1 /* 2 * linux/fs/ext2/super.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/inode.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 */ 18 19 #include <linux/config.h> 20 #include <linux/module.h> 21 #include <linux/string.h> 22 #include <linux/slab.h> 23 #include <linux/init.h> 24 #include <linux/blkdev.h> 25 #include <linux/parser.h> 26 #include <linux/random.h> 27 #include <linux/buffer_head.h> 28 #include <linux/smp_lock.h> 29 #include <linux/vfs.h> 30 #include <asm/uaccess.h> 31 #include "ext2.h" 32 #include "xattr.h" 33 #include "acl.h" 34 35 static void ext2_sync_super(struct super_block *sb, 36 struct ext2_super_block *es); 37 static int ext2_remount (struct super_block * sb, int * flags, char * data); 38 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf); 39 40 void ext2_error (struct super_block * sb, const char * function, 41 const char * fmt, ...) 42 { 43 va_list args; 44 struct ext2_sb_info *sbi = EXT2_SB(sb); 45 struct ext2_super_block *es = sbi->s_es; 46 47 if (!(sb->s_flags & MS_RDONLY)) { 48 sbi->s_mount_state |= EXT2_ERROR_FS; 49 es->s_state = 50 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS); 51 ext2_sync_super(sb, es); 52 } 53 54 va_start(args, fmt); 55 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 56 vprintk(fmt, args); 57 printk("\n"); 58 va_end(args); 59 60 if (test_opt(sb, ERRORS_PANIC)) 61 panic("EXT2-fs panic from previous error\n"); 62 if (test_opt(sb, ERRORS_RO)) { 63 printk("Remounting filesystem read-only\n"); 64 sb->s_flags |= MS_RDONLY; 65 } 66 } 67 68 void ext2_warning (struct super_block * sb, const char * function, 69 const char * fmt, ...) 70 { 71 va_list args; 72 73 va_start(args, fmt); 74 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 75 sb->s_id, function); 76 vprintk(fmt, args); 77 printk("\n"); 78 va_end(args); 79 } 80 81 void ext2_update_dynamic_rev(struct super_block *sb) 82 { 83 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 84 85 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 86 return; 87 88 ext2_warning(sb, __FUNCTION__, 89 "updating to rev %d because of new feature flag, " 90 "running e2fsck is recommended", 91 EXT2_DYNAMIC_REV); 92 93 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 94 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 95 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 96 /* leave es->s_feature_*compat flags alone */ 97 /* es->s_uuid will be set by e2fsck if empty */ 98 99 /* 100 * The rest of the superblock fields should be zero, and if not it 101 * means they are likely already in use, so leave them alone. We 102 * can leave it up to e2fsck to clean up any inconsistencies there. 103 */ 104 } 105 106 static void ext2_put_super (struct super_block * sb) 107 { 108 int db_count; 109 int i; 110 struct ext2_sb_info *sbi = EXT2_SB(sb); 111 112 ext2_xattr_put_super(sb); 113 if (!(sb->s_flags & MS_RDONLY)) { 114 struct ext2_super_block *es = sbi->s_es; 115 116 es->s_state = cpu_to_le16(sbi->s_mount_state); 117 ext2_sync_super(sb, es); 118 } 119 db_count = sbi->s_gdb_count; 120 for (i = 0; i < db_count; i++) 121 if (sbi->s_group_desc[i]) 122 brelse (sbi->s_group_desc[i]); 123 kfree(sbi->s_group_desc); 124 kfree(sbi->s_debts); 125 percpu_counter_destroy(&sbi->s_freeblocks_counter); 126 percpu_counter_destroy(&sbi->s_freeinodes_counter); 127 percpu_counter_destroy(&sbi->s_dirs_counter); 128 brelse (sbi->s_sbh); 129 sb->s_fs_info = NULL; 130 kfree(sbi); 131 132 return; 133 } 134 135 static kmem_cache_t * ext2_inode_cachep; 136 137 static struct inode *ext2_alloc_inode(struct super_block *sb) 138 { 139 struct ext2_inode_info *ei; 140 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL); 141 if (!ei) 142 return NULL; 143 #ifdef CONFIG_EXT2_FS_POSIX_ACL 144 ei->i_acl = EXT2_ACL_NOT_CACHED; 145 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 146 #endif 147 ei->vfs_inode.i_version = 1; 148 return &ei->vfs_inode; 149 } 150 151 static void ext2_destroy_inode(struct inode *inode) 152 { 153 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 154 } 155 156 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 157 { 158 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 159 160 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 161 SLAB_CTOR_CONSTRUCTOR) { 162 rwlock_init(&ei->i_meta_lock); 163 #ifdef CONFIG_EXT2_FS_XATTR 