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 <linux/log2.h> 34 #include <asm/uaccess.h> 35 #include "ext2.h" 36 #include "xattr.h" 37 #include "acl.h" 38 #include "xip.h" 39 40 static void ext2_sync_super(struct super_block *sb, 41 struct ext2_super_block *es); 42 static int ext2_remount (struct super_block * sb, int * flags, char * data); 43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); 44 45 void ext2_error (struct super_block * sb, const char * function, 46 const char * fmt, ...) 47 { 48 va_list args; 49 struct ext2_sb_info *sbi = EXT2_SB(sb); 50 struct ext2_super_block *es = sbi->s_es; 51 52 if (!(sb->s_flags & MS_RDONLY)) { 53 sbi->s_mount_state |= EXT2_ERROR_FS; 54 es->s_state = 55 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS); 56 ext2_sync_super(sb, es); 57 } 58 59 va_start(args, fmt); 60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 61 vprintk(fmt, args); 62 printk("\n"); 63 va_end(args); 64 65 if (test_opt(sb, ERRORS_PANIC)) 66 panic("EXT2-fs panic from previous error\n"); 67 if (test_opt(sb, ERRORS_RO)) { 68 printk("Remounting filesystem read-only\n"); 69 sb->s_flags |= MS_RDONLY; 70 } 71 } 72 73 void ext2_warning (struct super_block * sb, const char * function, 74 const char * fmt, ...) 75 { 76 va_list args; 77 78 va_start(args, fmt); 79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 80 sb->s_id, function); 81 vprintk(fmt, args); 82 printk("\n"); 83 va_end(args); 84 } 85 86 void ext2_update_dynamic_rev(struct super_block *sb) 87 { 88 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 89 90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 91 return; 92 93 ext2_warning(sb, __FUNCTION__, 94 "updating to rev %d because of new feature flag, " 95 "running e2fsck is recommended", 96 EXT2_DYNAMIC_REV); 97 98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 101 /* leave es->s_feature_*compat flags alone */ 102 /* es->s_uuid will be set by e2fsck if empty */ 103 104 /* 105 * The rest of the superblock fields should be zero, and if not it 106 * means they are likely already in use, so leave them alone. We 107 * can leave it up to e2fsck to clean up any inconsistencies there. 108 */ 109 } 110 111 static void ext2_put_super (struct super_block * sb) 112 { 113 int db_count; 114 int i; 115 struct ext2_sb_info *sbi = EXT2_SB(sb); 116 117 ext2_xattr_put_super(sb); 118 if (!(sb->s_flags & MS_RDONLY)) { 119 struct ext2_super_block *es = sbi->s_es; 120 121 es->s_state = cpu_to_le16(sbi->s_mount_state); 122 ext2_sync_super(sb, es); 123 } 124 db_count = sbi->s_gdb_count; 125 for (i = 0; i < db_count; i++) 126 if (sbi->s_group_desc[i]) 127 brelse (sbi->s_group_desc[i]); 128 kfree(sbi->s_group_desc); 129 kfree(sbi->s_debts); 130 percpu_counter_destroy(&sbi->s_freeblocks_counter); 131 percpu_counter_destroy(&sbi->s_freeinodes_counter); 132 percpu_counter_destroy(&sbi->s_dirs_counter); 133 brelse (sbi->s_sbh); 134 sb->s_fs_info = NULL; 135 kfree(sbi); 136 137 return; 138 } 139 140 static struct kmem_cache * ext2_inode_cachep; 141 142 static struct inode *ext2_alloc_inode(struct super_block *sb) 143 { 144 struct ext2_inode_info *ei; 145 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 146 if (!ei) 147 return NULL; 148 #ifdef CONFIG_EXT2_FS_POSIX_ACL 149 ei->i_acl = EXT2_ACL_NOT_CACHED; 150 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 151 #endif 152 ei->vfs_inode.i_version = 1; 153 return &ei->vfs_inode; 154 } 155 156 static void ext2_destroy_inode(struct inode *inode) 157 { 158 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 159 } 160 161 static void init_once(struct kmem_cache * cachep, void *foo) 162 { 163 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 164 165 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 static int init_inodecache(void) 173 { 174 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 175 sizeof(struct ext2_inode_info), 176 0, (SLAB_RECLAIM_ACCOUNT| 177 SLAB_MEM_SPREAD), 178 init_once); 179 if (ext2_inode_cachep == NULL) 180 return -ENOMEM; 181 return 0; 182 } 183 184 static void destroy_inodecache(void) 185 { 186 kmem_cache_destroy(ext2_inode_cachep); 187 } 188 189 static void ext2_clear_inode(struct inode *inode) 190 { 191 #ifdef CONFIG_EXT2_FS_POSIX_ACL 192 struct ext2_inode_info *ei = EXT2_I(inode); 193 194 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 195 posix_acl_release(ei->i_acl); 196 ei->i_acl = EXT2_ACL_NOT_CACHED; 197 } 198 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 199 posix_acl_release(ei->i_default_acl); 200 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 201 } 202 #endif 203 } 204 205 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 206 { 207 struct super_block *sb = vfs->mnt_sb; 208 struct ext2_sb_info *sbi = EXT2_SB(sb); 209 struct ext2_super_block *es = sbi->s_es; 210 unsigned long def_mount_opts; 211 212 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 213 214 if (sbi->s_sb_block != 1) 215 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 216 if (test_opt(sb, MINIX_DF)) 217 seq_puts(seq, ",minixdf"); 218 if (test_opt(sb, GRPID)) 219 