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/fs.h> 23 #include <linux/slab.h> 24 #include <linux/init.h> 25 #include <linux/blkdev.h> 26 #include <linux/parser.h> 27 #include <linux/random.h> 28 #include <linux/buffer_head.h> 29 #include <linux/smp_lock.h> 30 #include <linux/vfs.h> 31 #include <linux/seq_file.h> 32 #include <linux/mount.h> 33 #include <asm/uaccess.h> 34 #include "ext2.h" 35 #include "xattr.h" 36 #include "acl.h" 37 #include "xip.h" 38 39 static void ext2_sync_super(struct super_block *sb, 40 struct ext2_super_block *es); 41 static int ext2_remount (struct super_block * sb, int * flags, char * data); 42 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf); 43 44 void ext2_error (struct super_block * sb, const char * function, 45 const char * fmt, ...) 46 { 47 va_list args; 48 struct ext2_sb_info *sbi = EXT2_SB(sb); 49 struct ext2_super_block *es = sbi->s_es; 50 51 if (!(sb->s_flags & MS_RDONLY)) { 52 sbi->s_mount_state |= EXT2_ERROR_FS; 53 es->s_state = 54 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS); 55 ext2_sync_super(sb, es); 56 } 57 58 va_start(args, fmt); 59 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 60 vprintk(fmt, args); 61 printk("\n"); 62 va_end(args); 63 64 if (test_opt(sb, ERRORS_PANIC)) 65 panic("EXT2-fs panic from previous error\n"); 66 if (test_opt(sb, ERRORS_RO)) { 67 printk("Remounting filesystem read-only\n"); 68 sb->s_flags |= MS_RDONLY; 69 } 70 } 71 72 void ext2_warning (struct super_block * sb, const char * function, 73 const char * fmt, ...) 74 { 75 va_list args; 76 77 va_start(args, fmt); 78 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 79 sb->s_id, function); 80 vprintk(fmt, args); 81 printk("\n"); 82 va_end(args); 83 } 84 85 void ext2_update_dynamic_rev(struct super_block *sb) 86 { 87 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 88 89 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 90 return; 91 92 ext2_warning(sb, __FUNCTION__, 93 "updating to rev %d because of new feature flag, " 94 "running e2fsck is recommended", 95 EXT2_DYNAMIC_REV); 96 97 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 98 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 99 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 100 /* leave es->s_feature_*compat flags alone */ 101 /* es->s_uuid will be set by e2fsck if empty */ 102 103 /* 104 * The rest of the superblock fields should be zero, and if not it 105 * means they are likely already in use, so leave them alone. We 106 * can leave it up to e2fsck to clean up any inconsistencies there. 107 */ 108 } 109 110 static void ext2_put_super (struct super_block * sb) 111 { 112 int db_count; 113 int i; 114 struct ext2_sb_info *sbi = EXT2_SB(sb); 115 116 ext2_xattr_put_super(sb); 117 if (!(sb->s_flags & MS_RDONLY)) { 118 struct ext2_super_block *es = sbi->s_es; 119 120 es->s_state = cpu_to_le16(sbi->s_mount_state); 121 ext2_sync_super(sb, es); 122 } 123 db_count = sbi->s_gdb_count; 124 for (i = 0; i < db_count; i++) 125 if (sbi->s_group_desc[i]) 126 brelse (sbi->s_group_desc[i]); 127 kfree(sbi->s_group_desc); 128 kfree(sbi->s_debts); 129 percpu_counter_destroy(&sbi->s_freeblocks_counter); 130 percpu_counter_destroy(&sbi->s_freeinodes_counter); 131 percpu_counter_destroy(&sbi->s_dirs_counter); 132 brelse (sbi->s_sbh); 133 sb->s_fs_info = NULL; 134 kfree(sbi); 135 136 return; 137 } 138 139 static kmem_cache_t * ext2_inode_cachep; 140 141 static struct inode *ext2_alloc_inode(struct super_block *sb) 142 { 143 struct ext2_inode_info *ei; 144 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL); 145 if (!ei) 146 return NULL; 147 #ifdef CONFIG_EXT2_FS_POSIX_ACL 148 ei->i_acl = EXT2_ACL_NOT_CACHED; 149 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 150 #endif 151 ei->vfs_inode.i_version = 1; 152 return &ei->vfs_inode; 153 } 154 155 static void ext2_destroy_inode(struct inode *inode) 156 { 157 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 158 } 159 160 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 161 { 162 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 163 164 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 165 SLAB_CTOR_CONSTRUCTOR) { 166 rwlock_init(&ei->i_meta_lock); 167 #ifdef CONFIG_EXT2_FS_XATTR 168 init_rwsem(&ei->xattr_sem); 169 #endif 170 inode_init_once(&ei->vfs_inode); 171 } 172 } 173 174 static int init_inodecache(void) 175 { 176 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 177 sizeof(struct ext2_inode_info), 178 0, SLAB_RECLAIM_ACCOUNT, 179 init_once, NULL); 180 if (ext2_inode_cachep == NULL) 181 