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/module.h> 20 #include <linux/string.h> 21 #include <linux/fs.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 <linux/seq_file.h> 31 #include <linux/mount.h> 32 #include <asm/uaccess.h> 33 #include "ext2.h" 34 #include "xattr.h" 35 #include "acl.h" 36 #include "xip.h" 37 38 static void ext2_sync_super(struct super_block *sb, 39 struct ext2_super_block *es); 40 static int ext2_remount (struct super_block * sb, int * flags, char * data); 41 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); 42 43 void ext2_error (struct super_block * sb, const char * function, 44 const char * fmt, ...) 45 { 46 va_list args; 47 struct ext2_sb_info *sbi = EXT2_SB(sb); 48 struct ext2_super_block *es = sbi->s_es; 49 50 if (!(sb->s_flags & MS_RDONLY)) { 51 sbi->s_mount_state |= EXT2_ERROR_FS; 52 es->s_state = 53 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS); 54 ext2_sync_super(sb, es); 55 } 56 57 va_start(args, fmt); 58 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 59 vprintk(fmt, args); 60 printk("\n"); 61 va_end(args); 62 63 if (test_opt(sb, ERRORS_PANIC)) 64 panic("EXT2-fs panic from previous error\n"); 65 if (test_opt(sb, ERRORS_RO)) { 66 printk("Remounting filesystem read-only\n"); 67 sb->s_flags |= MS_RDONLY; 68 } 69 } 70 71 void ext2_warning (struct super_block * sb, const char * function, 72 const char * fmt, ...) 73 { 74 va_list args; 75 76 va_start(args, fmt); 77 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 78 sb->s_id, function); 79 vprintk(fmt, args); 80 printk("\n"); 81 va_end(args); 82 } 83 84 void ext2_update_dynamic_rev(struct super_block *sb) 85 { 86 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 87 88 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 89 return; 90 91 ext2_warning(sb, __FUNCTION__, 92 "updating to rev %d because of new feature flag, " 93 "running e2fsck is recommended", 94 EXT2_DYNAMIC_REV); 95 96 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 97 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 98 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 99 /* leave es->s_feature_*compat flags alone */ 100 /* es->s_uuid will be set by e2fsck if empty */ 101 102 /* 103 * The rest of the superblock fields should be zero, and if not it 104 * means they are likely already in use, so leave them alone. We 105 * can leave it up to e2fsck to clean up any inconsistencies there. 106 */ 107 } 108 109 static void ext2_put_super (struct super_block * sb) 110 { 111 int db_count; 112 int i; 113 struct ext2_sb_info *sbi = EXT2_SB(sb); 114 115 ext2_xattr_put_super(sb); 116 if (!(sb->s_flags & MS_RDONLY)) { 117 struct ext2_super_block *es = sbi->s_es; 118 119 es->s_state = cpu_to_le16(sbi->s_mount_state); 120 ext2_sync_super(sb, es); 121 } 122 db_count = sbi->s_gdb_count; 123 for (i = 0; i < db_count; i++) 124 if (sbi->s_group_desc[i]) 125 brelse (sbi->s_group_desc[i]); 126 kfree(sbi->s_group_desc); 127 kfree(sbi->s_debts); 128 percpu_counter_destroy(&sbi->s_freeblocks_counter); 129 percpu_counter_destroy(&sbi->s_freeinodes_counter); 130 percpu_counter_destroy(&sbi->s_dirs_counter); 131 brelse (sbi->s_sbh); 132 sb->s_fs_info = NULL; 133 kfree(sbi); 134 135 return; 136 } 137 138 static kmem_cache_t * ext2_inode_cachep; 139 140 static struct inode *ext2_alloc_inode(struct super_block *sb) 141 { 142 struct ext2_inode_info *ei; 143 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL); 144 if (!ei) 145 return NULL; 146 #ifdef CONFIG_EXT2_FS_POSIX_ACL 147 ei->i_acl = EXT2_ACL_NOT_CACHED; 148 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 149 #endif 150 ei->vfs_inode.i_version = 1; 151 return &ei->vfs_inode; 152 } 153 154 static void ext2_destroy_inode(struct inode *inode) 155 { 156 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 157 } 158 159 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 160 { 161 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 162 163 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 164 SLAB_CTOR_CONSTRUCTOR) { 165 rwlock_init(&ei->i_meta_lock); 166 #ifdef CONFIG_EXT2_FS_XATTR 167 init_rwsem(&ei->xattr_sem); 168 #endif 169 inode_init_once(&ei->vfs_inode); 170 } 171 } 172 173 static int init_inodecache(void) 174 { 175 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 176 sizeof(struct ext2_inode_info), 177 0, (SLAB_RECLAIM_ACCOUNT| 178 SLAB_MEM_SPREAD), 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"); 213 214 #if defined(CONFIG_QUOTA) 215 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 216 seq_puts(seq, ",usrquota"); 217 218 