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/vfs.h> 30 #include <linux/seq_file.h> 31 #include <linux/mount.h> 32 #include <linux/log2.h> 33 #include <linux/quotaops.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, int wait); 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 static int ext2_sync_fs(struct super_block *sb, int wait); 45 46 void ext2_error(struct super_block *sb, const char *function, 47 const char *fmt, ...) 48 { 49 struct va_format vaf; 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 spin_lock(&sbi->s_lock); 56 sbi->s_mount_state |= EXT2_ERROR_FS; 57 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 58 spin_unlock(&sbi->s_lock); 59 ext2_sync_super(sb, es, 1); 60 } 61 62 va_start(args, fmt); 63 64 vaf.fmt = fmt; 65 vaf.va = &args; 66 67 printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n", 68 sb->s_id, function, &vaf); 69 70 va_end(args); 71 72 if (test_opt(sb, ERRORS_PANIC)) 73 panic("EXT2-fs: panic from previous error\n"); 74 if (test_opt(sb, ERRORS_RO)) { 75 ext2_msg(sb, KERN_CRIT, 76 "error: remounting filesystem read-only"); 77 sb->s_flags |= MS_RDONLY; 78 } 79 } 80 81 void ext2_msg(struct super_block *sb, const char *prefix, 82 const char *fmt, ...) 83 { 84 struct va_format vaf; 85 va_list args; 86 87 va_start(args, fmt); 88 89 vaf.fmt = fmt; 90 vaf.va = &args; 91 92 printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf); 93 94 va_end(args); 95 } 96 97 /* 98 * This must be called with sbi->s_lock held. 99 */ 100 void ext2_update_dynamic_rev(struct super_block *sb) 101 { 102 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 103 104 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 105 return; 106 107 ext2_msg(sb, KERN_WARNING, 108 "warning: updating to rev %d because of " 109 "new feature flag, running e2fsck is recommended", 110 EXT2_DYNAMIC_REV); 111 112 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 113 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 114 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 115 /* leave es->s_feature_*compat flags alone */ 116 /* es->s_uuid will be set by e2fsck if empty */ 117 118 /* 119 * The rest of the superblock fields should be zero, and if not it 120 * means they are likely already in use, so leave them alone. We 121 * can leave it up to e2fsck to clean up any inconsistencies there. 122 */ 123 } 124 125 static void ext2_put_super (struct super_block * sb) 126 { 127 int db_count; 128 int i; 129 struct ext2_sb_info *sbi = EXT2_SB(sb); 130 131 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 132 133 if (sb->s_dirt) 134 ext2_write_super(sb); 135 136 ext2_xattr_put_super(sb); 137 if (!(sb->s_flags & MS_RDONLY)) { 138 struct ext2_super_block *es = sbi->s_es; 139 140 spin_lock(&sbi->s_lock); 141 es->s_state = cpu_to_le16(sbi->s_mount_state); 142 spin_unlock(&sbi->s_lock); 143 ext2_sync_super(sb, es, 1); 144 } 145 db_count = sbi->s_gdb_count; 146 for (i = 0; i < db_count; i++) 147 if (sbi->s_group_desc[i]) 148 brelse (sbi->s_group_desc[i]); 149 kfree(sbi->s_group_desc); 150 kfree(sbi->s_debts); 151 percpu_counter_destroy(&sbi->s_freeblocks_counter); 152 percpu_counter_destroy(&sbi->s_freeinodes_counter); 153 percpu_counter_destroy(&sbi->s_dirs_counter); 154 brelse (sbi->s_sbh); 155 sb->s_fs_info = NULL; 156 kfree(sbi->s_blockgroup_lock); 157 kfree(sbi); 158 } 159 160 static struct kmem_cache * ext2_inode_cachep; 161 162 static struct inode *ext2_alloc_inode(struct super_block *sb) 163 { 164 struct ext2_inode_info *ei; 165 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 166 if (!ei) 167 return NULL; 168 ei->i_block_alloc_info = NULL; 169 ei->vfs_inode.i_version = 1; 170 return &ei->vfs_inode; 171 } 172 173 static void ext2_i_callback(struct rcu_head *head) 174 { 175 struct inode *inode = container_of(head, struct inode, i_rcu); 176 INIT_LIST_HEAD(&inode->i_dentry); 177 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 178 } 179 180 static void ext2_destroy_inode(struct inode *inode) 181 { 182 call_rcu(&inode->i_rcu, ext2_i_callback); 183 } 184 185 static void init_once(void *foo) 186 { 187 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 188 189 rwlock_init(&ei->i_meta_lock); 190 #ifdef CONFIG_EXT2_FS_XATTR 191 init_rwsem(&ei->xattr_sem); 192 #endif 193 mutex_init(&ei->truncate_mutex); 194 inode_init_once(&ei->vfs_inode); 195 } 196 197 static int init_inodecache(void) 198 { 199 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 200 sizeof(struct ext2_inode_info), 201 0, (SLAB_RECLAIM_ACCOUNT| 202 SLAB_MEM_SPREAD), 203 init_once); 204 if (ext2_inode_cachep == NULL) 205 return -ENOMEM; 206 return 0; 207 } 208 209 static void destroy_inodecache(void) 210 { 211 kmem_cache_destroy(ext2_inode_cachep); 212 } 213 214 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 215 { 216 struct super_block *sb = vfs->mnt_sb; 217 struct ext2_sb_info *sbi = EXT2_SB(sb); 218 struct ext2_super_block *es = sbi->s_es; 219 unsigned long def_mount_opts; 220 221 spin_lock(&sbi->s_lock); 222 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 223 224 if (sbi->s_sb_block != 1) 225 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 226 if (test_opt(sb, MINIX_DF)) 227 seq_puts(seq, ",minixdf"); 228 if (test_opt(sb, GRPID)) 229 seq_puts(seq, ",grpid"); 230 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 231 seq_puts(seq, ",nogrpid"); 232 if (sbi->s_resuid != EXT2_DEF_RESUID || 233 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 234 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 235 } 236 if (sbi->s_resgid != EXT2_DEF_RESGID || 237 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 238 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 239 } 240 if (test_opt(sb, ERRORS_RO)) { 241 int def_errors = le16_to_cpu(es->s_errors); 242 243 if (def_errors == EXT2_ERRORS_PANIC || 244 def_errors == EXT2_ERRORS_CONTINUE) { 245 seq_puts(seq, ",errors=remount-ro"); 246 } 247 } 248 if (test_opt(sb, ERRORS_CONT)) 249 seq_puts(seq, ",errors=continue"); 250 if (test_opt(sb, ERRORS_PANIC)) 251 seq_puts(seq, ",errors=panic"); 252 if (test_opt(sb, NO_UID32)) 253 seq_puts(seq, ",nouid32"); 254 if (test_opt(sb, DEBUG)) 255 seq_puts(seq, ",debug"); 256 if (test_opt(sb, OLDALLOC)) 257 seq_puts(seq, ",oldalloc"); 258 259 #ifdef CONFIG_EXT2_FS_XATTR 260 if (test_opt(sb, XATTR_USER)) 261 seq_puts(seq, ",user_xattr"); 262 if (!test_opt(sb, XATTR_USER) && 263 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 264 seq_puts(seq, ",nouser_xattr"); 265 } 266 #endif 267 268 #ifdef CONFIG_EXT2_FS_POSIX_ACL 269 if (test_opt(sb, POSIX_ACL)) 270 seq_puts(seq, ",acl"); 271 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 272 seq_puts(seq, ",noacl"); 273 #endif 274 275 if (test_opt(sb, NOBH)) 276 seq_puts(seq, ",nobh"); 277 278 #if defined(CONFIG_QUOTA) 279 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 280 seq_puts(seq, ",usrquota"); 281 282 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 283 seq_puts(seq, ",grpquota"); 284 #endif 285 286 #if defined(CONFIG_EXT2_FS_XIP) 287 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 288 seq_puts(seq, ",xip"); 289 #endif 290 291 if (!test_opt(sb, RESERVATION)) 292 seq_puts(seq, ",noreservation"); 293 294 spin_unlock(&sbi->s_lock); 295 return 0; 296 } 297 298 #ifdef CONFIG_QUOTA 299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 300 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 301 #endif 302 303 static const struct super_operations ext2_sops = { 304 .alloc_inode = ext2_alloc_inode, 305 .destroy_inode = ext2_destroy_inode, 306 .write_inode = ext2_write_inode, 307 .evict_inode = ext2_evict_inode, 308 .put_super = ext2_put_super, 309 .write_super = ext2_write_super, 310 .sync_fs = ext2_sync_fs, 311 .statfs = ext2_statfs, 312 .remount_fs = ext2_remount, 313 .show_options = ext2_show_options, 314 #ifdef CONFIG_QUOTA 315 .quota_read = ext2_quota_read, 316 .quota_write = ext2_quota_write, 317 #endif 318 }; 319 320 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 321 u64 ino, u32 generation) 322 { 323 struct inode *inode; 324 325 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 326 return ERR_PTR(-ESTALE); 327 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 328 return ERR_PTR(-ESTALE); 329 330 /* 331 * ext2_iget isn't quite right if the inode is currently unallocated! 332 * However ext2_iget currently does appropriate checks to handle stale 333 * inodes so everything is OK. 334 */ 335 inode = ext2_iget(sb, ino); 336 if (IS_ERR(inode)) 337 return ERR_CAST(inode); 338 if (generation && inode->i_generation != generation) { 339 /* we didn't find the right inode.. */ 340 iput(inode); 341 return ERR_PTR(-ESTALE); 342 } 343 return inode; 344 } 345 346 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 347 int fh_len, int fh_type) 348 { 349 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 350 ext2_nfs_get_inode); 351 } 352 353 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 354 int fh_len, int fh_type) 355 { 356 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 357 ext2_nfs_get_inode); 358 } 359 360 /* Yes, most of these are left as NULL!! 361 * A NULL value implies the default, which works with ext2-like file 362 * systems, but can be improved upon. 363 * Currently only get_parent is required. 364 */ 365 static const struct export_operations ext2_export_ops = { 366 .fh_to_dentry = ext2_fh_to_dentry, 367 .fh_to_parent = ext2_fh_to_parent, 368 .get_parent = ext2_get_parent, 369 }; 370 371 static unsigned long get_sb_block(void **data) 372 { 373 unsigned long sb_block; 374 char *options = (char *) *data; 375 376 if (!options || strncmp(options, "sb=", 3) != 0) 377 return 1; /* Default location */ 378 options += 3; 379 sb_block = simple_strtoul(options, &options, 0); 380 if (*options && *options != ',') { 381 printk("EXT2-fs: Invalid sb specification: %s\n", 382 (char *) *data); 383 return 1; 384 } 385 if (*options == ',') 386 options++; 387 *data = (void *) options; 388 return sb_block; 389 } 390 391 enum { 392 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 393 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 394 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 395 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 396 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 397 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 398 }; 399 400 static const match_table_t tokens = { 401 {Opt_bsd_df, "bsddf"}, 402 {Opt_minix_df, "minixdf"}, 403 {Opt_grpid, "grpid"}, 404 {Opt_grpid, "bsdgroups"}, 405 {Opt_nogrpid, "nogrpid"}, 406 {Opt_nogrpid, "sysvgroups"}, 407 {Opt_resgid, "resgid=%u"}, 408 {Opt_resuid, "resuid=%u"}, 409 {Opt_sb, "sb=%u"}, 410 {Opt_err_cont, "errors=continue"}, 411 {Opt_err_panic, "errors=panic"}, 412 {Opt_err_ro, "errors=remount-ro"}, 413 {Opt_nouid32, "nouid32"}, 414 {Opt_nocheck, "check=none"}, 415 {Opt_nocheck, "nocheck"}, 416 {Opt_debug, "debug"}, 417 {Opt_oldalloc, "oldalloc"}, 418 {Opt_orlov, "orlov"}, 419 {Opt_nobh, "nobh"}, 420 {Opt_user_xattr, "user_xattr"}, 421 {Opt_nouser_xattr, "nouser_xattr"}, 422 {Opt_acl, "acl"}, 423 {Opt_noacl, "noacl"}, 424 {Opt_xip, "xip"}, 425 {Opt_grpquota, "grpquota"}, 426 {Opt_ignore, "noquota"}, 427 {Opt_quota, "quota"}, 428 {Opt_usrquota, "usrquota"}, 429 {Opt_reservation, "reservation"}, 430 {Opt_noreservation, "noreservation"}, 431 {Opt_err, NULL} 432 }; 433 434 static int parse_options(char *options, struct super_block *sb) 435 { 436 char *p; 437 struct ext2_sb_info *sbi = EXT2_SB(sb); 438 substring_t args[MAX_OPT_ARGS]; 439 int option; 440 441 if (!options) 442 return 1; 443 444 while ((p = strsep (&options, ",")) != NULL) { 445 int token; 446 if (!