seq_puts(seq, ",grpid"); 220 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 221 seq_puts(seq, ",nogrpid"); 222 if (sbi->s_resuid != EXT2_DEF_RESUID || 223 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 224 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 225 } 226 if (sbi->s_resgid != EXT2_DEF_RESGID || 227 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 228 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 229 } 230 if (test_opt(sb, ERRORS_CONT)) { 231 int def_errors = le16_to_cpu(es->s_errors); 232 233 if (def_errors == EXT2_ERRORS_PANIC || 234 def_errors == EXT2_ERRORS_RO) { 235 seq_puts(seq, ",errors=continue"); 236 } 237 } 238 if (test_opt(sb, ERRORS_RO)) 239 seq_puts(seq, ",errors=remount-ro"); 240 if (test_opt(sb, ERRORS_PANIC)) 241 seq_puts(seq, ",errors=panic"); 242 if (test_opt(sb, NO_UID32)) 243 seq_puts(seq, ",nouid32"); 244 if (test_opt(sb, DEBUG)) 245 seq_puts(seq, ",debug"); 246 if (test_opt(sb, OLDALLOC)) 247 seq_puts(seq, ",oldalloc"); 248 249 #ifdef CONFIG_EXT2_FS_XATTR 250 if (test_opt(sb, XATTR_USER)) 251 seq_puts(seq, ",user_xattr"); 252 if (!test_opt(sb, XATTR_USER) && 253 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 254 seq_puts(seq, ",nouser_xattr"); 255 } 256 #endif 257 258 #ifdef CONFIG_EXT2_FS_POSIX_ACL 259 if (test_opt(sb, POSIX_ACL)) 260 seq_puts(seq, ",acl"); 261 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 262 seq_puts(seq, ",noacl"); 263 #endif 264 265 if (test_opt(sb, NOBH)) 266 seq_puts(seq, ",nobh"); 267 268 #if defined(CONFIG_QUOTA) 269 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 270 seq_puts(seq, ",usrquota"); 271 272 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 273 seq_puts(seq, ",grpquota"); 274 #endif 275 276 #if defined(CONFIG_EXT2_FS_XIP) 277 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 278 seq_puts(seq, ",xip"); 279 #endif 280 281 return 0; 282 } 283 284 #ifdef CONFIG_QUOTA 285 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 286 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 287 #endif 288 289 static const struct super_operations ext2_sops = { 290 .alloc_inode = ext2_alloc_inode, 291 .destroy_inode = ext2_destroy_inode, 292 .read_inode = ext2_read_inode, 293 .write_inode = ext2_write_inode, 294 .put_inode = ext2_put_inode, 295 .delete_inode = ext2_delete_inode, 296 .put_super = ext2_put_super, 297 .write_super = ext2_write_super, 298 .statfs = ext2_statfs, 299 .remount_fs = ext2_remount, 300 .clear_inode = ext2_clear_inode, 301 .show_options = ext2_show_options, 302 #ifdef CONFIG_QUOTA 303 .quota_read = ext2_quota_read, 304 .quota_write = ext2_quota_write, 305 #endif 306 }; 307 308 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp) 309 { 310 __u32 *objp = vobjp; 311 unsigned long ino = objp[0]; 312 __u32 generation = objp[1]; 313 struct inode *inode; 314 struct dentry *result; 315 316 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 317 return ERR_PTR(-ESTALE); 318 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 319 return ERR_PTR(-ESTALE); 320 321 /* iget isn't really right if the inode is currently unallocated!! 322 * ext2_read_inode currently does appropriate checks, but 323 * it might be "neater" to call ext2_get_inode first and check 324 * if the inode is valid..... 325 */ 326 inode = iget(sb, ino); 327 if (inode == NULL) 328 return ERR_PTR(-ENOMEM); 329 if (is_bad_inode(inode) || 330 (generation && inode->i_generation != generation)) { 331 /* we didn't find the right inode.. */ 332 iput(inode); 333 return ERR_PTR(-ESTALE); 334 } 335 /* now to find a dentry. 336 * If possible, get a well-connected one 337 */ 338 result = d_alloc_anon(inode); 339 if (!result) { 340 iput(inode); 341 return ERR_PTR(-ENOMEM); 342 } 343 return result; 344 } 345 346 /* Yes, most of these are left as NULL!! 347 * A NULL value implies the default, which works with ext2-like file 348 * systems, but can be improved upon. 349 * Currently only get_parent is required. 350 */ 351 static struct export_operations ext2_export_ops = { 352 .get_parent = ext2_get_parent, 353 .get_dentry = ext2_get_dentry, 354 }; 355 356 static unsigned long get_sb_block(void **data) 357 { 358 unsigned long sb_block; 359 char *options = (char *) *data; 360 361 if (!options || strncmp(options, "sb=", 3) != 0) 362 return 1; /* Default location */ 363 options += 3; 364 sb_block = simple_strtoul(options, &options, 0); 365 if (*options && *options != ',') { 366 printk("EXT2-fs: Invalid sb specification: %s\n", 367 (char *) *data); 368 return 1; 369 } 370 if (*options == ',') 371 options++; 372 *data = (void *) options; 373 return sb_block; 374 } 375 376 enum { 377 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 378 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 379 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 380 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 381 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 382 Opt_usrquota, Opt_grpquota 383 }; 384 385 static match_table_t tokens = { 386 {Opt_bsd_df, "bsddf"}, 387 {Opt_minix_df, "minixdf"}, 388 {Opt_grpid, "grpid"}, 