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/exportfs.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 dentry * dentry, 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 struct kmem_cache * 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, GFP_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, struct kmem_cache * cachep, unsigned long flags) 161 { 162 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 163 164 rwlock_init(&ei->i_meta_lock); 165 #ifdef CONFIG_EXT2_FS_XATTR 166 init_rwsem(&ei->xattr_sem); 167 #endif 168 inode_init_once(&ei->vfs_inode); 169 } 170 171 static int init_inodecache(void) 172 { 173 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 174 sizeof(struct ext2_inode_info), 175 0, (SLAB_RECLAIM_ACCOUNT| 176 SLAB_MEM_SPREAD), 177 init_once); 178 if (ext2_inode_cachep == NULL) 179 return -ENOMEM; 180 return 0; 181 } 182 183 static void destroy_inodecache(void) 184 { 185 kmem_cache_destroy(ext2_inode_cachep); 186 } 187 188 static void ext2_clear_inode(struct inode *inode) 189 { 190 #ifdef CONFIG_EXT2_FS_POSIX_ACL 191 struct ext2_inode_info *ei = EXT2_I(inode); 192 193 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 194 posix_acl_release(ei->i_acl); 195 ei->i_acl = EXT2_ACL_NOT_CACHED; 196 } 197 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 198 posix_acl_release(ei->i_default_acl); 199 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 200 } 201 #endif 202 } 203 204 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 205 { 206 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb); 207 208 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID) 209 seq_puts(seq, ",grpid"); 210 211 #if defined(CONFIG_QUOTA) 212 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 213 seq_puts(seq, ",usrquota"); 214 215 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 216 seq_puts(seq, ",grpquota"); 217 #endif 218 219 #if defined(CONFIG_EXT2_FS_XIP) 220 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 221 seq_puts(seq, ",xip"); 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 const 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 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp) 252 { 253 __u32 *objp = vobjp; 254 unsigned long ino = objp[0]; 255 __u32 generation = objp[1]; 256 struct inode *inode; 257 struct dentry *result; 258 259 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 260 return ERR_PTR(-ESTALE); 261 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 262 return ERR_PTR(-ESTALE); 263 264 /* iget isn't really right if the inode is currently unallocated!! 265 * ext2_read_inode currently does appropriate checks, but 266 * it might be "neater" to call ext2_get_inode first and check 267 * if the inode is valid..... 268 */ 269 inode = iget(sb, ino); 270 if (inode == NULL) 271 return ERR_PTR(-ENOMEM); 272 if (is_bad_inode(inode) || 273 (generation && inode->i_generation != generation)) { 274 /* we didn't find the right inode.. */ 275 iput(inode); 276 return ERR_PTR(-ESTALE); 277 } 278 /* now to find a dentry. 279 * If possible, get a well-connected one 280 */ 281 result = d_alloc_anon(inode); 282 if (!result) { 283 iput(inode); 284 return ERR_PTR(-ENOMEM); 285 } 286 return result; 287 } 288 289 /* Yes, most of these are left as NULL!! 290 * A NULL value implies the default, which works with ext2-like file 291 * systems, but can be improved upon. 292 * Currently only get_parent is required. 293 */ 294 static struct export_operations ext2_export_ops = { 295 .get_parent = ext2_get_parent, 296 .get_dentry = ext2_get_dentry, 297 }; 298 299 static unsigned long get_sb_block(void **data) 300 { 301 unsigned long sb_block; 302 char *options = (char *) *data; 303 304 if (!options || strncmp(options, "sb=", 3) != 0) 305 return 1; /* Default location */ 306 options += 3; 307 sb_block = simple_strtoul(options, &options, 0); 308 if (*options && *options != ',') { 309 printk("EXT2-fs: Invalid sb specification: %s\n", 310 (char *) *data); 311 return 1; 312 } 313 if (*options == ',') 314 options++; 315 *data = (void *) options; 316 return sb_block; 317 } 318 319 enum { 320 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 321 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 322 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 323 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 