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 va_list args; 50 struct ext2_sb_info *sbi = EXT2_SB(sb); 51 struct ext2_super_block *es = sbi->s_es; 52 53 if (!(sb->s_flags & MS_RDONLY)) { 54 spin_lock(&sbi->s_lock); 55 sbi->s_mount_state |= EXT2_ERROR_FS; 56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 57 spin_unlock(&sbi->s_lock); 58 ext2_sync_super(sb, es, 1); 59 } 60 61 va_start(args, fmt); 62 printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function); 63 vprintk(fmt, args); 64 printk("\n"); 65 va_end(args); 66 67 if (test_opt(sb, ERRORS_PANIC)) 68 panic("EXT2-fs: panic from previous error\n"); 69 if (test_opt(sb, ERRORS_RO)) { 70 ext2_msg(sb, KERN_CRIT, 71 "error: remounting filesystem read-only"); 72 sb->s_flags |= MS_RDONLY; 73 } 74 } 75 76 void ext2_msg(struct super_block *sb, const char *prefix, 77 const char *fmt, ...) 78 { 79 va_list args; 80 81 va_start(args, fmt); 82 printk("%sEXT2-fs (%s): ", prefix, sb->s_id); 83 vprintk(fmt, args); 84 printk("\n"); 85 va_end(args); 86 } 87 88 /* 89 * This must be called with sbi->s_lock held. 90 */ 91 void ext2_update_dynamic_rev(struct super_block *sb) 92 { 93 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 94 95 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 96 return; 97 98 ext2_msg(sb, KERN_WARNING, 99 "warning: updating to rev %d because of " 100 "new feature flag, running e2fsck is recommended", 101 EXT2_DYNAMIC_REV); 102 103 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 104 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 105 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 106 /* leave es->s_feature_*compat flags alone */ 107 /* es->s_uuid will be set by e2fsck if empty */ 108 109 /* 110 * The rest of the superblock fields should be zero, and if not it 111 * means they are likely already in use, so leave them alone. We 112 * can leave it up to e2fsck to clean up any inconsistencies there. 113 */ 114 } 115 116 static void ext2_put_super (struct super_block * sb) 117 { 118 int db_count; 119 int i; 120 struct ext2_sb_info *sbi = EXT2_SB(sb); 121 122 dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 123 124 if (sb->s_dirt) 125 ext2_write_super(sb); 126 127 ext2_xattr_put_super(sb); 128 if (!(sb->s_flags & MS_RDONLY)) { 129 struct ext2_super_block *es = sbi->s_es; 130 131 spin_lock(&sbi->s_lock); 132 es->s_state = cpu_to_le16(sbi->s_mount_state); 133 spin_unlock(&sbi->s_lock); 134 ext2_sync_super(sb, es, 1); 135 } 136 db_count = sbi->s_gdb_count; 137 for (i = 0; i < db_count; i++) 138 if (sbi->s_group_desc[i]) 139 brelse (sbi->s_group_desc[i]); 140 kfree(sbi->s_group_desc); 141 kfree(sbi->s_debts); 142 percpu_counter_destroy(&sbi->s_freeblocks_counter); 143 percpu_counter_destroy(&sbi->s_freeinodes_counter); 144 percpu_counter_destroy(&sbi->s_dirs_counter); 145 brelse (sbi->s_sbh); 146 sb->s_fs_info = NULL; 147 kfree(sbi->s_blockgroup_lock); 148 kfree(sbi); 149 } 150 151 static struct kmem_cache * ext2_inode_cachep; 152 153 static struct inode *ext2_alloc_inode(struct super_block *sb) 154 { 155 struct ext2_inode_info *ei; 156 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 157 if (!ei) 158 return NULL; 159 ei->i_block_alloc_info = NULL; 160 ei->vfs_inode.i_version = 1; 161 return &ei->vfs_inode; 162 } 163 164 static void ext2_destroy_inode(struct inode *inode) 165 { 166 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 167 } 168 169 static void init_once(void *foo) 170 { 171 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 172 173 rwlock_init(&ei->i_meta_lock); 174 #ifdef CONFIG_EXT2_FS_XATTR 175 init_rwsem(&ei->xattr_sem); 176 #endif 177 mutex_init(&ei->truncate_mutex); 178 inode_init_once(&ei->vfs_inode); 179 } 180 181 static int init_inodecache(void) 182 { 183 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 184 sizeof(struct ext2_inode_info), 185 0, (SLAB_RECLAIM_ACCOUNT| 186 SLAB_MEM_SPREAD), 187 init_once); 188 if (ext2_inode_cachep == NULL) 189 return -ENOMEM; 190 return 0; 191 } 192 193 static void destroy_inodecache(void) 194 { 195 kmem_cache_destroy(ext2_inode_cachep); 196 } 197 198 static void ext2_clear_inode(struct inode *inode) 199 { 200 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 201 202 dquot_drop(inode); 203 ext2_discard_reservation(inode); 204 EXT2_I(inode)->i_block_alloc_info = NULL; 205 if (unlikely(rsv)) 206 kfree(rsv); 207 } 208 209 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 210 { 211 struct super_block *sb = vfs->mnt_sb; 212 struct ext2_sb_info *sbi = EXT2_SB(sb); 213 struct ext2_super_block *es = sbi->s_es; 214 unsigned long def_mount_opts; 215 216 spin_lock(&sbi->s_lock); 217 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 218 219 if (sbi->s_sb_block != 1) 220 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 221 if (test_opt(sb, MINIX_DF)) 222 seq_puts(seq, ",minixdf"); 223 if (test_opt(sb, GRPID)) 224 seq_puts(seq, ",grpid"); 225 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 226 seq_puts(seq, ",nogrpid"); 227 if (sbi->s_resuid != EXT2_DEF_RESUID || 228 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 229 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 230 } 231 if (sbi->s_resgid != EXT2_DEF_RESGID || 232 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 233 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 234 } 235 if (test_opt(sb, ERRORS_RO)) { 236 int def_errors = le16_to_cpu(es->s_errors); 237 238 if (def_errors == EXT2_ERRORS_PANIC || 239 def_errors == EXT2_ERRORS_CONTINUE) { 240 seq_puts(seq, ",errors=remount-ro"); 241 } 242 } 243 if (test_opt(sb, ERRORS_CONT)) 244 seq_puts(seq, ",errors=continue"); 245 if (test_opt(sb, ERRORS_PANIC)) 246 seq_puts(seq, ",errors=panic"); 247 if (test_opt(sb, NO_UID32)) 248 seq_puts(seq, ",nouid32"); 249 if (test_opt(sb, DEBUG)) 250 seq_puts(seq, ",debug"); 251 if (test_opt(sb, OLDALLOC)) 252 seq_puts(seq, ",oldalloc"); 253 254 #ifdef CONFIG_EXT2_FS_XATTR 255 if (test_opt(sb, XATTR_USER)) 256 seq_puts(seq, ",user_xattr"); 257 if (!test_opt(sb, XATTR_USER) && 258 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 259 seq_puts(seq, ",nouser_xattr"); 260 } 261 #endif 262 263 #ifdef CONFIG_EXT2_FS_POSIX_ACL 264 if (test_opt(sb, POSIX_ACL)) 265 seq_puts(seq, ",acl"); 266 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 267 seq_puts(seq, ",noacl"); 268 #endif 269 270 if (test_opt(sb, NOBH)) 271 seq_puts(seq, ",nobh"); 272 273 #if defined(CONFIG_QUOTA) 274 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 275 seq_puts(seq, ",usrquota"); 276 277 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 278 seq_puts(seq, ",grpquota"); 279 #endif 280 281 #if defined(CONFIG_EXT2_FS_XIP) 282 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 283 seq_puts(seq, ",xip"); 284 #endif 285 286 if (!test_opt(sb, RESERVATION)) 287 seq_puts(seq, ",noreservation"); 288 289 spin_unlock(&sbi->s_lock); 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 .sync_fs = ext2_sync_fs, 306 .statfs = ext2_statfs, 307 .remount_fs = ext2_remount, 308 .clear_inode = ext2_clear_inode, 309 .show_options = ext2_show_options, 310 #ifdef CONFIG_QUOTA 311 .quota_read = ext2_quota_read, 312 .quota_write = ext2_quota_write, 313 #endif 314 }; 315 316 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 317 u64 ino, u32 generation) 318 { 319 struct inode *inode; 320 321 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 322 return ERR_PTR(-ESTALE); 323 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 324 return ERR_PTR(-ESTALE); 325 326 /* iget isn't really right if the inode is currently unallocated!! 327 * ext2_read_inode currently does appropriate checks, but 328 * it might be "neater" to call ext2_get_inode first and check 329 * if the inode is valid..... 330 */ 331 inode = ext2_iget(sb, ino); 332 if (IS_ERR(inode)) 333 return ERR_CAST(inode); 334 if (generation && inode->i_generation != generation) { 335 /* we didn't find the right inode.. */ 336 iput(inode); 337 return ERR_PTR(-ESTALE); 338 } 339 return inode; 340 } 341 342 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 343 int fh_len, int fh_type) 344 { 345 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 346 ext2_nfs_get_inode); 347 } 348 349 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 350 int fh_len, int fh_type) 351 { 352 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 353 ext2_nfs_get_inode); 354 } 355 356 /* Yes, most of these are left as NULL!! 357 * A NULL value implies the default, which works with ext2-like file 358 * systems, but can be improved upon. 359 * Currently only get_parent is required. 