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 <linux/quotaops.h> 35 #include <asm/uaccess.h> 36 #include "ext2.h" 37 #include "xattr.h" 38 #include "acl.h" 39 #include "xip.h" 40 41 static void ext2_sync_super(struct super_block *sb, 42 struct ext2_super_block *es); 43 static int ext2_remount (struct super_block * sb, int * flags, char * data); 44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); 45 static int ext2_sync_fs(struct super_block *sb, int wait); 46 47 void ext2_error (struct super_block * sb, const char * function, 48 const char * fmt, ...) 49 { 50 va_list args; 51 struct ext2_sb_info *sbi = EXT2_SB(sb); 52 struct ext2_super_block *es = sbi->s_es; 53 54 if (!(sb->s_flags & MS_RDONLY)) { 55 sbi->s_mount_state |= EXT2_ERROR_FS; 56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 57 ext2_sync_super(sb, es); 58 } 59 60 va_start(args, fmt); 61 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 62 vprintk(fmt, args); 63 printk("\n"); 64 va_end(args); 65 66 if (test_opt(sb, ERRORS_PANIC)) 67 panic("EXT2-fs panic from previous error\n"); 68 if (test_opt(sb, ERRORS_RO)) { 69 printk("Remounting filesystem read-only\n"); 70 sb->s_flags |= MS_RDONLY; 71 } 72 } 73 74 void ext2_warning (struct super_block * sb, const char * function, 75 const char * fmt, ...) 76 { 77 va_list args; 78 79 va_start(args, fmt); 80 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 81 sb->s_id, function); 82 vprintk(fmt, args); 83 printk("\n"); 84 va_end(args); 85 } 86 87 void ext2_update_dynamic_rev(struct super_block *sb) 88 { 89 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 90 91 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 92 return; 93 94 ext2_warning(sb, __func__, 95 "updating to rev %d because of new feature flag, " 96 "running e2fsck is recommended", 97 EXT2_DYNAMIC_REV); 98 99 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 100 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 101 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 102 /* leave es->s_feature_*compat flags alone */ 103 /* es->s_uuid will be set by e2fsck if empty */ 104 105 /* 106 * The rest of the superblock fields should be zero, and if not it 107 * means they are likely already in use, so leave them alone. We 108 * can leave it up to e2fsck to clean up any inconsistencies there. 109 */ 110 } 111 112 static void ext2_put_super (struct super_block * sb) 113 { 114 int db_count; 115 int i; 116 struct ext2_sb_info *sbi = EXT2_SB(sb); 117 118 lock_kernel(); 119 120 if (sb->s_dirt) 121 ext2_write_super(sb); 122 123 ext2_xattr_put_super(sb); 124 if (!(sb->s_flags & MS_RDONLY)) { 125 struct ext2_super_block *es = sbi->s_es; 126 127 es->s_state = cpu_to_le16(sbi->s_mount_state); 128 ext2_sync_super(sb, es); 129 } 130 db_count = sbi->s_gdb_count; 131 for (i = 0; i < db_count; i++) 132 if (sbi->s_group_desc[i]) 133 brelse (sbi->s_group_desc[i]); 134 kfree(sbi->s_group_desc); 135 kfree(sbi->s_debts); 136 percpu_counter_destroy(&sbi->s_freeblocks_counter); 137 percpu_counter_destroy(&sbi->s_freeinodes_counter); 138 percpu_counter_destroy(&sbi->s_dirs_counter); 139 brelse (sbi->s_sbh); 140 sb->s_fs_info = NULL; 141 kfree(sbi->s_blockgroup_lock); 142 kfree(sbi); 143 144 unlock_kernel(); 145 } 146 147 static struct kmem_cache * ext2_inode_cachep; 148 149 static struct inode *ext2_alloc_inode(struct super_block *sb) 150 { 151 struct ext2_inode_info *ei; 152 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 153 if (!ei) 154 return NULL; 155 ei->i_block_alloc_info = NULL; 156 ei->vfs_inode.i_version = 1; 157 return &ei->vfs_inode; 158 } 159 160 static void ext2_destroy_inode(struct inode *inode) 161 { 162 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 163 } 164 165 static void init_once(void *foo) 166 { 167 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 168 169 rwlock_init(&ei->i_meta_lock); 170 #ifdef CONFIG_EXT2_FS_XATTR 171 init_rwsem(&ei->xattr_sem); 172 #endif 173 