return -ENOMEM; 182 return 0; 183 } 184 185 static void destroy_inodecache(void) 186 { 187 if (kmem_cache_destroy(ext2_inode_cachep)) 188 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n"); 189 } 190 191 static void ext2_clear_inode(struct inode *inode) 192 { 193 #ifdef CONFIG_EXT2_FS_POSIX_ACL 194 struct ext2_inode_info *ei = EXT2_I(inode); 195 196 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 197 posix_acl_release(ei->i_acl); 198 ei->i_acl = EXT2_ACL_NOT_CACHED; 199 } 200 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 201 posix_acl_release(ei->i_default_acl); 202 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 203 } 204 #endif 205 } 206 207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 208 { 209 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb); 210 211 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID) 212 seq_puts(seq, ",grpid"); 213 else 214 seq_puts(seq, ",nogrpid"); 215 216 #if defined(CONFIG_QUOTA) 217 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 218 seq_puts(seq, ",usrquota"); 219 220 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 221 seq_puts(seq, ",grpquota"); 222 #endif 223 224 return 0; 225 } 226 227 #ifdef CONFIG_QUOTA 228 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 229 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 230 #endif 231 232 static struct super_operations ext2_sops = { 233 .alloc_inode = ext2_alloc_inode, 234 .destroy_inode = ext2_destroy_inode, 235 .read_inode = ext2_read_inode, 236 .write_inode = ext2_write_inode, 237 .put_inode = ext2_put_inode, 238 .delete_inode = ext2_delete_inode, 239 .put_super = ext2_put_super, 240 .write_super = ext2_write_super, 241 .statfs = ext2_statfs, 242 .remount_fs = ext2_remount, 243 .clear_inode = ext2_clear_inode, 244 .show_options = ext2_show_options, 245 #ifdef CONFIG_QUOTA 246 .quota_read = ext2_quota_read, 247 .quota_write = ext2_quota_write, 248 #endif 249 }; 250 251 /* Yes, most of these are left as NULL!! 252 * A NULL value implies the default, which works with ext2-like file 253 * systems, but can be improved upon. 254 * Currently only get_parent is required. 255 */ 256 struct dentry *ext2_get_parent(struct dentry *child); 257 static struct export_operations ext2_export_ops = { 258 .get_parent = ext2_get_parent, 259 }; 260 261 static unsigned long get_sb_block(void **data) 262 { 263 unsigned long sb_block; 264 char *options = (char *) *data; 265 266 if (!options || strncmp(options, "sb=", 3) != 0) 267 return 1; /* Default location */ 268 options += 3; 269 sb_block = simple_strtoul(options, &options, 0); 270 if (*options && *options != ',') { 271 printk("EXT2-fs: Invalid sb specification: %s\n", 272 (char *) *data); 273 return 1; 274 } 275 if (*options == ',') 276 options++; 277 *data = (void *) options; 278 return sb_block; 279 } 280 281 enum { 282 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 283 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 284 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 285 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 286 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 287 Opt_usrquota, Opt_grpquota 288 }; 289 290 static match_table_t tokens = { 291 {Opt_bsd_df, "bsddf"}, 292 {Opt_minix_df, "minixdf"}, 293 {Opt_grpid, "grpid"}, 294 {Opt_grpid, "bsdgroups"}, 295 {Opt_nogrpid, "nogrpid"}, 296 {Opt_nogrpid, "sysvgroups"}, 297 {Opt_resgid, "resgid=%u"}, 298 {Opt_resuid, "resuid=%u"}, 299 {Opt_sb, "sb=%u"}, 300 {Opt_err_cont, "errors=continue"}, 301 {Opt_err_panic, "errors=panic"}, 302 {Opt_err_ro, "errors=remount-ro"}, 303 {Opt_nouid32, "nouid32"}, 304 {Opt_nocheck, "check=none"}, 305 {Opt_nocheck, "nocheck"}, 306 {Opt_debug, "debug"}, 307 {Opt_oldalloc, "oldalloc"}, 308 {Opt_orlov, "orlov"}, 309 {Opt_nobh, "nobh"}, 310 {Opt_user_xattr, "user_xattr"}, 311 {Opt_nouser_xattr, "nouser_xattr"}, 312 {Opt_acl, "acl"}, 313 {Opt_noacl, "noacl"}, 314 {Opt_xip, "xip"}, 315 {Opt_grpquota, "grpquota"}, 316 {Opt_ignore, "noquota"}, 317 {Opt_quota, "quota"}, 318 {Opt_usrquota, "usrquota"}, 319 {Opt_err, NULL} 320 }; 321 322 static int parse_options (char * options, 323 struct ext2_sb_info *sbi) 324 { 325 char * p; 326 substring_t args[MAX_OPT_ARGS]; 327 unsigned long kind = EXT2_MOUNT_ERRORS_CONT; 328 int option; 329 330 if (!options) 331 return 1; 332 333 while ((p = strsep (&options, ",")) != NULL) { 334 int token; 335 if (!