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 |= cpu_to_le16(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, __func__, 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->i_block_alloc_info = NULL; 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 mutex_init(&ei->truncate_mutex); 170 inode_init_once(&ei->vfs_inode); 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); 180 if (ext2_inode_cachep == NULL) 181 return -ENOMEM; 182 return 0; 183 } 184 185 static void destroy_inodecache(void) 186 { 187 kmem_cache_destroy(ext2_inode_cachep); 188 } 189 190 static void ext2_clear_inode(struct inode *inode) 191 { 192 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 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 ext2_discard_reservation(inode); 206 EXT2_I(inode)->i_block_alloc_info = NULL; 207 if (unlikely(rsv)) 208 kfree(rsv); 209 } 210 211 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 212 { 213 struct super_block *sb = vfs->mnt_sb; 214 struct ext2_sb_info *sbi = EXT2_SB(sb); 215 struct ext2_super_block *es = sbi->s_es; 216 unsigned long def_mount_opts; 217 218 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 219 220 if (sbi->s_sb_block != 1) 221 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 222 if (test_opt(sb, MINIX_DF)) 223 seq_puts(seq, ",minixdf"); 224 if (test_opt(sb, GRPID)) 225 seq_puts(seq, ",grpid"); 226 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 227 seq_puts(seq, ",nogrpid"); 228 if (sbi->s_resuid != EXT2_DEF_RESUID || 229 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 230 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 231 } 232 if (sbi->s_resgid != EXT2_DEF_RESGID || 233 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 234 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 235 } 236 if (test_opt(sb, ERRORS_RO)) { 237 int def_errors = le16_to_cpu(es->s_errors); 238 239 if (def_errors == EXT2_ERRORS_PANIC || 240 def_errors == EXT2_ERRORS_CONTINUE) { 241 seq_puts(seq, ",errors=remount-ro"); 242 } 243 } 244 if (test_opt(sb, ERRORS_CONT)) 245 seq_puts(seq, ",errors=continue"); 246 if (test_opt(sb, ERRORS_PANIC)) 247 seq_puts(seq, ",errors=panic"); 248 if (test_opt(sb, NO_UID32)) 249 seq_puts(seq, ",nouid32"); 250 if (test_opt(sb, DEBUG)) 251 seq_puts(seq, ",debug"); 252 if (test_opt(sb, OLDALLOC)) 253 seq_puts(seq, ",oldalloc"); 254 255 #ifdef CONFIG_EXT2_FS_XATTR 256 if (test_opt(sb, XATTR_USER)) 257 seq_puts(seq, ",user_xattr"); 258 if (!test_opt(sb, XATTR_USER) && 259 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 260 seq_puts(seq, ",nouser_xattr"); 261 } 262 #endif 263 264 #ifdef CONFIG_EXT2_FS_POSIX_ACL 265 if (test_opt(sb, POSIX_ACL)) 266 seq_puts(seq, ",acl"); 267 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 268 seq_puts(seq, ",noacl"); 269 #endif 270 271 if (test_opt(sb, NOBH)) 272 seq_puts(seq, ",nobh"); 273 274 #if defined(CONFIG_QUOTA) 275 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 276 seq_puts(seq, ",usrquota"); 277 278 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 279 seq_puts(seq, ",grpquota"); 280 #endif 281 282 #if defined(CONFIG_EXT2_FS_XIP) 283 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 284 seq_puts(seq, ",xip"); 285 #endif 286 287 if (!test_opt(sb, RESERVATION)) 288 seq_puts(seq, ",noreservation"); 289 290 return 0; 291 } 292 293 #ifdef CONFIG_QUOTA 294 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 295 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 296 #endif 297 298 static const struct super_operations ext2_sops = { 299 .alloc_inode = ext2_alloc_inode, 300 .destroy_inode = ext2_destroy_inode, 301 .write_inode = ext2_write_inode, 302 .delete_inode = ext2_delete_inode, 303 .put_super = ext2_put_super, 304 .write_super = ext2_write_super, 305 .statfs = ext2_statfs, 306 .remount_fs = ext2_remount, 307 .clear_inode = ext2_clear_inode, 308 .show_options = ext2_show_options, 309 #ifdef CONFIG_QUOTA 310 .quota_read = ext2_quota_read, 311 .quota_write = ext2_quota_write, 312 #endif 313 }; 314 315 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 316 u64 ino, u32 generation) 317 { 318 struct inode *inode; 319 320 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 321 return ERR_PTR(-ESTALE); 322 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 323 return ERR_PTR(-ESTALE); 324 325 /* iget isn't really right if the inode is currently unallocated!! 326 * ext2_read_inode currently does appropriate checks, but 327 * it might be "neater" to call ext2_get_inode first and check 328 * if the inode is valid..... 