mutex_init(&ei->truncate_mutex); 174 inode_init_once(&ei->vfs_inode); 175 } 176 177 static int init_inodecache(void) 178 { 179 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 180 sizeof(struct ext2_inode_info), 181 0, (SLAB_RECLAIM_ACCOUNT| 182 SLAB_MEM_SPREAD), 183 init_once); 184 if (ext2_inode_cachep == NULL) 185 return -ENOMEM; 186 return 0; 187 } 188 189 static void destroy_inodecache(void) 190 { 191 kmem_cache_destroy(ext2_inode_cachep); 192 } 193 194 static void ext2_clear_inode(struct inode *inode) 195 { 196 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 197 ext2_discard_reservation(inode); 198 EXT2_I(inode)->i_block_alloc_info = NULL; 199 if (unlikely(rsv)) 200 kfree(rsv); 201 } 202 203 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 204 { 205 struct super_block *sb = vfs->mnt_sb; 206 struct ext2_sb_info *sbi = EXT2_SB(sb); 207 struct ext2_super_block *es = sbi->s_es; 208 unsigned long def_mount_opts; 209 210 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 211 212 if (sbi->s_sb_block != 1) 213 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 214 if (test_opt(sb, MINIX_DF)) 215 seq_puts(seq, ",minixdf"); 216 if (test_opt(sb, GRPID)) 217 seq_puts(seq, ",grpid"); 218 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 219 seq_puts(seq, ",nogrpid"); 220 if (sbi->s_resuid != EXT2_DEF_RESUID || 221 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 222 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 223 } 224 if (sbi->s_resgid != EXT2_DEF_RESGID || 225 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 226 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 227 } 228 if (test_opt(sb, ERRORS_RO)) { 229 int def_errors = le16_to_cpu(es->s_errors); 230 231 if (def_errors == EXT2_ERRORS_PANIC || 232 def_errors == EXT2_ERRORS_CONTINUE) { 233 seq_puts(seq, ",errors=remount-ro"); 234 } 235 } 236 if (test_opt(sb, ERRORS_CONT)) 237 seq_puts(seq, ",errors=continue"); 238 if (test_opt(sb, ERRORS_PANIC)) 239 seq_puts(seq, ",errors=panic"); 240 if (test_opt(sb, NO_UID32)) 241 seq_puts(seq, ",nouid32"); 242 if (test_opt(sb, DEBUG)) 243 seq_puts(seq, ",debug"); 244 if (test_opt(sb, OLDALLOC)) 245 seq_puts(seq, ",oldalloc"); 246 247 #ifdef CONFIG_EXT2_FS_XATTR 248 if (test_opt(sb, XATTR_USER)) 249 seq_puts(seq, ",user_xattr"); 250 if (!test_opt(sb, XATTR_USER) && 251 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 252 seq_puts(seq, ",nouser_xattr"); 253 } 254 #endif 255 256 #ifdef CONFIG_EXT2_FS_POSIX_ACL 257 if (test_opt(sb, POSIX_ACL)) 258 seq_puts(seq, ",acl"); 259 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 260 seq_puts(seq, ",noacl"); 261 #endif 262 263 if (test_opt(sb, NOBH)) 264 seq_puts(seq, ",nobh"); 265 266 #if defined(CONFIG_QUOTA) 267 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 268 seq_puts(seq, ",usrquota"); 269 270 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 271 seq_puts(seq, ",grpquota"); 272 #endif 273 274 #if defined(CONFIG_EXT2_FS_XIP) 275 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 276 seq_puts(seq, ",xip"); 277 #endif 278 279 if (!test_opt(sb, RESERVATION)) 280 seq_puts(seq, ",noreservation"); 281 282 return 0; 283 } 284 285 #ifdef CONFIG_QUOTA 286 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 287 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 288 #endif 289 290 static const struct super_operations ext2_sops = { 291 .alloc_inode = ext2_alloc_inode, 292 .destroy_inode = ext2_destroy_inode, 293 .write_inode = ext2_write_inode, 294 .delete_inode = ext2_delete_inode, 295 .put_super = ext2_put_super, 296 .write_super = ext2_write_super, 297 .sync_fs = ext2_sync_fs, 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 inode *ext2_nfs_get_inode(struct super_block *sb, 309 u64 ino, u32 generation) 310 { 311 struct inode *inode; 312 313 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 314 return ERR_PTR(-ESTALE); 315 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 316 return ERR_PTR(-ESTALE); 317 318 /* iget isn't really right if the inode is currently unallocated!! 