164 init_rwsem(&ei->xattr_sem); 165 #endif 166 inode_init_once(&ei->vfs_inode); 167 } 168 } 169 170 static int init_inodecache(void) 171 { 172 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 173 sizeof(struct ext2_inode_info), 174 0, SLAB_RECLAIM_ACCOUNT, 175 init_once, NULL); 176 if (ext2_inode_cachep == NULL) 177 return -ENOMEM; 178 return 0; 179 } 180 181 static void destroy_inodecache(void) 182 { 183 if (kmem_cache_destroy(ext2_inode_cachep)) 184 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n"); 185 } 186 187 static void ext2_clear_inode(struct inode *inode) 188 { 189 #ifdef CONFIG_EXT2_FS_POSIX_ACL 190 struct ext2_inode_info *ei = EXT2_I(inode); 191 192 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 193 posix_acl_release(ei->i_acl); 194 ei->i_acl = EXT2_ACL_NOT_CACHED; 195 } 196 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 197 posix_acl_release(ei->i_default_acl); 198 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 199 } 200 #endif 201 if (!is_bad_inode(inode)) 202 ext2_discard_prealloc(inode); 203 } 204 205 206 #ifdef CONFIG_QUOTA 207 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 208 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 209 #endif 210 211 static struct super_operations ext2_sops = { 212 .alloc_inode = ext2_alloc_inode, 213 .destroy_inode = ext2_destroy_inode, 214 .read_inode = ext2_read_inode, 215 .write_inode = ext2_write_inode, 216 .delete_inode = ext2_delete_inode, 217 .put_super = ext2_put_super, 218 .write_super = ext2_write_super, 219 .statfs = ext2_statfs, 220 .remount_fs = ext2_remount, 221 .clear_inode = ext2_clear_inode, 222 #ifdef CONFIG_QUOTA 223 .quota_read = ext2_quota_read, 224 .quota_write = ext2_quota_write, 225 #endif 226 }; 227 228 /* Yes, most of these are left as NULL!! 229 * A NULL value implies the default, which works with ext2-like file 230 * systems, but can be improved upon. 231 * Currently only get_parent is required. 232 */ 233 struct dentry *ext2_get_parent(struct dentry *child); 234 static struct export_operations ext2_export_ops = { 235 .get_parent = ext2_get_parent, 236 }; 237 238 static unsigned long get_sb_block(void **data) 239 { 240 unsigned long sb_block; 241 char *options = (char *) *data; 242 243 if (!options || strncmp(options, "sb=", 3) != 0) 244 return 1; /* Default location */ 245 options += 3; 246 sb_block = simple_strtoul(options, &options, 0); 247 if (*options && *options != ',') { 248 printk("EXT2-fs: Invalid sb specification: %s\n", 249 (char *) *data); 250 return 1; 251 } 252 if (*options == ',') 253 options++; 254 *data = (void *) options; 255 return sb_block; 256 } 257 258 enum { 259 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 260 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro, 261 Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh, 262 Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, 263 Opt_ignore, Opt_err, 264 }; 265 266 static match_table_t tokens = { 267 {Opt_bsd_df, "bsddf"}, 268 {Opt_minix_df, "minixdf"}, 269 {Opt_grpid, "grpid"}, 270 {Opt_grpid, "bsdgroups"}, 271 {Opt_nogrpid, "nogrpid"}, 272 {Opt_nogrpid, "sysvgroups"}, 273 {Opt_resgid, "resgid=%u"}, 274 {Opt_resuid, "resuid=%u"}, 275 {Opt_sb, "sb=%u"}, 276 {Opt_err_cont, "errors=continue"}, 277 {Opt_err_panic, "errors=panic"}, 278 {Opt_err_ro, "errors=remount-ro"}, 279 {Opt_nouid32, "nouid32"}, 280 {Opt_nocheck, "check=none"}, 281 {Opt_nocheck, "nocheck"}, 282 {Opt_check, "check"}, 283 {Opt_debug, "debug"}, 284 {Opt_oldalloc, "oldalloc"}, 285 {Opt_orlov, "orlov"}, 286 {Opt_nobh, "nobh"}, 287 {Opt_user_xattr, "user_xattr"}, 288 {Opt_nouser_xattr, "nouser_xattr"}, 289 {Opt_acl, "acl"}, 290 {Opt_noacl, "noacl"}, 291 {Opt_ignore, "grpquota"}, 292 {Opt_ignore, "noquota"}, 293 {Opt_ignore, "quota"}, 294 {Opt_ignore, "usrquota"}, 295 {Opt_err, NULL} 296 }; 297 298 static int parse_options (char * options, 299 struct ext2_sb_info *sbi) 300 { 301 char * p; 302 substring_t args[MAX_OPT_ARGS]; 303 unsigned long kind = EXT2_MOUNT_ERRORS_CONT; 304 int option; 305 306 if (!options) 307 return 1; 308 309 while ((p = strsep (&options, ",")) != NULL) { 310 int token; 311 if (!