389 {Opt_grpid, "bsdgroups"}, 390 {Opt_nogrpid, "nogrpid"}, 391 {Opt_nogrpid, "sysvgroups"}, 392 {Opt_resgid, "resgid=%u"}, 393 {Opt_resuid, "resuid=%u"}, 394 {Opt_sb, "sb=%u"}, 395 {Opt_err_cont, "errors=continue"}, 396 {Opt_err_panic, "errors=panic"}, 397 {Opt_err_ro, "errors=remount-ro"}, 398 {Opt_nouid32, "nouid32"}, 399 {Opt_nocheck, "check=none"}, 400 {Opt_nocheck, "nocheck"}, 401 {Opt_debug, "debug"}, 402 {Opt_oldalloc, "oldalloc"}, 403 {Opt_orlov, "orlov"}, 404 {Opt_nobh, "nobh"}, 405 {Opt_user_xattr, "user_xattr"}, 406 {Opt_nouser_xattr, "nouser_xattr"}, 407 {Opt_acl, "acl"}, 408 {Opt_noacl, "noacl"}, 409 {Opt_xip, "xip"}, 410 {Opt_grpquota, "grpquota"}, 411 {Opt_ignore, "noquota"}, 412 {Opt_quota, "quota"}, 413 {Opt_usrquota, "usrquota"}, 414 {Opt_err, NULL} 415 }; 416 417 static int parse_options (char * options, 418 struct ext2_sb_info *sbi) 419 { 420 char * p; 421 substring_t args[MAX_OPT_ARGS]; 422 int option; 423 424 if (!options) 425 return 1; 426 427 while ((p = strsep (&options, ",")) != NULL) { 428 int token; 429 if (!*p) 430 continue; 431 432 token = match_token(p, tokens, args); 433 switch (token) { 434 case Opt_bsd_df: 435 clear_opt (sbi->s_mount_opt, MINIX_DF); 436 break; 437 case Opt_minix_df: 438 set_opt (sbi->s_mount_opt, MINIX_DF); 439 break; 440 case Opt_grpid: 441 set_opt (sbi->s_mount_opt, GRPID); 442 break; 443 case Opt_nogrpid: 444 clear_opt (sbi->s_mount_opt, GRPID); 445 break; 446 case Opt_resuid: 447 if (match_int(&args[0], &option)) 448 return 0; 449 sbi->s_resuid = option; 450 break; 451 case Opt_resgid: 452 if (match_int(&args[0], &option)) 453 return 0; 454 sbi->s_resgid = option; 455 break; 456 case Opt_sb: 457 /* handled by get_sb_block() instead of here */ 458 /* *sb_block = match_int(&args[0]); */ 459 break; 460 case Opt_err_panic: 461 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 462 clear_opt (sbi->s_mount_opt, ERRORS_RO); 463 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 464 break; 465 case Opt_err_ro: 466 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 467 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 468 set_opt (sbi->s_mount_opt, ERRORS_RO); 469 break; 470 case Opt_err_cont: 471 clear_opt (sbi->s_mount_opt, ERRORS_RO); 472 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 473 set_opt (sbi->s_mount_opt, ERRORS_CONT); 474 break; 475 case Opt_nouid32: 476 set_opt (sbi->s_mount_opt, NO_UID32); 477 break; 478 case Opt_nocheck: 479 clear_opt (sbi->s_mount_opt, CHECK); 480 break; 481 case Opt_debug: 482 set_opt (sbi->s_mount_opt, DEBUG); 483 break; 484 case Opt_oldalloc: 485 set_opt (sbi->s_mount_opt, OLDALLOC); 486 break; 487 case Opt_orlov: 488 clear_opt (sbi->s_mount_opt, OLDALLOC); 489 break; 490 case Opt_nobh: 491 set_opt (sbi->s_mount_opt, NOBH); 492 break; 493 #ifdef CONFIG_EXT2_FS_XATTR 494 case Opt_user_xattr: 495 set_opt (sbi->s_mount_opt, XATTR_USER); 496 break; 497 case Opt_nouser_xattr: 498 clear_opt (sbi->s_mount_opt, XATTR_USER); 499 break; 500 #else 501 case Opt_user_xattr: 502 case Opt_nouser_xattr: 503 printk("EXT2 (no)user_xattr options not supported\n"); 504 break; 505 #endif 506 #ifdef CONFIG_EXT2_FS_POSIX_ACL 507 case Opt_acl: 508 set_opt(sbi->s_mount_opt, POSIX_ACL); 509 break; 510 case Opt_noacl: 511 clear_opt(sbi->s_mount_opt, POSIX_ACL); 512 break; 513 #else 514 case Opt_acl: 515 case Opt_noacl: 516 printk("EXT2 (no)acl options not supported\n"); 517 break; 518 #endif 519 case Opt_xip: 520 #ifdef CONFIG_EXT2_FS_XIP 521 set_opt (sbi->s_mount_opt, XIP); 522 #else 523 printk("EXT2 xip option not supported\n"); 524 #endif 525 break; 526 527 #if defined(CONFIG_QUOTA) 528 case Opt_quota: 529 case Opt_usrquota: 530 set_opt(sbi->s_mount_opt, USRQUOTA); 531 break; 532 533 case Opt_grpquota: 534 set_opt(sbi->s_mount_opt, GRPQUOTA); 535 break; 536 #else 537 case Opt_quota: 538 case Opt_usrquota: 539 case Opt_grpquota: 540 printk(KERN_ERR 541 "EXT2-fs: quota operations not supported.\n"); 542 543 break; 544 #endif 545 546 case Opt_ignore: 547 break; 548 default: 549 return 0; 550 } 551 } 552 return 1; 553 } 554 555 static int ext2_setup_super (struct super_block * sb, 556 struct ext2_super_block * es, 557 int read_only) 558 { 559 int res = 0; 560 struct ext2_sb_info *sbi = EXT2_SB(sb); 561 562 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 563 printk ("EXT2-fs warning: revision level too high, " 564 "forcing read-only mode\n"); 565 res = MS_RDONLY; 566 } 567 if (read_only) 568 return res; 569 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 570 printk ("EXT2-fs warning: mounting unchecked fs, " 571 "running e2fsck is recommended\n"); 572 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 573 printk ("EXT2-fs warning: mounting fs with errors, " 574 "running e2fsck is recommended\n"); 575 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 576 le16_to_cpu(es->s_mnt_count) >= 577 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 578 printk ("EXT2-fs warning: maximal mount count reached, " 579 "running e2fsck is recommended\n"); 580 else if (le32_to_cpu(es->s_checkinterval) && 