319 * ext2_read_inode currently does appropriate checks, but 320 * it might be "neater" to call ext2_get_inode first and check 321 * if the inode is valid..... 322 */ 323 inode = ext2_iget(sb, ino); 324 if (IS_ERR(inode)) 325 return ERR_CAST(inode); 326 if (generation && inode->i_generation != generation) { 327 /* we didn't find the right inode.. */ 328 iput(inode); 329 return ERR_PTR(-ESTALE); 330 } 331 return inode; 332 } 333 334 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 335 int fh_len, int fh_type) 336 { 337 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 338 ext2_nfs_get_inode); 339 } 340 341 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 342 int fh_len, int fh_type) 343 { 344 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 345 ext2_nfs_get_inode); 346 } 347 348 /* Yes, most of these are left as NULL!! 349 * A NULL value implies the default, which works with ext2-like file 350 * systems, but can be improved upon. 351 * Currently only get_parent is required. 352 */ 353 static const struct export_operations ext2_export_ops = { 354 .fh_to_dentry = ext2_fh_to_dentry, 355 .fh_to_parent = ext2_fh_to_parent, 356 .get_parent = ext2_get_parent, 357 }; 358 359 static unsigned long get_sb_block(void **data) 360 { 361 unsigned long sb_block; 362 char *options = (char *) *data; 363 364 if (!options || strncmp(options, "sb=", 3) != 0) 365 return 1; /* Default location */ 366 options += 3; 367 sb_block = simple_strtoul(options, &options, 0); 368 if (*options && *options != ',') { 369 printk("EXT2-fs: Invalid sb specification: %s\n", 370 (char *) *data); 371 return 1; 372 } 373 if (*options == ',') 374 options++; 375 *data = (void *) options; 376 return sb_block; 377 } 378 379 enum { 380 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 381 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 382 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 383 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 384 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 385 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 386 }; 387 388 static const match_table_t tokens = { 389 {Opt_bsd_df, "bsddf"}, 390 {Opt_minix_df, "minixdf"}, 391 {Opt_grpid, "grpid"}, 392 {Opt_grpid, "bsdgroups"}, 393 {Opt_nogrpid, "nogrpid"}, 394 {Opt_nogrpid, "sysvgroups"}, 395 {Opt_resgid, "resgid=%u"}, 396 {Opt_resuid, "resuid=%u"}, 397 {Opt_sb, "sb=%u"}, 398 {Opt_err_cont, "errors=continue"}, 399 {Opt_err_panic, "errors=panic"}, 400 {Opt_err_ro, "errors=remount-ro"}, 401 {Opt_nouid32, "nouid32"}, 402 {Opt_nocheck, "check=none"}, 403 {Opt_nocheck, "nocheck"}, 404 {Opt_debug, "debug"}, 405 {Opt_oldalloc, "oldalloc"}, 406 {Opt_orlov, "orlov"}, 407 {Opt_nobh, "nobh"}, 408 {Opt_user_xattr, "user_xattr"}, 409 {Opt_nouser_xattr, "nouser_xattr"}, 410 {Opt_acl, "acl"}, 411 {Opt_noacl, "noacl"}, 412 {Opt_xip, "xip"}, 413 {Opt_grpquota, "grpquota"}, 414 {Opt_ignore, "noquota"}, 415 {Opt_quota, "quota"}, 416 {Opt_usrquota, "usrquota"}, 417 {Opt_reservation, "reservation"}, 418 {Opt_noreservation, "noreservation"}, 419 {Opt_err, NULL} 420 }; 421 422 static int parse_options (char * options, 423 struct ext2_sb_info *sbi) 424 { 425 char * p; 426 substring_t args[MAX_OPT_ARGS]; 427 int option; 428 429 if (!options) 430 return 1; 431 432 while ((p = strsep (&options, ",")) != NULL) { 433 int token; 434 if (!