360 */ 361 static const struct export_operations ext2_export_ops = { 362 .fh_to_dentry = ext2_fh_to_dentry, 363 .fh_to_parent = ext2_fh_to_parent, 364 .get_parent = ext2_get_parent, 365 }; 366 367 static unsigned long get_sb_block(void **data) 368 { 369 unsigned long sb_block; 370 char *options = (char *) *data; 371 372 if (!options || strncmp(options, "sb=", 3) != 0) 373 return 1; /* Default location */ 374 options += 3; 375 sb_block = simple_strtoul(options, &options, 0); 376 if (*options && *options != ',') { 377 printk("EXT2-fs: Invalid sb specification: %s\n", 378 (char *) *data); 379 return 1; 380 } 381 if (*options == ',') 382 options++; 383 *data = (void *) options; 384 return sb_block; 385 } 386 387 enum { 388 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 389 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 390 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 391 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 392 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 393 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 394 }; 395 396 static const match_table_t tokens = { 397 {Opt_bsd_df, "bsddf"}, 398 {Opt_minix_df, "minixdf"}, 399 {Opt_grpid, "grpid"}, 400 {Opt_grpid, "bsdgroups"}, 401 {Opt_nogrpid, "nogrpid"}, 402 {Opt_nogrpid, "sysvgroups"}, 403 {Opt_resgid, "resgid=%u"}, 404 {Opt_resuid, "resuid=%u"}, 405 {Opt_sb, "sb=%u"}, 406 {Opt_err_cont, "errors=continue"}, 407 {Opt_err_panic, "errors=panic"}, 408 {Opt_err_ro, "errors=remount-ro"}, 409 {Opt_nouid32, "nouid32"}, 410 {Opt_nocheck, "check=none"}, 411 {Opt_nocheck, "nocheck"}, 412 {Opt_debug, "debug"}, 413 {Opt_oldalloc, "oldalloc"}, 414 {Opt_orlov, "orlov"}, 415 {Opt_nobh, "nobh"}, 416 {Opt_user_xattr, "user_xattr"}, 417 {Opt_nouser_xattr, "nouser_xattr"}, 418 {Opt_acl, "acl"}, 419 {Opt_noacl, "noacl"}, 420 {Opt_xip, "xip"}, 421 {Opt_grpquota, "grpquota"}, 422 {Opt_ignore, "noquota"}, 423 {Opt_quota, "quota"}, 424 {Opt_usrquota, "usrquota"}, 425 {Opt_reservation, "reservation"}, 426 {Opt_noreservation, "noreservation"}, 427 {Opt_err, NULL} 428 }; 429 430 static int parse_options(char *options, struct super_block *sb) 431 { 432 char *p; 433 struct ext2_sb_info *sbi = EXT2_SB(sb); 434 substring_t args[MAX_OPT_ARGS]; 435 int option; 436 437 if (!options) 438 return 1; 439 440 while ((p = strsep (&options, ",")) != NULL) { 441 int token; 442 if (!*p) 443 continue; 444 445 token = match_token(p, tokens, args); 446 switch (token) { 447 case Opt_bsd_df: 448 clear_opt (sbi->s_mount_opt, MINIX_DF); 449 break; 450 case Opt_minix_df: 451 set_opt (sbi->s_mount_opt, MINIX_DF); 452 break; 453 case Opt_grpid: 454 set_opt (sbi->s_mount_opt, GRPID); 455 break; 456 case Opt_nogrpid: 457 clear_opt (sbi->s_mount_opt, GRPID); 458 break; 459 case Opt_resuid: 460 if (match_int(&args[0], &option)) 461 return 0; 462 sbi->s_resuid = option; 463 break; 464 case Opt_resgid: 465 if (match_int(&args[0], &option)) 466 return 0; 467 sbi->s_resgid = option; 468 break; 469 case Opt_sb: 470 /* handled by get_sb_block() instead of here */ 471 /* *sb_block = match_int(&args[0]); */ 472 break; 473 case Opt_err_panic: 474 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 475 clear_opt (sbi->s_mount_opt, ERRORS_RO); 476 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 477 break; 478 case Opt_err_ro: 479 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 480 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 481 set_opt (sbi->s_mount_opt, ERRORS_RO); 482 break; 483 case Opt_err_cont: 484 clear_opt (sbi->s_mount_opt, ERRORS_RO); 485 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 486 set_opt (sbi->s_mount_opt, ERRORS_CONT); 487 break; 488 case Opt_nouid32: 489 set_opt (sbi->s_mount_opt, NO_UID32); 490 break; 491 case Opt_nocheck: 492 clear_opt (sbi->s_mount_opt, CHECK); 493 break; 494 case