329 */ 330 inode = ext2_iget(sb, ino); 331 if (IS_ERR(inode)) 332 return ERR_CAST(inode); 333 if (generation && inode->i_generation != generation) { 334 /* we didn't find the right inode.. */ 335 iput(inode); 336 return ERR_PTR(-ESTALE); 337 } 338 return inode; 339 } 340 341 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 342 int fh_len, int fh_type) 343 { 344 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 345 ext2_nfs_get_inode); 346 } 347 348 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 349 int fh_len, int fh_type) 350 { 351 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 352 ext2_nfs_get_inode); 353 } 354 355 /* Yes, most of these are left as NULL!! 356 * A NULL value implies the default, which works with ext2-like file 357 * systems, but can be improved upon. 358 * Currently only get_parent is required. 359 */ 360 static const struct export_operations ext2_export_ops = { 361 .fh_to_dentry = ext2_fh_to_dentry, 362 .fh_to_parent = ext2_fh_to_parent, 363 .get_parent = ext2_get_parent, 364 }; 365 366 static unsigned long get_sb_block(void **data) 367 { 368 unsigned long sb_block; 369 char *options = (char *) *data; 370 371 if (!options || strncmp(options, "sb=", 3) != 0) 372 return 1; /* Default location */ 373 options += 3; 374 sb_block = simple_strtoul(options, &options, 0); 375 if (*options && *options != ',') { 376 printk("EXT2-fs: Invalid sb specification: %s\n", 377 (char *) *data); 378 return 1; 379 } 380 if (*options == ',') 381 options++; 382 *data = (void *) options; 383 return sb_block; 384 } 385 386 enum { 387 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 388 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 389 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 390 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 391 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 392 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 393 }; 394 395 static match_table_t tokens = { 396 {Opt_bsd_df, "bsddf"}, 397 {Opt_minix_df, "minixdf"}, 398 {Opt_grpid, "grpid"}, 399 {Opt_grpid, "bsdgroups"}, 400 {Opt_nogrpid, "nogrpid"}, 401 {Opt_nogrpid, "sysvgroups"}, 402 {Opt_resgid, "resgid=%u"}, 403 {Opt_resuid, "resuid=%u"}, 404 {Opt_sb, "sb=%u"}, 405 {Opt_err_cont, "errors=continue"}, 406 {Opt_err_panic, "errors=panic"}, 407 {Opt_err_ro, "errors=remount-ro"}, 408 {Opt_nouid32, "nouid32"}, 409 {Opt_nocheck, "check=none"}, 410 {Opt_nocheck, "nocheck"}, 411 {Opt_debug, "debug"}, 412 {Opt_oldalloc, "oldalloc"}, 413 {Opt_orlov, "orlov"}, 414 {Opt_nobh, "nobh"}, 415 {Opt_user_xattr, "user_xattr"}, 416 {Opt_nouser_xattr, "nouser_xattr"}, 417 {Opt_acl, "acl"}, 418 {Opt_noacl, "noacl"}, 419 {Opt_xip, "xip"}, 420 {Opt_grpquota, "grpquota"}, 421 {Opt_ignore, "noquota"}, 422 {Opt_quota, "quota"}, 423 {Opt_usrquota, "usrquota"}, 424 {Opt_reservation, "reservation"}, 425 {Opt_noreservation, "noreservation"}, 426 {Opt_err, NULL} 427 }; 428 429 static int parse_options (char * options, 430 struct ext2_sb_info *sbi) 431 { 432 char * p; 433 substring_t args[MAX_OPT_ARGS]; 434 int option; 435 436 if (!options) 437 return 1; 438 439 while ((p = strsep (&options, ",")) != NULL) { 440 int token; 441 if (!*p) 442 continue; 443 444 token = match_token(p, tokens, args); 445 switch (token) { 446 case Opt_bsd_df: 447 clear_opt (sbi->s_mount_opt, MINIX_DF); 448 break; 449 case Opt_minix_df: 450 set_opt (sbi->s_mount_opt, MINIX_DF); 451 break; 452 case Opt_grpid: 453 set_opt (sbi->s_mount_opt, GRPID); 454 break; 455 case Opt_nogrpid: 456 clear_opt (sbi->s_mount_opt, GRPID); 457 break; 458 case Opt_resuid: 459 if (match_int(&args[0], &option)) 460 return 0; 461 sbi->s_resuid = option; 462 break; 463 case Opt_resgid: 464 if (match_int(&args[0], &option)) 465 return 0; 466 sbi->s_resgid = option; 467 break; 468 case Opt_sb: 469 /* handled by get_sb_block() instead of here */ 470 /* *sb_block = match_int(&args[0]); */ 471 break; 472 case Opt_err_panic: 473 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 474 clear_opt (sbi->s_mount_opt, ERRORS_RO); 475 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 476 break; 477 case Opt_err_ro: 478 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 479 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 480 set_opt (sbi->s_mount_opt, ERRORS_RO); 481 break; 482 case Opt_err_cont: 483 clear_opt (sbi->s_mount_opt, ERRORS_RO); 484 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 485 set_opt (sbi->s_mount_opt, ERRORS_CONT); 486 break; 487 case Opt_nouid32: 488 set_opt (sbi->s_mount_opt, NO_UID32); 489 break; 490 case Opt_nocheck: 491 clear_opt (sbi->s_mount_opt, CHECK); 492 break; 493 case Opt_debug: 494 set_opt (sbi->s_mount_opt, DEBUG); 495 break; 496 case Opt_oldalloc: 497 set_opt (sbi->s_mount_opt, OLDALLOC); 498 break; 499 case Opt_orlov: 500 clear_opt (sbi->s_mount_opt, OLDALLOC); 501 break; 502 case Opt_nobh: 503 set_opt (sbi->s_mount_opt, NOBH); 504 break; 505 #ifdef CONFIG_EXT2_FS_XATTR 506 case Opt_user_xattr: 507 set_opt (sbi->s_mount_opt, XATTR_USER); 508 break; 509 case Opt_nouser_xattr: 