*p) 435 continue; 436 437 token = match_token(p, tokens, args); 438 switch (token) { 439 case Opt_bsd_df: 440 clear_opt (sbi->s_mount_opt, MINIX_DF); 441 break; 442 case Opt_minix_df: 443 set_opt (sbi->s_mount_opt, MINIX_DF); 444 break; 445 case Opt_grpid: 446 set_opt (sbi->s_mount_opt, GRPID); 447 break; 448 case Opt_nogrpid: 449 clear_opt (sbi->s_mount_opt, GRPID); 450 break; 451 case Opt_resuid: 452 if (match_int(&args[0], &option)) 453 return 0; 454 sbi->s_resuid = option; 455 break; 456 case Opt_resgid: 457 if (match_int(&args[0], &option)) 458 return 0; 459 sbi->s_resgid = option; 460 break; 461 case Opt_sb: 462 /* handled by get_sb_block() instead of here */ 463 /* *sb_block = match_int(&args[0]); */ 464 break; 465 case Opt_err_panic: 466 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 467 clear_opt (sbi->s_mount_opt, ERRORS_RO); 468 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 469 break; 470 case Opt_err_ro: 471 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 472 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 473 set_opt (sbi->s_mount_opt, ERRORS_RO); 474 break; 475 case Opt_err_cont: 476 clear_opt (sbi->s_mount_opt, ERRORS_RO); 477 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 478 set_opt (sbi->s_mount_opt, ERRORS_CONT); 479 break; 480 case Opt_nouid32: 481 set_opt (sbi->s_mount_opt, NO_UID32); 482 break; 483 case Opt_nocheck: 484 clear_opt (sbi->s_mount_opt, CHECK); 485 break; 486 case Opt_debug: 487 set_opt (sbi->s_mount_opt, DEBUG); 488 break; 489 case Opt_oldalloc: 490 set_opt (sbi->s_mount_opt, OLDALLOC); 491 break; 492 case Opt_orlov: 493 clear_opt (sbi->s_mount_opt, OLDALLOC); 494 break; 495 case Opt_nobh: 496 set_opt (sbi->s_mount_opt, NOBH); 497 break; 498 #ifdef CONFIG_EXT2_FS_XATTR 499 case Opt_user_xattr: 500 set_opt (sbi->s_mount_opt, XATTR_USER); 501 break; 502 case Opt_nouser_xattr: 503 clear_opt (sbi->s_mount_opt, XATTR_USER); 504 break; 505 #else 506 case Opt_user_xattr: 507 case Opt_nouser_xattr: 508 printk("EXT2 (no)user_xattr options not supported\n"); 509 break; 510 #endif 511 #ifdef CONFIG_EXT2_FS_POSIX_ACL 512 case Opt_acl: 513 set_opt(sbi->s_mount_opt, POSIX_ACL); 514 break; 515 case Opt_noacl: 516 clear_opt(sbi->s_mount_opt, POSIX_ACL); 517 break; 518 #else 519 case Opt_acl: 520 case Opt_noacl: 521 printk("EXT2 (no)acl options not supported\n"); 522 break; 523 #endif 524 case Opt_xip: 525 #ifdef CONFIG_EXT2_FS_XIP 526 set_opt (sbi->s_mount_opt, XIP); 527 #else 528 printk("EXT2 xip option not supported\n"); 529 #endif 530 break; 531 532 #if defined(CONFIG_QUOTA) 533 case Opt_quota: 534 case Opt_usrquota: 535 set_opt(sbi->s_mount_opt, USRQUOTA); 536 break; 537 538 case Opt_grpquota: 539 set_opt(sbi->s_mount_opt, GRPQUOTA); 540 break; 541 #else 542 case Opt_quota: 543 case Opt_usrquota: 544 case Opt_grpquota: 545 printk(KERN_ERR 546 "EXT2-fs: quota operations not supported.\n"); 547 548 break; 549 #endif 550 551 case Opt_reservation: 552 set_opt(sbi->s_mount_opt, RESERVATION); 553 printk("reservations ON\n"); 554 break; 555 case Opt_noreservation: 556 clear_opt(sbi->s_mount_opt, RESERVATION); 557 printk("reservations OFF\n"); 558 break; 559 case Opt_ignore: 560 break; 561 default: 562 return 0; 563 } 564 } 565 return 1; 566 } 567 568 static int ext2_setup_super (struct super_block * sb, 569 struct ext2_super_block * es, 570 int read_only) 571 { 572 int res = 0; 573 struct ext2_sb_info *sbi = EXT2_SB(sb); 574 575 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 576 printk ("EXT2-fs warning: revision level too high, " 577 "forcing read-only mode\n"); 578 res = MS_RDONLY; 579 } 580 if (read_only) 581 return res; 582 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 583 printk ("EXT2-fs warning: mounting unchecked fs, " 584 "running e2fsck is recommended\n"); 585 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 586 printk ("EXT2-fs warning: mounting fs with errors, " 587 "running e2fsck is recommended\n"); 588 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 589 le16_to_cpu(es->s_mnt_count) >= 590 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 591 printk ("EXT2-fs warning: maximal mount count reached, " 592 "running e2fsck is recommended\n"); 593 else if (le32_to_cpu(es->s_checkinterval) && 594 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 595 printk ("EXT2-fs warning: checktime reached, " 596 "running e2fsck is recommended\n"); 597 if (!le16_to_cpu(es->s_max_mnt_count)) 598 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 