Opt_debug: 495 set_opt (sbi->s_mount_opt, DEBUG); 496 break; 497 case Opt_oldalloc: 498 set_opt (sbi->s_mount_opt, OLDALLOC); 499 break; 500 case Opt_orlov: 501 clear_opt (sbi->s_mount_opt, OLDALLOC); 502 break; 503 case Opt_nobh: 504 set_opt (sbi->s_mount_opt, NOBH); 505 break; 506 #ifdef CONFIG_EXT2_FS_XATTR 507 case Opt_user_xattr: 508 set_opt (sbi->s_mount_opt, XATTR_USER); 509 break; 510 case Opt_nouser_xattr: 511 clear_opt (sbi->s_mount_opt, XATTR_USER); 512 break; 513 #else 514 case Opt_user_xattr: 515 case Opt_nouser_xattr: 516 ext2_msg(sb, KERN_INFO, "(no)user_xattr options" 517 "not supported"); 518 break; 519 #endif 520 #ifdef CONFIG_EXT2_FS_POSIX_ACL 521 case Opt_acl: 522 set_opt(sbi->s_mount_opt, POSIX_ACL); 523 break; 524 case Opt_noacl: 525 clear_opt(sbi->s_mount_opt, POSIX_ACL); 526 break; 527 #else 528 case Opt_acl: 529 case Opt_noacl: 530 ext2_msg(sb, KERN_INFO, 531 "(no)acl options not supported"); 532 break; 533 #endif 534 case Opt_xip: 535 #ifdef CONFIG_EXT2_FS_XIP 536 set_opt (sbi->s_mount_opt, XIP); 537 #else 538 ext2_msg(sb, KERN_INFO, "xip option not supported"); 539 #endif 540 break; 541 542 #if defined(CONFIG_QUOTA) 543 case Opt_quota: 544 case Opt_usrquota: 545 set_opt(sbi->s_mount_opt, USRQUOTA); 546 break; 547 548 case Opt_grpquota: 549 set_opt(sbi->s_mount_opt, GRPQUOTA); 550 break; 551 #else 552 case Opt_quota: 553 case Opt_usrquota: 554 case Opt_grpquota: 555 ext2_msg(sb, KERN_INFO, 556 "quota operations not supported"); 557 break; 558 #endif 559 560 case Opt_reservation: 561 set_opt(sbi->s_mount_opt, RESERVATION); 562 ext2_msg(sb, KERN_INFO, "reservations ON"); 563 break; 564 case Opt_noreservation: 565 clear_opt(sbi->s_mount_opt, RESERVATION); 566 ext2_msg(sb, KERN_INFO, "reservations OFF"); 567 break; 568 case Opt_ignore: 569 break; 570 default: 571 return 0; 572 } 573 } 574 return 1; 575 } 576 577 static int ext2_setup_super (struct super_block * sb, 578 struct ext2_super_block * es, 579 int read_only) 580 { 581 int res = 0; 582 struct ext2_sb_info *sbi = EXT2_SB(sb); 583 584 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 585 ext2_msg(sb, KERN_ERR, 586 "error: revision level too high, " 587 "forcing read-only mode"); 588 res = MS_RDONLY; 589 } 590 if (read_only) 591 return res; 592 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 593 ext2_msg(sb, KERN_WARNING, 594 "warning: mounting unchecked fs, " 595 "running e2fsck is recommended"); 596 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 597 ext2_msg(sb, KERN_WARNING, 598 "warning: mounting fs with errors, " 599 "running e2fsck is recommended"); 600 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 601 le16_to_cpu(es->s_mnt_count) >= 602 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 603 ext2_msg(sb, KERN_WARNING, 604 "warning: maximal mount count reached, " 605 "running e2fsck is recommended"); 606 else if (le32_to_cpu(es->s_checkinterval) && 607 (le32_to_cpu(es->s_lastcheck) + 608 le32_to_cpu(es->s_checkinterval) <= get_seconds())) 609 ext2_msg(sb, KERN_WARNING, 610 "warning: checktime reached, " 611 "running e2fsck is recommended"); 612 if (!le16_to_cpu(es->s_max_mnt_count)) 613 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 614 le16_add_cpu(&es->s_mnt_count, 1); 615 if (test_opt (sb, DEBUG)) 616 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, " 617 "bpg=%lu, ipg=%lu, mo=%04lx]", 618 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 619 sbi->s_frag_size, 620 sbi->s_groups_count, 621 EXT2_BLOCKS_PER_GROUP(sb), 622 EXT2_INODES_PER_GROUP(sb), 623 sbi->s_mount_opt); 624 return res; 625 } 626 627 static int ext2_check_descriptors(struct super_block *sb) 628 { 629 int i; 630 struct ext2_sb_info *sbi = EXT2_SB(sb); 631 632 ext2_debug ("Checking group descriptors"); 633 634 for (i = 0; i < sbi->s_groups_count; i++) { 635 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 636 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 637 ext2_fsblk_t last_block; 638 639 if (i == sbi->s_groups_count - 1) 640 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 641 else 642 last_block = first_block + 643 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 