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 219 seq_puts(seq, ",grpquota"); 220 #endif 221 222 #if defined(CONFIG_EXT2_FS_XIP) 223 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 224 seq_puts(seq, ",xip"); 225 #endif 226 227 return 0; 228 } 229 230 #ifdef CONFIG_QUOTA 231 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 232 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 233 #endif 234 235 static struct super_operations ext2_sops = { 236 .alloc_inode = ext2_alloc_inode, 237 .destroy_inode = ext2_destroy_inode, 238 .read_inode = ext2_read_inode, 239 .write_inode = ext2_write_inode, 240 .put_inode = ext2_put_inode, 241 .delete_inode = ext2_delete_inode, 242 .put_super = ext2_put_super, 243 .write_super = ext2_write_super, 244 .statfs = ext2_statfs, 245 .remount_fs = ext2_remount, 246 .clear_inode = ext2_clear_inode, 247 .show_options = ext2_show_options, 248 #ifdef CONFIG_QUOTA 249 .quota_read = ext2_quota_read, 250 .quota_write = ext2_quota_write, 251 #endif 252 }; 253 254 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp) 255 { 256 __u32 *objp = vobjp; 257 unsigned long ino = objp[0]; 258 __u32 generation = objp[1]; 259 struct inode *inode; 260 struct dentry *result; 261 262 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 263 return ERR_PTR(-ESTALE); 264 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 265 return ERR_PTR(-ESTALE); 266 267 /* iget isn't really right if the inode is currently unallocated!! 268 * ext2_read_inode currently does appropriate checks, but 269 * it might be "neater" to call ext2_get_inode first and check 270 * if the inode is valid..... 271 */ 272 inode = iget(sb, ino); 273 if (inode == NULL) 274 return ERR_PTR(-ENOMEM); 275 if (is_bad_inode(inode) || 276 (generation && inode->i_generation != generation)) { 277 /* we didn't find the right inode.. */ 278 iput(inode); 279 return ERR_PTR(-ESTALE); 280 } 281 /* now to find a dentry. 282 * If possible, get a well-connected one 283 */ 284 result = d_alloc_anon(inode); 285 if (!result) { 286 iput(inode); 287 return ERR_PTR(-ENOMEM); 288 } 289 return result; 290 } 291 292 /* Yes, most of these are left as NULL!! 293 * A NULL value implies the default, which works with ext2-like file 294 * systems, but can be improved upon. 295 * Currently only get_parent is required. 296 */ 297 static struct export_operations ext2_export_ops = { 298 .get_parent = ext2_get_parent, 299 .get_dentry = ext2_get_dentry, 300 }; 301 302 static unsigned long get_sb_block(void **data) 303 { 304 unsigned long sb_block; 305 char *options = (char *) *data; 306 307 if (!options || strncmp(options, "sb=", 3) != 0) 308 return 1; /* Default location */ 309 options += 3; 310 sb_block = simple_strtoul(options, &options, 0); 311 if (*options && *options != ',') { 312 printk("EXT2-fs: Invalid sb specification: %s\n", 313 (char *) *data); 314 return 1; 315 } 316 if (*options == ',') 317 options++; 318 *data = (void *) options; 319 return sb_block; 320 } 321 322 enum { 323 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 324 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 325 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 326 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 327 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 328 Opt_usrquota, Opt_grpquota 329 }; 330 331 static match_table_t tokens = { 332 {Opt_bsd_df, "bsddf"}, 333 {Opt_minix_df, "minixdf"}, 334 {Opt_grpid, "grpid"}, 335 {Opt_grpid, "bsdgroups"}, 336 {Opt_nogrpid, "nogrpid"}, 337 {Opt_nogrpid, "sysvgroups"}, 338 {Opt_resgid, "resgid=%u"}, 339 {Opt_resuid, "resuid=%u"}, 340 {Opt_sb, "sb=%u"}, 341 {Opt_err_cont, "errors=continue"}, 342 {Opt_err_panic, "errors=panic"}, 343 {Opt_err_ro, "errors=remount-ro"}, 344 {Opt_nouid32, "nouid32"}, 345 {Opt_nocheck, "check=none"}, 346 {Opt_nocheck, "nocheck"}, 347 {Opt_debug, "debug"}, 348 {Opt_oldalloc, "oldalloc"}, 349 {Opt_orlov, "orlov"}, 350 {Opt_nobh, "nobh"}, 351 {Opt_user_xattr, "user_xattr"}, 352 {Opt_nouser_xattr, "nouser_xattr"}, 353 {Opt_acl, "acl"}, 354 {Opt_noacl, "noacl"}, 355 {Opt_xip, "xip"}, 356 {Opt_grpquota, "grpquota"}, 357 {Opt_ignore, "noquota"}, 358 {Opt_quota, "quota"}, 359 {Opt_usrquota, "usrquota"}, 360 {Opt_err, NULL} 361 }; 362 363 static int parse_options (char * options, 364 struct ext2_sb_info *sbi) 365 { 366 char * p; 367 substring_t args[MAX_OPT_ARGS]; 368 unsigned long kind = EXT2_MOUNT_ERRORS_CONT; 369 int option; 370 371 if (!options) 372 return 1; 373 374 while ((p = strsep (&options, ",")) != NULL) { 375 int token; 376 if (!