324 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 325 Opt_usrquota, Opt_grpquota 326 }; 327 328 static match_table_t tokens = { 329 {Opt_bsd_df, "bsddf"}, 330 {Opt_minix_df, "minixdf"}, 331 {Opt_grpid, "grpid"}, 332 {Opt_grpid, "bsdgroups"}, 333 {Opt_nogrpid, "nogrpid"}, 334 {Opt_nogrpid, "sysvgroups"}, 335 {Opt_resgid, "resgid=%u"}, 336 {Opt_resuid, "resuid=%u"}, 337 {Opt_sb, "sb=%u"}, 338 {Opt_err_cont, "errors=continue"}, 339 {Opt_err_panic, "errors=panic"}, 340 {Opt_err_ro, "errors=remount-ro"}, 341 {Opt_nouid32, "nouid32"}, 342 {Opt_nocheck, "check=none"}, 343 {Opt_nocheck, "nocheck"}, 344 {Opt_debug, "debug"}, 345 {Opt_oldalloc, "oldalloc"}, 346 {Opt_orlov, "orlov"}, 347 {Opt_nobh, "nobh"}, 348 {Opt_user_xattr, "user_xattr"}, 349 {Opt_nouser_xattr, "nouser_xattr"}, 350 {Opt_acl, "acl"}, 351 {Opt_noacl, "noacl"}, 352 {Opt_xip, "xip"}, 353 {Opt_grpquota, "grpquota"}, 354 {Opt_ignore, "noquota"}, 355 {Opt_quota, "quota"}, 356 {Opt_usrquota, "usrquota"}, 357 {Opt_err, NULL} 358 }; 359 360 static int parse_options (char * options, 361 struct ext2_sb_info *sbi) 362 { 363 char * p; 364 substring_t args[MAX_OPT_ARGS]; 365 int option; 366 367 if (!options) 368 return 1; 369 370 while ((p = strsep (&options, ",")) != NULL) { 371 int token; 372 if (!*p) 373 continue; 374 375 token = match_token(p, tokens, args); 376 switch (token) { 377 case Opt_bsd_df: 378 clear_opt (sbi->s_mount_opt, MINIX_DF); 379 break; 380 case Opt_minix_df: 381 set_opt (sbi->s_mount_opt, MINIX_DF); 382 break; 383 case Opt_grpid: 384 set_opt (sbi->s_mount_opt, GRPID); 385 break; 386 case Opt_nogrpid: 387 clear_opt (sbi->s_mount_opt, GRPID); 388 break; 389 case Opt_resuid: 390 if (match_int(&args[0], &option)) 391 return 0; 392 sbi->s_resuid = option; 393 break; 394 case Opt_resgid: 395 if (match_int(&args[0], &option)) 396 return 0; 397 sbi->s_resgid = option; 398 break; 399 case Opt_sb: 400 /* handled by get_sb_block() instead of here */ 401 /* *sb_block = match_int(&args[0]); */ 402 break; 403 case Opt_err_panic: 404 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 405 clear_opt (sbi->s_mount_opt, ERRORS_RO); 406 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 407 break; 408 case Opt_err_ro: 409 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 410 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 411 set_opt (sbi->s_mount_opt, ERRORS_RO); 412 break; 413 case Opt_err_cont: 414 clear_opt (sbi->s_mount_opt, ERRORS_RO); 415 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 416 set_opt (sbi->s_mount_opt, ERRORS_CONT); 417 break; 418 case Opt_nouid32: 419 set_opt (sbi->s_mount_opt, NO_UID32); 420 break; 421 case Opt_nocheck: 422 clear_opt (sbi->s_mount_opt, CHECK); 423 break; 424 case Opt_debug: 425 set_opt (sbi->s_mount_opt, DEBUG); 426 break; 427 case Opt_oldalloc: 428 set_opt (sbi->s_mount_opt, OLDALLOC); 429 break; 430 case Opt_orlov: 431 clear_opt (sbi->s_mount_opt, OLDALLOC); 432 break; 433 case Opt_nobh: 434 set_opt (sbi->s_mount_opt, NOBH); 435 break; 436 #ifdef CONFIG_EXT2_FS_XATTR 437 case Opt_user_xattr: 438 set_opt (sbi->s_mount_opt, XATTR_USER); 439 break; 440 case Opt_nouser_xattr: 441 clear_opt (sbi->s_mount_opt, XATTR_USER); 442 break; 443 #else 444 case Opt_user_xattr: 445 case Opt_nouser_xattr: 446 printk("EXT2 (no)user_xattr options not supported\n"); 447 break; 448 #endif 449 #ifdef CONFIG_EXT2_FS_POSIX_ACL 450 case Opt_acl: 451 set_opt(sbi->s_mount_opt, POSIX_ACL); 452 break; 453 case Opt_noacl: 454 clear_opt(sbi->s_mount_opt, POSIX_ACL); 455 break; 456 #else 457 case Opt_acl: 458 case Opt_noacl: 459 printk("EXT2 (no)acl options not supported\n"); 460 break; 461 #endif 462 case Opt_xip: 463 #ifdef CONFIG_EXT2_FS_XIP 464 set_opt (sbi->s_mount_opt, XIP); 465 #else 466 printk("EXT2 xip option not supported\n"); 467 #endif 468 break; 469 470 #if defined(CONFIG_QUOTA) 471 case Opt_quota: 472 case Opt_usrquota: 473 set_opt(sbi->s_mount_opt, USRQUOTA); 474 break; 475 476 case Opt_grpquota: 477 set_opt(sbi->s_mount_opt, GRPQUOTA); 478 break; 479 #else 480 case Opt_quota: 481 case Opt_usrquota: 482 case Opt_grpquota: 483 printk(KERN_ERR 484 "EXT2-fs: quota operations not supported.