644 645 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 646 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 647 { 648 ext2_error (sb, "ext2_check_descriptors", 649 "Block bitmap for group %d" 650 " not in group (block %lu)!", 651 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 652 return 0; 653 } 654 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 655 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 656 { 657 ext2_error (sb, "ext2_check_descriptors", 658 "Inode bitmap for group %d" 659 " not in group (block %lu)!", 660 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 661 return 0; 662 } 663 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 664 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 665 last_block) 666 { 667 ext2_error (sb, "ext2_check_descriptors", 668 "Inode table for group %d" 669 " not in group (block %lu)!", 670 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 671 return 0; 672 } 673 } 674 return 1; 675 } 676 677 /* 678 * Maximal file size. There is a direct, and {,double-,triple-}indirect 679 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 680 * We need to be 1 filesystem block less than the 2^32 sector limit. 681 */ 682 static loff_t ext2_max_size(int bits) 683 { 684 loff_t res = EXT2_NDIR_BLOCKS; 685 int meta_blocks; 686 loff_t upper_limit; 687 688 /* This is calculated to be the largest file size for a 689 * dense, file such that the total number of 690 * sectors in the file, including data and all indirect blocks, 691 * does not exceed 2^32 -1 692 * __u32 i_blocks representing the total number of 693 * 512 bytes blocks of the file 694 */ 695 upper_limit = (1LL << 32) - 1; 696 697 /* total blocks in file system block size */ 698 upper_limit >>= (bits - 9); 699 700 701 /* indirect blocks */ 702 meta_blocks = 1; 703 /* double indirect blocks */ 704 meta_blocks += 1 + (1LL << (bits-2)); 705 /* tripple indirect blocks */ 706 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 707 708 upper_limit -= meta_blocks; 709 upper_limit <<= bits; 710 711 res += 1LL << (bits-2); 712 res += 1LL << (2*(bits-2)); 713 res += 1LL << (3*(bits-2)); 714 res <<= bits; 715 if (res > upper_limit) 716 res = upper_limit; 717 718 if (res > MAX_LFS_FILESIZE) 719 res = MAX_LFS_FILESIZE; 720 721 return res; 722 } 723 724 static unsigned long descriptor_loc(struct super_block *sb, 725 unsigned long logic_sb_block, 726 int nr) 727 { 728 struct ext2_sb_info *sbi = EXT2_SB(sb); 729 unsigned long bg, first_meta_bg; 730 int has_super = 0; 731 732 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 733 734 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 735 nr < first_meta_bg) 736 return (logic_sb_block + nr + 1); 737 bg = sbi->s_desc_per_block * nr; 738 if (ext2_bg_has_super(sb, bg)) 739 has_super = 1; 740 741 return ext2_group_first_block_no(sb, bg) + has_super; 742 } 743 744 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 745 { 746 struct buffer_head * bh; 747 struct ext2_sb_info * sbi; 748 struct ext2_super_block * es; 749 struct inode *root; 750 unsigned long block; 751 unsigned long sb_block = get_sb_block(&data); 752 unsigned long logic_sb_block; 753 unsigned long offset = 0; 754 unsigned long def_mount_opts; 755 long ret = -EINVAL; 756 int blocksize = BLOCK_SIZE; 757 int db_count; 758 int i, j; 759 __le32 features; 760 int err; 761 762 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 763 if (!sbi) 764 return -ENOMEM; 765 766 sbi->s_blockgroup_lock = 767 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 768 if (!sbi->s_blockgroup_lock) { 769 kfree(sbi); 770 return -ENOMEM; 771 } 772 sb->s_fs_info = sbi; 773 sbi->s_sb_block = sb_block; 774 775 spin_lock_init(&sbi->s_lock); 776 777 /* 778 * See what the current blocksize for the device is, and 779 * use that as the blocksize. Otherwise (or if the blocksize 780 * is smaller than the default) use the default. 781 * This is important for devices that have a hardware 782 * sectorsize that is larger than the default. 