*p) 377 continue; 378 379 token = match_token(p, tokens, args); 380 switch (token) { 381 case Opt_bsd_df: 382 clear_opt (sbi->s_mount_opt, MINIX_DF); 383 break; 384 case Opt_minix_df: 385 set_opt (sbi->s_mount_opt, MINIX_DF); 386 break; 387 case Opt_grpid: 388 set_opt (sbi->s_mount_opt, GRPID); 389 break; 390 case Opt_nogrpid: 391 clear_opt (sbi->s_mount_opt, GRPID); 392 break; 393 case Opt_resuid: 394 if (match_int(&args[0], &option)) 395 return 0; 396 sbi->s_resuid = option; 397 break; 398 case Opt_resgid: 399 if (match_int(&args[0], &option)) 400 return 0; 401 sbi->s_resgid = option; 402 break; 403 case Opt_sb: 404 /* handled by get_sb_block() instead of here */ 405 /* *sb_block = match_int(&args[0]); */ 406 break; 407 case Opt_err_panic: 408 kind = EXT2_MOUNT_ERRORS_PANIC; 409 break; 410 case Opt_err_ro: 411 kind = EXT2_MOUNT_ERRORS_RO; 412 break; 413 case Opt_err_cont: 414 kind = EXT2_MOUNT_ERRORS_CONT; 415 break; 416 case Opt_nouid32: 417 set_opt (sbi->s_mount_opt, NO_UID32); 418 break; 419 case Opt_nocheck: 420 clear_opt (sbi->s_mount_opt, CHECK); 421 break; 422 case Opt_debug: 423 set_opt (sbi->s_mount_opt, DEBUG); 424 break; 425 case Opt_oldalloc: 426 set_opt (sbi->s_mount_opt, OLDALLOC); 427 break; 428 case Opt_orlov: 429 clear_opt (sbi->s_mount_opt, OLDALLOC); 430 break; 431 case Opt_nobh: 432 set_opt (sbi->s_mount_opt, NOBH); 433 break; 434 #ifdef CONFIG_EXT2_FS_XATTR 435 case Opt_user_xattr: 436 set_opt (sbi->s_mount_opt, XATTR_USER); 437 break; 438 case Opt_nouser_xattr: 439 clear_opt (sbi->s_mount_opt, XATTR_USER); 440 break; 441 #else 442 case Opt_user_xattr: 443 case Opt_nouser_xattr: 444 printk("EXT2 (no)user_xattr options not supported\n"); 445 break; 446 #endif 447 #ifdef CONFIG_EXT2_FS_POSIX_ACL 448 case Opt_acl: 449 set_opt(sbi->s_mount_opt, POSIX_ACL); 450 break; 451 case Opt_noacl: 452 clear_opt(sbi->s_mount_opt, POSIX_ACL); 453 break; 454 #else 455 case Opt_acl: 456 case Opt_noacl: 457 printk("EXT2 (no)acl options not supported\n"); 458 break; 459 #endif 460 case Opt_xip: 461 #ifdef CONFIG_EXT2_FS_XIP 462 set_opt (sbi->s_mount_opt, XIP); 463 #else 464 printk("EXT2 xip option not supported\n"); 465 #endif 466 break; 467 468 #if defined(CONFIG_QUOTA) 469 case Opt_quota: 470 case Opt_usrquota: 471 set_opt(sbi->s_mount_opt, USRQUOTA); 472 break; 473 474 case Opt_grpquota: 475 set_opt(sbi->s_mount_opt, GRPQUOTA); 476 break; 477 #else 478 case Opt_quota: 479 case Opt_usrquota: 480 case Opt_grpquota: 481 printk(KERN_ERR 482 "EXT2-fs: quota operations not supported.\n"); 483 484 break; 485 #endif 486 487 case Opt_ignore: 488 break; 489 default: 490 return 0; 491 } 492 } 493 sbi->s_mount_opt |= kind; 494 return 1; 495 } 496 497 static int ext2_setup_super (struct super_block * sb, 498 struct ext2_super_block * es, 499 int read_only) 500 { 501 int res = 0; 502 struct ext2_sb_info *sbi = EXT2_SB(sb); 503 504 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 505 printk ("EXT2-fs warning: revision level too high, " 506 "forcing read-only mode\n"); 507 res = MS_RDONLY; 508 } 509 if (read_only) 510 return res; 511 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 512 printk ("EXT2-fs warning: mounting unchecked fs, " 513 "running e2fsck is recommended\n"); 514 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 515 printk ("EXT2-fs warning: mounting fs with errors, " 516 "running e2fsck is recommended\n"); 517 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 518 le16_to_cpu(es->s_mnt_count) >= 519 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 520 printk ("EXT2-fs warning: maximal mount count reached, " 521 "running e2fsck is recommended\n"); 522 else if (le32_to_cpu(es->s_checkinterval) && 523 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 524 printk ("EXT2-fs warning: checktime reached, " 525 "running e2fsck is recommended\n"); 526 if (!le16_to_cpu(es->s_max_mnt_count)) 527 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 528 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 529 ext2_write_super(sb); 530 if (test_opt (sb, DEBUG)) 531 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 532 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 533 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 534 sbi->s_frag_size, 535 sbi->s_groups_count, 536 EXT2_BLOCKS_PER_GROUP(sb), 537 EXT2_INODES_PER_GROUP(sb), 538 sbi->s_mount_opt); 539 return res; 540 } 541 542 static int ext2_check_descriptors (struct super_block * sb) 543 { 544 int i; 545 int desc_block = 0; 546 struct ext2_sb_info *sbi = EXT2_SB(sb); 547 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block); 548 struct ext2_group_desc * gdp = NULL; 549 550 ext2_debug ("Checking group descriptors"); 551 552 for (i = 0; i < sbi->s_groups_count; i++) 553 { 554 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) 555 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; 556 if (le32_to_cpu(gdp->bg_block_bitmap) < block || 557 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 558 { 559 ext2_error (sb, "ext2_check_descriptors", 560 "Block bitmap for group %d" 561 " not in group (block %lu)!", 562 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 563 return 0; 564 } 565 if (le32_to_cpu(gdp->bg_inode_bitmap) < block || 566 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) 567 { 568 ext2_error (sb, "ext2_check_descriptors", 569 "Inode bitmap for group %d" 570 " not in group (block %lu)!", 571 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 572 return 0; 573 } 574 if (le32_to_cpu(gdp->bg_inode_table) < block || 575 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >= 576 block + EXT2_BLOCKS_PER_GROUP(sb)) 577 { 578 ext2_error (sb, "ext2_check_descriptors", 579 "Inode table for group %d" 580 " not in group (block %lu)!", 581 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 582 return 0; 583 } 584 block += EXT2_BLOCKS_PER_GROUP(sb); 585 gdp++; 586 } 587 return 1; 588 } 589 590 #define log2(n) ffz(~(n)) 591 592 /* 593 * Maximal file size. There is a direct, and {,double-,triple-}indirect 594 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 595 * We need to be 1 filesystem block less than the 2^32 sector limit. 596 */ 597 static loff_t ext2_max_size(int bits) 598 { 599 loff_t res = EXT2_NDIR_BLOCKS; 600 /* This constant is calculated to be the largest file size for a 601 * dense, 4k-blocksize file such that the total number of 602 * sectors in the file, including data and all indirect blocks, 603 * does not exceed 2^32. */ 604 const loff_t upper_limit = 0x1ff7fffd000LL; 605 606 res += 1LL << (bits-2); 607 res += 1LL << (2*(bits-2)); 608 res += 1LL << (3*(bits-2)); 609 res <<= bits; 610 if (res > upper_limit) 611 res = upper_limit; 612 return res; 613 } 614 615 static unsigned long descriptor_loc(struct super_block *sb, 616 unsigned long logic_sb_block, 617 int nr) 618 { 619 struct ext2_sb_info *sbi = EXT2_SB(sb); 620 unsigned long bg, first_data_block, first_meta_bg; 621 int has_super = 0; 622 623 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 624 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 625 626 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 627 nr < first_meta_bg) 628 return (logic_sb_block + nr + 1); 629 bg = sbi->s_desc_per_block * nr; 630 if (ext2_bg_has_super(sb, bg)) 631 has_super = 1; 632 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 633 } 634 635 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 636 { 637 struct buffer_head * bh; 638 struct ext2_sb_info * sbi; 639 struct ext2_super_block * es; 640 struct inode *root; 641 unsigned long block; 642 unsigned long sb_block = get_sb_block(&data); 643 unsigned long logic_sb_block; 644 unsigned long offset = 0; 645 unsigned long def_mount_opts; 646 int blocksize = BLOCK_SIZE; 647 int db_count; 648 int i, j; 649 __le32 features; 650 651 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL); 652 if (!sbi) 653 return -ENOMEM; 654 sb->s_fs_info = sbi; 655 memset(sbi, 0, sizeof(*sbi)); 656 657 /* 658 * See what the current blocksize for the device is, and 659 * use that as the blocksize. Otherwise (or if the blocksize 660 * is smaller than the default) use the default. 661 * This is important for devices that have a hardware 662 * sectorsize that is larger than the default. 663 */ 664 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 665 if (!blocksize) { 666 printk ("EXT2-fs: unable to set blocksize\n"); 667 goto failed_sbi; 668 } 669 670 /* 671 * If the superblock doesn't start on a hardware sector boundary, 672 * calculate the offset. 673 */ 674 if (blocksize != BLOCK_SIZE) { 675 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 676 offset = (sb_block*BLOCK_SIZE) % blocksize; 677 } else { 678 logic_sb_block = sb_block; 679 } 680 681 if (!