*p) 447 continue; 448 449 token = match_token(p, tokens, args); 450 switch (token) { 451 case Opt_bsd_df: 452 clear_opt (sbi->s_mount_opt, MINIX_DF); 453 break; 454 case Opt_minix_df: 455 set_opt (sbi->s_mount_opt, MINIX_DF); 456 break; 457 case Opt_grpid: 458 set_opt (sbi->s_mount_opt, GRPID); 459 break; 460 case Opt_nogrpid: 461 clear_opt (sbi->s_mount_opt, GRPID); 462 break; 463 case Opt_resuid: 464 if (match_int(&args[0], &option)) 465 return 0; 466 sbi->s_resuid = option; 467 break; 468 case Opt_resgid: 469 if (match_int(&args[0], &option)) 470 return 0; 471 sbi->s_resgid = option; 472 break; 473 case Opt_sb: 474 /* handled by get_sb_block() instead of here */ 475 /* *sb_block = match_int(&args[0]); */ 476 break; 477 case Opt_err_panic: 478 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 479 clear_opt (sbi->s_mount_opt, ERRORS_RO); 480 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 481 break; 482 case Opt_err_ro: 483 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 484 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 485 set_opt (sbi->s_mount_opt, ERRORS_RO); 486 break; 487 case Opt_err_cont: 488 clear_opt (sbi->s_mount_opt, ERRORS_RO); 489 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 490 set_opt (sbi->s_mount_opt, ERRORS_CONT); 491 break; 492 case Opt_nouid32: 493 set_opt (sbi->s_mount_opt, NO_UID32); 494 break; 495 case Opt_nocheck: 496 clear_opt (sbi->s_mount_opt, CHECK); 497 break; 498 case Opt_debug: 499 set_opt (sbi->s_mount_opt, DEBUG); 500 break; 501 case Opt_oldalloc: 502 set_opt (sbi->s_mount_opt, OLDALLOC); 503 break; 504 case Opt_orlov: 505 clear_opt (sbi->s_mount_opt, OLDALLOC); 506 break; 507 case Opt_nobh: 508 set_opt (sbi->s_mount_opt, NOBH); 509 break; 510 #ifdef CONFIG_EXT2_FS_XATTR 511 case Opt_user_xattr: 512 set_opt (sbi->s_mount_opt, XATTR_USER); 513 break; 514 case Opt_nouser_xattr: 515 clear_opt (sbi->s_mount_opt, XATTR_USER); 516 break; 517 #else 518 case Opt_user_xattr: 519 case Opt_nouser_xattr: 520 ext2_msg(sb, KERN_INFO, "(no)user_xattr options" 521 "not supported"); 522 break; 523 #endif 524 #ifdef CONFIG_EXT2_FS_POSIX_ACL 525 case Opt_acl: 526 set_opt(sbi->s_mount_opt, POSIX_ACL); 527 break; 528 case Opt_noacl: 529 clear_opt(sbi->s_mount_opt, POSIX_ACL); 530 break; 531 #else 532 case Opt_acl: 533 case Opt_noacl: 534 ext2_msg(sb, KERN_INFO, 535 "(no)acl options not supported"); 536 break; 537 #endif 538 case Opt_xip: 539 #ifdef CONFIG_EXT2_FS_XIP 540 set_opt (sbi->s_mount_opt, XIP); 541 #else 542 ext2_msg(sb, KERN_INFO, "xip option not supported"); 543 #endif 544 break; 545 546 #if defined(CONFIG_QUOTA) 547 case Opt_quota: 548 case Opt_usrquota: 549 set_opt(sbi->s_mount_opt, USRQUOTA); 550 break; 551 552 case Opt_grpquota: 553 set_opt(sbi->s_mount_opt, GRPQUOTA); 554 break; 555 #else 556 case Opt_quota: 557 case Opt_usrquota: 558 case Opt_grpquota: 559 ext2_msg(sb, KERN_INFO, 560 "quota operations not supported"); 561 break; 562 #endif 563 564 case Opt_reservation: 565 set_opt(sbi->s_mount_opt, RESERVATION); 566 ext2_msg(sb, KERN_INFO, "reservations ON"); 567 break; 568 case Opt_noreservation: 569 clear_opt(sbi->s_mount_opt, RESERVATION); 570 ext2_msg(sb, KERN_INFO, "reservations OFF"); 571 break; 572 case Opt_ignore: 573 break; 574 default: 575 return 0; 576 } 577 } 578 return 1; 579 } 580 581 static int ext2_setup_super (struct super_block * sb, 582 struct ext2_super_block * es, 583 int read_only) 584 { 585 int res = 0; 586 struct ext2_sb_info *sbi = EXT2_SB(sb); 587 588 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 589 ext2_msg(sb, KERN_ERR, 590 "error: revision level too high, " 591 "forcing read-only mode"); 592 res = MS_RDONLY; 593 } 594 if (read_only) 595 return res; 596 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 597 ext2_msg(sb, KERN_WARNING, 598 "warning: mounting unchecked fs, " 599 "running e2fsck is recommended"); 600 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 601 ext2_msg(sb, KERN_WARNING, 602 "warning: mounting fs with errors, " 603 "running e2fsck is recommended"); 604 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 605 le16_to_cpu(es->s_mnt_count) >= 606 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 607 ext2_msg(sb, KERN_WARNING, 608 "warning: maximal mount count reached, " 609 "running e2fsck is recommended"); 610 else if (le32_to_cpu(es->s_checkinterval) && 611 (le32_to_cpu(es->s_lastcheck) + 612 le32_to_cpu(es->s_checkinterval) <= get_seconds())) 613 ext2_msg(sb, KERN_WARNING, 614 "warning: checktime reached, " 615 "running e2fsck is recommended"); 616 if (!le16_to_cpu(es->s_max_mnt_count)) 617 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 618 le16_add_cpu(&es->s_mnt_count, 1); 619 if (test_opt (sb, DEBUG)) 620 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, " 621 "bpg=%lu, ipg=%lu, mo=%04lx]", 622 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 623 sbi->s_frag_size, 624 sbi->s_groups_count, 625 EXT2_BLOCKS_PER_GROUP(sb), 626 EXT2_INODES_PER_GROUP(sb), 627 sbi->s_mount_opt); 628 return res; 629 } 