510 clear_opt (sbi->s_mount_opt, XATTR_USER); 511 break; 512 #else 513 case Opt_user_xattr: 514 case Opt_nouser_xattr: 515 printk("EXT2 (no)user_xattr options not supported\n"); 516 break; 517 #endif 518 #ifdef CONFIG_EXT2_FS_POSIX_ACL 519 case Opt_acl: 520 set_opt(sbi->s_mount_opt, POSIX_ACL); 521 break; 522 case Opt_noacl: 523 clear_opt(sbi->s_mount_opt, POSIX_ACL); 524 break; 525 #else 526 case Opt_acl: 527 case Opt_noacl: 528 printk("EXT2 (no)acl options not supported\n"); 529 break; 530 #endif 531 case Opt_xip: 532 #ifdef CONFIG_EXT2_FS_XIP 533 set_opt (sbi->s_mount_opt, XIP); 534 #else 535 printk("EXT2 xip option not supported\n"); 536 #endif 537 break; 538 539 #if defined(CONFIG_QUOTA) 540 case Opt_quota: 541 case Opt_usrquota: 542 set_opt(sbi->s_mount_opt, USRQUOTA); 543 break; 544 545 case Opt_grpquota: 546 set_opt(sbi->s_mount_opt, GRPQUOTA); 547 break; 548 #else 549 case Opt_quota: 550 case Opt_usrquota: 551 case Opt_grpquota: 552 printk(KERN_ERR 553 "EXT2-fs: quota operations not supported.\n"); 554 555 break; 556 #endif 557 558 case Opt_reservation: 559 set_opt(sbi->s_mount_opt, RESERVATION); 560 printk("reservations ON\n"); 561 break; 562 case Opt_noreservation: 563 clear_opt(sbi->s_mount_opt, RESERVATION); 564 printk("reservations OFF\n"); 565 break; 566 case Opt_ignore: 567 break; 568 default: 569 return 0; 570 } 571 } 572 return 1; 573 } 574 575 static int ext2_setup_super (struct super_block * sb, 576 struct ext2_super_block * es, 577 int read_only) 578 { 579 int res = 0; 580 struct ext2_sb_info *sbi = EXT2_SB(sb); 581 582 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 583 printk ("EXT2-fs warning: revision level too high, " 584 "forcing read-only mode\n"); 585 res = MS_RDONLY; 586 } 587 if (read_only) 588 return res; 589 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 590 printk ("EXT2-fs warning: mounting unchecked fs, " 591 "running e2fsck is recommended\n"); 592 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 593 printk ("EXT2-fs warning: mounting fs with errors, " 594 "running e2fsck is recommended\n"); 595 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 596 le16_to_cpu(es->s_mnt_count) >= 597 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 598 printk ("EXT2-fs warning: maximal mount count reached, " 599 "running e2fsck is recommended\n"); 600 else if (le32_to_cpu(es->s_checkinterval) && 601 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 602 printk ("EXT2-fs warning: checktime reached, " 603 "running e2fsck is recommended\n"); 604 if (!le16_to_cpu(es->s_max_mnt_count)) 605 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 606 le16_add_cpu(&es->s_mnt_count, 1); 607 ext2_write_super(sb); 608 if (test_opt (sb, DEBUG)) 609 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 610 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 611 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 612 sbi->s_frag_size, 613 sbi->s_groups_count, 614 EXT2_BLOCKS_PER_GROUP(sb), 615 EXT2_INODES_PER_GROUP(sb), 616 sbi->s_mount_opt); 617 return res; 618 } 619 620 static int ext2_check_descriptors(struct super_block *sb) 621 { 622 int i; 623 struct ext2_sb_info *sbi = EXT2_SB(sb); 624 625 ext2_debug ("Checking group descriptors"); 626 627 for (i = 0; i < sbi->s_groups_count; i++) { 628 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 629 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 630 ext2_fsblk_t last_block; 631 632 if (i == sbi->s_groups_count - 1) 633 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 634 else 635 last_block = first_block + 636 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 637 638 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 639 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 640 { 641 ext2_error (sb, "ext2_check_descriptors", 642 "Block bitmap for group %d" 643 " not in group (block %lu)!", 644 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 645 return 0; 646 } 647 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 648 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 649 { 650 ext2_error (sb, "ext2_check_descriptors", 651 "Inode bitmap for group %d" 652 " not in group (block %lu)!", 653 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 654 return 0; 655 } 656 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 657 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 658 last_block) 659 { 660 ext2_error (sb, "ext2_check_descriptors", 661 "Inode table for group %d" 662 " not in group (block %lu)!", 663 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 664 return 0; 665 } 666 } 667 return 1; 668 } 669 670 /* 671 * Maximal file size. There is a direct, and {,double-,triple-}indirect 672 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 673 * We need to be 1 filesystem block less than the 2^32 sector limit. 