 387 } 388 389 /* assumes you already have a cluster lock on the directory. */ 390 static int ocfs2_extend_dir(struct ocfs2_super *osb, 391 struct inode *dir, 392 struct buffer_head *parent_fe_bh, 393 struct buffer_head **new_de_bh) 394 { 395 int status = 0; 396 int credits, num_free_extents; 397 loff_t dir_i_size; 398 struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 399 struct ocfs2_alloc_context *data_ac = NULL; 400 struct ocfs2_alloc_context *meta_ac = NULL; 401 struct ocfs2_journal_handle *handle = NULL; 402 struct buffer_head *new_bh = NULL; 403 struct ocfs2_dir_entry * de; 404 struct super_block *sb = osb->sb; 405 406 mlog_entry_void(); 407 408 dir_i_size = i_size_read(dir); 409 mlog(0, "extending dir %llu (i_size = %lld)\n", 410 (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size); 411 412 handle = ocfs2_alloc_handle(osb); 413 if (handle == NULL) { 414 status = -ENOMEM; 415 mlog_errno(status); 416 goto bail; 417 } 418 419 /* dir->i_size is always block aligned. */ 420 spin_lock(&OCFS2_I(dir)->ip_lock); 421 if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) { 422 spin_unlock(&OCFS2_I(dir)->ip_lock); 423 num_free_extents = ocfs2_num_free_extents(osb, dir, fe); 424 if (num_free_extents < 0) { 425 status = num_free_extents; 426 mlog_errno(status); 427 goto bail; 428 } 429 430 if (!num_free_extents) { 431 status = ocfs2_reserve_new_metadata(osb, handle, 432 fe, &meta_ac); 433 if (status < 0) { 434 if (status != -ENOSPC) 435 mlog_errno(status); 436 goto bail; 437 } 438 } 439 440 status = ocfs2_reserve_clusters(osb, handle, 1, &data_ac); 441 if (status < 0) { 442 if (status != -ENOSPC) 443 mlog_errno(status); 444 goto bail; 445 } 446 447 credits = ocfs2_calc_extend_credits(sb, fe, 1); 448 } else { 449 spin_unlock(&OCFS2_I(dir)->ip_lock); 450 credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS; 451 } 452 453 handle = ocfs2_start_trans(osb, handle, credits); 454 if (IS_ERR(handle)) { 455 status = PTR_ERR(handle); 456 handle = NULL; 457 mlog_errno(status); 458 goto bail; 459 } 460 461 status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh, 462 data_ac, meta_ac, &new_bh); 463 if (status < 0) { 464 mlog_errno(status); 465 goto bail; 466 } 467 468 ocfs2_set_new_buffer_uptodate(dir, new_bh); 469 470 status = ocfs2_journal_access(handle, dir, new_bh, 471 OCFS2_JOURNAL_ACCESS_CREATE); 472 if (status < 0) { 473 mlog_errno(status); 474 goto bail; 475 } 476 memset(new_bh->b_data, 0, sb->s_blocksize); 477 de = (struct ocfs2_dir_entry *) new_bh->b_data; 478 de->inode = 0; 479 de->rec_len = cpu_to_le16(sb->s_blocksize); 480 status = ocfs2_journal_dirty(handle, new_bh); 481 if (status < 0) { 482 mlog_errno(status); 483 goto bail; 484 } 485 486 dir_i_size += dir->i_sb->s_blocksize; 487 i_size_write(dir, dir_i_size); 488 dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size); 489 status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh); 490 if (status < 0) { 491 mlog_errno(status); 492 goto bail; 493 } 494 495 *new_de_bh = new_bh; 496 get_bh(*new_de_bh); 497 bail: 498 if (handle) 499 ocfs2_commit_trans(handle); 500 501 if (data_ac) 502 ocfs2_free_alloc_context(data_ac); 503 if (meta_ac) 504 ocfs2_free_alloc_context(meta_ac); 505 506 if (new_bh) 507 brelse(new_bh); 508 509 mlog_exit(status); 510 return status; 511 } 512 513 /* 514 * Search the dir for a good spot, extending it if necessary. The 515 * block containing an appropriate record is returned in ret_de_bh. 516 */ 517 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb, 518 struct inode *dir, 519 struct buffer_head *parent_fe_bh, 520 const char *name, 521 int namelen, 522 struct buffer_head **ret_de_bh) 523 { 524 unsigned long offset; 525 struct buffer_head * bh = NULL; 526 unsigned short rec_len; 527 struct ocfs2_dinode *fe; 528 struct ocfs2_dir_entry *de; 529 struct super_block *sb; 530 int status; 531 532 mlog_entry_void(); 533 534 mlog(0, "getting ready to insert namelen %d into dir %llu\n", 535 namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno); 536 537 BUG_ON(!S_ISDIR(dir->i_mode)); 538 fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 539 BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir)); 540 541 sb = dir->i_sb; 542 543 if (!namelen) { 544 status = -EINVAL; 545 mlog_errno(status); 546 goto bail; 547 } 548 549 bh = ocfs2_bread(dir, 0, &status, 0); 550 if (!bh) { 551 mlog_errno(status); 552 goto bail; 553 } 554 555 rec_len = OCFS2_DIR_REC_LEN(namelen); 556 offset = 0; 557 de = (struct ocfs2_dir_entry *) bh->b_data; 558 while (1) { 559 if ((char *)de >= sb->s_blocksize + bh->b_data) { 560 brelse(bh); 561 bh = NULL; 562 563 if (i_size_read(dir) <= offset) { 564 status = ocfs2_extend_dir(osb, 565 dir, 566 parent_fe_bh, 567 &bh); 568 if (status < 0) { 569 mlog_errno(status); 570 goto bail; 571 } 572 BUG_ON(!bh); 573 *ret_de_bh = bh; 574 get_bh(*ret_de_bh); 575 goto bail; 576 } 577 bh = ocfs2_bread(dir, 578 offset >> sb->s_blocksize_bits, 579 &status, 580 0); 581 if (!bh) { 582 mlog_errno(status); 583 goto bail; 584 } 585 /* move to next block */ 586 de = (struct ocfs2_dir_entry *) bh->b_data; 587 } 588 if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { 589 status = -ENOENT; 590 goto bail; 591 } 592 if (ocfs2_match(namelen, name, de)) { 593 status = -EEXIST; 594 goto bail; 595 } 596 if (((le64_to_cpu(de->inode) == 0) && 597 (le16_to_cpu(de->rec_len) >= rec_len)) || 598 (le16_to_cpu(de->rec_len) >= 599 (OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) { 600 /* Ok, we found a spot. Return this bh and let 601 * the caller actually fill it in. */ 602 *ret_de_bh = bh; 603 get_bh(*ret_de_bh); 604 status = 0; 605 goto bail; 606 } 607 offset += le16_to_cpu(de->rec_len); 608 de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len)); 609 } 610 611 status = 0; 612 bail: 613 if (bh) 614 brelse(bh); 615 616 mlog_exit(status); 617 return status; 618 } 619