(bh = sb_bread(sb, logic_sb_block))) { 682 printk ("EXT2-fs: unable to read superblock\n"); 683 goto failed_sbi; 684 } 685 /* 686 * Note: s_es must be initialized as soon as possible because 687 * some ext2 macro-instructions depend on its value 688 */ 689 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 690 sbi->s_es = es; 691 sb->s_magic = le16_to_cpu(es->s_magic); 692 693 if (sb->s_magic != EXT2_SUPER_MAGIC) 694 goto cantfind_ext2; 695 696 /* Set defaults before we parse the mount options */ 697 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 698 if (def_mount_opts & EXT2_DEFM_DEBUG) 699 set_opt(sbi->s_mount_opt, DEBUG); 700 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 701 set_opt(sbi->s_mount_opt, GRPID); 702 if (def_mount_opts & EXT2_DEFM_UID16) 703 set_opt(sbi->s_mount_opt, NO_UID32); 704 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 705 set_opt(sbi->s_mount_opt, XATTR_USER); 706 if (def_mount_opts & EXT2_DEFM_ACL) 707 set_opt(sbi->s_mount_opt, POSIX_ACL); 708 709 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 710 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 711 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) 712 set_opt(sbi->s_mount_opt, ERRORS_RO); 713 714 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 715 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 716 717 if (!parse_options ((char *) data, sbi)) 718 goto failed_mount; 719 720 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 721 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 722 MS_POSIXACL : 0); 723 724 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 725 EXT2_MOUNT_XIP if not */ 726 727 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 728 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 729 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 730 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 731 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 732 "running e2fsck is recommended\n"); 733 /* 734 * Check feature flags regardless of the revision level, since we 735 * previously didn't change the revision level when setting the flags, 736 * so there is a chance incompat flags are set on a rev 0 filesystem. 737 */ 738 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 739 if (features) { 740 printk("EXT2-fs: %s: couldn't mount because of " 741 "unsupported optional features (%x).\n", 742 sb->s_id, le32_to_cpu(features)); 743 goto failed_mount; 744 } 745 if (!(sb->s_flags & MS_RDONLY) && 746 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 747 printk("EXT2-fs: %s: couldn't mount RDWR because of " 748 "unsupported optional features (%x).\n", 749 sb->s_id, le32_to_cpu(features)); 750 goto failed_mount; 751 } 752 753 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 754 755 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) || 756 (sb->s_blocksize != blocksize))) { 757 if (!silent) 758 printk("XIP: Unsupported blocksize\n"); 759 goto failed_mount; 760 } 761 762 /* If the blocksize doesn't match, re-read the thing.. */ 763 if (sb->s_blocksize != blocksize) { 764 brelse(bh); 765 766 if (!sb_set_blocksize(sb, blocksize)) { 767 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 768 goto failed_sbi; 769 } 770 771 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 772 offset = (sb_block*BLOCK_SIZE) % blocksize; 773 bh = sb_bread(sb, logic_sb_block); 774 if(!bh) { 775 printk("EXT2-fs: Couldn't read superblock on " 776 "2nd try.\n"); 777 goto failed_sbi; 778 } 779 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 780 sbi->s_es = es; 781 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 782 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 783 goto failed_mount; 784 } 785 } 786 787 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 788 789 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 790 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 791 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 792 } else { 793 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 794 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 795 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 796 (sbi->s_inode_size & (sbi->s_inode_size - 1)) || 797 (sbi->s_inode_size > blocksize)) { 798 printk ("EXT2-fs: unsupported inode size: %d\n", 799 sbi->s_inode_size); 800 goto failed_mount; 801 } 802 } 803 804 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 805 le32_to_cpu(es->s_log_frag_size); 806 if (sbi->s_frag_size == 0) 807 goto cantfind_ext2; 808 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 809 810 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 811 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 812 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 813 814 if (EXT2_INODE_SIZE(sb) == 0) 815 goto cantfind_ext2; 816 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 817 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 818 goto cantfind_ext2; 819 sbi->s_itb_per_group = sbi->s_inodes_per_group / 820 sbi->s_inodes_per_block; 821 sbi->s_desc_per_block = sb->s_blocksize / 822 sizeof (struct ext2_group_desc); 823 sbi->s_sbh = bh; 824 sbi->s_mount_state = le16_to_cpu(es->s_state); 825 sbi->s_addr_per_block_bits = 826 log2 (EXT2_ADDR_PER_BLOCK(sb)); 827 sbi->s_desc_per_block_bits = 828 log2 (EXT2_DESC_PER_BLOCK(sb)); 829 830 if (sb->s_magic != EXT2_SUPER_MAGIC) 831 goto cantfind_ext2; 832 833 if (sb->s_blocksize != bh->b_size) { 834 if (!silent) 835 printk ("VFS: Unsupported blocksize on dev " 836 "%s.