581 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 582 printk ("EXT2-fs warning: checktime reached, " 583 "running e2fsck is recommended\n"); 584 if (!le16_to_cpu(es->s_max_mnt_count)) 585 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 586 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 587 ext2_write_super(sb); 588 if (test_opt (sb, DEBUG)) 589 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 590 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 591 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 592 sbi->s_frag_size, 593 sbi->s_groups_count, 594 EXT2_BLOCKS_PER_GROUP(sb), 595 EXT2_INODES_PER_GROUP(sb), 596 sbi->s_mount_opt); 597 return res; 598 } 599 600 static int ext2_check_descriptors (struct super_block * sb) 601 { 602 int i; 603 int desc_block = 0; 604 struct ext2_sb_info *sbi = EXT2_SB(sb); 605 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block); 606 unsigned long last_block; 607 struct ext2_group_desc * gdp = NULL; 608 609 ext2_debug ("Checking group descriptors"); 610 611 for (i = 0; i < sbi->s_groups_count; i++) 612 { 613 if (i == sbi->s_groups_count - 1) 614 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 615 else 616 last_block = first_block + 617 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 618 619 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) 620 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; 621 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 622 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 623 { 624 ext2_error (sb, "ext2_check_descriptors", 625 "Block bitmap for group %d" 626 " not in group (block %lu)!", 627 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 628 return 0; 629 } 630 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 631 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 632 { 633 ext2_error (sb, "ext2_check_descriptors", 634 "Inode bitmap for group %d" 635 " not in group (block %lu)!", 636 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 637 return 0; 638 } 639 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 640 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 641 last_block) 642 { 643 ext2_error (sb, "ext2_check_descriptors", 644 "Inode table for group %d" 645 " not in group (block %lu)!", 646 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 647 return 0; 648 } 649 first_block += EXT2_BLOCKS_PER_GROUP(sb); 650 gdp++; 651 } 652 return 1; 653 } 654 655 /* 656 * Maximal file size. There is a direct, and {,double-,triple-}indirect 657 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 658 * We need to be 1 filesystem block less than the 2^32 sector limit. 659 */ 660 static loff_t ext2_max_size(int bits) 661 { 662 loff_t res = EXT2_NDIR_BLOCKS; 663 /* This constant is calculated to be the largest file size for a 664 * dense, 4k-blocksize file such that the total number of 665 * sectors in the file, including data and all indirect blocks, 666 * does not exceed 2^32. */ 667 const loff_t upper_limit = 0x1ff7fffd000LL; 668 669 res += 1LL << (bits-2); 670 res += 1LL << (2*(bits-2)); 671 res += 1LL << (3*(bits-2)); 672 res <<= bits; 673 if (res > upper_limit) 674 res = upper_limit; 675 return res; 676 } 677 678 static unsigned long descriptor_loc(struct super_block *sb, 679 unsigned long logic_sb_block, 680 int nr) 681 { 682 struct ext2_sb_info *sbi = EXT2_SB(sb); 683 unsigned long bg, first_data_block, first_meta_bg; 684 int has_super = 0; 685 686 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 687 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 688 689 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 690 nr < first_meta_bg) 691 return (logic_sb_block + nr + 1); 692 bg = sbi->s_desc_per_block * nr; 693 if (ext2_bg_has_super(sb, bg)) 694 has_super = 1; 695 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 696 } 697 698 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 699 { 700 struct buffer_head * bh; 701 struct ext2_sb_info * sbi; 702 struct ext2_super_block * es; 703 struct inode *root; 704 unsigned long block; 705 unsigned long sb_block = get_sb_block(&data); 706 unsigned long logic_sb_block; 707 unsigned long offset = 0; 708 unsigned long def_mount_opts; 709 int blocksize = BLOCK_SIZE; 710 int db_count; 711 int i, j; 712 __le32 features; 713 int err; 714 715 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 716 if (!sbi) 717 return -ENOMEM; 718 sb->s_fs_info = sbi; 719 sbi->s_sb_block = sb_block; 720 721 /* 722 * See what the current blocksize for the device is, and 723 * use that as the blocksize. Otherwise (or if the blocksize 724 * is smaller than the default) use the default. 725 * This is important for devices that have a hardware 726 * sectorsize that is larger than the default. 727 */ 728 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 729 if (!blocksize) { 730 printk ("EXT2-fs: unable to set blocksize\n"); 731 goto failed_sbi; 732 } 733 734 /* 735 * If the superblock doesn't start on a hardware sector boundary, 736 * calculate the offset. 