*p) 336 continue; 337 338 token = match_token(p, tokens, args); 339 switch (token) { 340 case Opt_bsd_df: 341 clear_opt (sbi->s_mount_opt, MINIX_DF); 342 break; 343 case Opt_minix_df: 344 set_opt (sbi->s_mount_opt, MINIX_DF); 345 break; 346 case Opt_grpid: 347 set_opt (sbi->s_mount_opt, GRPID); 348 break; 349 case Opt_nogrpid: 350 clear_opt (sbi->s_mount_opt, GRPID); 351 break; 352 case Opt_resuid: 353 if (match_int(&args[0], &option)) 354 return 0; 355 sbi->s_resuid = option; 356 break; 357 case Opt_resgid: 358 if (match_int(&args[0], &option)) 359 return 0; 360 sbi->s_resgid = option; 361 break; 362 case Opt_sb: 363 /* handled by get_sb_block() instead of here */ 364 /* *sb_block = match_int(&args[0]); */ 365 break; 366 case Opt_err_panic: 367 kind = EXT2_MOUNT_ERRORS_PANIC; 368 break; 369 case Opt_err_ro: 370 kind = EXT2_MOUNT_ERRORS_RO; 371 break; 372 case Opt_err_cont: 373 kind = EXT2_MOUNT_ERRORS_CONT; 374 break; 375 case Opt_nouid32: 376 set_opt (sbi->s_mount_opt, NO_UID32); 377 break; 378 case Opt_nocheck: 379 clear_opt (sbi->s_mount_opt, CHECK); 380 break; 381 case Opt_debug: 382 set_opt (sbi->s_mount_opt, DEBUG); 383 break; 384 case Opt_oldalloc: 385 set_opt (sbi->s_mount_opt, OLDALLOC); 386 break; 387 case Opt_orlov: 388 clear_opt (sbi->s_mount_opt, OLDALLOC); 389 break; 390 case Opt_nobh: 391 set_opt (sbi->s_mount_opt, NOBH); 392 break; 393 #ifdef CONFIG_EXT2_FS_XATTR 394 case Opt_user_xattr: 395 set_opt (sbi->s_mount_opt, XATTR_USER); 396 break; 397 case Opt_nouser_xattr: 398 clear_opt (sbi->s_mount_opt, XATTR_USER); 399 break; 400 #else 401 case Opt_user_xattr: 402 case Opt_nouser_xattr: 403 printk("EXT2 (no)user_xattr options not supported\n"); 404 break; 405 #endif 406 #ifdef CONFIG_EXT2_FS_POSIX_ACL 407 case Opt_acl: 408 set_opt(sbi->s_mount_opt, POSIX_ACL); 409 break; 410 case Opt_noacl: 411 clear_opt(sbi->s_mount_opt, POSIX_ACL); 412 break; 413 #else 414 case Opt_acl: 415 case Opt_noacl: 416 printk("EXT2 (no)acl options not supported\n"); 417 break; 418 #endif 419 case Opt_xip: 420 #ifdef CONFIG_EXT2_FS_XIP 421 set_opt (sbi->s_mount_opt, XIP); 422 #else 423 printk("EXT2 xip option not supported\n"); 424 #endif 425 break; 426 427 #if defined(CONFIG_QUOTA) 428 case Opt_quota: 429 case Opt_usrquota: 430 set_opt(sbi->s_mount_opt, USRQUOTA); 431 break; 432 433 case Opt_grpquota: 434 set_opt(sbi->s_mount_opt, GRPQUOTA); 435 break; 436 #else 437 case Opt_quota: 438 case Opt_usrquota: 439 case Opt_grpquota: 440 printk(KERN_ERR 441 "EXT2-fs: quota operations not supported.\n"); 442 443 break; 444 #endif 445 446 case Opt_ignore: 447 break; 448 default: 449 return 0; 450 } 451 } 452 sbi->s_mount_opt |= kind; 453 return 1; 454 } 455 456 static int ext2_setup_super (struct super_block * sb, 457 struct ext2_super_block * es, 458 int read_only) 459 { 460 int res = 0; 461 struct ext2_sb_info *sbi = EXT2_SB(sb); 462 463 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 464 printk ("EXT2-fs warning: revision level too high, " 465 "forcing read-only mode\n"); 466 res = MS_RDONLY; 467 } 468 if (read_only) 469 return res; 470 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 471 printk ("EXT2-fs warning: mounting unchecked fs, " 472 "running e2fsck is recommended\n"); 473 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 474 printk ("EXT2-fs warning: mounting fs with errors, " 475 "running e2fsck is recommended\n"); 476 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 477 le16_to_cpu(es->s_mnt_count) >= 478 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 479 printk ("EXT2-fs warning: maximal mount count reached, " 480 "running e2fsck is recommended\n"); 481 else if (le32_to_cpu(es->s_checkinterval) && 482 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 483 printk ("EXT2-fs warning: checktime reached, " 484 "running e2fsck is recommended\n"); 485 if (!le16_to_cpu(es->s_max_mnt_count)) 486 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 487 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 488 ext2_write_super(sb); 489 if (test_opt (sb, DEBUG)) 490 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 491 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 492 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 493 sbi->s_frag_size, 494 sbi->s_groups_count, 495 EXT2_BLOCKS_PER_GROUP(sb), 496 EXT2_INODES_PER_GROUP(sb), 497 sbi->s_mount_opt); 498 return res; 499 } 500 501 static int ext2_check_descriptors (struct super_block * sb) 502 { 503 int i; 504 int desc_block = 0; 505 struct ext2_sb_info *sbi = EXT2_SB(sb); 506 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block); 507 struct ext2_group_desc * gdp = NULL; 508 509 ext2_debug ("Checking group descriptors"); 510 511 for (i = 0; i < sbi->s_groups_count; i++) 512 { 513 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) 514 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; 515 if (le32_to_cpu(gdp->bg_block_bitmap) < block || 516 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 517 { 518 ext2_error (sb, "ext2_check_descriptors", 519 "Block bitmap for group %d" 520 " not in group (block %lu)!", 521 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 522 return 0; 523 } 524 if (le32_to_cpu(gdp->bg_inode_bitmap) < block || 525 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 526 { 527 ext2_error (sb, "ext2_check_descriptors", 528 "Inode bitmap for group %d" 529 " not in group (block %lu)!", 530 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 531 return 0; 532 } 533 if (le32_to_cpu(gdp->bg_inode_table) < block || 534 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >= 535 block + EXT2_BLOCKS_PER_GROUP(sb)) 536 { 537 ext2_error (sb, "ext2_check_descriptors", 538 "Inode table for group %d" 539 " not in group (block %lu)!", 540 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 541 return 0; 542 } 543 block += EXT2_BLOCKS_PER_GROUP(sb); 544 gdp++; 545 } 546 return 1; 547 } 548 549 #define log2(n) ffz(~(n)) 550 551 /* 552 * Maximal file size. There is a direct, and {,double-,triple-}indirect 553 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 554 * We need to be 1 filesystem block less than the 2^32 sector limit. 555 */ 556 static loff_t ext2_max_size(int bits) 557 { 558 loff_t res = EXT2_NDIR_BLOCKS; 559 /* This constant is calculated to be the largest file size for a 560 * dense, 4k-blocksize file such that the total number of 561 * sectors in the file, including data and all indirect blocks, 562 * does not exceed 2^32. */ 563 const loff_t upper_limit = 0x1ff7fffd000LL; 564 565 res += 1LL << (bits-2); 566 res += 1LL << (2*(bits-2)); 567 res += 1LL << (3*(bits-2)); 568 res <<= bits; 569 if (res > upper_limit) 570 res = upper_limit; 571 return res; 572 } 573 574 static unsigned long descriptor_loc(struct super_block *sb, 575 unsigned long logic_sb_block, 576 int nr) 577 { 578 struct ext2_sb_info *sbi = EXT2_SB(sb); 579 unsigned long bg, first_data_block, first_meta_bg; 580 int has_super = 0; 581 582 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 583 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 584 585 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 586 nr < first_meta_bg) 587 return (logic_sb_block + nr + 1); 588 bg = sbi->s_desc_per_block * nr; 589 if (ext2_bg_has_super(sb, bg)) 590 has_super = 1; 591 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 592 } 593 594 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 595 { 596 struct buffer_head * bh; 597 struct ext2_sb_info * sbi; 598 struct ext2_super_block * es; 599 struct inode *root; 600 unsigned long block; 601 unsigned long sb_block = get_sb_block(&data); 602 unsigned long logic_sb_block; 603 unsigned long offset = 0; 604 unsigned long def_mount_opts; 605 int blocksize = BLOCK_SIZE; 606 int db_count; 607 int i, j; 608 __le32 features; 609 610 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL); 611 if (!sbi) 612 return -ENOMEM; 613 sb->s_fs_info = sbi; 614 memset(sbi, 0, sizeof(*sbi)); 615 616 /* 617 * See what the current blocksize for the device is, and 618 * use that as the blocksize. Otherwise (or if the blocksize 619 * is smaller than the default) use the default. 620 * This is important for devices that have a hardware 621 * sectorsize that is larger than the default. 622 */ 623 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 624 if (!blocksize) { 625 printk ("EXT2-fs: unable to set blocksize\n"); 626 goto failed_sbi; 627 } 628 629 /* 630 * If the superblock doesn't start on a hardware sector boundary, 631 * calculate the offset. 632 */ 633 if (blocksize != BLOCK_SIZE) { 634 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 635 offset = (sb_block*BLOCK_SIZE) % blocksize; 636 } else { 637 logic_sb_block = sb_block; 638 } 639 640 if (!