\n"); 485 486 break; 487 #endif 488 489 case Opt_ignore: 490 break; 491 default: 492 return 0; 493 } 494 } 495 return 1; 496 } 497 498 static int ext2_setup_super (struct super_block * sb, 499 struct ext2_super_block * es, 500 int read_only) 501 { 502 int res = 0; 503 struct ext2_sb_info *sbi = EXT2_SB(sb); 504 505 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 506 printk ("EXT2-fs warning: revision level too high, " 507 "forcing read-only mode\n"); 508 res = MS_RDONLY; 509 } 510 if (read_only) 511 return res; 512 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 513 printk ("EXT2-fs warning: mounting unchecked fs, " 514 "running e2fsck is recommended\n"); 515 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 516 printk ("EXT2-fs warning: mounting fs with errors, " 517 "running e2fsck is recommended\n"); 518 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 519 le16_to_cpu(es->s_mnt_count) >= 520 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 521 printk ("EXT2-fs warning: maximal mount count reached, " 522 "running e2fsck is recommended\n"); 523 else if (le32_to_cpu(es->s_checkinterval) && 524 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 525 printk ("EXT2-fs warning: checktime reached, " 526 "running e2fsck is recommended\n"); 527 if (!le16_to_cpu(es->s_max_mnt_count)) 528 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 529 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 530 ext2_write_super(sb); 531 if (test_opt (sb, DEBUG)) 532 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 533 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 534 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 535 sbi->s_frag_size, 536 sbi->s_groups_count, 537 EXT2_BLOCKS_PER_GROUP(sb), 538 EXT2_INODES_PER_GROUP(sb), 539 sbi->s_mount_opt); 540 return res; 541 } 542 543 static int ext2_check_descriptors (struct super_block * sb) 544 { 545 int i; 546 int desc_block = 0; 547 struct ext2_sb_info *sbi = EXT2_SB(sb); 548 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block); 549 unsigned long last_block; 550 struct ext2_group_desc * gdp = NULL; 551 552 ext2_debug ("Checking group descriptors"); 553 554 for (i = 0; i < sbi->s_groups_count; i++) 555 { 556 if (i == sbi->s_groups_count - 1) 557 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 558 else 559 last_block = first_block + 560 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 561 562 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) 563 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; 564 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 565 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 566 { 567 ext2_error (sb, "ext2_check_descriptors", 568 "Block bitmap for group %d" 569 " not in group (block %lu)!", 570 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 571 return 0; 572 } 573 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 574 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 575 { 576 ext2_error (sb, "ext2_check_descriptors", 577 "Inode bitmap for group %d" 578 " not in group (block %lu)!", 579 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 580 return 0; 581 } 582 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 583 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 584 last_block) 585 { 586 ext2_error (sb, "ext2_check_descriptors", 587 "Inode table for group %d" 588 " not in group (block %lu)!", 589 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 590 return 0; 591 } 592 first_block += EXT2_BLOCKS_PER_GROUP(sb); 593 gdp++; 594 } 595 return 1; 596 } 597 598 /* 599 * Maximal file size. There is a direct, and {,double-,triple-}indirect 600 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 601 * We need to be 1 filesystem block less than the 2^32 sector limit. 602 */ 603 static loff_t ext2_max_size(int bits) 604 { 605 loff_t res = EXT2_NDIR_BLOCKS; 606 /* This constant is calculated to be the largest file size for a 607 * dense, 4k-blocksize file such that the total number of 608 * sectors in the file, including data and all indirect blocks, 609 * does not exceed 2^32. */ 610 const loff_t upper_limit = 0x1ff7fffd000LL; 611 612 res += 1LL << (bits-2); 613 res += 1LL << (2*(bits-2)); 614 res += 1LL << (3*(bits-2)); 615 res <<= bits; 616 if (res > upper_limit) 617 res = upper_limit; 618 return res; 619 } 620 621 static unsigned long descriptor_loc(struct super_block *sb, 622 unsigned long logic_sb_block, 623 int nr) 624 { 625 struct ext2_sb_info *sbi = EXT2_SB(sb); 626 unsigned long