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_path.dentry->d_inode; 83 struct super_block * sb = inode->i_sb; 84 unsigned int ra_sectors = 16; 85 int lock_level = 0; 86 87 mlog_entry("dirino=%llu\n", 88 (unsigned long long)OCFS2_I(inode)->ip_blkno); 89 90 stored = 0; 91 bh = NULL; 92 93 error = ocfs2_meta_lock_atime(inode, filp->f_vfsmnt, &lock_level); 94 if (lock_level && error >= 0) { 95 /* We release EX lock which used to update atime 96 * and get PR lock again to reduce contention 97 * on commonly accessed directories. */ 98 ocfs2_meta_unlock(inode, 1); 99 lock_level = 0; 100 error = ocfs2_meta_lock(inode, NULL, 0); 101 } 102 if (error < 0) { 103 if (error != -ENOENT) 104 mlog_errno(error); 105 /* we haven't got any yet, so propagate the error. */ 106 stored = error; 107 goto bail_nolock; 108 } 109 110 offset = filp->f_pos & (sb->s_blocksize - 1); 111 112 while (!error && !stored && filp->f_pos < i_size_read(inode)) { 113 blk = (filp->f_pos) >> sb->s_blocksize_bits; 114 bh = ocfs2_bread(inode, blk, &err, 0); 115 if (!bh) { 116 mlog(ML_ERROR, 117 "directory #%llu contains a hole at offset %lld\n", 118 (unsigned long long)OCFS2_I(inode)->ip_blkno, 119 filp->f_pos); 120 filp->f_pos += sb->s_blocksize - offset; 121 continue; 122 } 123 124 /* The idea here is to begin with 8k read-ahead and to stay 125 * 4k ahead of our current position. 126 * 127 * TODO: Use the pagecache for this. We just need to 128 * make sure it's cluster-safe... */ 129 if (!last_ra_blk 130 || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) { 131 for (i = ra_sectors >> (sb->s_blocksize_bits - 9); 132 i > 0; i--) { 133 tmp = ocfs2_bread(inode, ++blk, &err, 1); 134 if (tmp) 135 brelse(tmp); 136 } 137 last_ra_blk = blk; 138 ra_sectors = 8; 139 } 140 141 revalidate: 142 /* If the dir block has changed since the last call to 143 * readdir(2), then we might be pointing to an invalid 144 * dirent right now. Scan from the start of the block 145 * to make sure. */ 146 if (filp->f_version != inode->i_version) { 147 for (i = 0; i < sb->s_blocksize && i < offset; ) { 148 de = (struct ocfs2_dir_entry *) (bh->b_data + i); 149 /* It's too expensive to do a full 150 * dirent test each time round this 151 * loop, but we do have to test at 152 * least that it is non-zero. A 153 * failure will be detected in the 154 * dirent test below. */ 155 if (le16_to_cpu(de->rec_len) < 156 OCFS2_DIR_REC_LEN(1)) 157 break; 158 i += le16_to_cpu(de->rec_len); 159 } 160 offset = i; 161 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) 162 | offset; 163 filp->f_version = inode->i_version; 164 } 165 166 while (!error && filp->f_pos < i_size_read(inode) 167 && offset < sb->s_blocksize) { 168 de = (struct ocfs2_dir_entry *) (bh->b_data + offset); 169 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 170 /* On error, skip the f_pos to the 171 next block. */ 172 filp->f_pos = (filp->f_pos | 173 (sb->s_blocksize - 1)) + 1; 174 brelse(bh); 175 goto bail; 176 } 177 offset += le16_to_cpu(de->rec_len); 178 if (le64_to_cpu(de->inode)) { 179 /* We might block in the next section 180 * if the data destination is 181 * currently swapped out. So, use a 182 * version stamp to detect whether or 183 * not the directory has been modified 184 * during the copy operation. 