(bh = sb_bread(sb, logic_sb_block))) { 641 printk ("EXT2-fs: unable to read superblock\n"); 642 goto failed_sbi; 643 } 644 /* 645 * Note: s_es must be initialized as soon as possible because 646 * some ext2 macro-instructions depend on its value 647 */ 648 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 649 sbi->s_es = es; 650 sb->s_magic = le16_to_cpu(es->s_magic); 651 652 if (sb->s_magic != EXT2_SUPER_MAGIC) 653 goto cantfind_ext2; 654 655 /* Set defaults before we parse the mount options */ 656 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 657 if (def_mount_opts & EXT2_DEFM_DEBUG) 658 set_opt(sbi->s_mount_opt, DEBUG); 659 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 660 set_opt(sbi->s_mount_opt, GRPID); 661 if (def_mount_opts & EXT2_DEFM_UID16) 662 set_opt(sbi->s_mount_opt, NO_UID32); 663 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 664 set_opt(sbi->s_mount_opt, XATTR_USER); 665 if (def_mount_opts & EXT2_DEFM_ACL) 666 set_opt(sbi->s_mount_opt, POSIX_ACL); 667 668 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 669 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 670 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) 671 set_opt(sbi->s_mount_opt, ERRORS_RO); 672 673 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 674 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 675 676 if (!parse_options ((char *) data, sbi)) 677 goto failed_mount; 678 679 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 680 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 681 MS_POSIXACL : 0); 682 683 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 684 EXT2_MOUNT_XIP if not */ 685 686 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 687 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 688 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 689 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 690 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 691 "running e2fsck is recommended\n"); 692 /* 693 * Check feature flags regardless of the revision level, since we 694 * previously didn't change the revision level when setting the flags, 695 * so there is a chance incompat flags are set on a rev 0 filesystem. 696 */ 697 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 698 if (features) { 699 printk("EXT2-fs: %s: couldn't mount because of " 700 "unsupported optional features (%x).\n", 701 sb->s_id, le32_to_cpu(features)); 702 goto failed_mount; 703 } 704 if (!(sb->s_flags & MS_RDONLY) && 705 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 706 printk("EXT2-fs: %s: couldn't mount RDWR because of " 707 "unsupported optional features (%x).\n", 708 sb->s_id, le32_to_cpu(features)); 709 goto failed_mount; 710 } 711 712 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 713 714 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) || 715 (sb->s_blocksize != blocksize))) { 716 if (!silent) 717 printk("XIP: Unsupported blocksize\n"); 718 goto failed_mount; 719 } 720 721 /* If the blocksize doesn't match, re-read the thing.. */ 722 if (sb->s_blocksize != blocksize) { 723 brelse(bh); 724 725 if (!sb_set_blocksize(sb, blocksize)) { 726 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 727 goto failed_sbi; 728 } 729 730 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 731 offset = (sb_block*BLOCK_SIZE) % blocksize; 732 bh = sb_bread(sb, logic_sb_block); 733 if(!bh) { 734 printk("EXT2-fs: Couldn't read superblock on " 735 "2nd try.\n"); 736 goto failed_sbi; 737 } 738 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 739 sbi->s_es = es; 740 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 741 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 742 goto failed_mount; 743 } 744 } 745 746 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 747 748 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 749 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 750 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 751 } else { 752 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 753 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 754 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 755 (sbi->s_inode_size & (sbi->s_inode_size - 1)) || 756 (sbi->s_inode_size > blocksize)) { 757 printk ("EXT2-fs: unsupported inode size: %d\n", 758 sbi->s_inode_size); 759 goto failed_mount; 760 } 761 } 762 763 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 764 le32_to_cpu(es->s_log_frag_size); 765 if (sbi->s_frag_size == 0) 766 goto cantfind_ext2; 767 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 768 769 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 770 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 771 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 772 773 if (EXT2_INODE_SIZE(sb) == 0) 774 goto cantfind_ext2; 775 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 776 if (sbi->s_inodes_per_block == 0) 777 goto cantfind_ext2; 778 sbi->s_itb_per_group = sbi->s_inodes_per_group / 779 sbi->s_inodes_per_block; 780 sbi->s_desc_per_block = sb->s_blocksize / 781 sizeof (struct ext2_group_desc); 782 sbi->s_sbh = bh; 783 sbi->s_mount_state = le16_to_cpu(es->s_state); 784 sbi->s_addr_per_block_bits = 785 log2 (EXT2_ADDR_PER_BLOCK(sb)); 786 sbi->s_desc_per_block_bits = 787 log2 (EXT2_DESC_PER_BLOCK(sb)); 788 789 if (sb->s_magic != EXT2_SUPER_MAGIC) 790 goto cantfind_ext2; 791 792 if (sb->s_blocksize != bh->b_size) { 793 if (!silent) 794 printk ("VFS: Unsupported blocksize on dev " 795 "%s.