*p) 312 continue; 313 314 token = match_token(p, tokens, args); 315 switch (token) { 316 case Opt_bsd_df: 317 clear_opt (sbi->s_mount_opt, MINIX_DF); 318 break; 319 case Opt_minix_df: 320 set_opt (sbi->s_mount_opt, MINIX_DF); 321 break; 322 case Opt_grpid: 323 set_opt (sbi->s_mount_opt, GRPID); 324 break; 325 case Opt_nogrpid: 326 clear_opt (sbi->s_mount_opt, GRPID); 327 break; 328 case Opt_resuid: 329 if (match_int(&args[0], &option)) 330 return 0; 331 sbi->s_resuid = option; 332 break; 333 case Opt_resgid: 334 if (match_int(&args[0], &option)) 335 return 0; 336 sbi->s_resgid = option; 337 break; 338 case Opt_sb: 339 /* handled by get_sb_block() instead of here */ 340 /* *sb_block = match_int(&args[0]); */ 341 break; 342 case Opt_err_panic: 343 kind = EXT2_MOUNT_ERRORS_PANIC; 344 break; 345 case Opt_err_ro: 346 kind = EXT2_MOUNT_ERRORS_RO; 347 break; 348 case Opt_err_cont: 349 kind = EXT2_MOUNT_ERRORS_CONT; 350 break; 351 case Opt_nouid32: 352 set_opt (sbi->s_mount_opt, NO_UID32); 353 break; 354 case Opt_check: 355 #ifdef CONFIG_EXT2_CHECK 356 set_opt (sbi->s_mount_opt, CHECK); 357 #else 358 printk("EXT2 Check option not supported\n"); 359 #endif 360 break; 361 case Opt_nocheck: 362 clear_opt (sbi->s_mount_opt, CHECK); 363 break; 364 case Opt_debug: 365 set_opt (sbi->s_mount_opt, DEBUG); 366 break; 367 case Opt_oldalloc: 368 set_opt (sbi->s_mount_opt, OLDALLOC); 369 break; 370 case Opt_orlov: 371 clear_opt (sbi->s_mount_opt, OLDALLOC); 372 break; 373 case Opt_nobh: 374 set_opt (sbi->s_mount_opt, NOBH); 375 break; 376 #ifdef CONFIG_EXT2_FS_XATTR 377 case Opt_user_xattr: 378 set_opt (sbi->s_mount_opt, XATTR_USER); 379 break; 380 case Opt_nouser_xattr: 381 clear_opt (sbi->s_mount_opt, XATTR_USER); 382 break; 383 #else 384 case Opt_user_xattr: 385 case Opt_nouser_xattr: 386 printk("EXT2 (no)user_xattr options not supported\n"); 387 break; 388 #endif 389 #ifdef CONFIG_EXT2_FS_POSIX_ACL 390 case Opt_acl: 391 set_opt(sbi->s_mount_opt, POSIX_ACL); 392 break; 393 case Opt_noacl: 394 clear_opt(sbi->s_mount_opt, POSIX_ACL); 395 break; 396 #else 397 case Opt_acl: 398 case Opt_noacl: 399 printk("EXT2 (no)acl options not supported\n"); 400 break; 401 #endif 402 case Opt_ignore: 403 break; 404 default: 405 return 0; 406 } 407 } 408 sbi->s_mount_opt |= kind; 409 return 1; 410 } 411 412 static int ext2_setup_super (struct super_block * sb, 413 struct ext2_super_block * es, 414 int read_only) 415 { 416 int res = 0; 417 struct ext2_sb_info *sbi = EXT2_SB(sb); 418 419 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 420 printk ("EXT2-fs warning: revision level too high, " 421 "forcing read-only mode\n"); 422 res = MS_RDONLY; 423 } 424 if (read_only) 425 return res; 426 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 427 printk ("EXT2-fs warning: mounting unchecked fs, " 428 "running e2fsck is recommended\n"); 429 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 430 printk ("EXT2-fs warning: mounting fs with errors, " 431 "running e2fsck is recommended\n"); 432 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 433 le16_to_cpu(es->s_mnt_count) >= 434 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 435 printk ("EXT2-fs warning: maximal mount count reached, " 436 "running e2fsck is recommended\n"); 437 else if (le32_to_cpu(es->s_checkinterval) && 438 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 439 printk ("EXT2-fs warning: checktime reached, " 440 "running e2fsck is recommended\n"); 441 if (!le16_to_cpu(es->s_max_mnt_count)) 442 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 443 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 444 ext2_write_super(sb); 445 if (test_opt (sb, DEBUG)) 446 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 447 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 448 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 449 sbi->s_frag_size, 450 sbi->s_groups_count, 451 EXT2_BLOCKS_PER_GROUP(sb), 452 EXT2_INODES_PER_GROUP(sb), 453 sbi->s_mount_opt); 454 #ifdef CONFIG_EXT2_CHECK 455 if (test_opt (sb, CHECK)) { 456 ext2_check_blocks_bitmap (sb); 457 ext2_check_inodes_bitmap (sb); 458 } 459 #endif 460 return res; 461 } 462 463 static int ext2_check_descriptors (struct super_block * sb) 464 { 465 int i; 466 int desc_block = 0; 467 struct ext2_sb_info *sbi = EXT2_SB(sb); 468 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block); 469 struct ext2_group_desc * gdp = NULL; 470 471 ext2_debug ("Checking group descriptors"); 472 473 for (i = 0; i < sbi->s_groups_count; i++) 474 { 475 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) 476 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; 477 if (le32_to_cpu(gdp->bg_block_bitmap) < block || 478 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 479 { 480 ext2_error (sb, "ext2_check_descriptors", 481 "Block bitmap for group %d" 482 " not in group (block %lu)!", 483 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 484 return 0; 485 } 486 if (le32_to_cpu(gdp->bg_inode_bitmap) < block || 487 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 488 { 489 ext2_error (sb, "ext2_check_descriptors", 490 "Inode bitmap for group %d" 491 " not in group (block %lu)!", 492 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 493 return 0; 494 } 495 if (le32_to_cpu(gdp->bg_inode_table) < block || 496 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >= 497 block + EXT2_BLOCKS_PER_GROUP(sb)) 498 { 499 ext2_error (sb, "ext2_check_descriptors", 500 "Inode table for group %d" 501 " not in group (block %lu)!", 502 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 503 return 0; 504 } 505 block += EXT2_BLOCKS_PER_GROUP(sb); 506 gdp++; 507 } 508 return 1; 509 } 510 511 #define log2(n) ffz(~(n)) 512 513 /* 514 * Maximal file size. There is a direct, and {,double-,triple-}indirect 515 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 516 * We need to be 1 filesystem block less than the 2^32 sector limit. 517 */ 518 static loff_t ext2_max_size(int bits) 519 { 520 loff_t res = EXT2_NDIR_BLOCKS; 521 /* This constant is calculated to be the largest file size for a 522 * dense, 4k-blocksize file such that the total number of 523 * sectors in the file, including data and all indirect blocks, 524 * does not exceed 2^32. */ 525 const loff_t upper_limit = 0x1ff7fffd000LL; 526 527 res += 1LL << (bits-2); 528 res += 1LL << (2*(bits-2)); 529 res += 1LL << (3*(bits-2)); 530 res <<= bits; 531 if (res > upper_limit) 532 res = upper_limit; 533 return res; 534 } 535 536 static unsigned long descriptor_loc(struct super_block *sb, 537 unsigned long logic_sb_block, 538 int nr) 539 { 540 struct ext2_sb_info *sbi = EXT2_SB(sb); 541 unsigned long bg, first_data_block, first_meta_bg; 542 int has_super = 0; 543 544 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 545 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 546 547 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 548 nr < first_meta_bg) 549 return (logic_sb_block + nr + 1); 550 bg = sbi->s_desc_per_block * nr; 551 if (ext2_bg_has_super(sb, bg)) 552 has_super = 1; 553 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 554 } 555 556 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 557 { 558 struct buffer_head * bh; 559 struct ext2_sb_info * sbi; 560 struct ext2_super_block * es; 561 struct inode *root; 562 unsigned long block; 563 unsigned long sb_block = get_sb_block(&data); 564 unsigned long logic_sb_block; 565 unsigned long offset = 0; 566 unsigned long def_mount_opts; 567 int blocksize = BLOCK_SIZE; 568 int db_count; 569 int i, j; 570 __le32 features; 571 572 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL); 573 if (!sbi) 574 return -ENOMEM; 575 sb->s_fs_info = sbi; 576 memset(sbi, 0, sizeof(*sbi)); 577 578 /* 579 * See what the current blocksize for the device is, and 580 * use that as the blocksize. Otherwise (or if the blocksize 581 * is smaller than the default) use the default. 582 * This is important for devices that have a hardware 583 * sectorsize that is larger than the default. 584 */ 585 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 586 if (!blocksize) { 587 printk ("EXT2-fs: unable to set blocksize\n"); 588 goto failed_sbi; 589 } 590 591 /* 592 * If the superblock doesn't start on a hardware sector boundary, 593 * calculate the offset. 594 */ 595 if (blocksize != BLOCK_SIZE) { 596 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 597 offset = (sb_block*BLOCK_SIZE) % blocksize; 598 } else { 599 logic_sb_block = sb_block; 600 } 601 602 if (!