630 631 static int ext2_check_descriptors(struct super_block *sb) 632 { 633 int i; 634 struct ext2_sb_info *sbi = EXT2_SB(sb); 635 636 ext2_debug ("Checking group descriptors"); 637 638 for (i = 0; i < sbi->s_groups_count; i++) { 639 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 640 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 641 ext2_fsblk_t last_block; 642 643 if (i == sbi->s_groups_count - 1) 644 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 645 else 646 last_block = first_block + 647 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 648 649 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 650 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 651 { 652 ext2_error (sb, "ext2_check_descriptors", 653 "Block bitmap for group %d" 654 " not in group (block %lu)!", 655 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 656 return 0; 657 } 658 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 659 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 660 { 661 ext2_error (sb, "ext2_check_descriptors", 662 "Inode bitmap for group %d" 663 " not in group (block %lu)!", 664 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 665 return 0; 666 } 667 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 668 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 669 last_block) 670 { 671 ext2_error (sb, "ext2_check_descriptors", 672 "Inode table for group %d" 673 " not in group (block %lu)!", 674 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 675 return 0; 676 } 677 } 678 return 1; 679 } 680 681 /* 682 * Maximal file size. There is a direct, and {,double-,triple-}indirect 683 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 684 * We need to be 1 filesystem block less than the 2^32 sector limit. 685 */ 686 static loff_t ext2_max_size(int bits) 687 { 688 loff_t res = EXT2_NDIR_BLOCKS; 689 int meta_blocks; 690 loff_t upper_limit; 691 692 /* This is calculated to be the largest file size for a 693 * dense, file such that the total number of 694 * sectors in the file, including data and all indirect blocks, 695 * does not exceed 2^32 -1 696 * __u32 i_blocks representing the total number of 697 * 512 bytes blocks of the file 698 */ 699 upper_limit = (1LL << 32) - 1; 700 701 /* total blocks in file system block size */ 702 upper_limit >>= (bits - 9); 703 704 705 /* indirect blocks */ 706 meta_blocks = 1; 707 /* double indirect blocks */ 708 meta_blocks += 1 + (1LL << (bits-2)); 709 /* tripple indirect blocks */ 710 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 711 712 upper_limit -= meta_blocks; 713 upper_limit <<= bits; 714 715 res += 1LL << (bits-2); 716 res += 1LL << (2*(bits-2)); 717 res += 1LL << (3*(bits-2)); 718 res <<= bits; 719 if (res > upper_limit) 720 res = upper_limit; 721 722 if (res > MAX_LFS_FILESIZE) 723 res = MAX_LFS_FILESIZE; 724 725 return res; 726 } 727 728 static unsigned long descriptor_loc(struct super_block *sb, 729 unsigned long logic_sb_block, 730 int nr) 731 { 732 struct ext2_sb_info *sbi = EXT2_SB(sb); 733 unsigned long bg, first_meta_bg; 734 int has_super = 0; 735 736 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 737 738 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 739 nr < first_meta_bg) 740 return (logic_sb_block + nr + 1); 741 bg = sbi->s_desc_per_block * nr; 742 if (ext2_bg_has_super(sb, bg)) 743 has_super = 1; 744 745 return ext2_group_first_block_no(sb, bg) + has_super; 746 } 747 748 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 749 { 750 struct buffer_head * bh; 751 struct ext2_sb_info * sbi; 752 struct ext2_super_block * es; 753 struct inode *root; 754 unsigned long block; 755 unsigned long sb_block = get_sb_block(&data); 756 unsigned long logic_sb_block; 757 unsigned long offset = 0; 758 unsigned long def_mount_opts; 759 long ret = -EINVAL; 760 int blocksize = BLOCK_SIZE; 761 int db_count; 762 int i, j; 763 __le32 features; 764 int err; 765 766 err = -ENOMEM; 767 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 768 if (!sbi) 769 goto failed_unlock; 770 771 sbi->s_blockgroup_lock = 772 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 773 if (!sbi->s_blockgroup_lock) { 774 kfree(sbi); 775 goto failed_unlock; 776 } 777 sb->s_fs_info = sbi; 778 sbi->s_sb_block = sb_block; 779 780 spin_lock_init(&sbi->s_lock); 781 782 /* 783 * See what the current blocksize for the device is, and 784 * use that as the blocksize. Otherwise (or if the blocksize 785 * is smaller than the default) use the default. 786 * This is important for devices that have a hardware 787 * sectorsize that is larger than the default. 788 */ 789 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 790 if (!blocksize) { 791 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize"); 792 goto failed_sbi; 793 } 794 795 /* 796 * If the superblock doesn't start on a hardware sector boundary, 797 * calculate the offset. 798 */ 799 if (blocksize != BLOCK_SIZE) { 800 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 801 offset = (sb_block*BLOCK_SIZE) % blocksize; 802 } else { 803 logic_sb_block = sb_block; 804 } 805 806 if (!