185 */ 186 unsigned long version = filp->f_version; 187 unsigned char d_type = DT_UNKNOWN; 188 189 if (de->file_type < OCFS2_FT_MAX) 190 d_type = ocfs2_filetype_table[de->file_type]; 191 error = filldir(dirent, de->name, 192 de->name_len, 193 filp->f_pos, 194 ino_from_blkno(sb, le64_to_cpu(de->inode)), 195 d_type); 196 if (error) 197 break; 198 if (version != filp->f_version) 199 goto revalidate; 200 stored ++; 201 } 202 filp->f_pos += le16_to_cpu(de->rec_len); 203 } 204 offset = 0; 205 brelse(bh); 206 } 207 208 stored = 0; 209 bail: 210 ocfs2_meta_unlock(inode, lock_level); 211 212 bail_nolock: 213 mlog_exit(stored); 214 215 return stored; 216 } 217 218 /* 219 * NOTE: this should always be called with parent dir i_mutex taken. 220 */ 221 int ocfs2_find_files_on_disk(const char *name, 222 int namelen, 223 u64 *blkno, 224 struct inode *inode, 225 struct buffer_head **dirent_bh, 226 struct ocfs2_dir_entry **dirent) 227 { 228 int status = -ENOENT; 229 230 mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n", 231 namelen, name, blkno, inode, dirent_bh, dirent); 232 233 *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent); 234 if (!*dirent_bh || !*dirent) { 235 status = -ENOENT; 236 goto leave; 237 } 238 239 *blkno = le64_to_cpu((*dirent)->inode); 240 241 status = 0; 242 leave: 243 if (status < 0) { 244 *dirent = NULL; 245 if (*dirent_bh) { 246 brelse(*dirent_bh); 247 *dirent_bh = NULL; 248 } 249 } 250 251 mlog_exit(status); 252 return status; 253 } 254 255 /* Check for a name within a directory. 256 * 257 * Return 0 if the name does not exist 258 * Return -EEXIST if the directory contains the name 259 * 260 * Callers should have i_mutex + a cluster lock on dir 261 */ 262 int ocfs2_check_dir_for_entry(struct inode *dir, 263 const char *name, 264 int namelen) 265 { 266 int ret; 267 struct buffer_head *dirent_bh = NULL; 268 struct ocfs2_dir_entry *dirent = NULL; 269 270 mlog_entry("dir %llu, name '%.*s'\n", 271 (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name); 272 273 ret = -EEXIST; 274 dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent); 275 if (dirent_bh) 276 goto bail; 277 278 ret = 0; 279 bail: 280 if (dirent_bh) 281 brelse(dirent_bh); 282 283 mlog_exit(ret); 284 return ret; 285 } 286 287 /* 288 * routine to check that the specified directory is empty (for rmdir) 289 */ 290 int ocfs2_empty_dir(struct inode *inode) 291 { 292 unsigned long offset; 293 struct buffer_head * bh; 294 struct ocfs2_dir_entry * de, * de1; 295 struct super_block * sb; 296 int err; 297 298 sb = inode->i_sb; 299 if ((i_size_read(inode) < 300 (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) || 301 !(bh = ocfs2_bread(inode, 0, &err, 0))) { 302 mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n", 303 (unsigned long long)OCFS2_I(inode)->ip_blkno); 304 return 1; 305 } 306 307 de = (struct ocfs2_dir_entry *) bh->b_data; 308 de1 = (struct ocfs2_dir_entry *) 309 ((char *)de + le16_to_cpu(de->rec_len)); 310 if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) || 311 !le64_to_cpu(de1->inode) || 312 strcmp(".", de->name) || 313 strcmp("..", de1->name)) { 314 mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n", 315 (unsigned long long)OCFS2_I(inode)->ip_blkno); 316 brelse(bh); 317 return 1; 318 } 319 offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len); 320 de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len)); 321 while (offset < i_size_read(inode) ) { 322 if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) { 323 brelse(bh); 324 bh = ocfs2_bread(inode, 325 offset >> sb->s_blocksize_bits, &err, 0); 326 if (!bh) { 327 mlog(ML_ERROR, "dir %llu has a hole at %lu\n", 328 (unsigned long long)OCFS2_I(inode)->ip_blkno, offset); 329 offset += sb->s_blocksize; 330 continue; 331 } 332 de = (struct ocfs2_dir_entry *) bh->b_data; 333 } 334 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { 335 brelse(bh); 336 return 1; 337 } 338 if (le64_to_cpu(de->inode)) { 339 brelse(bh); 340 return 0; 341 } 342 offset += le16_to_cpu(de->rec_len); 343 de = (struct ocfs2_dir_entry *) 344 ((char *)de + le16_to_cpu(de->rec_len)); 345 } 346 brelse(bh); 347 return 1; 348 } 349 350 /* returns a bh of the 1st new block in the allocation. */ 351 int ocfs2_do_extend_dir(struct super_block *sb, 352 handle_t *handle, 353 struct inode *dir, 354 struct buffer_head *parent_fe_bh, 355 struct ocfs2_alloc_context *data_ac, 356 struct ocfs2_alloc_context *meta_ac, 357 struct buffer_head **new_bh) 358 { 359 int status; 360 int extend; 361 u64 p_blkno; 362 363 spin_lock(&OCFS2_I(dir)->ip_lock); 364 extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)); 365 spin_unlock(&OCFS2_I(dir)->ip_lock); 366 367 if (extend) { 368 status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1, 369 parent_fe_bh, handle, 370 data_ac, meta_ac, NULL); 371 BUG_ON(status == -EAGAIN); 372 if (status < 0) { 373 mlog_errno(status); 374 goto bail; 375 } 376 } 377 378 status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >> 379 (sb->s_blocksize_bits - 9)), 380 1, &p_blkno, NULL); 381 if (status < 0) { 382 mlog_errno(status); 383 goto bail; 384 } 385 386 *new_bh = sb_getblk(sb, p_blkno); 387 if (!*new_bh) { 388 status = -EIO; 389 mlog_errno(status); 390 goto bail; 391 } 392 status = 0; 393 bail: 394 mlog_exit(status); 395 return status; 396 } 397 398 /* assumes you already have a cluster lock on the directory. */ 399 static int ocfs2_extend_dir(struct ocfs2_super *osb, 400 struct inode *dir, 401 struct buffer_head *parent_fe_bh, 402 struct buffer_head **new_de_bh) 403 { 404 int status = 0; 405 int credits, num_free_extents; 406 loff_t dir_i_size; 407 struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 408 struct ocfs2_alloc_context *data_ac = NULL; 409 struct ocfs2_alloc_context *meta_ac = NULL; 410 handle_t *handle = NULL; 411 struct buffer_head *new_bh = NULL; 412 struct ocfs2_dir_entry * de; 413 struct super_block *sb = osb->sb; 414 415 mlog_entry_void(); 416 417 dir_i_size = i_size_read(dir); 418 mlog(0, "extending dir %llu (i_size = %lld)\n", 419 (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size); 420 421 /* dir->i_size is always block aligned. */ 422 spin_lock(&OCFS2_I(dir)->ip_lock); 423 if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) { 424 spin_unlock(&OCFS2_I(dir)->ip_lock); 425 num_free_extents = ocfs2_num_free_extents(osb, dir, fe); 426 if (num_free_extents < 0) { 427 status = num_free_extents; 428 mlog_errno(status); 429 goto bail; 430 } 431 432 if (!num_free_extents) { 433 status = ocfs2_reserve_new_metadata(osb, fe, &meta_ac); 434 if (status < 0) { 435 if (status != -ENOSPC) 436 mlog_errno(status); 437 goto bail; 438 } 439 } 440 441 status = ocfs2_reserve_clusters(osb, 1, &data_ac); 442 if (status < 0) { 443 if (status != -ENOSPC) 444 mlog_errno(status); 445 goto bail; 446 } 447 448 credits = ocfs2_calc_extend_credits(sb, fe, 1); 449 } else { 450 spin_unlock(&OCFS2_I(dir)->ip_lock); 451 credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS; 452 } 453 454 handle = ocfs2_start_trans(osb, credits); 455 if (IS_ERR(handle)) { 456 status = PTR_ERR(handle); 457 handle = NULL; 458 mlog_errno(status); 459 goto bail; 460 } 461 462 status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh, 463 data_ac, meta_ac, &new_bh); 464 if (status < 0) { 465 mlog_errno(status); 466 goto bail; 467 } 468 469 ocfs2_set_new_buffer_uptodate(dir, new_bh); 470 471 status = ocfs2_journal_access(handle, dir, new_bh, 