bg, first_data_block, first_meta_bg; 627 int has_super = 0; 628 629 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 630 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 631 632 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 633 nr < first_meta_bg) 634 return (logic_sb_block + nr + 1); 635 bg = sbi->s_desc_per_block * nr; 636 if (ext2_bg_has_super(sb, bg)) 637 has_super = 1; 638 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 639 } 640 641 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 642 { 643 struct buffer_head * bh; 644 struct ext2_sb_info * sbi; 645 struct ext2_super_block * es; 646 struct inode *root; 647 unsigned long block; 648 unsigned long sb_block = get_sb_block(&data); 649 unsigned long logic_sb_block; 650 unsigned long offset = 0; 651 unsigned long def_mount_opts; 652 int blocksize = BLOCK_SIZE; 653 int db_count; 654 int i, j; 655 __le32 features; 656 657 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 658 if (!sbi) 659 return -ENOMEM; 660 sb->s_fs_info = sbi; 661 662 /* 663 * See what the current blocksize for the device is, and 664 * use that as the blocksize. Otherwise (or if the blocksize 665 * is smaller than the default) use the default. 666 * This is important for devices that have a hardware 667 * sectorsize that is larger than the default. 668 */ 669 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 670 if (!blocksize) { 671 printk ("EXT2-fs: unable to set blocksize\n"); 672 goto failed_sbi; 673 } 674 675 /* 676 * If the superblock doesn't start on a hardware sector boundary, 677 * calculate the offset. 678 */ 679 if (blocksize != BLOCK_SIZE) { 680 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 681 offset = (sb_block*BLOCK_SIZE) % blocksize; 682 } else { 683 logic_sb_block = sb_block; 684 } 685 686 if (!(bh = sb_bread(sb, logic_sb_block))) { 687 printk ("EXT2-fs: unable to read superblock\n"); 688 goto failed_sbi; 689 } 690 /* 691 * Note: s_es must be initialized as soon as possible because 692 * some ext2 macro-instructions depend on its value 693 */ 694 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 695 sbi->s_es = es; 696 sb->s_magic = le16_to_cpu(es->s_magic); 697 698 if (sb->s_magic != EXT2_SUPER_MAGIC) 699 goto cantfind_ext2; 700 701 /* Set defaults before we parse the mount options */ 702 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 703 if (def_mount_opts & EXT2_DEFM_DEBUG) 704 set_opt(sbi->s_mount_opt, DEBUG); 705 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 706 set_opt(sbi->s_mount_opt, GRPID); 707 if (def_mount_opts & EXT2_DEFM_UID16) 708 set_opt(sbi->s_mount_opt, NO_UID32); 709 #ifdef CONFIG_EXT2_FS_XATTR 710 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 711 set_opt(sbi->s_mount_opt, XATTR_USER); 712 #endif 713 #ifdef CONFIG_EXT2_FS_POSIX_ACL 714 if (def_mount_opts & EXT2_DEFM_ACL) 715 set_opt(sbi->s_mount_opt, POSIX_ACL); 716 #endif 717 718 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 719 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 720 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) 721 set_opt(sbi->s_mount_opt, ERRORS_RO); 722 else 723 set_opt(sbi->s_mount_opt, ERRORS_CONT); 724 725 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 726 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 727 728 if (!parse_options ((char *) data, sbi)) 729 goto failed_mount; 730 731 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 732 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 733 MS_POSIXACL : 0); 734 735 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 736 EXT2_MOUNT_XIP if not */ 737 738 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 739 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 740 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 741 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 742 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 743 "running e2fsck is recommended\n"); 744 /* 745 * Check feature flags regardless of the revision level, since we 746 * previously didn't change the revision level when setting the flags, 747 * so there is a chance incompat flags are set on a rev 0 filesystem. 748 */ 749 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 750 if (features) { 751 printk("EXT2-fs: %s: couldn't mount because of " 752 "unsupported optional features (%x).