599 le16_add_cpu(&es->s_mnt_count, 1); 600 ext2_write_super(sb); 601 if (test_opt (sb, DEBUG)) 602 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 603 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 604 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 605 sbi->s_frag_size, 606 sbi->s_groups_count, 607 EXT2_BLOCKS_PER_GROUP(sb), 608 EXT2_INODES_PER_GROUP(sb), 609 sbi->s_mount_opt); 610 return res; 611 } 612 613 static int ext2_check_descriptors(struct super_block *sb) 614 { 615 int i; 616 struct ext2_sb_info *sbi = EXT2_SB(sb); 617 618 ext2_debug ("Checking group descriptors"); 619 620 for (i = 0; i < sbi->s_groups_count; i++) { 621 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 622 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 623 ext2_fsblk_t last_block; 624 625 if (i == sbi->s_groups_count - 1) 626 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 627 else 628 last_block = first_block + 629 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 630 631 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 632 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 633 { 634 ext2_error (sb, "ext2_check_descriptors", 635 "Block bitmap for group %d" 636 " not in group (block %lu)!", 637 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 638 return 0; 639 } 640 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 641 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 642 { 643 ext2_error (sb, "ext2_check_descriptors", 644 "Inode bitmap for group %d" 645 " not in group (block %lu)!", 646 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 647 return 0; 648 } 649 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 650 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 651 last_block) 652 { 653 ext2_error (sb, "ext2_check_descriptors", 654 "Inode table for group %d" 655 " not in group (block %lu)!", 656 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 657 return 0; 658 } 659 } 660 return 1; 661 } 662 663 /* 664 * Maximal file size. There is a direct, and {,double-,triple-}indirect 665 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 666 * We need to be 1 filesystem block less than the 2^32 sector limit. 667 */ 668 static loff_t ext2_max_size(int bits) 669 { 670 loff_t res = EXT2_NDIR_BLOCKS; 671 int meta_blocks; 672 loff_t upper_limit; 673 674 /* This is calculated to be the largest file size for a 675 * dense, file such that the total number of 676 * sectors in the file, including data and all indirect blocks, 677 * does not exceed 2^32 -1 678 * __u32 i_blocks representing the total number of 679 * 512 bytes blocks of the file 680 */ 681 upper_limit = (1LL << 32) - 1; 682 683 /* total blocks in file system block size */ 684 upper_limit >>= (bits - 9); 685 686 687 /* indirect blocks */ 688 meta_blocks = 1; 689 /* double indirect blocks */ 690 meta_blocks += 1 + (1LL << (bits-2)); 691 /* tripple indirect blocks */ 692 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 693 694 upper_limit -= meta_blocks; 695 upper_limit <<= bits; 696 697 res += 1LL << (bits-2); 698 res += 1LL << (2*(bits-2)); 699 res += 1LL << (3*(bits-2)); 700 res <<= bits; 701 if (res > upper_limit) 702 res = upper_limit; 703 704 if (res > MAX_LFS_FILESIZE) 705 res = MAX_LFS_FILESIZE; 706 707 return res; 708 } 709 710 static unsigned long descriptor_loc(struct super_block *sb, 711 unsigned long logic_sb_block, 712 int nr) 713 { 714 struct ext2_sb_info *sbi = EXT2_SB(sb); 715 unsigned long bg, first_meta_bg; 716 int has_super = 0; 717 718 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 719 720 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 721 nr < first_meta_bg) 722 return (logic_sb_block + nr + 1); 723 bg = sbi->s_desc_per_block * nr; 724 if (ext2_bg_has_super(sb, bg)) 725 has_super = 1; 726 727 return ext2_group_first_block_no(sb, bg) + has_super; 728 } 729 730 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 731 { 732 struct buffer_head * bh; 733 struct ext2_sb_info * sbi; 734 struct ext2_super_block * es; 735 struct inode *root; 736 unsigned long block; 737 unsigned long sb_block = get_sb_block(&data); 738 unsigned long logic_sb_block; 739 unsigned long offset = 0; 740 unsigned long def_mount_opts; 741 long ret = -EINVAL; 742 int blocksize = BLOCK_SIZE; 743 int db_count; 744 int i, j; 745 __le32 features; 746 int err; 747 748 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 749 if (!sbi) 750 return -ENOMEM; 751 752 sbi->s_blockgroup_lock = 753 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 754 if (!sbi->s_blockgroup_lock) { 755 kfree(sbi); 756 return -ENOMEM; 757 } 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->s_blockgroup_lock); 1088 kfree(sbi); 1089 return ret; 1090 } 1091 1092 static void ext2_commit_super (struct super_block * sb, 1093 struct ext2_super_block * es) 1094 { 1095 es->s_wtime = cpu_to_le32(get_seconds()); 1096 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1097 sb->s_dirt = 0; 1098 } 1099 1100 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1101 { 1102 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1103 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1104 es->s_wtime = cpu_to_le32(get_seconds()); 1105 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1106 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1107 sb->s_dirt = 0; 1108 } 1109 1110 /* 1111 * In the second extended file system, it is not necessary to 1112 * write the super block since we use a mapping of the 1113 * disk super block in a buffer. 1114 * 1115 * However, this function is still used to set the fs valid 1116 * flags to 0. We need to set this flag to 0 since the fs 1117 * may have been checked while mounted and e2fsck may have 1118 * set s_state to EXT2_VALID_FS after some corrections. 1119 */ 1120 1121 static int ext2_sync_fs(struct super_block *sb, int wait) 1122 { 1123 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 1124 1125 lock_kernel(); 1126 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1127 ext2_debug("setting valid to 0\n"); 1128 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1129 es->s_free_blocks_count = 1130 cpu_to_le32(ext2_count_free_blocks(sb)); 1131 es->s_free_inodes_count = 1132 cpu_to_le32(ext2_count_free_inodes(sb)); 1133 es->s_mtime = cpu_to_le32(get_seconds()); 1134 ext2_sync_super(sb, es); 1135 } else { 1136 ext2_commit_super(sb, es); 1137 } 1138 sb->s_dirt = 0; 1139 unlock_kernel(); 1140 1141 return 0; 1142 } 1143 1144 1145 void ext2_write_super(struct super_block *sb) 1146 { 1147 if (!(sb->s_flags & MS_RDONLY)) 1148 ext2_sync_fs(sb, 1); 1149 else 1150 sb->s_dirt = 0; 1151 } 1152 1153 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1154 { 1155 struct ext2_sb_info * sbi = EXT2_SB(sb); 1156 struct ext2_super_block * es; 1157 unsigned long old_mount_opt = sbi->s_mount_opt; 1158 struct ext2_mount_options old_opts; 1159 unsigned long old_sb_flags; 1160 int err; 1161 1162 lock_kernel(); 1163 1164 /* Store the old options */ 1165 old_sb_flags = sb->s_flags; 1166 old_opts.s_mount_opt = sbi->s_mount_opt; 1167 old_opts.s_resuid = sbi->s_resuid; 1168 old_opts.s_resgid = sbi->s_resgid; 1169 1170 /* 1171 * Allow the "check" option to be passed as a remount option. 1172 */ 1173 if (!parse_options (data, sbi)) { 1174 err = -EINVAL; 1175 goto restore_opts; 1176 } 1177 1178 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1179 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1180 1181 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1182 EXT2_MOUNT_XIP if not */ 1183 1184 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1185 printk("XIP: Unsupported blocksize\n"); 1186 err = -EINVAL; 1187 goto restore_opts; 1188 } 1189 1190 es = sbi->s_es; 1191 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1192 (old_mount_opt & EXT2_MOUNT_XIP)) && 1193 invalidate_inodes(sb)) { 1194 ext2_warning(sb, __func__, "refusing change of xip flag " 1195 "with busy inodes while remounting"); 1196 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1197 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1198 } 1199 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1200 unlock_kernel(); 1201 return 0; 1202 } 1203 if (*flags & MS_RDONLY) { 1204 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1205 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1206 unlock_kernel(); 1207 return 0; 1208 } 1209 /* 1210 * OK, we are remounting a valid rw partition rdonly, so set 1211 * the rdonly flag and then mark the partition as valid again. 