674 */ 675 static loff_t ext2_max_size(int bits) 676 { 677 loff_t res = EXT2_NDIR_BLOCKS; 678 int meta_blocks; 679 loff_t upper_limit; 680 681 /* This is calculated to be the largest file size for a 682 * dense, file such that the total number of 683 * sectors in the file, including data and all indirect blocks, 684 * does not exceed 2^32 -1 685 * __u32 i_blocks representing the total number of 686 * 512 bytes blocks of the file 687 */ 688 upper_limit = (1LL << 32) - 1; 689 690 /* total blocks in file system block size */ 691 upper_limit >>= (bits - 9); 692 693 694 /* indirect blocks */ 695 meta_blocks = 1; 696 /* double indirect blocks */ 697 meta_blocks += 1 + (1LL << (bits-2)); 698 /* tripple indirect blocks */ 699 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 700 701 upper_limit -= meta_blocks; 702 upper_limit <<= bits; 703 704 res += 1LL << (bits-2); 705 res += 1LL << (2*(bits-2)); 706 res += 1LL << (3*(bits-2)); 707 res <<= bits; 708 if (res > upper_limit) 709 res = upper_limit; 710 711 if (res > MAX_LFS_FILESIZE) 712 res = MAX_LFS_FILESIZE; 713 714 return res; 715 } 716 717 static unsigned long descriptor_loc(struct super_block *sb, 718 unsigned long logic_sb_block, 719 int nr) 720 { 721 struct ext2_sb_info *sbi = EXT2_SB(sb); 722 unsigned long bg, first_meta_bg; 723 int has_super = 0; 724 725 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 726 727 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 728 nr < first_meta_bg) 729 return (logic_sb_block + nr + 1); 730 bg = sbi->s_desc_per_block * nr; 731 if (ext2_bg_has_super(sb, bg)) 732 has_super = 1; 733 734 return ext2_group_first_block_no(sb, bg) + has_super; 735 } 736 737 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 738 { 739 struct buffer_head * bh; 740 struct ext2_sb_info * sbi; 741 struct ext2_super_block * es; 742 struct inode *root; 743 unsigned long block; 744 unsigned long sb_block = get_sb_block(&data); 745 unsigned long logic_sb_block; 746 unsigned long offset = 0; 747 unsigned long def_mount_opts; 748 long ret = -EINVAL; 749 int blocksize = BLOCK_SIZE; 750 int db_count; 751 int i, j; 752 __le32 features; 753 int err; 754 755 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 756 if (!sbi) 757 return -ENOMEM; 758 sb->s_fs_info = sbi; 759 sbi->s_sb_block = sb_block; 760 761 /* 762 * See what the current blocksize for the device is, and 763 * use that as the blocksize. Otherwise (or if the blocksize 764 * is smaller than the default) use the default. 765 * This is important for devices that have a hardware 766 * sectorsize that is larger than the default. 767 */ 768 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 769 if (!blocksize) { 770 printk ("EXT2-fs: unable to set blocksize\n"); 771 goto failed_sbi; 772 } 773 774 /* 775 * If the superblock doesn't start on a hardware sector boundary, 776 * calculate the offset. 777 */ 778 if (blocksize != BLOCK_SIZE) { 779 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 780 offset = (sb_block*BLOCK_SIZE) % blocksize; 781 } else { 782 logic_sb_block = sb_block; 783 } 784 785 if (!(bh = sb_bread(sb, logic_sb_block))) { 786 printk ("EXT2-fs: unable to read superblock\n"); 787 goto failed_sbi; 788 } 789 /* 790 * Note: s_es must be initialized as soon as possible because 791 * some ext2 macro-instructions depend on its value 792 */ 793 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 794 sbi->s_es = es; 795 sb->s_magic = le16_to_cpu(es->s_magic); 796 797 if (sb->s_magic != EXT2_SUPER_MAGIC) 798 goto cantfind_ext2; 799 800 /* Set defaults before we parse the mount options */ 801 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 802 if (def_mount_opts & EXT2_DEFM_DEBUG) 803 set_opt(sbi->s_mount_opt, DEBUG); 804 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 805 set_opt(sbi->s_mount_opt, GRPID); 806 if (def_mount_opts & EXT2_DEFM_UID16) 807 set_opt(sbi->s_mount_opt, NO_UID32); 808 #ifdef CONFIG_EXT2_FS_XATTR 809 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 810 set_opt(sbi->s_mount_opt, XATTR_USER); 811 #endif 812 #ifdef CONFIG_EXT2_FS_POSIX_ACL 813 if (def_mount_opts & EXT2_DEFM_ACL) 814 set_opt(sbi->s_mount_opt, POSIX_ACL); 815 #endif 816 817 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 818 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 819 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 820 set_opt(sbi->s_mount_opt, ERRORS_CONT); 821 else 822 set_opt(sbi->s_mount_opt, ERRORS_RO); 823 824 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 825 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 826 827 set_opt(sbi->s_mount_opt, RESERVATION); 828 829 if (!parse_options ((char *) data, sbi)) 830 goto failed_mount; 831 832 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 833 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 834 MS_POSIXACL : 0); 835 836 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 837 EXT2_MOUNT_XIP if not */ 838 839 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 840 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 841 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 842 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 843 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 844 "running e2fsck is recommended\n"); 845 /* 846 * Check feature flags regardless of the revision level, since we 847 * previously didn't change the revision level when setting the flags, 848 * so there is a chance incompat flags are set on a rev 0 filesystem. 