\n", sb->s_id); 837 goto failed_mount; 838 } 839 840 if (sb->s_blocksize != sbi->s_frag_size) { 841 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 842 sbi->s_frag_size, sb->s_blocksize); 843 goto failed_mount; 844 } 845 846 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 847 printk ("EXT2-fs: #blocks per group too big: %lu\n", 848 sbi->s_blocks_per_group); 849 goto failed_mount; 850 } 851 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 852 printk ("EXT2-fs: #fragments per group too big: %lu\n", 853 sbi->s_frags_per_group); 854 goto failed_mount; 855 } 856 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 857 printk ("EXT2-fs: #inodes per group too big: %lu\n", 858 sbi->s_inodes_per_group); 859 goto failed_mount; 860 } 861 862 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 863 goto cantfind_ext2; 864 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - 865 le32_to_cpu(es->s_first_data_block) + 866 EXT2_BLOCKS_PER_GROUP(sb) - 1) / 867 EXT2_BLOCKS_PER_GROUP(sb); 868 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 869 EXT2_DESC_PER_BLOCK(sb); 870 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 871 if (sbi->s_group_desc == NULL) { 872 printk ("EXT2-fs: not enough memory\n"); 873 goto failed_mount; 874 } 875 bgl_lock_init(&sbi->s_blockgroup_lock); 876 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts), 877 GFP_KERNEL); 878 if (!sbi->s_debts) { 879 printk ("EXT2-fs: not enough memory\n"); 880 goto failed_mount_group_desc; 881 } 882 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts)); 883 for (i = 0; i < db_count; i++) { 884 block = descriptor_loc(sb, logic_sb_block, i); 885 sbi->s_group_desc[i] = sb_bread(sb, block); 886 if (!sbi->s_group_desc[i]) { 887 for (j = 0; j < i; j++) 888 brelse (sbi->s_group_desc[j]); 889 printk ("EXT2-fs: unable to read group descriptors\n"); 890 goto failed_mount_group_desc; 891 } 892 } 893 if (!ext2_check_descriptors (sb)) { 894 printk ("EXT2-fs: group descriptors corrupted!\n"); 895 goto failed_mount2; 896 } 897 sbi->s_gdb_count = db_count; 898 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 899 spin_lock_init(&sbi->s_next_gen_lock); 900 901 percpu_counter_init(&sbi->s_freeblocks_counter, 902 ext2_count_free_blocks(sb)); 903 percpu_counter_init(&sbi->s_freeinodes_counter, 904 ext2_count_free_inodes(sb)); 905 percpu_counter_init(&sbi->s_dirs_counter, 906 ext2_count_dirs(sb)); 907 /* 908 * set up enough so that it can read an inode 909 */ 910 sb->s_op = &ext2_sops; 911 sb->s_export_op = &ext2_export_ops; 912 sb->s_xattr = ext2_xattr_handlers; 913 root = iget(sb, EXT2_ROOT_INO); 914 sb->s_root = d_alloc_root(root); 915 if (!sb->s_root) { 916 iput(root); 917 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 918 goto failed_mount3; 919 } 920 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 921 dput(sb->s_root); 922 sb->s_root = NULL; 923 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 924 goto failed_mount3; 925 } 926 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 927 ext2_warning(sb, __FUNCTION__, 928 "mounting ext3 filesystem as ext2"); 929 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 930 return 0; 931 932 cantfind_ext2: 933 if (!silent) 934 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 935 sb->s_id); 936 goto failed_mount; 937 failed_mount3: 938 percpu_counter_destroy(&sbi->s_freeblocks_counter); 939 percpu_counter_destroy(&sbi->s_freeinodes_counter); 940 percpu_counter_destroy(&sbi->s_dirs_counter); 941 failed_mount2: 942 for (i = 0; i < db_count; i++) 943 brelse(sbi->s_group_desc[i]); 944 failed_mount_group_desc: 945 kfree(sbi->s_group_desc); 946 kfree(sbi->s_debts); 947 failed_mount: 948 brelse(bh); 949 failed_sbi: 950 sb->s_fs_info = NULL; 951 kfree(sbi); 952 return -EINVAL; 953 } 954 955 static void ext2_commit_super (struct super_block * sb, 956 struct ext2_super_block * es) 957 { 958 es->s_wtime = cpu_to_le32(get_seconds()); 959 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 960 sb->s_dirt = 0; 961 } 962 963 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 964 { 965 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 966 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 967 es->s_wtime = cpu_to_le32(get_seconds()); 968 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 969 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 970 sb->s_dirt = 0; 971 } 972 973 /* 974 * In the second extended file system, it is not necessary to 975 * write the super block since we use a mapping of the 976 * disk super block in a buffer. 