(bh = sb_bread(sb, logic_sb_block))) { 603 printk ("EXT2-fs: unable to read superblock\n"); 604 goto failed_sbi; 605 } 606 /* 607 * Note: s_es must be initialized as soon as possible because 608 * some ext2 macro-instructions depend on its value 609 */ 610 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 611 sbi->s_es = es; 612 sb->s_magic = le16_to_cpu(es->s_magic); 613 614 if (sb->s_magic != EXT2_SUPER_MAGIC) 615 goto cantfind_ext2; 616 617 /* Set defaults before we parse the mount options */ 618 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 619 if (def_mount_opts & EXT2_DEFM_DEBUG) 620 set_opt(sbi->s_mount_opt, DEBUG); 621 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 622 set_opt(sbi->s_mount_opt, GRPID); 623 if (def_mount_opts & EXT2_DEFM_UID16) 624 set_opt(sbi->s_mount_opt, NO_UID32); 625 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 626 set_opt(sbi->s_mount_opt, XATTR_USER); 627 if (def_mount_opts & EXT2_DEFM_ACL) 628 set_opt(sbi->s_mount_opt, POSIX_ACL); 629 630 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 631 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 632 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) 633 set_opt(sbi->s_mount_opt, ERRORS_RO); 634 635 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 636 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 637 638 if (!parse_options ((char *) data, sbi)) 639 goto failed_mount; 640 641 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 642 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 643 MS_POSIXACL : 0); 644 645 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 646 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 647 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 648 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 649 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 650 "running e2fsck is recommended\n"); 651 /* 652 * Check feature flags regardless of the revision level, since we 653 * previously didn't change the revision level when setting the flags, 654 * so there is a chance incompat flags are set on a rev 0 filesystem. 655 */ 656 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 657 if (features) { 658 printk("EXT2-fs: %s: couldn't mount because of " 659 "unsupported optional features (%x).\n", 660 sb->s_id, le32_to_cpu(features)); 661 goto failed_mount; 662 } 663 if (!(sb->s_flags & MS_RDONLY) && 664 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 665 printk("EXT2-fs: %s: couldn't mount RDWR because of " 666 "unsupported optional features (%x).\n", 667 sb->s_id, le32_to_cpu(features)); 668 goto failed_mount; 669 } 670 671 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 672 673 /* If the blocksize doesn't match, re-read the thing.. */ 674 if (sb->s_blocksize != blocksize) { 675 brelse(bh); 676 677 if (!sb_set_blocksize(sb, blocksize)) { 678 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 679 goto failed_sbi; 680 } 681 682 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 683 offset = (sb_block*BLOCK_SIZE) % blocksize; 684 bh = sb_bread(sb, logic_sb_block); 685 if(!bh) { 686 printk("EXT2-fs: Couldn't read superblock on " 687 "2nd try.\n"); 688 goto failed_sbi; 689 } 690 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 691 sbi->s_es = es; 692 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 693 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 694 goto failed_mount; 695 } 696 } 697 698 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 699 700 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 701 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 702 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 703 } else { 704 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 705 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 706 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 707 (sbi->s_inode_size & (sbi->s_inode_size - 1)) || 708 (sbi->s_inode_size > blocksize)) { 709 printk ("EXT2-fs: unsupported inode size: %d\n", 710 sbi->s_inode_size); 711 goto failed_mount; 712 } 713 } 714 715 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 716 le32_to_cpu(es->s_log_frag_size); 717 if (sbi->s_frag_size == 0) 718 goto cantfind_ext2; 719 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 720 721 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 722 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 723 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 724 725 if (EXT2_INODE_SIZE(sb) == 0) 726 goto cantfind_ext2; 727 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 728 if (sbi->s_inodes_per_block == 0) 729 goto cantfind_ext2; 730 sbi->s_itb_per_group = sbi->s_inodes_per_group / 731 sbi->s_inodes_per_block; 732 sbi->s_desc_per_block = sb->s_blocksize / 733 sizeof (struct ext2_group_desc); 734 sbi->s_sbh = bh; 735 sbi->s_mount_state = le16_to_cpu(es->s_state); 736 sbi->s_addr_per_block_bits = 737 log2 (EXT2_ADDR_PER_BLOCK(sb)); 738 sbi->s_desc_per_block_bits = 739 log2 (EXT2_DESC_PER_BLOCK(sb)); 740 741 if (sb->s_magic != EXT2_SUPER_MAGIC) 742 goto cantfind_ext2; 743 744 if (sb->s_blocksize != bh->b_size) { 745 if (!silent) 746 printk ("VFS: Unsupported blocksize on dev " 747 "%s.