849 */ 850 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 851 if (features) { 852 printk("EXT2-fs: %s: couldn't mount because of " 853 "unsupported optional features (%x).\n", 854 sb->s_id, le32_to_cpu(features)); 855 goto failed_mount; 856 } 857 if (!(sb->s_flags & MS_RDONLY) && 858 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 859 printk("EXT2-fs: %s: couldn't mount RDWR because of " 860 "unsupported optional features (%x).\n", 861 sb->s_id, le32_to_cpu(features)); 862 goto failed_mount; 863 } 864 865 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 866 867 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 868 if (!silent) 869 printk("XIP: Unsupported blocksize\n"); 870 goto failed_mount; 871 } 872 873 /* If the blocksize doesn't match, re-read the thing.. */ 874 if (sb->s_blocksize != blocksize) { 875 brelse(bh); 876 877 if (!sb_set_blocksize(sb, blocksize)) { 878 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 879 goto failed_sbi; 880 } 881 882 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 883 offset = (sb_block*BLOCK_SIZE) % blocksize; 884 bh = sb_bread(sb, logic_sb_block); 885 if(!bh) { 886 printk("EXT2-fs: Couldn't read superblock on " 887 "2nd try.\n"); 888 goto failed_sbi; 889 } 890 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 891 sbi->s_es = es; 892 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 893 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 894 goto failed_mount; 895 } 896 } 897 898 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 899 900 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 901 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 902 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 903 } else { 904 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 905 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 906 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 907 !is_power_of_2(sbi->s_inode_size) || 908 (sbi->s_inode_size > blocksize)) { 909 printk ("EXT2-fs: unsupported inode size: %d\n", 910 sbi->s_inode_size); 911 goto failed_mount; 912 } 913 } 914 915 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 916 le32_to_cpu(es->s_log_frag_size); 917 if (sbi->s_frag_size == 0) 918 goto cantfind_ext2; 919 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 920 921 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 922 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 923 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 924 925 if (EXT2_INODE_SIZE(sb) == 0) 926 goto cantfind_ext2; 927 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 928 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 929 goto cantfind_ext2; 930 sbi->s_itb_per_group = sbi->s_inodes_per_group / 931 sbi->s_inodes_per_block; 932 sbi->s_desc_per_block = sb->s_blocksize / 933 sizeof (struct ext2_group_desc); 934 sbi->s_sbh = bh; 935 sbi->s_mount_state = le16_to_cpu(es->s_state); 936 sbi->s_addr_per_block_bits = 937 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 938 sbi->s_desc_per_block_bits = 939 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 940 941 if (sb->s_magic != EXT2_SUPER_MAGIC) 942 goto cantfind_ext2; 943 944 if (sb->s_blocksize != bh->b_size) { 945 if (!silent) 946 printk ("VFS: Unsupported blocksize on dev " 947 "%s.\n", sb->s_id); 948 goto failed_mount; 949 } 950 951 if (sb->s_blocksize != sbi->s_frag_size) { 952 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 953 sbi->s_frag_size, sb->s_blocksize); 954 goto failed_mount; 955 } 956 957 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 958 printk ("EXT2-fs: #blocks per group too big: %lu\n", 959 sbi->s_blocks_per_group); 960 goto failed_mount; 961 } 962 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 963 printk ("EXT2-fs: #fragments per group too big: %lu\n", 964 sbi->s_frags_per_group); 965 goto failed_mount; 966 } 967 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 968 printk ("EXT2-fs: #inodes per group too big: %lu\n", 969 sbi->s_inodes_per_group); 970 goto failed_mount; 971 } 972 973 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 