977 * 978 * However, this function is still used to set the fs valid 979 * flags to 0. We need to set this flag to 0 since the fs 980 * may have been checked while mounted and e2fsck may have 981 * set s_state to EXT2_VALID_FS after some corrections. 982 */ 983 984 void ext2_write_super (struct super_block * sb) 985 { 986 struct ext2_super_block * es; 987 lock_kernel(); 988 if (!(sb->s_flags & MS_RDONLY)) { 989 es = EXT2_SB(sb)->s_es; 990 991 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 992 ext2_debug ("setting valid to 0\n"); 993 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 994 ~EXT2_VALID_FS); 995 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 996 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 997 es->s_mtime = cpu_to_le32(get_seconds()); 998 ext2_sync_super(sb, es); 999 } else 1000 ext2_commit_super (sb, es); 1001 } 1002 sb->s_dirt = 0; 1003 unlock_kernel(); 1004 } 1005 1006 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1007 { 1008 struct ext2_sb_info * sbi = EXT2_SB(sb); 1009 struct ext2_super_block * es; 1010 unsigned long old_mount_opt = sbi->s_mount_opt; 1011 struct ext2_mount_options old_opts; 1012 unsigned long old_sb_flags; 1013 int err; 1014 1015 /* Store the old options */ 1016 old_sb_flags = sb->s_flags; 1017 old_opts.s_mount_opt = sbi->s_mount_opt; 1018 old_opts.s_resuid = sbi->s_resuid; 1019 old_opts.s_resgid = sbi->s_resgid; 1020 1021 /* 1022 * Allow the "check" option to be passed as a remount option. 1023 */ 1024 if (!parse_options (data, sbi)) { 1025 err = -EINVAL; 1026 goto restore_opts; 1027 } 1028 1029 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1030 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1031 1032 es = sbi->s_es; 1033 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1034 (old_mount_opt & EXT2_MOUNT_XIP)) && 1035 invalidate_inodes(sb)) 1036 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ 1037 "xip remain in cache (no functional problem)"); 1038 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1039 return 0; 1040 if (*flags & MS_RDONLY) { 1041 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1042 !(sbi->s_mount_state & EXT2_VALID_FS)) 1043 return 0; 1044 /* 1045 * OK, we are remounting a valid rw partition rdonly, so set 1046 * the rdonly flag and then mark the partition as valid again. 1047 */ 1048 es->s_state = cpu_to_le16(sbi->s_mount_state); 1049 es->s_mtime = cpu_to_le32(get_seconds()); 1050 } else { 1051 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1052 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1053 if (ret) { 1054 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1055 "unsupported optional features (%x).\n", 1056 sb->s_id, le32_to_cpu(ret)); 1057 err = -EROFS; 1058 goto restore_opts; 1059 } 1060 /* 1061 * Mounting a RDONLY partition read-write, so reread and 1062 * store the current valid flag. (It may have been changed 1063 * by e2fsck since we originally mounted the partition.) 1064 */ 1065 sbi->s_mount_state = le16_to_cpu(es->s_state); 1066 if (!ext2_setup_super (sb, es, 0)) 1067 sb->s_flags &= ~MS_RDONLY; 1068 } 1069 ext2_sync_super(sb, es); 1070 return 0; 1071 restore_opts: 1072 sbi->s_mount_opt = old_opts.s_mount_opt; 1073 sbi->s_resuid = old_opts.s_resuid; 1074 sbi->s_resgid = old_opts.s_resgid; 1075 sb->s_flags = old_sb_flags; 1076 return err; 1077 } 1078 1079 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1080 { 1081 struct super_block *sb = dentry->d_sb; 1082 struct ext2_sb_info *sbi = EXT2_SB(sb); 1083 unsigned long overhead; 1084 int i; 1085 1086 if (test_opt (sb, MINIX_DF)) 1087 overhead = 0; 1088 else { 1089 /* 1090 * Compute the overhead (FS structures) 1091 */ 1092 1093 /* 1094 * All of the blocks before first_data_block are 1095 * overhead 1096 */ 1097 overhead = le32_to_cpu(sbi->s_es->s_first_data_block); 1098 1099 /* 1100 * Add the overhead attributed to the superblock and 1101 * block group descriptors. If the sparse superblocks 1102 * feature is turned on, then not all groups have this. 1103 */ 1104 for (i = 0; i < sbi->s_groups_count; i++) 1105 overhead += ext2_bg_has_super(sb, i) + 1106 ext2_bg_num_gdb(sb, i); 1107 1108 /* 1109 * Every block group has an inode bitmap, a block 1110 * bitmap, and an inode table. 