\n", sb->s_id); 748 goto failed_mount; 749 } 750 751 if (sb->s_blocksize != sbi->s_frag_size) { 752 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 753 sbi->s_frag_size, sb->s_blocksize); 754 goto failed_mount; 755 } 756 757 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 758 printk ("EXT2-fs: #blocks per group too big: %lu\n", 759 sbi->s_blocks_per_group); 760 goto failed_mount; 761 } 762 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 763 printk ("EXT2-fs: #fragments per group too big: %lu\n", 764 sbi->s_frags_per_group); 765 goto failed_mount; 766 } 767 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 768 printk ("EXT2-fs: #inodes per group too big: %lu\n", 769 sbi->s_inodes_per_group); 770 goto failed_mount; 771 } 772 773 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 774 goto cantfind_ext2; 775 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - 776 le32_to_cpu(es->s_first_data_block) + 777 EXT2_BLOCKS_PER_GROUP(sb) - 1) / 778 EXT2_BLOCKS_PER_GROUP(sb); 779 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 780 EXT2_DESC_PER_BLOCK(sb); 781 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 782 if (sbi->s_group_desc == NULL) { 783 printk ("EXT2-fs: not enough memory\n"); 784 goto failed_mount; 785 } 786 percpu_counter_init(&sbi->s_freeblocks_counter); 787 percpu_counter_init(&sbi->s_freeinodes_counter); 788 percpu_counter_init(&sbi->s_dirs_counter); 789 bgl_lock_init(&sbi->s_blockgroup_lock); 790 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts), 791 GFP_KERNEL); 792 if (!sbi->s_debts) { 793 printk ("EXT2-fs: not enough memory\n"); 794 goto failed_mount_group_desc; 795 } 796 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts)); 797 for (i = 0; i < db_count; i++) { 798 block = descriptor_loc(sb, logic_sb_block, i); 799 sbi->s_group_desc[i] = sb_bread(sb, block); 800 if (!sbi->s_group_desc[i]) { 801 for (j = 0; j < i; j++) 802 brelse (sbi->s_group_desc[j]); 803 printk ("EXT2-fs: unable to read group descriptors\n"); 804 goto failed_mount_group_desc; 805 } 806 } 807 if (!ext2_check_descriptors (sb)) { 808 printk ("EXT2-fs: group descriptors corrupted!\n"); 809 db_count = i; 810 goto failed_mount2; 811 } 812 sbi->s_gdb_count = db_count; 813 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 814 spin_lock_init(&sbi->s_next_gen_lock); 815 /* 816 * set up enough so that it can read an inode 817 */ 818 sb->s_op = &ext2_sops; 819 sb->s_export_op = &ext2_export_ops; 820 sb->s_xattr = ext2_xattr_handlers; 821 root = iget(sb, EXT2_ROOT_INO); 822 sb->s_root = d_alloc_root(root); 823 if (!sb->s_root) { 824 iput(root); 825 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 826 goto failed_mount2; 827 } 828 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 829 dput(sb->s_root); 830 sb->s_root = NULL; 831 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 832 goto failed_mount2; 833 } 834 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 835 ext2_warning(sb, __FUNCTION__, 836 "mounting ext3 filesystem as ext2\n"); 837 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 838 percpu_counter_mod(&sbi->s_freeblocks_counter, 839 ext2_count_free_blocks(sb)); 840 percpu_counter_mod(&sbi->s_freeinodes_counter, 841 ext2_count_free_inodes(sb)); 842 percpu_counter_mod(&sbi->s_dirs_counter, 843 ext2_count_dirs(sb)); 844 return 0; 845 846 cantfind_ext2: 847 if (!silent) 848 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 849 sb->s_id); 850 goto failed_mount; 851 852 failed_mount2: 853 for (i = 0; i < db_count; i++) 854 brelse(sbi->s_group_desc[i]); 855 failed_mount_group_desc: 856 kfree(sbi->s_group_desc); 857 kfree(sbi->s_debts); 858 failed_mount: 859 brelse(bh); 860 failed_sbi: 861 sb->s_fs_info = NULL; 862 kfree(sbi); 863 return -EINVAL; 864 } 865 866 static void ext2_commit_super (struct super_block * sb, 867 struct ext2_super_block * es) 868 { 869 es->s_wtime = cpu_to_le32(get_seconds()); 870 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 871 sb->s_dirt = 0; 872 } 873 874 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 875 { 876 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 877 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 878 es->s_wtime = cpu_to_le32(get_seconds()); 879 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 880 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 881 sb->s_dirt = 0; 882 } 883 884 /* 885 * In the second extended file system, it is not necessary to 886 * write the super block since we use a mapping of the 887 * disk super block in a buffer. 888 * 889 * However, this function is still used to set the fs valid 890 * flags to 0. We need to set this flag to 0 since the fs 891 * may have been checked while mounted and e2fsck may have 892 * set s_state to EXT2_VALID_FS after some corrections. 893 */ 894 895 void ext2_write_super (struct super_block * sb) 896 { 897 struct ext2_super_block * es; 898 lock_kernel(); 899 if (!(sb->s_flags & MS_RDONLY)) { 900 es = EXT2_SB(sb)->s_es; 901 902 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 903 ext2_debug ("setting valid to 0\n"); 904 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 905 ~EXT2_VALID_FS); 906 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 907 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 908 es->s_mtime = cpu_to_le32(get_seconds()); 909 ext2_sync_super(sb, es); 910 } else 911 ext2_commit_super (sb, es); 912 } 913 sb->s_dirt = 0; 914 unlock_kernel(); 915 } 916 917 static int ext2_remount (struct super_block * sb, int * flags, char * data) 918 { 919 struct ext2_sb_info * sbi = EXT2_SB(sb); 920 struct ext2_super_block * es; 921 922 /* 923 * Allow the "check" option to be passed as a remount option. 924 */ 925 if (!parse_options (data, sbi)) 926 return -EINVAL; 927 928 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 929 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 930 931 es = sbi->s_es; 932 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 933 return 0; 934 if (*flags & MS_RDONLY) { 935 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 936 !(sbi->s_mount_state & EXT2_VALID_FS)) 937 return 0; 938 /* 939 * OK, we are remounting a valid rw partition rdonly, so set 940 * the rdonly flag and then mark the partition as valid again. 941 */ 942 es->s_state = cpu_to_le16(sbi->s_mount_state); 943 es->s_mtime = cpu_to_le32(get_seconds()); 944 } else { 945 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 946 ~EXT2_FEATURE_RO_COMPAT_SUPP); 947 if (ret) { 948 printk("EXT2-fs: %s: couldn't remount RDWR because of " 949 "unsupported optional features (%x).\n", 950 sb->s_id, le32_to_cpu(ret)); 951 return -EROFS; 952 } 953 /* 954 * Mounting a RDONLY partition read-write, so reread and 955 * store the current valid flag. (It may have been changed 956 * by e2fsck since we originally mounted the partition.) 957 */ 958 sbi->s_mount_state = le16_to_cpu(es->s_state); 959 if (!ext2_setup_super (sb, es, 0)) 960 sb->s_flags &= ~MS_RDONLY; 961 } 962 ext2_sync_super(sb, es); 963 return 0; 964 } 965 966 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf) 967 { 968 struct ext2_sb_info *sbi = EXT2_SB(sb); 969 unsigned long overhead; 970 int i; 971 972 if (test_opt (sb, MINIX_DF)) 973 overhead = 0; 974 else { 975 /* 976 * Compute the overhead (FS structures) 977 */ 978 979 /* 980 * All of the blocks before first_data_block are 981 * overhead 982 */ 983 overhead = le32_to_cpu(sbi->s_es->s_first_data_block); 984 985 /* 986 * Add the overhead attributed to the superblock and 987 * block group descriptors. If the sparse superblocks 988 * feature is turned on, then not all groups have this. 989 */ 990 for (i = 0; i < sbi->s_groups_count; i++) 991 overhead += ext2_bg_has_super(sb, i) + 992 ext2_bg_num_gdb(sb, i); 993 994 /* 995 * Every block group has an inode bitmap, a block 996 * bitmap, and an inode table. 