974 goto cantfind_ext2; 975 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 976 le32_to_cpu(es->s_first_data_block) - 1) 977 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 978 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 979 EXT2_DESC_PER_BLOCK(sb); 980 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 981 if (sbi->s_group_desc == NULL) { 982 printk ("EXT2-fs: not enough memory\n"); 983 goto failed_mount; 984 } 985 bgl_lock_init(&sbi->s_blockgroup_lock); 986 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 987 if (!sbi->s_debts) { 988 printk ("EXT2-fs: not enough memory\n"); 989 goto failed_mount_group_desc; 990 } 991 for (i = 0; i < db_count; i++) { 992 block = descriptor_loc(sb, logic_sb_block, i); 993 sbi->s_group_desc[i] = sb_bread(sb, block); 994 if (!sbi->s_group_desc[i]) { 995 for (j = 0; j < i; j++) 996 brelse (sbi->s_group_desc[j]); 997 printk ("EXT2-fs: unable to read group descriptors\n"); 998 goto failed_mount_group_desc; 999 } 1000 } 1001 if (!ext2_check_descriptors (sb)) { 1002 printk ("EXT2-fs: group descriptors corrupted!\n"); 1003 goto failed_mount2; 1004 } 1005 sbi->s_gdb_count = db_count; 1006 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1007 spin_lock_init(&sbi->s_next_gen_lock); 1008 1009 /* per fileystem reservation list head & lock */ 1010 spin_lock_init(&sbi->s_rsv_window_lock); 1011 sbi->s_rsv_window_root = RB_ROOT; 1012 /* 1013 * Add a single, static dummy reservation to the start of the 1014 * reservation window list --- it gives us a placeholder for 1015 * append-at-start-of-list which makes the allocation logic 1016 * _much_ simpler. 1017 */ 1018 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1019 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1020 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1021 sbi->s_rsv_window_head.rsv_goal_size = 0; 1022 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1023 1024 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1025 ext2_count_free_blocks(sb)); 1026 if (!err) { 1027 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1028 ext2_count_free_inodes(sb)); 1029 } 1030 if (!err) { 1031 err = percpu_counter_init(&sbi->s_dirs_counter, 1032 ext2_count_dirs(sb)); 1033 } 1034 if (err) { 1035 printk(KERN_ERR "EXT2-fs: insufficient memory\n"); 1036 goto failed_mount3; 1037 } 1038 /* 1039 * set up enough so that it can read an inode 1040 */ 1041 sb->s_op = &ext2_sops; 1042 sb->s_export_op = &ext2_export_ops; 1043 sb->s_xattr = ext2_xattr_handlers; 1044 root = ext2_iget(sb, EXT2_ROOT_INO); 1045 if (IS_ERR(root)) { 1046 ret = PTR_ERR(root); 1047 goto failed_mount3; 1048 } 1049 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1050 iput(root); 1051 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 1052 goto failed_mount3; 1053 } 1054 1055 sb->s_root = d_alloc_root(root); 1056 if (!sb->s_root) { 1057 iput(root); 1058 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 1059 ret = -ENOMEM; 1060 goto failed_mount3; 1061 } 1062 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1063 ext2_warning(sb, __func__, 1064 "mounting ext3 filesystem as ext2"); 1065 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 1066 return 0; 1067 1068 cantfind_ext2: 1069 if (!silent) 1070 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 1071 sb->s_id); 1072 goto failed_mount; 1073 failed_mount3: 1074 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1075 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1076 percpu_counter_destroy(&sbi->s_dirs_counter); 1077 failed_mount2: 1078 for (i = 0; i < db_count; i++) 1079 brelse(sbi->s_group_desc[i]); 1080 failed_mount_group_desc: 1081 kfree(sbi->s_group_desc); 1082 kfree(sbi->s_debts); 1083 failed_mount: 1084 brelse(bh); 1085 failed_sbi: 1086 sb->s_fs_info = NULL; 1087 kfree(sbi); 1088 return ret; 1089 } 1090 1091 static void ext2_commit_super (struct super_block * sb, 1092 struct ext2_super_block * es) 1093 { 1094 es->s_wtime = cpu_to_le32(get_seconds()); 1095 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1096 sb->s_dirt = 0; 1097 } 1098 1099 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1100 { 1101 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1102 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1103 es->s_wtime = cpu_to_le32(get_seconds()); 1104 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1105 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1106 sb->s_dirt = 0; 1107 } 1108 1109 /* 1110 * In the second extended file system, it is not necessary to 1111 * write the super block since we use a mapping of the 1112 * disk super block in a buffer. 1113 * 1114 * However, this function is still used to set the fs valid 1115 * flags to 0. We need to set this flag to 0 since the fs 1116 * may have been checked while mounted and e2fsck may have 1117 * set s_state to EXT2_VALID_FS after some corrections. 