737 */ 738 if (blocksize != BLOCK_SIZE) { 739 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 740 offset = (sb_block*BLOCK_SIZE) % blocksize; 741 } else { 742 logic_sb_block = sb_block; 743 } 744 745 if (!(bh = sb_bread(sb, logic_sb_block))) { 746 printk ("EXT2-fs: unable to read superblock\n"); 747 goto failed_sbi; 748 } 749 /* 750 * Note: s_es must be initialized as soon as possible because 751 * some ext2 macro-instructions depend on its value 752 */ 753 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 754 sbi->s_es = es; 755 sb->s_magic = le16_to_cpu(es->s_magic); 756 757 if (sb->s_magic != EXT2_SUPER_MAGIC) 758 goto cantfind_ext2; 759 760 /* Set defaults before we parse the mount options */ 761 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 762 if (def_mount_opts & EXT2_DEFM_DEBUG) 763 set_opt(sbi->s_mount_opt, DEBUG); 764 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 765 set_opt(sbi->s_mount_opt, GRPID); 766 if (def_mount_opts & EXT2_DEFM_UID16) 767 set_opt(sbi->s_mount_opt, NO_UID32); 768 #ifdef CONFIG_EXT2_FS_XATTR 769 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 770 set_opt(sbi->s_mount_opt, XATTR_USER); 771 #endif 772 #ifdef CONFIG_EXT2_FS_POSIX_ACL 773 if (def_mount_opts & EXT2_DEFM_ACL) 774 set_opt(sbi->s_mount_opt, POSIX_ACL); 775 #endif 776 777 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 778 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 779 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) 780 set_opt(sbi->s_mount_opt, ERRORS_RO); 781 else 782 set_opt(sbi->s_mount_opt, ERRORS_CONT); 783 784 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 785 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 786 787 if (!parse_options ((char *) data, sbi)) 788 goto failed_mount; 789 790 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 791 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 792 MS_POSIXACL : 0); 793 794 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 795 EXT2_MOUNT_XIP if not */ 796 797 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 798 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 799 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 800 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 801 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 802 "running e2fsck is recommended\n"); 803 /* 804 * Check feature flags regardless of the revision level, since we 805 * previously didn't change the revision level when setting the flags, 806 * so there is a chance incompat flags are set on a rev 0 filesystem. 807 */ 808 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 809 if (features) { 810 printk("EXT2-fs: %s: couldn't mount because of " 811 "unsupported optional features (%x).\n", 812 sb->s_id, le32_to_cpu(features)); 813 goto failed_mount; 814 } 815 if (!(sb->s_flags & MS_RDONLY) && 816 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 817 printk("EXT2-fs: %s: couldn't mount RDWR because of " 818 "unsupported optional features (%x).\n", 819 sb->s_id, le32_to_cpu(features)); 820 goto failed_mount; 821 } 822 823 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 824 825 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) || 826 (sb->s_blocksize != blocksize))) { 827 if (!silent) 828 printk("XIP: Unsupported blocksize\n"); 829 goto failed_mount; 830 } 831 832 /* If the blocksize doesn't match, re-read the thing.. */ 833 if (sb->s_blocksize != blocksize) { 834 brelse(bh); 835 836 if (!sb_set_blocksize(sb, blocksize)) { 837 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 838 goto failed_sbi; 839 } 840 841 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 842 offset = (sb_block*BLOCK_SIZE) % blocksize; 843 bh = sb_bread(sb, logic_sb_block); 844 if(!bh) { 845 printk("EXT2-fs: Couldn't read superblock on " 846 "2nd try.\n"); 847 goto failed_sbi; 848 } 849 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 850 sbi->s_es = es; 851 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 852 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 853 goto failed_mount; 854 } 855 } 856 857 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 858 859 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 860 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 861 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 862 } else { 863 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 864 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 865 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 866 !is_power_of_2(sbi->s_inode_size) || 867 (sbi->s_inode_size > blocksize)) { 868 printk ("EXT2-fs: unsupported inode size: %d\n", 869 sbi->s_inode_size); 870 goto failed_mount; 871 } 872 } 873 874 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 875 le32_to_cpu(es->s_log_frag_size); 876 if (sbi->s_frag_size == 0) 877 goto cantfind_ext2; 878 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 879 880 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 881 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 882 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 883 884 if (EXT2_INODE_SIZE(sb) == 0) 885 