\n", sb->s_id); 796 goto failed_mount; 797 } 798 799 if (sb->s_blocksize != sbi->s_frag_size) { 800 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 801 sbi->s_frag_size, sb->s_blocksize); 802 goto failed_mount; 803 } 804 805 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 806 printk ("EXT2-fs: #blocks per group too big: %lu\n", 807 sbi->s_blocks_per_group); 808 goto failed_mount; 809 } 810 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 811 printk ("EXT2-fs: #fragments per group too big: %lu\n", 812 sbi->s_frags_per_group); 813 goto failed_mount; 814 } 815 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 816 printk ("EXT2-fs: #inodes per group too big: %lu\n", 817 sbi->s_inodes_per_group); 818 goto failed_mount; 819 } 820 821 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 822 goto cantfind_ext2; 823 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - 824 le32_to_cpu(es->s_first_data_block) + 825 EXT2_BLOCKS_PER_GROUP(sb) - 1) / 826 EXT2_BLOCKS_PER_GROUP(sb); 827 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 828 EXT2_DESC_PER_BLOCK(sb); 829 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 830 if (sbi->s_group_desc == NULL) { 831 printk ("EXT2-fs: not enough memory\n"); 832 goto failed_mount; 833 } 834 percpu_counter_init(&sbi->s_freeblocks_counter); 835 percpu_counter_init(&sbi->s_freeinodes_counter); 836 percpu_counter_init(&sbi->s_dirs_counter); 837 bgl_lock_init(&sbi->s_blockgroup_lock); 838 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts), 839 GFP_KERNEL); 840 if (!sbi->s_debts) { 841 printk ("EXT2-fs: not enough memory\n"); 842 goto failed_mount_group_desc; 843 } 844 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts)); 845 for (i = 0; i < db_count; i++) { 846 block = descriptor_loc(sb, logic_sb_block, i); 847 sbi->s_group_desc[i] = sb_bread(sb, block); 848 if (!sbi->s_group_desc[i]) { 849 for (j = 0; j < i; j++) 850 brelse (sbi->s_group_desc[j]); 851 printk ("EXT2-fs: unable to read group descriptors\n"); 852 goto failed_mount_group_desc; 853 } 854 } 855 if (!ext2_check_descriptors (sb)) { 856 printk ("EXT2-fs: group descriptors corrupted!\n"); 857 db_count = i; 858 goto failed_mount2; 859 } 860 sbi->s_gdb_count = db_count; 861 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 862 spin_lock_init(&sbi->s_next_gen_lock); 863 /* 864 * set up enough so that it can read an inode 865 */ 866 sb->s_op = &ext2_sops; 867 sb->s_export_op = &ext2_export_ops; 868 sb->s_xattr = ext2_xattr_handlers; 869 root = iget(sb, EXT2_ROOT_INO); 870 sb->s_root = d_alloc_root(root); 871 if (!sb->s_root) { 872 iput(root); 873 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 874 goto failed_mount2; 875 } 876 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 877 dput(sb->s_root); 878 sb->s_root = NULL; 879 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 880 goto failed_mount2; 881 } 882 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 883 ext2_warning(sb, __FUNCTION__, 884 "mounting ext3 filesystem as ext2"); 885 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 886 percpu_counter_mod(&sbi->s_freeblocks_counter, 887 ext2_count_free_blocks(sb)); 888 percpu_counter_mod(&sbi->s_freeinodes_counter, 889 ext2_count_free_inodes(sb)); 890 percpu_counter_mod(&sbi->s_dirs_counter, 891 ext2_count_dirs(sb)); 892 return 0; 893 894 cantfind_ext2: 895 if (!silent) 896 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 897 sb->s_id); 898 goto failed_mount; 899 900 failed_mount2: 901 for (i = 0; i < db_count; i++) 902 brelse(sbi->s_group_desc[i]); 903 failed_mount_group_desc: 904 kfree(sbi->s_group_desc); 905 kfree(sbi->s_debts); 906 failed_mount: 907 brelse(bh); 908 failed_sbi: 909 sb->s_fs_info = NULL; 910 kfree(sbi); 911 return -EINVAL; 912 } 913 914 static void ext2_commit_super (struct super_block * sb, 915 struct ext2_super_block * es) 916 { 917 es->s_wtime = cpu_to_le32(get_seconds()); 918 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 919 sb->s_dirt = 0; 920 } 921 922 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 923 { 924 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 925 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 926 es->s_wtime = cpu_to_le32(get_seconds()); 927 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 928 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 929 sb->s_dirt = 0; 930 } 931 932 /* 933 * In the second extended file system, it is not necessary to 934 * write the super block since we use a mapping of the 935 * disk super block in a buffer. 