997 */ 998 overhead += (sbi->s_groups_count * 999 (2 + sbi->s_itb_per_group)); 1000 } 1001 1002 buf->f_type = EXT2_SUPER_MAGIC; 1003 buf->f_bsize = sb->s_blocksize; 1004 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead; 1005 buf->f_bfree = ext2_count_free_blocks(sb); 1006 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count); 1007 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count)) 1008 buf->f_bavail = 0; 1009 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count); 1010 buf->f_ffree = ext2_count_free_inodes (sb); 1011 buf->f_namelen = EXT2_NAME_LEN; 1012 return 0; 1013 } 1014 1015 static struct super_block *ext2_get_sb(struct file_system_type *fs_type, 1016 int flags, const char *dev_name, void *data) 1017 { 1018 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super); 1019 } 1020 1021 #ifdef CONFIG_QUOTA 1022 1023 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1024 * acquiring the locks... As quota files are never truncated and quota code 1025 * itself serializes the operations (and noone else should touch the files) 1026 * we don't have to be afraid of races */ 1027 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1028 size_t len, loff_t off) 1029 { 1030 struct inode *inode = sb_dqopt(sb)->files[type]; 1031 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1032 int err = 0; 1033 int offset = off & (sb->s_blocksize - 1); 1034 int tocopy; 1035 size_t toread; 1036 struct buffer_head tmp_bh; 1037 struct buffer_head *bh; 1038 loff_t i_size = i_size_read(inode); 1039 1040 if (off > i_size) 1041 return 0; 1042 if (off+len > i_size) 1043 len = i_size-off; 1044 toread = len; 1045 while (toread > 0) { 1046 tocopy = sb->s_blocksize - offset < toread ? 1047 sb->s_blocksize - offset : toread; 1048 1049 tmp_bh.b_state = 0; 1050 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1051 if (err) 1052 return err; 1053 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1054 memset(data, 0, tocopy); 1055 else { 1056 bh = sb_bread(sb, tmp_bh.b_blocknr); 1057 if (!bh) 1058 return -EIO; 1059 memcpy(data, bh->b_data+offset, tocopy); 1060 brelse(bh); 1061 } 1062 offset = 0; 1063 toread -= tocopy; 1064 data += tocopy; 1065 blk++; 1066 } 1067 return len; 1068 } 1069 1070 /* Write to quotafile */ 1071 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1072 const char *data, size_t len, loff_t off) 1073 { 1074 struct inode *inode = sb_dqopt(sb)->files[type]; 1075 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1076 int err = 0; 1077 int offset = off & (sb->s_blocksize - 1); 1078 int tocopy; 1079 size_t towrite = len; 1080 struct buffer_head tmp_bh; 1081 struct buffer_head *bh; 1082 1083 down(&inode->i_sem); 1084 while (towrite > 0) { 1085 tocopy = sb->s_blocksize - offset < towrite ? 1086 sb->s_blocksize - offset : towrite; 1087 1088 tmp_bh.b_state = 0; 1089 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1090 if (err) 1091 goto out; 1092 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1093 bh = sb_bread(sb, tmp_bh.b_blocknr); 1094 else 1095 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1096 if (!bh) { 1097 err = -EIO; 1098 goto out; 1099 } 1100 lock_buffer(bh); 1101 memcpy(bh->b_data+offset, data, tocopy); 1102 flush_dcache_page(bh->b_page); 1103 set_buffer_uptodate(bh); 1104 mark_buffer_dirty(bh); 1105 unlock_buffer(bh); 1106 brelse(bh); 1107 offset = 0; 1108 towrite -= tocopy; 1109 data += tocopy; 1110 blk++; 1111 } 1112 out: 1113 if (len == towrite) 1114 return err; 1115 if (inode->i_size < off+len-towrite) 1116 i_size_write(inode, off+len-towrite); 1117 inode->i_version++; 1118 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1119 mark_inode_dirty(inode); 1120 up(&inode->i_sem); 1121 return len - towrite; 1122 } 1123 1124 #endif 1125 1126 static struct file_system_type ext2_fs_type = { 1127 .owner = THIS_MODULE, 1128 .name = "ext2", 1129 .get_sb = ext2_get_sb, 1130 .kill_sb = kill_block_super, 1131 .fs_flags = FS_REQUIRES_DEV, 1132 }; 1133 1134 static int __init init_ext2_fs(void) 1135 { 1136 int err = init_ext2_xattr(); 1137 if (err) 1138 return err; 1139 err = init_inodecache(); 1140 if (err) 1141 goto out1; 1142 err = register_filesystem(&ext2_fs_type); 1143 if (err) 1144 goto out; 1145 return 0; 1146 out: 1147 destroy_inodecache(); 1148 out1: 1149 exit_ext2_xattr(); 1150 return err; 1151 } 1152 1153 static void __exit exit_ext2_fs(void) 1154 { 1155 unregister_filesystem(&ext2_fs_type); 1156 destroy_inodecache(); 1157 exit_ext2_xattr(); 1158 } 1159 1160 module_init(init_ext2_fs) 1161 module_exit(exit_ext2_fs) 1162