(bh = sb_bread(sb, logic_sb_block))) { 807 ext2_msg(sb, KERN_ERR, "error: unable to read superblock"); 808 goto failed_sbi; 809 } 810 /* 811 * Note: s_es must be initialized as soon as possible because 812 * some ext2 macro-instructions depend on its value 813 */ 814 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 815 sbi->s_es = es; 816 sb->s_magic = le16_to_cpu(es->s_magic); 817 818 if (sb->s_magic != EXT2_SUPER_MAGIC) 819 goto cantfind_ext2; 820 821 /* Set defaults before we parse the mount options */ 822 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 823 if (def_mount_opts & EXT2_DEFM_DEBUG) 824 set_opt(sbi->s_mount_opt, DEBUG); 825 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 826 set_opt(sbi->s_mount_opt, GRPID); 827 if (def_mount_opts & EXT2_DEFM_UID16) 828 set_opt(sbi->s_mount_opt, NO_UID32); 829 #ifdef CONFIG_EXT2_FS_XATTR 830 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 831 set_opt(sbi->s_mount_opt, XATTR_USER); 832 #endif 833 #ifdef CONFIG_EXT2_FS_POSIX_ACL 834 if (def_mount_opts & EXT2_DEFM_ACL) 835 set_opt(sbi->s_mount_opt, POSIX_ACL); 836 #endif 837 838 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 839 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 840 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 841 set_opt(sbi->s_mount_opt, ERRORS_CONT); 842 else 843 set_opt(sbi->s_mount_opt, ERRORS_RO); 844 845 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 846 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 847 848 set_opt(sbi->s_mount_opt, RESERVATION); 849 850 if (!parse_options((char *) data, sb)) 851 goto failed_mount; 852 853 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 854 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 855 MS_POSIXACL : 0); 856 857 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 858 EXT2_MOUNT_XIP if not */ 859 860 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 861 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 862 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 863 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 864 ext2_msg(sb, KERN_WARNING, 865 "warning: feature flags set on rev 0 fs, " 866 "running e2fsck is recommended"); 867 /* 868 * Check feature flags regardless of the revision level, since we 869 * previously didn't change the revision level when setting the flags, 870 * so there is a chance incompat flags are set on a rev 0 filesystem. 871 */ 872 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 873 if (features) { 874 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of " 875 "unsupported optional features (%x)", 876 le32_to_cpu(features)); 877 goto failed_mount; 878 } 879 if (!(sb->s_flags & MS_RDONLY) && 880 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 881 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of " 882 "unsupported optional features (%x)", 883 le32_to_cpu(features)); 884 goto failed_mount; 885 } 886 887 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 888 889 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 890 if (!silent) 891 ext2_msg(sb, KERN_ERR, 892 "error: unsupported blocksize for xip"); 893 goto failed_mount; 894 } 895 896 /* If the blocksize doesn't match, re-read the thing.. */ 897 if (sb->s_blocksize != blocksize) { 898 brelse(bh); 899 900 if (!sb_set_blocksize(sb, blocksize)) { 901 ext2_msg(sb, KERN_ERR, 902 "error: bad blocksize %d", blocksize); 903 goto failed_sbi; 904 } 905 906 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 907 offset = (sb_block*BLOCK_SIZE) % blocksize; 908 bh = sb_bread(sb, logic_sb_block); 909 if(!bh) { 910 ext2_msg(sb, KERN_ERR, "error: couldn't read" 911 "superblock on 2nd try"); 912 goto failed_sbi; 913 } 914 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 915 sbi->s_es = es; 916 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 917 ext2_msg(sb, KERN_ERR, "error: magic mismatch"); 918 goto failed_mount; 919 } 920 } 921 922 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 923 924 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 925 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 926 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 927 } else { 928 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 929 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 930 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 931 !is_power_of_2(sbi->s_inode_size) || 932 (sbi->s_inode_size > blocksize)) { 933 ext2_msg(sb, KERN_ERR, 934 "error: unsupported inode size: %d", 935 sbi->s_inode_size); 936 goto failed_mount; 937 } 938 } 939 940 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 941 le32_to_cpu(es->s_log_frag_size); 942 if (sbi->s_frag_size == 0) 943 goto cantfind_ext2; 944 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 945 946 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 947 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 948 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 949 950 if (EXT2_INODE_SIZE(sb) == 0) 951 goto cantfind_ext2; 952 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 953 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 954 goto cantfind_ext2; 955 sbi->s_itb_per_group = sbi->s_inodes_per_group / 956 sbi->s_inodes_per_block; 957 sbi->s_desc_per_block = sb->s_blocksize / 958 sizeof (struct ext2_group_desc); 959 sbi->s_sbh = bh; 960 sbi->s_mount_state = le16_to_cpu(es->s_state); 961 sbi->s_addr_per_block_bits = 962 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 963 sbi->s_desc_per_block_bits = 964 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 965 966 if (sb->s_magic != EXT2_SUPER_MAGIC) 967 goto cantfind_ext2; 968 969 if (sb->s_blocksize != bh->b_size) { 970 if (!silent) 971 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize"); 972 goto failed_mount; 973 } 974 975 if (sb->s_blocksize != sbi->s_frag_size) { 976 ext2_msg(sb, KERN_ERR, 977 "error: fragsize %lu != blocksize %lu" 978 "(not supported yet)", 979 sbi->s_frag_size, sb->s_blocksize); 980 goto failed_mount; 981 } 982 983 