936 * 937 * However, this function is still used to set the fs valid 938 * flags to 0. We need to set this flag to 0 since the fs 939 * may have been checked while mounted and e2fsck may have 940 * set s_state to EXT2_VALID_FS after some corrections. 941 */ 942 943 void ext2_write_super (struct super_block * sb) 944 { 945 struct ext2_super_block * es; 946 lock_kernel(); 947 if (!(sb->s_flags & MS_RDONLY)) { 948 es = EXT2_SB(sb)->s_es; 949 950 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 951 ext2_debug ("setting valid to 0\n"); 952 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 953 ~EXT2_VALID_FS); 954 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 955 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 956 es->s_mtime = cpu_to_le32(get_seconds()); 957 ext2_sync_super(sb, es); 958 } else 959 ext2_commit_super (sb, es); 960 } 961 sb->s_dirt = 0; 962 unlock_kernel(); 963 } 964 965 static int ext2_remount (struct super_block * sb, int * flags, char * data) 966 { 967 struct ext2_sb_info * sbi = EXT2_SB(sb); 968 struct ext2_super_block * es; 969 unsigned long old_mount_opt = sbi->s_mount_opt; 970 struct ext2_mount_options old_opts; 971 unsigned long old_sb_flags; 972 int err; 973 974 /* Store the old options */ 975 old_sb_flags = sb->s_flags; 976 old_opts.s_mount_opt = sbi->s_mount_opt; 977 old_opts.s_resuid = sbi->s_resuid; 978 old_opts.s_resgid = sbi->s_resgid; 979 980 /* 981 * Allow the "check" option to be passed as a remount option. 982 */ 983 if (!parse_options (data, sbi)) { 984 err = -EINVAL; 985 goto restore_opts; 986 } 987 988 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 989 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 990 991 es = sbi->s_es; 992 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 993 (old_mount_opt & EXT2_MOUNT_XIP)) && 994 invalidate_inodes(sb)) 995 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ 996 "xip remain in cache (no functional problem)"); 997 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 998 return 0; 999 if (*flags & MS_RDONLY) { 1000 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1001 !(sbi->s_mount_state & EXT2_VALID_FS)) 1002 return 0; 1003 /* 1004 * OK, we are remounting a valid rw partition rdonly, so set 1005 * the rdonly flag and then mark the partition as valid again. 1006 */ 1007 es->s_state = cpu_to_le16(sbi->s_mount_state); 1008 es->s_mtime = cpu_to_le32(get_seconds()); 1009 } else { 1010 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1011 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1012 if (ret) { 1013 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1014 "unsupported optional features (%x).\n", 1015 sb->s_id, le32_to_cpu(ret)); 1016 err = -EROFS; 1017 goto restore_opts; 1018 } 1019 /* 1020 * Mounting a RDONLY partition read-write, so reread and 1021 * store the current valid flag. (It may have been changed 1022 * by e2fsck since we originally mounted the partition.) 1023 */ 1024 sbi->s_mount_state = le16_to_cpu(es->s_state); 1025 if (!ext2_setup_super (sb, es, 0)) 1026 sb->s_flags &= ~MS_RDONLY; 1027 } 1028 ext2_sync_super(sb, es); 1029 return 0; 1030 restore_opts: 1031 sbi->s_mount_opt = old_opts.s_mount_opt; 1032 sbi->s_resuid = old_opts.s_resuid; 1033 sbi->s_resgid = old_opts.s_resgid; 1034 sb->s_flags = old_sb_flags; 1035 return err; 1036 } 1037 1038 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf) 1039 { 1040 struct ext2_sb_info *sbi = EXT2_SB(sb); 1041 unsigned long overhead; 1042 int i; 1043 1044 if (test_opt (sb, MINIX_DF)) 1045 overhead = 0; 1046 else { 1047 /* 1048 * Compute the overhead (FS structures) 1049 */ 1050 1051 /* 1052 * All of the blocks before first_data_block are 1053 * overhead 1054 */ 1055 overhead = le32_to_cpu(sbi->s_es->s_first_data_block); 1056 1057 /* 1058 * Add the overhead attributed to the superblock and 1059 * block group descriptors. If the sparse superblocks 1060 * feature is turned on, then not all groups have this. 1061 */ 1062 for (i = 0; i < sbi->s_groups_count; i++) 1063 overhead += ext2_bg_has_super(sb, i) + 1064 ext2_bg_num_gdb(sb, i); 1065 1066 /* 1067 * Every block group has an inode bitmap, a block 1068 * bitmap, and an inode table. 