\n", 753 sb->s_id, le32_to_cpu(features)); 754 goto failed_mount; 755 } 756 if (!(sb->s_flags & MS_RDONLY) && 757 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 758 printk("EXT2-fs: %s: couldn't mount RDWR because of " 759 "unsupported optional features (%x).\n", 760 sb->s_id, le32_to_cpu(features)); 761 goto failed_mount; 762 } 763 764 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 765 766 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) || 767 (sb->s_blocksize != blocksize))) { 768 if (!silent) 769 printk("XIP: Unsupported blocksize\n"); 770 goto failed_mount; 771 } 772 773 /* If the blocksize doesn't match, re-read the thing.. */ 774 if (sb->s_blocksize != blocksize) { 775 brelse(bh); 776 777 if (!sb_set_blocksize(sb, blocksize)) { 778 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 779 goto failed_sbi; 780 } 781 782 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 783 offset = (sb_block*BLOCK_SIZE) % blocksize; 784 bh = sb_bread(sb, logic_sb_block); 785 if(!bh) { 786 printk("EXT2-fs: Couldn't read superblock on " 787 "2nd try.\n"); 788 goto failed_sbi; 789 } 790 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 791 sbi->s_es = es; 792 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 793 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 794 goto failed_mount; 795 } 796 } 797 798 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 799 800 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 801 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 802 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 803 } else { 804 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 805 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 806 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 807 (sbi->s_inode_size & (sbi->s_inode_size - 1)) || 808 (sbi->s_inode_size > blocksize)) { 809 printk ("EXT2-fs: unsupported inode size: %d\n", 810 sbi->s_inode_size); 811 goto failed_mount; 812 } 813 } 814 815 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 816 le32_to_cpu(es->s_log_frag_size); 817 if (sbi->s_frag_size == 0) 818 goto cantfind_ext2; 819 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 820 821 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 822 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 823 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 824 825 if (EXT2_INODE_SIZE(sb) == 0) 826 goto cantfind_ext2; 827 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 828 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 829 goto cantfind_ext2; 830 sbi->s_itb_per_group = sbi->s_inodes_per_group / 831 sbi->s_inodes_per_block; 832 sbi->s_desc_per_block = sb->s_blocksize / 833 sizeof (struct ext2_group_desc); 834 sbi->s_sbh = bh; 835 sbi->s_mount_state = le16_to_cpu(es->s_state); 836 sbi->s_addr_per_block_bits = 837 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 838 sbi->s_desc_per_block_bits = 839 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 840 841 if (sb->s_magic != EXT2_SUPER_MAGIC) 842 goto cantfind_ext2; 843 844 if (sb->s_blocksize != bh->b_size) { 845 if (!silent) 846 printk ("VFS: Unsupported blocksize on dev " 847 "%s.\n", sb->s_id); 848 goto failed_mount; 849 } 850 851 if (sb->s_blocksize != sbi->s_frag_size) { 852 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 853 sbi->s_frag_size, sb->s_blocksize); 854 goto failed_mount; 855 } 856 857 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 858 printk ("EXT2-fs: #blocks per group too big: %lu\n", 859 sbi->s_blocks_per_group); 860 goto failed_mount; 861 } 862 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 863 printk ("EXT2-fs: #fragments per group too big: %lu\n", 864 sbi->s_frags_per_group); 865 goto failed_mount; 866 } 867 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 868 printk ("EXT2-fs: #inodes per group too big: %lu\n", 869 sbi->s_inodes_per_group); 870 goto failed_mount; 871 } 872 873 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 874 goto cantfind_ext2; 875 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 876 le32_to_cpu(es->s_first_data_block) - 1) 877 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 878 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 879 EXT2_DESC_PER_BLOCK(sb); 880 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 881 if (sbi->s_group_desc == NULL) { 882 printk ("EXT2-fs: not enough memory\n"); 883 goto failed_mount; 884 } 885 bgl_lock_init(&sbi->s_blockgroup_lock); 886 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 887 if (!sbi->s_debts) { 888 printk ("EXT2-fs: not enough memory\n"); 889 goto failed_mount_group_desc; 890 } 891 for (i = 0; i < db_count; i++) { 892 block = descriptor_loc(sb, logic_sb_block, i); 893 sbi->s_group_desc[i] = sb_bread(sb, block); 894 if (!sbi->s_group_desc[i]) { 895 for (j = 0; j < i; j++) 896 brelse (sbi->s_group_desc[j]); 897 printk ("EXT2-fs: unable to read group descriptors\n"); 898 goto failed_mount_group_desc; 899 } 900 } 901 if (!ext2_check_descriptors (sb)) { 902 printk ("EXT2-fs: group descriptors corrupted!\n"); 903 goto failed_mount2; 904 } 905 sbi->s_gdb_count = db_count; 906 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 907 spin_lock_init(&sbi->s_next_gen_lock); 908 909 percpu_counter_init(&sbi->s_freeblocks_counter, 910 ext2_count_free_blocks(sb)); 911 percpu_counter_init(&sbi->s_freeinodes_counter, 912 ext2_count_free_inodes(sb)); 913 percpu_counter_init(&sbi->s_dirs_counter, 914 ext2_count_dirs(sb)); 915 /* 916 * set up enough so that it can read an inode 917 */ 918 sb->s_op = &ext2_sops; 919 sb->s_export_op = &ext2_export_ops; 920 sb->s_xattr = ext2_xattr_handlers; 921 root = iget(sb, EXT2_ROOT_INO); 922 sb->s_root = d_alloc_root(root); 923 if (!sb->s_root) { 924 iput(root); 925 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 926 goto failed_mount3; 927 } 928 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 929 dput(sb->s_root); 930 sb->s_root = NULL; 931 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 932 goto failed_mount3; 933 } 934 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 935 ext2_warning(sb, __FUNCTION__, 936 "mounting ext3 filesystem as ext2"); 937 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 938 return 0; 939 940 cantfind_ext2: 941 if (!silent) 942 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 943 sb->s_id); 944 goto failed_mount; 945 failed_mount3: 946 percpu_counter_destroy(&sbi->s_freeblocks_counter); 947 percpu_counter_destroy(&sbi->s_freeinodes_counter); 948 percpu_counter_destroy(&sbi->s_dirs_counter); 949 failed_mount2: 950 for (i = 0; i < db_count; i++) 951 brelse(sbi->s_group_desc[i]); 952 failed_mount_group_desc: 953 kfree(sbi->s_group_desc); 954 kfree(sbi->s_debts); 955 failed_mount: 956 brelse(bh); 957 failed_sbi: 958 sb->s_fs_info = NULL; 959 kfree(sbi); 960 return -EINVAL; 961 } 962 963 static void ext2_commit_super (struct super_block * sb, 964 struct ext2_super_block * es) 965 { 966 es->s_wtime = cpu_to_le32(get_seconds()); 967 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 968 sb->s_dirt = 0; 969 } 970 971 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 972 { 973 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 974 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 975 es->s_wtime = cpu_to_le32(get_seconds()); 976 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 977 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 978 sb->s_dirt = 0; 979 } 980 981 /* 982 * In the second extended file system, it is not necessary to 983 * write the super block since we use a mapping of the 984 * disk super block in a buffer. 985 * 986 * However, this function is still used to set the fs valid 987 * flags to 0. We need to set this flag to 0 since the fs 988 * may have been checked while mounted and e2fsck may have 989 * set s_state to EXT2_VALID_FS after some corrections. 990 */ 991 992 void ext2_write_super (struct super_block * sb) 993 { 994 struct ext2_super_block * es; 995 lock_kernel(); 996 if (!(sb->s_flags & MS_RDONLY)) { 997 es = EXT2_SB(sb)->s_es; 998 999 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 1000 ext2_debug ("setting valid to 0\n"); 1001 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 1002 ~EXT2_VALID_FS); 1003 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1004 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1005 es->s_mtime = cpu_to_le32(get_seconds()); 1006 ext2_sync_super(sb, es); 1007 } else 1008 ext2_commit_super (sb, es); 1009 } 1010 sb->s_dirt = 0; 1011 unlock_kernel(); 1012 } 1013 1014 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1015 { 1016 struct ext2_sb_info * sbi = EXT2_SB(sb); 1017 struct ext2_super_block * es; 1018 unsigned long old_mount_opt = sbi->s_mount_opt; 1019 struct ext2_mount_options old_opts; 1020 unsigned long old_sb_flags; 1021 int err; 1022 1023 /* Store the old options */ 1024 old_sb_flags = sb->s_flags; 1025 old_opts.s_mount_opt = sbi->s_mount_opt; 1026 old_opts.s_resuid = sbi->s_resuid; 1027 old_opts.s_resgid = sbi->s_resgid; 1028 1029 /* 1030 * Allow the "check" option to be passed as a remount option. 