1118 */ 1119 1120 void ext2_write_super (struct super_block * sb) 1121 { 1122 struct ext2_super_block * es; 1123 lock_kernel(); 1124 if (!(sb->s_flags & MS_RDONLY)) { 1125 es = EXT2_SB(sb)->s_es; 1126 1127 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1128 ext2_debug ("setting valid to 0\n"); 1129 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1130 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1131 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1132 es->s_mtime = cpu_to_le32(get_seconds()); 1133 ext2_sync_super(sb, es); 1134 } else 1135 ext2_commit_super (sb, es); 1136 } 1137 sb->s_dirt = 0; 1138 unlock_kernel(); 1139 } 1140 1141 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1142 { 1143 struct ext2_sb_info * sbi = EXT2_SB(sb); 1144 struct ext2_super_block * es; 1145 unsigned long old_mount_opt = sbi->s_mount_opt; 1146 struct ext2_mount_options old_opts; 1147 unsigned long old_sb_flags; 1148 int err; 1149 1150 /* Store the old options */ 1151 old_sb_flags = sb->s_flags; 1152 old_opts.s_mount_opt = sbi->s_mount_opt; 1153 old_opts.s_resuid = sbi->s_resuid; 1154 old_opts.s_resgid = sbi->s_resgid; 1155 1156 /* 1157 * Allow the "check" option to be passed as a remount option. 1158 */ 1159 if (!parse_options (data, sbi)) { 1160 err = -EINVAL; 1161 goto restore_opts; 1162 } 1163 1164 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1165 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1166 1167 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1168 EXT2_MOUNT_XIP if not */ 1169 1170 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1171 printk("XIP: Unsupported blocksize\n"); 1172 err = -EINVAL; 1173 goto restore_opts; 1174 } 1175 1176 es = sbi->s_es; 1177 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1178 (old_mount_opt & EXT2_MOUNT_XIP)) && 1179 invalidate_inodes(sb)) 1180 ext2_warning(sb, __func__, "busy inodes while remounting "\ 1181 "xip remain in cache (no functional problem)"); 1182 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1183 return 0; 1184 if (*flags & MS_RDONLY) { 1185 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1186 !(sbi->s_mount_state & EXT2_VALID_FS)) 1187 return 0; 1188 /* 1189 * OK, we are remounting a valid rw partition rdonly, so set 1190 * the rdonly flag and then mark the partition as valid again. 1191 */ 1192 es->s_state = cpu_to_le16(sbi->s_mount_state); 1193 es->s_mtime = cpu_to_le32(get_seconds()); 1194 } else { 1195 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1196 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1197 if (ret) { 1198 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1199 "unsupported optional features (%x).\n", 1200 sb->s_id, le32_to_cpu(ret)); 1201 err = -EROFS; 1202 goto restore_opts; 1203 } 1204 /* 1205 * Mounting a RDONLY partition read-write, so reread and 1206 * store the current valid flag. (It may have been changed 1207 * by e2fsck since we originally mounted the partition.) 1208 */ 1209 sbi->s_mount_state = le16_to_cpu(es->s_state); 1210 if (!ext2_setup_super (sb, es, 0)) 1211 sb->s_flags &= ~MS_RDONLY; 1212 } 1213 ext2_sync_super(sb, es); 1214 return 0; 1215 restore_opts: 1216 sbi->s_mount_opt = old_opts.s_mount_opt; 1217 sbi->s_resuid = old_opts.s_resuid; 1218 sbi->s_resgid = old_opts.s_resgid; 1219 sb->s_flags = old_sb_flags; 1220 return err; 1221 } 1222 1223 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1224 { 1225 struct super_block *sb = dentry->d_sb; 1226 struct ext2_sb_info *sbi = EXT2_SB(sb); 1227 struct ext2_super_block *es = sbi->s_es; 1228 u64 fsid; 1229 1230 if (test_opt (sb, MINIX_DF)) 1231 sbi->s_overhead_last = 0; 1232 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1233 unsigned long i, overhead = 0; 1234 smp_rmb(); 1235 1236 /* 1237 * Compute the overhead (FS structures). This is constant 1238 * for a given filesystem unless the number of block groups 1239 * changes so we cache the previous value until it does. 1240 */ 1241 1242 /* 1243 * All of the blocks before first_data_block are 1244 * overhead 1245 */ 1246 overhead = le32_to_cpu(es->s_first_data_block); 1247 1248 /* 1249 * Add the overhead attributed to the superblock and 1250 * block group descriptors. If the sparse superblocks 1251 * feature is turned on, then not all groups have this. 1252 */ 1253 for (i = 0; i < sbi->s_groups_count; i++) 1254 overhead += ext2_bg_has_super(sb, i) + 1255 ext2_bg_num_gdb(sb, i); 1256 1257 /* 1258 * Every block group has an inode bitmap, a block 1259 * bitmap, and an inode table. 