1111 */ 1112 overhead += (sbi->s_groups_count * 1113 (2 + sbi->s_itb_per_group)); 1114 } 1115 1116 buf->f_type = EXT2_SUPER_MAGIC; 1117 buf->f_bsize = sb->s_blocksize; 1118 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead; 1119 buf->f_bfree = ext2_count_free_blocks(sb); 1120 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count); 1121 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count)) 1122 buf->f_bavail = 0; 1123 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count); 1124 buf->f_ffree = ext2_count_free_inodes (sb); 1125 buf->f_namelen = EXT2_NAME_LEN; 1126 return 0; 1127 } 1128 1129 static int ext2_get_sb(struct file_system_type *fs_type, 1130 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1131 { 1132 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1133 } 1134 1135 #ifdef CONFIG_QUOTA 1136 1137 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1138 * acquiring the locks... As quota files are never truncated and quota code 1139 * itself serializes the operations (and noone else should touch the files) 1140 * we don't have to be afraid of races */ 1141 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1142 size_t len, loff_t off) 1143 { 1144 struct inode *inode = sb_dqopt(sb)->files[type]; 1145 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1146 int err = 0; 1147 int offset = off & (sb->s_blocksize - 1); 1148 int tocopy; 1149 size_t toread; 1150 struct buffer_head tmp_bh; 1151 struct buffer_head *bh; 1152 loff_t i_size = i_size_read(inode); 1153 1154 if (off > i_size) 1155 return 0; 1156 if (off+len > i_size) 1157 len = i_size-off; 1158 toread = len; 1159 while (toread > 0) { 1160 tocopy = sb->s_blocksize - offset < toread ? 1161 sb->s_blocksize - offset : toread; 1162 1163 tmp_bh.b_state = 0; 1164 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1165 if (err) 1166 return err; 1167 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1168 memset(data, 0, tocopy); 1169 else { 1170 bh = sb_bread(sb, tmp_bh.b_blocknr); 1171 if (!bh) 1172 return -EIO; 1173 memcpy(data, bh->b_data+offset, tocopy); 1174 brelse(bh); 1175 } 1176 offset = 0; 1177 toread -= tocopy; 1178 data += tocopy; 1179 blk++; 1180 } 1181 return len; 1182 } 1183 1184 /* Write to quotafile */ 1185 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1186 const char *data, size_t len, loff_t off) 1187 { 1188 struct inode *inode = sb_dqopt(sb)->files[type]; 1189 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1190 int err = 0; 1191 int offset = off & (sb->s_blocksize - 1); 1192 int tocopy; 1193 size_t towrite = len; 1194 struct buffer_head tmp_bh; 1195 struct buffer_head *bh; 1196 1197 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1198 while (towrite > 0) { 1199 tocopy = sb->s_blocksize - offset < towrite ? 1200 sb->s_blocksize - offset : towrite; 1201 1202 tmp_bh.b_state = 0; 1203 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1204 if (err) 1205 goto out; 1206 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1207 bh = sb_bread(sb, tmp_bh.b_blocknr); 1208 else 1209 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1210 if (!bh) { 1211 err = -EIO; 1212 goto out; 1213 } 1214 lock_buffer(bh); 1215 memcpy(bh->b_data+offset, data, tocopy); 1216 flush_dcache_page(bh->b_page); 1217 set_buffer_uptodate(bh); 1218 mark_buffer_dirty(bh); 1219 unlock_buffer(bh); 1220 brelse(bh); 1221 offset = 0; 1222 towrite -= tocopy; 1223 data += tocopy; 1224 blk++; 1225 } 1226 out: 1227 if (len == towrite) 1228 return err; 1229 if (inode->i_size < off+len-towrite) 1230 i_size_write(inode, off+len-towrite); 1231 inode->i_version++; 1232 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1233 mark_inode_dirty(inode); 1234 mutex_unlock(&inode->i_mutex); 1235 return len - towrite; 1236 } 1237 1238 #endif 1239 1240 static struct file_system_type ext2_fs_type = { 1241 .owner = THIS_MODULE, 1242 .name = "ext2", 1243 .get_sb = ext2_get_sb, 1244 .kill_sb = kill_block_super, 1245 .fs_flags = FS_REQUIRES_DEV, 1246 }; 1247 1248 static int __init init_ext2_fs(void) 1249 { 1250 int err = init_ext2_xattr(); 1251 if (err) 1252 return err; 1253 err = init_inodecache(); 1254 if (err) 1255 goto out1; 1256 err = register_filesystem(&ext2_fs_type); 1257 if (err) 1258 goto out; 1259 return 0; 1260 out: 1261 destroy_inodecache(); 1262 out1: 1263 exit_ext2_xattr(); 1264 return err; 1265 } 1266 1267 static void __exit exit_ext2_fs(void) 1268 { 1269 unregister_filesystem(&ext2_fs_type); 1270 destroy_inodecache(); 1271 exit_ext2_xattr(); 1272 } 1273 1274 module_init(init_ext2_fs) 1275 module_exit(exit_ext2_fs) 1276