1212 */ 1213 es->s_state = cpu_to_le16(sbi->s_mount_state); 1214 es->s_mtime = cpu_to_le32(get_seconds()); 1215 } else { 1216 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1217 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1218 if (ret) { 1219 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1220 "unsupported optional features (%x).\n", 1221 sb->s_id, le32_to_cpu(ret)); 1222 err = -EROFS; 1223 goto restore_opts; 1224 } 1225 /* 1226 * Mounting a RDONLY partition read-write, so reread and 1227 * store the current valid flag. (It may have been changed 1228 * by e2fsck since we originally mounted the partition.) 1229 */ 1230 sbi->s_mount_state = le16_to_cpu(es->s_state); 1231 if (!ext2_setup_super (sb, es, 0)) 1232 sb->s_flags &= ~MS_RDONLY; 1233 } 1234 ext2_sync_super(sb, es); 1235 unlock_kernel(); 1236 return 0; 1237 restore_opts: 1238 sbi->s_mount_opt = old_opts.s_mount_opt; 1239 sbi->s_resuid = old_opts.s_resuid; 1240 sbi->s_resgid = old_opts.s_resgid; 1241 sb->s_flags = old_sb_flags; 1242 unlock_kernel(); 1243 return err; 1244 } 1245 1246 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1247 { 1248 struct super_block *sb = dentry->d_sb; 1249 struct ext2_sb_info *sbi = EXT2_SB(sb); 1250 struct ext2_super_block *es = sbi->s_es; 1251 u64 fsid; 1252 1253 if (test_opt (sb, MINIX_DF)) 1254 sbi->s_overhead_last = 0; 1255 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1256 unsigned long i, overhead = 0; 1257 smp_rmb(); 1258 1259 /* 1260 * Compute the overhead (FS structures). This is constant 1261 * for a given filesystem unless the number of block groups 1262 * changes so we cache the previous value until it does. 1263 */ 1264 1265 /* 1266 * All of the blocks before first_data_block are 1267 * overhead 1268 */ 1269 overhead = le32_to_cpu(es->s_first_data_block); 1270 1271 /* 1272 * Add the overhead attributed to the superblock and 1273 * block group descriptors. If the sparse superblocks 1274 * feature is turned on, then not all groups have this. 1275 */ 1276 for (i = 0; i < sbi->s_groups_count; i++) 1277 overhead += ext2_bg_has_super(sb, i) + 1278 ext2_bg_num_gdb(sb, i); 1279 1280 /* 1281 * Every block group has an inode bitmap, a block 1282 * bitmap, and an inode table. 1283 */ 1284 overhead += (sbi->s_groups_count * 1285 (2 + sbi->s_itb_per_group)); 1286 sbi->s_overhead_last = overhead; 1287 smp_wmb(); 1288 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1289 } 1290 1291 buf->f_type = EXT2_SUPER_MAGIC; 1292 buf->f_bsize = sb->s_blocksize; 1293 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1294 buf->f_bfree = ext2_count_free_blocks(sb); 1295 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1296 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1297 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1298 buf->f_bavail = 0; 1299 buf->f_files = le32_to_cpu(es->s_inodes_count); 1300 buf->f_ffree = ext2_count_free_inodes(sb); 1301 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1302 buf->f_namelen = EXT2_NAME_LEN; 1303 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1304 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1305 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1306 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1307 return 0; 1308 } 1309 1310 static int ext2_get_sb(struct file_system_type *fs_type, 1311 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1312 { 1313 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1314 } 1315 1316 #ifdef CONFIG_QUOTA 1317 1318 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1319 * acquiring the locks... As quota files are never truncated and quota code 1320 * itself serializes the operations (and noone else should touch the files) 1321 * we don't have to be afraid of races */ 1322 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1323 size_t len, loff_t off) 1324 { 1325 struct inode *inode = sb_dqopt(sb)->files[type]; 1326 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1327 int err = 0; 1328 int offset = off & (sb->s_blocksize - 1); 1329 int tocopy; 1330 size_t toread; 1331 struct buffer_head tmp_bh; 1332 struct buffer_head *bh; 1333 loff_t i_size = i_size_read(inode); 1334 1335 if (off > i_size) 1336 return 0; 1337 if (off+len > i_size) 1338 len = i_size-off; 1339 toread = len; 1340 while (toread > 0) { 1341 tocopy = sb->s_blocksize - offset < toread ? 1342 sb->s_blocksize - offset : toread; 1343 1344 tmp_bh.b_state = 0; 1345 tmp_bh.b_size = sb->s_blocksize; 1346 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1347 if (err < 0) 1348 return err; 1349 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1350 memset(data, 0, tocopy); 1351 else { 1352 bh = sb_bread(sb, tmp_bh.b_blocknr); 1353 if (!bh) 1354 return -EIO; 1355 memcpy(data, bh->b_data+offset, tocopy); 1356 brelse(bh); 1357 } 1358 offset = 0; 1359 toread -= tocopy; 1360 data += tocopy; 1361 blk++; 1362 } 1363 return len; 1364 } 1365 1366 /* Write to quotafile */ 1367 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1368 const char *data, size_t len, loff_t off) 1369 { 1370 struct inode *inode = sb_dqopt(sb)->files[type]; 1371 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1372 int err = 0; 1373 int offset = off & (sb->s_blocksize - 1); 1374 int tocopy; 1375 size_t towrite = len; 1376 struct buffer_head tmp_bh; 1377 struct buffer_head *bh; 1378 1379 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1380 while (towrite > 0) { 1381 tocopy = sb->s_blocksize - offset < towrite ? 1382 sb->s_blocksize - offset : towrite; 1383 1384 tmp_bh.b_state = 0; 1385 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1386 if (err < 0) 1387 goto out; 1388 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1389 bh = sb_bread(sb, tmp_bh.b_blocknr); 1390 else 1391 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1392 if (!bh) { 1393 err = -EIO; 1394 goto out; 1395 } 1396 lock_buffer(bh); 1397 memcpy(bh->b_data+offset, data, tocopy); 1398 flush_dcache_page(bh->b_page); 1399 set_buffer_uptodate(bh); 1400 mark_buffer_dirty(bh); 1401 unlock_buffer(bh); 1402 brelse(bh); 1403 offset = 0; 1404 towrite -= tocopy; 1405 data += tocopy; 1406 blk++; 1407 } 1408 out: 1409 if (len == towrite) { 1410 mutex_unlock(&inode->i_mutex); 1411 return err; 1412 } 1413 if (inode->i_size < off+len-towrite) 1414 i_size_write(inode, off+len-towrite); 1415 inode->i_version++; 1416 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1417 mark_inode_dirty(inode); 1418 mutex_unlock(&inode->i_mutex); 1419 return len - towrite; 1420 } 1421 1422 #endif 1423 1424 static struct file_system_type ext2_fs_type = { 1425 .owner = THIS_MODULE, 1426 .name = "ext2", 1427 .get_sb = ext2_get_sb, 1428 .kill_sb = kill_block_super, 1429 .fs_flags = FS_REQUIRES_DEV, 1430 }; 1431 1432 static int __init init_ext2_fs(void) 1433 { 1434 int err = init_ext2_xattr(); 1435 if (err) 1436 return err; 1437 err = init_inodecache(); 1438 if (err) 1439 goto out1; 1440 err = register_filesystem(&ext2_fs_type); 1441 if (err) 1442 goto out; 1443 return 0; 1444 out: 1445 destroy_inodecache(); 1446 out1: 1447 exit_ext2_xattr(); 1448 return err; 1449 } 1450 1451 static void __exit exit_ext2_fs(void) 1452 { 1453 unregister_filesystem(&ext2_fs_type); 1454 destroy_inodecache(); 1455 exit_ext2_xattr(); 1456 } 1457 1458 module_init(init_ext2_fs) 1459 module_exit(exit_ext2_fs) 1460