472 OCFS2_JOURNAL_ACCESS_CREATE); 473 if (status < 0) { 474 mlog_errno(status); 475 goto bail; 476 } 477 memset(new_bh->b_data, 0, sb->s_blocksize); 478 de = (struct ocfs2_dir_entry *) new_bh->b_data; 479 de->inode = 0; 480 de->rec_len = cpu_to_le16(sb->s_blocksize); 481 status = ocfs2_journal_dirty(handle, new_bh); 482 if (status < 0) { 483 mlog_errno(status); 484 goto bail; 485 } 486 487 dir_i_size += dir->i_sb->s_blocksize; 488 i_size_write(dir, dir_i_size); 489 dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size); 490 status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh); 491 if (status < 0) { 492 mlog_errno(status); 493 goto bail; 494 } 495 496 *new_de_bh = new_bh; 497 get_bh(*new_de_bh); 498 bail: 499 if (handle) 500 ocfs2_commit_trans(osb, handle); 501 502 if (data_ac) 503 ocfs2_free_alloc_context(data_ac); 504 if (meta_ac) 505 ocfs2_free_alloc_context(meta_ac); 506 507 if (new_bh) 508 brelse(new_bh); 509 510 mlog_exit(status); 511 return status; 512 } 513 514 /* 515 * Search the dir for a good spot, extending it if necessary. The 516 * block containing an appropriate record is returned in ret_de_bh. 517 */ 518 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb, 519 struct inode *dir, 520 struct buffer_head *parent_fe_bh, 521 const char *name, 522 int namelen, 523 struct buffer_head **ret_de_bh) 524 { 525 unsigned long offset; 526 struct buffer_head * bh = NULL; 527 unsigned short rec_len; 528 struct ocfs2_dinode *fe; 529 struct ocfs2_dir_entry *de; 530 struct super_block *sb; 531 int status; 532 533 mlog_entry_void(); 534 535 mlog(0, "getting ready to insert namelen %d into dir %llu\n", 536 namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno); 537 538 BUG_ON(!S_ISDIR(dir->i_mode)); 539 fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; 540 BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir)); 541 542 sb = dir->i_sb; 543 544 if (!namelen) { 545 status = -EINVAL; 546 mlog_errno(status); 547 goto bail; 548 } 549 550 bh = ocfs2_bread(dir, 0, &status, 0); 551 if (!bh) { 552 mlog_errno(status); 553 goto bail; 554 } 555 556 rec_len = OCFS2_DIR_REC_LEN(namelen); 557 offset = 0; 558 de = (struct ocfs2_dir_entry *) bh->b_data; 559 while (1) { 560 if ((char *)de >= sb->s_blocksize + bh->b_data) { 561 brelse(bh); 562 bh = NULL; 563 564 if (i_size_read(dir) <= offset) { 565 status = ocfs2_extend_dir(osb, 566 dir, 567 parent_fe_bh, 568 &bh); 569 if (status < 0) { 570 mlog_errno(status); 571 goto bail; 572 } 573 BUG_ON(!bh); 574 *ret_de_bh = bh; 575 get_bh(*ret_de_bh); 576 goto bail; 577 } 578 bh = ocfs2_bread(dir, 579 offset >> sb->s_blocksize_bits, 580 &status, 581 0); 582 if (!bh) { 583 mlog_errno(status); 584 goto bail; 585 } 586 /* move to next block */ 587 de = (struct ocfs2_dir_entry *) bh->b_data; 588 } 589 if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { 590 status = -ENOENT; 591 goto bail; 592 } 593 if (ocfs2_match(namelen, name, de)) { 594 status = -EEXIST; 595 goto bail; 596 } 597 if (((le64_to_cpu(de->inode) == 0) && 598 (le16_to_cpu(de->rec_len) >= rec_len)) || 599 (le16_to_cpu(de->rec_len) >= 600 (OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) { 601 /* Ok, we found a spot. Return this bh and let 602 * the caller actually fill it in. */ 603 *ret_de_bh = bh; 604 get_bh(*ret_de_bh); 605 status = 0; 606 goto bail; 607 } 608 offset += le16_to_cpu(de->rec_len); 609 de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len)); 610 } 611 612 status = 0; 613 bail: 614 if (bh) 615 brelse(bh); 616 617 mlog_exit(status); 618 return status; 619 } 620