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 984 ext2_msg(sb, KERN_ERR, 985 "error: #blocks per group too big: %lu", 986 sbi->s_blocks_per_group); 987 goto failed_mount; 988 } 989 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 990 ext2_msg(sb, KERN_ERR, 991 "error: #fragments per group too big: %lu", 992 sbi->s_frags_per_group); 993 goto failed_mount; 994 } 995 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 996 ext2_msg(sb, KERN_ERR, 997 "error: #inodes per group too big: %lu", 998 sbi->s_inodes_per_group); 999 goto failed_mount; 1000 } 1001 1002 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 1003 goto cantfind_ext2; 1004 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 1005 le32_to_cpu(es->s_first_data_block) - 1) 1006 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 1007 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 1008 EXT2_DESC_PER_BLOCK(sb); 1009 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 1010 if (sbi->s_group_desc == NULL) { 1011 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1012 goto failed_mount; 1013 } 1014 bgl_lock_init(sbi->s_blockgroup_lock); 1015 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 1016 if (!sbi->s_debts) { 1017 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1018 goto failed_mount_group_desc; 1019 } 1020 for (i = 0; i < db_count; i++) { 1021 block = descriptor_loc(sb, logic_sb_block, i); 1022 sbi->s_group_desc[i] = sb_bread(sb, block); 1023 if (!sbi->s_group_desc[i]) { 1024 for (j = 0; j < i; j++) 1025 brelse (sbi->s_group_desc[j]); 1026 ext2_msg(sb, KERN_ERR, 1027 "error: unable to read group descriptors"); 1028 goto failed_mount_group_desc; 1029 } 1030 } 1031 if (!ext2_check_descriptors (sb)) { 1032 ext2_msg(sb, KERN_ERR, "group descriptors corrupted"); 1033 goto failed_mount2; 1034 } 1035 sbi->s_gdb_count = db_count; 1036 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1037 spin_lock_init(&sbi->s_next_gen_lock); 1038 1039 /* per fileystem reservation list head & lock */ 1040 spin_lock_init(&sbi->s_rsv_window_lock); 1041 sbi->s_rsv_window_root = RB_ROOT; 1042 /* 1043 * Add a single, static dummy reservation to the start of the 1044 * reservation window list --- it gives us a placeholder for 1045 * append-at-start-of-list which makes the allocation logic 1046 * _much_ simpler. 1047 */ 1048 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1049 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1050 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1051 sbi->s_rsv_window_head.rsv_goal_size = 0; 1052 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1053 1054 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1055 ext2_count_free_blocks(sb)); 1056 if (!err) { 1057 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1058 ext2_count_free_inodes(sb)); 1059 } 1060 if (!err) { 1061 err = percpu_counter_init(&sbi->s_dirs_counter, 1062 ext2_count_dirs(sb)); 1063 } 1064 if (err) { 1065 ext2_msg(sb, KERN_ERR, "error: insufficient memory"); 1066 goto failed_mount3; 1067 } 1068 /* 1069 * set up enough so that it can read an inode 1070 */ 1071 sb->s_op = &ext2_sops; 1072 sb->s_export_op = &ext2_export_ops; 1073 sb->s_xattr = ext2_xattr_handlers; 1074 1075 #ifdef CONFIG_QUOTA 1076 sb->dq_op = &dquot_operations; 1077 sb->s_qcop = &dquot_quotactl_ops; 1078 #endif 1079 1080 root = ext2_iget(sb, EXT2_ROOT_INO); 1081 if (IS_ERR(root)) { 1082 ret = PTR_ERR(root); 1083 goto failed_mount3; 1084 } 1085 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1086 iput(root); 1087 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck"); 1088 goto failed_mount3; 1089 } 1090 1091 sb->s_root = d_alloc_root(root); 1092 if (!sb->s_root) { 1093 iput(root); 1094 ext2_msg(sb, KERN_ERR, "error: get root inode failed"); 1095 ret = -ENOMEM; 1096 goto failed_mount3; 1097 } 1098 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1099 ext2_msg(sb, KERN_WARNING, 1100 "warning: mounting ext3 filesystem as ext2"); 1101 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY)) 1102 sb->s_flags |= MS_RDONLY; 1103 ext2_write_super(sb); 1104 return 0; 1105 1106 cantfind_ext2: 1107 if (!silent) 1108 ext2_msg(sb, KERN_ERR, 1109 "error: can't find an ext2 filesystem on dev %s.", 1110 sb->s_id); 1111 goto failed_mount; 1112 failed_mount3: 1113 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1114 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1115 percpu_counter_destroy(&sbi->s_dirs_counter); 1116 failed_mount2: 1117 for (i = 0; i < db_count; i++) 1118 brelse(sbi->s_group_desc[i]); 1119 failed_mount_group_desc: 1120 kfree(sbi->s_group_desc); 1121 kfree(sbi->s_debts); 1122 failed_mount: 1123 brelse(bh); 1124 failed_sbi: 1125 sb->s_fs_info = NULL; 1126 kfree(sbi->s_blockgroup_lock); 1127 kfree(sbi); 1128 failed_unlock: 1129 return ret; 1130 } 1131 1132 static void ext2_clear_super_error(struct super_block *sb) 1133 { 1134 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh; 1135 1136 if (buffer_write_io_error(sbh)) { 1137 /* 1138 * Oh, dear. A previous attempt to write the 1139 * superblock failed. This could happen because the 1140 * USB device was yanked out. Or it could happen to 1141 * be a transient write error and maybe the block will 1142 * be remapped. Nothing we can do but to retry the 1143 * write and hope for the best. 1144 */ 1145 ext2_msg(sb, KERN_ERR, 1146 "previous I/O error to superblock detected\n"); 1147 clear_buffer_write_io_error(sbh); 1148 set_buffer_uptodate(sbh); 1149 } 1150 } 1151 1152 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es, 1153 int wait) 1154 { 1155 ext2_clear_super_error(sb); 1156 spin_lock(&EXT2_SB(sb)->s_lock); 1157 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1158 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1159 es->s_wtime = cpu_to_le32(get_seconds()); 1160 /* unlock before we do IO */ 1161 spin_unlock(&EXT2_SB(sb)->s_lock); 1162 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1163 if (wait) 1164 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1165 sb->s_dirt = 0; 1166 } 1167 1168 /* 1169 * In the second extended file system, it is not necessary to 1170 * write the super block since we use a mapping of the 1171 * disk super block in a buffer. 