783 */ 784 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 785 if (!blocksize) { 786 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize"); 787 goto failed_sbi; 788 } 789 790 /* 791 * If the superblock doesn't start on a hardware sector boundary, 792 * calculate the offset. 793 */ 794 if (blocksize != BLOCK_SIZE) { 795 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 796 offset = (sb_block*BLOCK_SIZE) % blocksize; 797 } else { 798 logic_sb_block = sb_block; 799 } 800 801 if (!(bh = sb_bread(sb, logic_sb_block))) { 802 ext2_msg(sb, KERN_ERR, "error: unable to read superblock"); 803 goto failed_sbi; 804 } 805 /* 806 * Note: s_es must be initialized as soon as possible because 807 * some ext2 macro-instructions depend on its value 808 */ 809 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 810 sbi->s_es = es; 811 sb->s_magic = le16_to_cpu(es->s_magic); 812 813 if (sb->s_magic != EXT2_SUPER_MAGIC) 814 goto cantfind_ext2; 815 816 /* Set defaults before we parse the mount options */ 817 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 818 if (def_mount_opts & EXT2_DEFM_DEBUG) 819 set_opt(sbi->s_mount_opt, DEBUG); 820 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 821 set_opt(sbi->s_mount_opt, GRPID); 822 if (def_mount_opts & EXT2_DEFM_UID16) 823 set_opt(sbi->s_mount_opt, NO_UID32); 824 #ifdef CONFIG_EXT2_FS_XATTR 825 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 826 set_opt(sbi->s_mount_opt, XATTR_USER); 827 #endif 828 #ifdef CONFIG_EXT2_FS_POSIX_ACL 829 if (def_mount_opts & EXT2_DEFM_ACL) 830 set_opt(sbi->s_mount_opt, POSIX_ACL); 831 #endif 832 833 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 834 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 835 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 836 set_opt(sbi->s_mount_opt, ERRORS_CONT); 837 else 838 set_opt(sbi->s_mount_opt, ERRORS_RO); 839 840 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 841 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 842 843 set_opt(sbi->s_mount_opt, RESERVATION); 844 845 if (!parse_options((char *) data, sb)) 846 goto failed_mount; 847 848 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 849 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 850 MS_POSIXACL : 0); 851 852 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 853 EXT2_MOUNT_XIP if not */ 854 855 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 856 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 857 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 858 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 859 ext2_msg(sb, KERN_WARNING, 860 "warning: feature flags set on rev 0 fs, " 861 "running e2fsck is recommended"); 862 /* 863 * Check feature flags regardless of the revision level, since we 864 * previously didn't change the revision level when setting the flags, 865 * so there is a chance incompat flags are set on a rev 0 filesystem. 866 */ 867 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 868 if (features) { 869 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of " 870 "unsupported optional features (%x)", 871 le32_to_cpu(features)); 872 goto failed_mount; 873 } 874 if (!(sb->s_flags & MS_RDONLY) && 875 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 876 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of " 877 "unsupported optional features (%x)", 878 le32_to_cpu(features)); 879 goto failed_mount; 880 } 881 882 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 883 884 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 885 if (!silent) 886 ext2_msg(sb, KERN_ERR, 887 "error: unsupported blocksize for xip"); 888 goto failed_mount; 889 } 890 891 /* If the blocksize doesn't match, re-read the thing.. */ 892 if (sb->s_blocksize != blocksize) { 893 brelse(bh); 894 895 if (!sb_set_blocksize(sb, blocksize)) { 896 ext2_msg(sb, KERN_ERR, "error: blocksize is too small"); 897 goto failed_sbi; 898 } 899 900 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 901 offset = (sb_block*BLOCK_SIZE) % blocksize; 902 bh = sb_bread(sb, logic_sb_block); 903 if(!bh) { 904 ext2_msg(sb, KERN_ERR, "error: couldn't read" 905 "superblock on 2nd try"); 906 goto failed_sbi; 907 } 908 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 909 sbi->s_es = es; 910 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 911 ext2_msg(sb, KERN_ERR, "error: magic mismatch"); 912 goto failed_mount; 913 } 914 } 915 916 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 917 918 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 919 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 920 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 921 } else { 922 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 923 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 924 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 925 !is_power_of_2(sbi->s_inode_size) || 926 (sbi->s_inode_size > blocksize)) { 927 ext2_msg(sb, KERN_ERR, 928 "error: unsupported inode size: %d", 929 sbi->s_inode_size); 930 goto failed_mount; 931 } 932 } 933 934 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 935 le32_to_cpu(es->s_log_frag_size); 936 if (sbi->s_frag_size == 0) 937 goto cantfind_ext2; 938 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 939 940 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 941 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 942 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 943 944 if (EXT2_INODE_SIZE(sb) == 0) 945 goto cantfind_ext2; 946 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 947 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 948 goto cantfind_ext2; 949 sbi->s_itb_per_group = sbi->s_inodes_per_group / 950 sbi->s_inodes_per_block; 951 sbi->s_desc_per_block = sb->s_blocksize / 952 sizeof (struct ext2_group_desc); 953 sbi->s_sbh = bh; 954 sbi->s_mount_state = le16_to_cpu(es->s_state); 955 sbi->s_addr_per_block_bits = 956 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 957 sbi->s_desc_per_block_bits = 958 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 959 960 if (sb->s_magic != EXT2_SUPER_MAGIC) 961 goto cantfind_ext2; 962 963 if (sb->s_blocksize != bh->b_size) { 964 if (!silent) 965 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize"); 966 goto failed_mount; 967 } 968 969 if (sb->s_blocksize != sbi->s_frag_size) { 970 ext2_msg(sb, KERN_ERR, 971 "error: fragsize %lu != blocksize %lu" 972 "(not supported yet)", 973 sbi->s_frag_size, sb->s_blocksize); 974 goto failed_mount; 975 } 976 977 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 978 ext2_msg(sb, KERN_ERR, 979 "error: #blocks per group too big: %lu", 980 sbi->s_blocks_per_group); 981 goto failed_mount; 982 } 983 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 984 ext2_msg(sb, KERN_ERR, 985 "error: #fragments per group too big: %lu", 986 sbi->s_frags_per_group); 987 goto failed_mount; 988 } 989 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 990 ext2_msg(sb, KERN_ERR, 991 "error: #inodes per group too big: %lu", 992 sbi->s_inodes_per_group); 993 goto failed_mount; 994 } 995 996 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 997 goto cantfind_ext2; 998 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 999 le32_to_cpu(es->s_first_data_block) - 1) 1000 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 1001 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 1002 EXT2_DESC_PER_BLOCK(sb); 1003 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 1004 if (sbi->s_group_desc == NULL) { 1005 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1006 goto failed_mount; 1007 } 1008 bgl_lock_init(sbi->s_blockgroup_lock); 1009 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 1010 if (!sbi->s_debts) { 1011 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1012 goto failed_mount_group_desc; 1013 } 1014 for (i = 0; i < db_count; i++) { 1015 block = descriptor_loc(sb, logic_sb_block, i); 1016 sbi->s_group_desc[i] = sb_bread(sb, block); 1017 if (!sbi->s_group_desc[i]) { 1018 for (j = 0; j < i; j++) 1019 brelse (sbi->s_group_desc[j]); 1020 ext2_msg(sb, KERN_ERR, 1021 "error: unable to read group descriptors"); 1022 goto failed_mount_group_desc; 1023 } 1024 } 1025 if (!ext2_check_descriptors (sb)) { 1026 ext2_msg(sb, KERN_ERR, "group descriptors corrupted"); 1027 goto failed_mount2; 1028 } 1029 sbi->s_gdb_count = db_count; 1030 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1031 spin_lock_init(&sbi->s_next_gen_lock); 1032 1033 /* per fileystem reservation list head & lock */ 1034 spin_lock_init(&sbi->s_rsv_window_lock); 1035 sbi->s_rsv_window_root = RB_ROOT; 1036 /* 1037 * Add a single, static dummy reservation to the start of the 1038 * reservation window list --- it gives us a placeholder for 1039 * append-at-start-of-list which makes the allocation logic 1040 * _much_ simpler. 