1031 */ 1032 if (!parse_options (data, sbi)) { 1033 err = -EINVAL; 1034 goto restore_opts; 1035 } 1036 1037 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1038 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1039 1040 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1041 EXT2_MOUNT_XIP if not */ 1042 1043 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1044 printk("XIP: Unsupported blocksize\n"); 1045 err = -EINVAL; 1046 goto restore_opts; 1047 } 1048 1049 es = sbi->s_es; 1050 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1051 (old_mount_opt & EXT2_MOUNT_XIP)) && 1052 invalidate_inodes(sb)) 1053 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ 1054 "xip remain in cache (no functional problem)"); 1055 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1056 return 0; 1057 if (*flags & MS_RDONLY) { 1058 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1059 !(sbi->s_mount_state & EXT2_VALID_FS)) 1060 return 0; 1061 /* 1062 * OK, we are remounting a valid rw partition rdonly, so set 1063 * the rdonly flag and then mark the partition as valid again. 1064 */ 1065 es->s_state = cpu_to_le16(sbi->s_mount_state); 1066 es->s_mtime = cpu_to_le32(get_seconds()); 1067 } else { 1068 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1069 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1070 if (ret) { 1071 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1072 "unsupported optional features (%x).\n", 1073 sb->s_id, le32_to_cpu(ret)); 1074 err = -EROFS; 1075 goto restore_opts; 1076 } 1077 /* 1078 * Mounting a RDONLY partition read-write, so reread and 1079 * store the current valid flag. (It may have been changed 1080 * by e2fsck since we originally mounted the partition.) 1081 */ 1082 sbi->s_mount_state = le16_to_cpu(es->s_state); 1083 if (!ext2_setup_super (sb, es, 0)) 1084 sb->s_flags &= ~MS_RDONLY; 1085 } 1086 ext2_sync_super(sb, es); 1087 return 0; 1088 restore_opts: 1089 sbi->s_mount_opt = old_opts.s_mount_opt; 1090 sbi->s_resuid = old_opts.s_resuid; 1091 sbi->s_resgid = old_opts.s_resgid; 1092 sb->s_flags = old_sb_flags; 1093 return err; 1094 } 1095 1096 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1097 { 1098 struct super_block *sb = dentry->d_sb; 1099 struct ext2_sb_info *sbi = EXT2_SB(sb); 1100 struct ext2_super_block *es = sbi->s_es; 1101 u64 fsid; 1102 1103 if (test_opt (sb, MINIX_DF)) 1104 sbi->s_overhead_last = 0; 1105 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1106 unsigned long i, overhead = 0; 1107 smp_rmb(); 1108 1109 /* 1110 * Compute the overhead (FS structures). This is constant 1111 * for a given filesystem unless the number of block groups 1112 * changes so we cache the previous value until it does. 1113 */ 1114 1115 /* 1116 * All of the blocks before first_data_block are 1117 * overhead 1118 */ 1119 overhead = le32_to_cpu(es->s_first_data_block); 1120 1121 /* 1122 * Add the overhead attributed to the superblock and 1123 * block group descriptors. If the sparse superblocks 1124 * feature is turned on, then not all groups have this. 1125 */ 1126 for (i = 0; i < sbi->s_groups_count; i++) 1127 overhead += ext2_bg_has_super(sb, i) + 1128 ext2_bg_num_gdb(sb, i); 1129 1130 /* 1131 * Every block group has an inode bitmap, a block 1132 * bitmap, and an inode table. 1133 */ 1134 overhead += (sbi->s_groups_count * 1135 (2 + sbi->s_itb_per_group)); 1136 sbi->s_overhead_last = overhead; 1137 smp_wmb(); 1138 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1139 } 1140 1141 buf->f_type = EXT2_SUPER_MAGIC; 1142 buf->f_bsize = sb->s_blocksize; 1143 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1144 buf->f_bfree = ext2_count_free_blocks(sb); 1145 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1146 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1147 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1148 buf->f_bavail = 0; 1149 buf->f_files = le32_to_cpu(es->s_inodes_count); 1150 buf->f_ffree = ext2_count_free_inodes(sb); 1151 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1152 buf->f_namelen = EXT2_NAME_LEN; 1153 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1154 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1155 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1156 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1157 return 0; 1158 } 1159 1160 static int ext2_get_sb(struct file_system_type *fs_type, 1161 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1162 { 1163 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1164 } 1165 1166 #ifdef CONFIG_QUOTA 1167 1168 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1169 * acquiring the locks... As quota files are never truncated and quota code 1170 * itself serializes the operations (and noone else should touch the files) 1171 * we don't have to be afraid of races */ 1172 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1173 size_t len, loff_t off) 1174 { 1175 struct inode *inode = sb_dqopt(sb)->files[type]; 1176 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1177 int err = 0; 1178 int offset = off & (sb->s_blocksize - 1); 1179 int tocopy; 1180 size_t toread; 1181 struct buffer_head tmp_bh; 1182 struct buffer_head *bh; 1183 loff_t i_size = i_size_read(inode); 1184 1185 if (off > i_size) 1186 return 0; 1187 if (off+len > i_size) 1188 len = i_size-off; 1189 toread = len; 1190 while (toread > 0) { 1191 tocopy = sb->s_blocksize - offset < toread ? 1192 sb->s_blocksize - offset : toread; 1193 1194 tmp_bh.b_state = 0; 1195 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1196 if (err) 1197 return err; 1198 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1199 memset(data, 0, tocopy); 1200 else { 1201 bh = sb_bread(sb, tmp_bh.b_blocknr); 1202 if (!bh) 1203 return -EIO; 1204 memcpy(data, bh->b_data+offset, tocopy); 1205 brelse(bh); 1206 } 1207 offset = 0; 1208 toread -= tocopy; 1209 data += tocopy; 1210 blk++; 1211 } 1212 return len; 1213 } 1214 1215 /* Write to quotafile */ 1216 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1217 const char *data, size_t len, loff_t off) 1218 { 1219 struct inode *inode = sb_dqopt(sb)->files[type]; 1220 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1221 int err = 0; 1222 int offset = off & (sb->s_blocksize - 1); 1223 int tocopy; 1224 size_t towrite = len; 1225 struct buffer_head tmp_bh; 1226 struct buffer_head *bh; 1227 1228 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1229 while (towrite > 0) { 1230 tocopy = sb->s_blocksize - offset < towrite ? 1231 sb->s_blocksize - offset : towrite; 1232 1233 tmp_bh.b_state = 0; 1234 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1235 if (err) 1236 goto out; 1237 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1238 bh = sb_bread(sb, tmp_bh.b_blocknr); 1239 else 1240 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1241 if (!bh) { 1242 err = -EIO; 1243 goto out; 1244 } 1245 lock_buffer(bh); 1246 memcpy(bh->b_data+offset, data, tocopy); 1247 flush_dcache_page(bh->b_page); 1248 set_buffer_uptodate(bh); 1249 mark_buffer_dirty(bh); 1250 unlock_buffer(bh); 1251 brelse(bh); 1252 offset = 0; 1253 towrite -= tocopy; 1254 data += tocopy; 1255 blk++; 1256 } 1257 out: 1258 if (len == towrite) 1259 return err; 1260 if (inode->i_size < off+len-towrite) 1261 i_size_write(inode, off+len-towrite); 1262 inode->i_version++; 1263 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1264 mark_inode_dirty(inode); 1265 mutex_unlock(&inode->i_mutex); 1266 return len - towrite; 1267 } 1268 1269 #endif 1270 1271 static struct file_system_type ext2_fs_type = { 1272 .owner = THIS_MODULE, 1273 .name = "ext2", 1274 .get_sb = ext2_get_sb, 1275 .kill_sb = kill_block_super, 1276 .fs_flags = FS_REQUIRES_DEV, 1277 }; 1278 1279 static int __init init_ext2_fs(void) 1280 { 1281 int err = init_ext2_xattr(); 1282 if (err) 1283 return err; 1284 err = init_inodecache(); 1285 if (err) 1286 goto out1; 1287 err = register_filesystem(&ext2_fs_type); 1288 if (err) 1289 goto out; 1290 return 0; 1291 out: 1292 destroy_inodecache(); 1293 out1: 1294 exit_ext2_xattr(); 1295 return err; 1296 } 1297 1298 static void __exit exit_ext2_fs(void) 1299 { 1300 unregister_filesystem(&ext2_fs_type); 1301 destroy_inodecache(); 1302 exit_ext2_xattr(); 1303 } 1304 1305 module_init(init_ext2_fs) 1306 module_exit(exit_ext2_fs) 1307