goto cantfind_ext2; 886 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 887 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 888 goto cantfind_ext2; 889 sbi->s_itb_per_group = sbi->s_inodes_per_group / 890 sbi->s_inodes_per_block; 891 sbi->s_desc_per_block = sb->s_blocksize / 892 sizeof (struct ext2_group_desc); 893 sbi->s_sbh = bh; 894 sbi->s_mount_state = le16_to_cpu(es->s_state); 895 sbi->s_addr_per_block_bits = 896 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 897 sbi->s_desc_per_block_bits = 898 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 899 900 if (sb->s_magic != EXT2_SUPER_MAGIC) 901 goto cantfind_ext2; 902 903 if (sb->s_blocksize != bh->b_size) { 904 if (!silent) 905 printk ("VFS: Unsupported blocksize on dev " 906 "%s.\n", sb->s_id); 907 goto failed_mount; 908 } 909 910 if (sb->s_blocksize != sbi->s_frag_size) { 911 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 912 sbi->s_frag_size, sb->s_blocksize); 913 goto failed_mount; 914 } 915 916 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 917 printk ("EXT2-fs: #blocks per group too big: %lu\n", 918 sbi->s_blocks_per_group); 919 goto failed_mount; 920 } 921 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 922 printk ("EXT2-fs: #fragments per group too big: %lu\n", 923 sbi->s_frags_per_group); 924 goto failed_mount; 925 } 926 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 927 printk ("EXT2-fs: #inodes per group too big: %lu\n", 928 sbi->s_inodes_per_group); 929 goto failed_mount; 930 } 931 932 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 933 goto cantfind_ext2; 934 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 935 le32_to_cpu(es->s_first_data_block) - 1) 936 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 937 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 938 EXT2_DESC_PER_BLOCK(sb); 939 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 940 if (sbi->s_group_desc == NULL) { 941 printk ("EXT2-fs: not enough memory\n"); 942 goto failed_mount; 943 } 944 bgl_lock_init(&sbi->s_blockgroup_lock); 945 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 946 if (!sbi->s_debts) { 947 printk ("EXT2-fs: not enough memory\n"); 948 goto failed_mount_group_desc; 949 } 950 for (i = 0; i < db_count; i++) { 951 block = descriptor_loc(sb, logic_sb_block, i); 952 sbi->s_group_desc[i] = sb_bread(sb, block); 953 if (!sbi->s_group_desc[i]) { 954 for (j = 0; j < i; j++) 955 brelse (sbi->s_group_desc[j]); 956 printk ("EXT2-fs: unable to read group descriptors\n"); 957 goto failed_mount_group_desc; 958 } 959 } 960 if (!ext2_check_descriptors (sb)) { 961 printk ("EXT2-fs: group descriptors corrupted!\n"); 962 goto failed_mount2; 963 } 964 sbi->s_gdb_count = db_count; 965 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 966 spin_lock_init(&sbi->s_next_gen_lock); 967 968 err = percpu_counter_init(&sbi->s_freeblocks_counter, 969 ext2_count_free_blocks(sb)); 970 if (!err) { 971 err = percpu_counter_init(&sbi->s_freeinodes_counter, 972 ext2_count_free_inodes(sb)); 973 } 974 if (!err) { 975 err = percpu_counter_init(&sbi->s_dirs_counter, 976 ext2_count_dirs(sb)); 977 } 978 if (err) { 979 printk(KERN_ERR "EXT2-fs: insufficient memory\n"); 980 goto failed_mount3; 981 } 982 /* 983 * set up enough so that it can read an inode 984 */ 985 sb->s_op = &ext2_sops; 986 sb->s_export_op = &ext2_export_ops; 987 sb->s_xattr = ext2_xattr_handlers; 988 root = iget(sb, EXT2_ROOT_INO); 989 sb->s_root = d_alloc_root(root); 990 if (!sb->s_root) { 991 iput(root); 992 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 993 goto failed_mount3; 994 } 995 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 996 dput(sb->s_root); 997 sb->s_root = NULL; 998 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 999 goto failed_mount3; 1000 } 1001 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1002 ext2_warning(sb, __FUNCTION__, 1003 "mounting ext3 filesystem as ext2"); 1004 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 1005 return 0; 1006 1007 cantfind_ext2: 1008 if (!silent) 1009 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 1010 sb->s_id); 1011 goto failed_mount; 1012 failed_mount3: 1013 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1014 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1015 percpu_counter_destroy(&sbi->s_dirs_counter); 1016 failed_mount2: 1017 for (i = 0; i < db_count; i++) 1018 brelse(sbi->s_group_desc[i]); 1019 failed_mount_group_desc: 1020 kfree(sbi->s_group_desc); 1021 kfree(sbi->s_debts); 1022 failed_mount: 1023 brelse(bh); 1024 failed_sbi: 1025 sb->s_fs_info = NULL; 1026 kfree(sbi); 1027 return -EINVAL; 1028 } 1029 1030 static void ext2_commit_super (struct super_block * sb, 1031 struct ext2_super_block * es) 1032 { 1033 es->s_wtime = cpu_to_le32(get_seconds()); 1034 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1035 sb->s_dirt = 0; 1036 } 1037 1038 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1039 { 1040 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1041 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1042 es->s_wtime = cpu_to_le32(get_seconds()); 1043 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1044 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1045 sb->s_dirt = 0; 1046 } 1047 1048 /* 1049 * In the second extended file system, it is not necessary to 1050 * write the super block since we use a mapping of the 1051 * disk super block in a buffer. 