1069 */ 1070 overhead += (sbi->s_groups_count * 1071 (2 + sbi->s_itb_per_group)); 1072 } 1073 1074 buf->f_type = EXT2_SUPER_MAGIC; 1075 buf->f_bsize = sb->s_blocksize; 1076 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead; 1077 buf->f_bfree = ext2_count_free_blocks(sb); 1078 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count); 1079 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count)) 1080 buf->f_bavail = 0; 1081 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count); 1082 buf->f_ffree = ext2_count_free_inodes (sb); 1083 buf->f_namelen = EXT2_NAME_LEN; 1084 return 0; 1085 } 1086 1087 static struct super_block *ext2_get_sb(struct file_system_type *fs_type, 1088 int flags, const char *dev_name, void *data) 1089 { 1090 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super); 1091 } 1092 1093 #ifdef CONFIG_QUOTA 1094 1095 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1096 * acquiring the locks... As quota files are never truncated and quota code 1097 * itself serializes the operations (and noone else should touch the files) 1098 * we don't have to be afraid of races */ 1099 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1100 size_t len, loff_t off) 1101 { 1102 struct inode *inode = sb_dqopt(sb)->files[type]; 1103 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1104 int err = 0; 1105 int offset = off & (sb->s_blocksize - 1); 1106 int tocopy; 1107 size_t toread; 1108 struct buffer_head tmp_bh; 1109 struct buffer_head *bh; 1110 loff_t i_size = i_size_read(inode); 1111 1112 if (off > i_size) 1113 return 0; 1114 if (off+len > i_size) 1115 len = i_size-off; 1116 toread = len; 1117 while (toread > 0) { 1118 tocopy = sb->s_blocksize - offset < toread ? 1119 sb->s_blocksize - offset : toread; 1120 1121 tmp_bh.b_state = 0; 1122 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1123 if (err) 1124 return err; 1125 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1126 memset(data, 0, tocopy); 1127 else { 1128 bh = sb_bread(sb, tmp_bh.b_blocknr); 1129 if (!bh) 1130 return -EIO; 1131 memcpy(data, bh->b_data+offset, tocopy); 1132 brelse(bh); 1133 } 1134 offset = 0; 1135 toread -= tocopy; 1136 data += tocopy; 1137 blk++; 1138 } 1139 return len; 1140 } 1141 1142 /* Write to quotafile */ 1143 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1144 const char *data, size_t len, loff_t off) 1145 { 1146 struct inode *inode = sb_dqopt(sb)->files[type]; 1147 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1148 int err = 0; 1149 int offset = off & (sb->s_blocksize - 1); 1150 int tocopy; 1151 size_t towrite = len; 1152 struct buffer_head tmp_bh; 1153 struct buffer_head *bh; 1154 1155 down(&inode->i_sem); 1156 while (towrite > 0) { 1157 tocopy = sb->s_blocksize - offset < towrite ? 1158 sb->s_blocksize - offset : towrite; 1159 1160 tmp_bh.b_state = 0; 1161 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1162 if (err) 1163 goto out; 1164 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1165 bh = sb_bread(sb, tmp_bh.b_blocknr); 1166 else 1167 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1168 if (!bh) { 1169 err = -EIO; 1170 goto out; 1171 } 1172 lock_buffer(bh); 1173 memcpy(bh->b_data+offset, data, tocopy); 1174 flush_dcache_page(bh->b_page); 1175 set_buffer_uptodate(bh); 1176 mark_buffer_dirty(bh); 1177 unlock_buffer(bh); 1178 brelse(bh); 1179 offset = 0; 1180 towrite -= tocopy; 1181 data += tocopy; 1182 blk++; 1183 } 1184 out: 1185 if (len == towrite) 1186 return err; 1187 if (inode->i_size < off+len-towrite) 1188 i_size_write(inode, off+len-towrite); 1189 inode->i_version++; 1190 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1191 mark_inode_dirty(inode); 1192 up(&inode->i_sem); 1193 return len - towrite; 1194 } 1195 1196 #endif 1197 1198 static struct file_system_type ext2_fs_type = { 1199 .owner = THIS_MODULE, 1200 .name = "ext2", 1201 .get_sb = ext2_get_sb, 1202 .kill_sb = kill_block_super, 1203 .fs_flags = FS_REQUIRES_DEV, 1204 }; 1205 1206 static int __init init_ext2_fs(void) 1207 { 1208 int err = init_ext2_xattr(); 1209 if (err) 1210 return err; 1211 err = init_inodecache(); 1212 if (err) 1213 goto out1; 1214 err = register_filesystem(&ext2_fs_type); 1215 if (err) 1216 goto out; 1217 return 0; 1218 out: 1219 destroy_inodecache(); 1220 out1: 1221 exit_ext2_xattr(); 1222 return err; 1223 } 1224 1225 static void __exit exit_ext2_fs(void) 1226 { 1227 unregister_filesystem(&ext2_fs_type); 1228 destroy_inodecache(); 1229 exit_ext2_xattr(); 1230 } 1231 1232 module_init(init_ext2_fs) 1233 module_exit(exit_ext2_fs) 1234