1172 * 1173 * However, this function is still used to set the fs valid 1174 * flags to 0. We need to set this flag to 0 since the fs 1175 * may have been checked while mounted and e2fsck may have 1176 * set s_state to EXT2_VALID_FS after some corrections. 1177 */ 1178 static int ext2_sync_fs(struct super_block *sb, int wait) 1179 { 1180 struct ext2_sb_info *sbi = EXT2_SB(sb); 1181 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 1182 1183 spin_lock(&sbi->s_lock); 1184 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1185 ext2_debug("setting valid to 0\n"); 1186 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1187 } 1188 spin_unlock(&sbi->s_lock); 1189 ext2_sync_super(sb, es, wait); 1190 return 0; 1191 } 1192 1193 1194 void ext2_write_super(struct super_block *sb) 1195 { 1196 if (!(sb->s_flags & MS_RDONLY)) 1197 ext2_sync_fs(sb, 1); 1198 else 1199 sb->s_dirt = 0; 1200 } 1201 1202 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1203 { 1204 struct ext2_sb_info * sbi = EXT2_SB(sb); 1205 struct ext2_super_block * es; 1206 unsigned long old_mount_opt = sbi->s_mount_opt; 1207 struct ext2_mount_options old_opts; 1208 unsigned long old_sb_flags; 1209 int err; 1210 1211 spin_lock(&sbi->s_lock); 1212 1213 /* Store the old options */ 1214 old_sb_flags = sb->s_flags; 1215 old_opts.s_mount_opt = sbi->s_mount_opt; 1216 old_opts.s_resuid = sbi->s_resuid; 1217 old_opts.s_resgid = sbi->s_resgid; 1218 1219 /* 1220 * Allow the "check" option to be passed as a remount option. 1221 */ 1222 if (!parse_options(data, sb)) { 1223 err = -EINVAL; 1224 goto restore_opts; 1225 } 1226 1227 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1228 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1229 1230 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1231 EXT2_MOUNT_XIP if not */ 1232 1233 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1234 ext2_msg(sb, KERN_WARNING, 1235 "warning: unsupported blocksize for xip"); 1236 err = -EINVAL; 1237 goto restore_opts; 1238 } 1239 1240 es = sbi->s_es; 1241 if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) { 1242 ext2_msg(sb, KERN_WARNING, "warning: refusing change of " 1243 "xip flag with busy inodes while remounting"); 1244 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1245 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1246 } 1247 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1248 spin_unlock(&sbi->s_lock); 1249 return 0; 1250 } 1251 if (*flags & MS_RDONLY) { 1252 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1253 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1254 spin_unlock(&sbi->s_lock); 1255 return 0; 1256 } 1257 1258 /* 1259 * OK, we are remounting a valid rw partition rdonly, so set 1260 * the rdonly flag and then mark the partition as valid again. 1261 */ 1262 es->s_state = cpu_to_le16(sbi->s_mount_state); 1263 es->s_mtime = cpu_to_le32(get_seconds()); 1264 spin_unlock(&sbi->s_lock); 1265 1266 err = dquot_suspend(sb, -1); 1267 if (err < 0) { 1268 spin_lock(&sbi->s_lock); 1269 goto restore_opts; 1270 } 1271 1272 ext2_sync_super(sb, es, 1); 1273 } else { 1274 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1275 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1276 if (ret) { 1277 ext2_msg(sb, KERN_WARNING, 1278 "warning: couldn't remount RDWR because of " 1279 "unsupported optional features (%x).", 1280 le32_to_cpu(ret)); 1281 err = -EROFS; 1282 goto restore_opts; 1283 } 1284 /* 1285 * Mounting a RDONLY partition read-write, so reread and 1286 * store the current valid flag. (It may have been changed 1287 * by e2fsck since we originally mounted the partition.) 1288 */ 1289 sbi->s_mount_state = le16_to_cpu(es->s_state); 1290 if (!ext2_setup_super (sb, es, 0)) 1291 sb->s_flags &= ~MS_RDONLY; 1292 spin_unlock(&sbi->s_lock); 1293 1294 ext2_write_super(sb); 1295 1296 dquot_resume(sb, -1); 1297 } 1298 1299 return 0; 1300 restore_opts: 1301 sbi->s_mount_opt = old_opts.s_mount_opt; 1302 sbi->s_resuid = old_opts.s_resuid; 1303 sbi->s_resgid = old_opts.s_resgid; 1304 sb->s_flags = old_sb_flags; 1305 spin_unlock(&sbi->s_lock); 1306 return err; 1307 } 1308 1309 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1310 { 1311 struct super_block *sb = dentry->d_sb; 1312 struct ext2_sb_info *sbi = EXT2_SB(sb); 1313 struct ext2_super_block *es = sbi->s_es; 1314 u64 fsid; 1315 1316 spin_lock(&sbi->s_lock); 1317 1318 if (test_opt (sb, MINIX_DF)) 1319 sbi->s_overhead_last = 0; 1320 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1321 unsigned long i, overhead = 0; 1322 smp_rmb(); 1323 1324 /* 1325 * Compute the overhead (FS structures). This is constant 1326 * for a given filesystem unless the number of block groups 1327 * changes so we cache the previous value until it does. 1328 */ 1329 1330 /* 1331 * All of the blocks before first_data_block are 1332 * overhead 1333 */ 1334 overhead = le32_to_cpu(es->s_first_data_block); 1335 1336 /* 1337 * Add the overhead attributed to the superblock and 1338 * block group descriptors. If the sparse superblocks 1339 * feature is turned on, then not all groups have this. 1340 */ 1341 for (i = 0; i < sbi->s_groups_count; i++) 1342 overhead += ext2_bg_has_super(sb, i) + 1343 ext2_bg_num_gdb(sb, i); 1344 1345 /* 1346 * Every block group has an inode bitmap, a block 1347 * bitmap, and an inode table. 