1052 * 1053 * However, this function is still used to set the fs valid 1054 * flags to 0. We need to set this flag to 0 since the fs 1055 * may have been checked while mounted and e2fsck may have 1056 * set s_state to EXT2_VALID_FS after some corrections. 1057 */ 1058 1059 void ext2_write_super (struct super_block * sb) 1060 { 1061 struct ext2_super_block * es; 1062 lock_kernel(); 1063 if (!(sb->s_flags & MS_RDONLY)) { 1064 es = EXT2_SB(sb)->s_es; 1065 1066 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 1067 ext2_debug ("setting valid to 0\n"); 1068 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 1069 ~EXT2_VALID_FS); 1070 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1071 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1072 es->s_mtime = cpu_to_le32(get_seconds()); 1073 ext2_sync_super(sb, es); 1074 } else 1075 ext2_commit_super (sb, es); 1076 } 1077 sb->s_dirt = 0; 1078 unlock_kernel(); 1079 } 1080 1081 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1082 { 1083 struct ext2_sb_info * sbi = EXT2_SB(sb); 1084 struct ext2_super_block * es; 1085 unsigned long old_mount_opt = sbi->s_mount_opt; 1086 struct ext2_mount_options old_opts; 1087 unsigned long old_sb_flags; 1088 int err; 1089 1090 /* Store the old options */ 1091 old_sb_flags = sb->s_flags; 1092 old_opts.s_mount_opt = sbi->s_mount_opt; 1093 old_opts.s_resuid = sbi->s_resuid; 1094 old_opts.s_resgid = sbi->s_resgid; 1095 1096 /* 1097 * Allow the "check" option to be passed as a remount option. 1098 */ 1099 if (!parse_options (data, sbi)) { 1100 err = -EINVAL; 1101 goto restore_opts; 1102 } 1103 1104 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1105 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1106 1107 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1108 EXT2_MOUNT_XIP if not */ 1109 1110 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1111 printk("XIP: Unsupported blocksize\n"); 1112 err = -EINVAL; 1113 goto restore_opts; 1114 } 1115 1116 es = sbi->s_es; 1117 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1118 (old_mount_opt & EXT2_MOUNT_XIP)) && 1119 invalidate_inodes(sb)) 1120 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ 1121 "xip remain in cache (no functional problem)"); 1122 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1123 return 0; 1124 if (*flags & MS_RDONLY) { 1125 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1126 !(sbi->s_mount_state & EXT2_VALID_FS)) 1127 return 0; 1128 /* 1129 * OK, we are remounting a valid rw partition rdonly, so set 1130 * the rdonly flag and then mark the partition as valid again. 1131 */ 1132 es->s_state = cpu_to_le16(sbi->s_mount_state); 1133 es->s_mtime = cpu_to_le32(get_seconds()); 1134 } else { 1135 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1136 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1137 if (ret) { 1138 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1139 "unsupported optional features (%x).\n", 1140 sb->s_id, le32_to_cpu(ret)); 1141 err = -EROFS; 1142 goto restore_opts; 1143 } 1144 /* 1145 * Mounting a RDONLY partition read-write, so reread and 1146 * store the current valid flag. (It may have been changed 1147 * by e2fsck since we originally mounted the partition.) 1148 */ 1149 sbi->s_mount_state = le16_to_cpu(es->s_state); 1150 if (!ext2_setup_super (sb, es, 0)) 1151 sb->s_flags &= ~MS_RDONLY; 1152 } 1153 ext2_sync_super(sb, es); 1154 return 0; 1155 restore_opts: 1156 sbi->s_mount_opt = old_opts.s_mount_opt; 1157 sbi->s_resuid = old_opts.s_resuid; 1158 sbi->s_resgid = old_opts.s_resgid; 1159 sb->s_flags = old_sb_flags; 1160 return err; 1161 } 1162 1163 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1164 { 1165 struct super_block *sb = dentry->d_sb; 1166 struct ext2_sb_info *sbi = EXT2_SB(sb); 1167 struct ext2_super_block *es = sbi->s_es; 1168 u64 fsid; 1169 1170 if (test_opt (sb, MINIX_DF)) 1171 sbi->s_overhead_last = 0; 1172 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1173 unsigned long i, overhead = 0; 1174 smp_rmb(); 1175 1176 /* 1177 * Compute the overhead (FS structures). This is constant 1178 * for a given filesystem unless the number of block groups 1179 * changes so we cache the previous value until it does. 1180 */ 1181 1182 /* 1183 * All of the blocks before first_data_block are 1184 * overhead 1185 */ 1186 overhead = le32_to_cpu(es->s_first_data_block); 1187 1188 /* 1189 * Add the overhead attributed to the superblock and 1190 * block group descriptors. If the sparse superblocks 1191 * feature is turned on, then not all groups have this. 1192 */ 1193 for (i = 0; i < sbi->s_groups_count; i++) 1194 overhead += ext2_bg_has_super(sb, i) + 1195 ext2_bg_num_gdb(sb, i); 1196 1197 /* 1198 * Every block group has an inode bitmap, a block 1199 * bitmap, and an inode table. 