1260 */ 1261 overhead += (sbi->s_groups_count * 1262 (2 + sbi->s_itb_per_group)); 1263 sbi->s_overhead_last = overhead; 1264 smp_wmb(); 1265 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1266 } 1267 1268 buf->f_type = EXT2_SUPER_MAGIC; 1269 buf->f_bsize = sb->s_blocksize; 1270 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1271 buf->f_bfree = ext2_count_free_blocks(sb); 1272 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1273 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1274 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1275 buf->f_bavail = 0; 1276 buf->f_files = le32_to_cpu(es->s_inodes_count); 1277 buf->f_ffree = ext2_count_free_inodes(sb); 1278 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1279 buf->f_namelen = EXT2_NAME_LEN; 1280 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1281 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1282 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1283 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1284 return 0; 1285 } 1286 1287 static int ext2_get_sb(struct file_system_type *fs_type, 1288 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1289 { 1290 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1291 } 1292 1293 #ifdef CONFIG_QUOTA 1294 1295 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1296 * acquiring the locks... As quota files are never truncated and quota code 1297 * itself serializes the operations (and noone else should touch the files) 1298 * we don't have to be afraid of races */ 1299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1300 size_t len, loff_t off) 1301 { 1302 struct inode *inode = sb_dqopt(sb)->files[type]; 1303 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1304 int err = 0; 1305 int offset = off & (sb->s_blocksize - 1); 1306 int tocopy; 1307 size_t toread; 1308 struct buffer_head tmp_bh; 1309 struct buffer_head *bh; 1310 loff_t i_size = i_size_read(inode); 1311 1312 if (off > i_size) 1313 return 0; 1314 if (off+len > i_size) 1315 len = i_size-off; 1316 toread = len; 1317 while (toread > 0) { 1318 tocopy = sb->s_blocksize - offset < toread ? 1319 sb->s_blocksize - offset : toread; 1320 1321 tmp_bh.b_state = 0; 1322 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1323 if (err < 0) 1324 return err; 1325 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1326 memset(data, 0, tocopy); 1327 else { 1328 bh = sb_bread(sb, tmp_bh.b_blocknr); 1329 if (!bh) 1330 return -EIO; 1331 memcpy(data, bh->b_data+offset, tocopy); 1332 brelse(bh); 1333 } 1334 offset = 0; 1335 toread -= tocopy; 1336 data += tocopy; 1337 blk++; 1338 } 1339 return len; 1340 } 1341 1342 /* Write to quotafile */ 1343 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1344 const char *data, size_t len, loff_t off) 1345 { 1346 struct inode *inode = sb_dqopt(sb)->files[type]; 1347 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1348 int err = 0; 1349 int offset = off & (sb->s_blocksize - 1); 1350 int tocopy; 1351 size_t towrite = len; 1352 struct buffer_head tmp_bh; 1353 struct buffer_head *bh; 1354 1355 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1356 while (towrite > 0) { 1357 tocopy = sb->s_blocksize - offset < towrite ? 1358 sb->s_blocksize - offset : towrite; 1359 1360 tmp_bh.b_state = 0; 1361 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1362 if (err < 0) 1363 goto out; 1364 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1365 bh = sb_bread(sb, tmp_bh.b_blocknr); 1366 else 1367 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1368 if (!bh) { 1369 err = -EIO; 1370 goto out; 1371 } 1372 lock_buffer(bh); 1373 memcpy(bh->b_data+offset, data, tocopy); 1374 flush_dcache_page(bh->b_page); 1375 set_buffer_uptodate(bh); 1376 mark_buffer_dirty(bh); 1377 unlock_buffer(bh); 1378 brelse(bh); 1379 offset = 0; 1380 towrite -= tocopy; 1381 data += tocopy; 1382 blk++; 1383 } 1384 out: 1385 if (len == towrite) 1386 return err; 1387 if (inode->i_size < off+len-towrite) 1388 i_size_write(inode, off+len-towrite); 1389 inode->i_version++; 1390 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1391 mark_inode_dirty(inode); 1392 mutex_unlock(&inode->i_mutex); 1393 return len - towrite; 1394 } 1395 1396 #endif 1397 1398 static struct file_system_type ext2_fs_type = { 1399 .owner = THIS_MODULE, 1400 .name = "ext2", 1401 .get_sb = ext2_get_sb, 1402 .kill_sb = kill_block_super, 1403 .fs_flags = FS_REQUIRES_DEV, 1404 }; 1405 1406 static int __init init_ext2_fs(void) 1407 { 1408 int err = init_ext2_xattr(); 1409 if (err) 1410 return err; 1411 err = init_inodecache(); 1412 if (err) 1413 goto out1; 1414 err = register_filesystem(&ext2_fs_type); 1415 if (err) 1416 goto out; 1417 return 0; 1418 out: 1419 destroy_inodecache(); 1420 out1: 1421 exit_ext2_xattr(); 1422 return err; 1423 } 1424 1425 static void __exit exit_ext2_fs(void) 1426 { 1427 unregister_filesystem(&ext2_fs_type); 1428 destroy_inodecache(); 1429 exit_ext2_xattr(); 1430 } 1431 1432 module_init(init_ext2_fs) 1433 module_exit(exit_ext2_fs) 1434