1348 */ 1349 overhead += (sbi->s_groups_count * 1350 (2 + sbi->s_itb_per_group)); 1351 sbi->s_overhead_last = overhead; 1352 smp_wmb(); 1353 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1354 } 1355 1356 buf->f_type = EXT2_SUPER_MAGIC; 1357 buf->f_bsize = sb->s_blocksize; 1358 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1359 buf->f_bfree = ext2_count_free_blocks(sb); 1360 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1361 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1362 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1363 buf->f_bavail = 0; 1364 buf->f_files = le32_to_cpu(es->s_inodes_count); 1365 buf->f_ffree = ext2_count_free_inodes(sb); 1366 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1367 buf->f_namelen = EXT2_NAME_LEN; 1368 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1369 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1370 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1371 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1372 spin_unlock(&sbi->s_lock); 1373 return 0; 1374 } 1375 1376 static struct dentry *ext2_mount(struct file_system_type *fs_type, 1377 int flags, const char *dev_name, void *data) 1378 { 1379 return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super); 1380 } 1381 1382 #ifdef CONFIG_QUOTA 1383 1384 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1385 * acquiring the locks... As quota files are never truncated and quota code 1386 * itself serializes the operations (and no one else should touch the files) 1387 * we don't have to be afraid of races */ 1388 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1389 size_t len, loff_t off) 1390 { 1391 struct inode *inode = sb_dqopt(sb)->files[type]; 1392 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1393 int err = 0; 1394 int offset = off & (sb->s_blocksize - 1); 1395 int tocopy; 1396 size_t toread; 1397 struct buffer_head tmp_bh; 1398 struct buffer_head *bh; 1399 loff_t i_size = i_size_read(inode); 1400 1401 if (off > i_size) 1402 return 0; 1403 if (off+len > i_size) 1404 len = i_size-off; 1405 toread = len; 1406 while (toread > 0) { 1407 tocopy = sb->s_blocksize - offset < toread ? 1408 sb->s_blocksize - offset : toread; 1409 1410 tmp_bh.b_state = 0; 1411 tmp_bh.b_size = sb->s_blocksize; 1412 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1413 if (err < 0) 1414 return err; 1415 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1416 memset(data, 0, tocopy); 1417 else { 1418 bh = sb_bread(sb, tmp_bh.b_blocknr); 1419 if (!bh) 1420 return -EIO; 1421 memcpy(data, bh->b_data+offset, tocopy); 1422 brelse(bh); 1423 } 1424 offset = 0; 1425 toread -= tocopy; 1426 data += tocopy; 1427 blk++; 1428 } 1429 return len; 1430 } 1431 1432 /* Write to quotafile */ 1433 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1434 const char *data, size_t len, loff_t off) 1435 { 1436 struct inode *inode = sb_dqopt(sb)->files[type]; 1437 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1438 int err = 0; 1439 int offset = off & (sb->s_blocksize - 1); 1440 int tocopy; 1441 size_t towrite = len; 1442 struct buffer_head tmp_bh; 1443 struct buffer_head *bh; 1444 1445 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1446 while (towrite > 0) { 1447 tocopy = sb->s_blocksize - offset < towrite ? 1448 sb->s_blocksize - offset : towrite; 1449 1450 tmp_bh.b_state = 0; 1451 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1452 if (err < 0) 1453 goto out; 1454 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1455 bh = sb_bread(sb, tmp_bh.b_blocknr); 1456 else 1457 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1458 if (!bh) { 1459 err = -EIO; 1460 goto out; 1461 } 1462 lock_buffer(bh); 1463 memcpy(bh->b_data+offset, data, tocopy); 1464 flush_dcache_page(bh->b_page); 1465 set_buffer_uptodate(bh); 1466 mark_buffer_dirty(bh); 1467 unlock_buffer(bh); 1468 brelse(bh); 1469 offset = 0; 1470 towrite -= tocopy; 1471 data += tocopy; 1472 blk++; 1473 } 1474 out: 1475 if (len == towrite) { 1476 mutex_unlock(&inode->i_mutex); 1477 return err; 1478 } 1479 if (inode->i_size < off+len-towrite) 1480 i_size_write(inode, off+len-towrite); 1481 inode->i_version++; 1482 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1483 mark_inode_dirty(inode); 1484 mutex_unlock(&inode->i_mutex); 1485 return len - towrite; 1486 } 1487 1488 #endif 1489 1490 static struct file_system_type ext2_fs_type = { 1491 .owner = THIS_MODULE, 1492 .name = "ext2", 1493 .mount = ext2_mount, 1494 .kill_sb = kill_block_super, 1495 .fs_flags = FS_REQUIRES_DEV, 1496 }; 1497 1498 static int __init init_ext2_fs(void) 1499 { 1500 int err = init_ext2_xattr(); 1501 if (err) 1502 return err; 1503 err = init_inodecache(); 1504 if (err) 1505 goto out1; 1506 err = register_filesystem(&ext2_fs_type); 1507 if (err) 1508 goto out; 1509 return 0; 1510 out: 1511 destroy_inodecache(); 1512 out1: 1513 exit_ext2_xattr(); 1514 return err; 1515 } 1516 1517 static void __exit exit_ext2_fs(void) 1518 { 1519 unregister_filesystem(&ext2_fs_type); 1520 destroy_inodecache(); 1521 exit_ext2_xattr(); 1522 } 1523 1524 module_init(init_ext2_fs) 1525 module_exit(exit_ext2_fs) 1526