1200 */ 1201 overhead += (sbi->s_groups_count * 1202 (2 + sbi->s_itb_per_group)); 1203 sbi->s_overhead_last = overhead; 1204 smp_wmb(); 1205 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1206 } 1207 1208 buf->f_type = EXT2_SUPER_MAGIC; 1209 buf->f_bsize = sb->s_blocksize; 1210 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1211 buf->f_bfree = ext2_count_free_blocks(sb); 1212 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1213 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1214 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1215 buf->f_bavail = 0; 1216 buf->f_files = le32_to_cpu(es->s_inodes_count); 1217 buf->f_ffree = ext2_count_free_inodes(sb); 1218 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1219 buf->f_namelen = EXT2_NAME_LEN; 1220 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1221 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1222 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1223 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1224 return 0; 1225 } 1226 1227 static int ext2_get_sb(struct file_system_type *fs_type, 1228 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1229 { 1230 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1231 } 1232 1233 #ifdef CONFIG_QUOTA 1234 1235 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1236 * acquiring the locks... As quota files are never truncated and quota code 1237 * itself serializes the operations (and noone else should touch the files) 1238 * we don't have to be afraid of races */ 1239 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1240 size_t len, loff_t off) 1241 { 1242 struct inode *inode = sb_dqopt(sb)->files[type]; 1243 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1244 int err = 0; 1245 int offset = off & (sb->s_blocksize - 1); 1246 int tocopy; 1247 size_t toread; 1248 struct buffer_head tmp_bh; 1249 struct buffer_head *bh; 1250 loff_t i_size = i_size_read(inode); 1251 1252 if (off > i_size) 1253 return 0; 1254 if (off+len > i_size) 1255 len = i_size-off; 1256 toread = len; 1257 while (toread > 0) { 1258 tocopy = sb->s_blocksize - offset < toread ? 1259 sb->s_blocksize - offset : toread; 1260 1261 tmp_bh.b_state = 0; 1262 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1263 if (err) 1264 return err; 1265 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1266 memset(data, 0, tocopy); 1267 else { 1268 bh = sb_bread(sb, tmp_bh.b_blocknr); 1269 if (!bh) 1270 return -EIO; 1271 memcpy(data, bh->b_data+offset, tocopy); 1272 brelse(bh); 1273 } 1274 offset = 0; 1275 toread -= tocopy; 1276 data += tocopy; 1277 blk++; 1278 } 1279 return len; 1280 } 1281 1282 /* Write to quotafile */ 1283 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1284 const char *data, size_t len, loff_t off) 1285 { 1286 struct inode *inode = sb_dqopt(sb)->files[type]; 1287 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1288 int err = 0; 1289 int offset = off & (sb->s_blocksize - 1); 1290 int tocopy; 1291 size_t towrite = len; 1292 struct buffer_head tmp_bh; 1293 struct buffer_head *bh; 1294 1295 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1296 while (towrite > 0) { 1297 tocopy = sb->s_blocksize - offset < towrite ? 1298 sb->s_blocksize - offset : towrite; 1299 1300 tmp_bh.b_state = 0; 1301 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1302 if (err) 1303 goto out; 1304 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1305 bh = sb_bread(sb, tmp_bh.b_blocknr); 1306 else 1307 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1308 if (!bh) { 1309 err = -EIO; 1310 goto out; 1311 } 1312 lock_buffer(bh); 1313 memcpy(bh->b_data+offset, data, tocopy); 1314 flush_dcache_page(bh->b_page); 1315 set_buffer_uptodate(bh); 1316 mark_buffer_dirty(bh); 1317 unlock_buffer(bh); 1318 brelse(bh); 1319 offset = 0; 1320 towrite -= tocopy; 1321 data += tocopy; 1322 blk++; 1323 } 1324 out: 1325 if (len == towrite) 1326 return err; 1327 if (inode->i_size < off+len-towrite) 1328 i_size_write(inode, off+len-towrite); 1329 inode->i_version++; 1330 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1331 mark_inode_dirty(inode); 1332 mutex_unlock(&inode->i_mutex); 1333 return len - towrite; 1334 } 1335 1336 #endif 1337 1338 static struct file_system_type ext2_fs_type = { 1339 .owner = THIS_MODULE, 1340 .name = "ext2", 1341 .get_sb = ext2_get_sb, 1342 .kill_sb = kill_block_super, 1343 .fs_flags = FS_REQUIRES_DEV, 1344 }; 1345 1346 static int __init init_ext2_fs(void) 1347 { 1348 int err = init_ext2_xattr(); 1349 if (err) 1350 return err; 1351 err = init_inodecache(); 1352 if (err) 1353 goto out1; 1354 err = register_filesystem(&ext2_fs_type); 1355 if (err) 1356 goto out; 1357 return 0; 1358 out: 1359 destroy_inodecache(); 1360 out1: 1361 exit_ext2_xattr(); 1362 return err; 1363 } 1364 1365 static void __exit exit_ext2_fs(void) 1366 { 1367 unregister_filesystem(&ext2_fs_type); 1368 destroy_inodecache(); 1369 exit_ext2_xattr(); 1370 } 1371 1372 module_init(init_ext2_fs) 1373 module_exit(exit_ext2_fs) 1374