1041 */ 1042 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1043 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1044 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1045 sbi->s_rsv_window_head.rsv_goal_size = 0; 1046 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1047 1048 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1049 ext2_count_free_blocks(sb)); 1050 if (!err) { 1051 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1052 ext2_count_free_inodes(sb)); 1053 } 1054 if (!err) { 1055 err = percpu_counter_init(&sbi->s_dirs_counter, 1056 ext2_count_dirs(sb)); 1057 } 1058 if (err) { 1059 ext2_msg(sb, KERN_ERR, "error: insufficient memory"); 1060 goto failed_mount3; 1061 } 1062 /* 1063 * set up enough so that it can read an inode 1064 */ 1065 sb->s_op = &ext2_sops; 1066 sb->s_export_op = &ext2_export_ops; 1067 sb->s_xattr = ext2_xattr_handlers; 1068 1069 #ifdef CONFIG_QUOTA 1070 sb->dq_op = &dquot_operations; 1071 sb->s_qcop = &dquot_quotactl_ops; 1072 #endif 1073 1074 root = ext2_iget(sb, EXT2_ROOT_INO); 1075 if (IS_ERR(root)) { 1076 ret = PTR_ERR(root); 1077 goto failed_mount3; 1078 } 1079 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1080 iput(root); 1081 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck"); 1082 goto failed_mount3; 1083 } 1084 1085 sb->s_root = d_alloc_root(root); 1086 if (!sb->s_root) { 1087 iput(root); 1088 ext2_msg(sb, KERN_ERR, "error: get root inode failed"); 1089 ret = -ENOMEM; 1090 goto failed_mount3; 1091 } 1092 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1093 ext2_msg(sb, KERN_WARNING, 1094 "warning: mounting ext3 filesystem as ext2"); 1095 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY)) 1096 sb->s_flags |= MS_RDONLY; 1097 ext2_write_super(sb); 1098 return 0; 1099 1100 cantfind_ext2: 1101 if (!silent) 1102 ext2_msg(sb, KERN_ERR, 1103 "error: can't find an ext2 filesystem on dev %s.", 1104 sb->s_id); 1105 goto failed_mount; 1106 failed_mount3: 1107 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1108 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1109 percpu_counter_destroy(&sbi->s_dirs_counter); 1110 failed_mount2: 1111 for (i = 0; i < db_count; i++) 1112 brelse(sbi->s_group_desc[i]); 1113 failed_mount_group_desc: 1114 kfree(sbi->s_group_desc); 1115 kfree(sbi->s_debts); 1116 failed_mount: 1117 brelse(bh); 1118 failed_sbi: 1119 sb->s_fs_info = NULL; 1120 kfree(sbi->s_blockgroup_lock); 1121 kfree(sbi); 1122 return ret; 1123 } 1124 1125 static void ext2_clear_super_error(struct super_block *sb) 1126 { 1127 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh; 1128 1129 if (buffer_write_io_error(sbh)) { 1130 /* 1131 * Oh, dear. A previous attempt to write the 1132 * superblock failed. This could happen because the 1133 * USB device was yanked out. Or it could happen to 1134 * be a transient write error and maybe the block will 1135 * be remapped. Nothing we can do but to retry the 1136 * write and hope for the best. 1137 */ 1138 ext2_msg(sb, KERN_ERR, 1139 "previous I/O error to superblock detected\n"); 1140 clear_buffer_write_io_error(sbh); 1141 set_buffer_uptodate(sbh); 1142 } 1143 } 1144 1145 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es, 1146 int wait) 1147 { 1148 ext2_clear_super_error(sb); 1149 spin_lock(&EXT2_SB(sb)->s_lock); 1150 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1151 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1152 es->s_wtime = cpu_to_le32(get_seconds()); 1153 /* unlock before we do IO */ 1154 spin_unlock(&EXT2_SB(sb)->s_lock); 1155 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1156 if (wait) 1157 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1158 sb->s_dirt = 0; 1159 } 1160 1161 /* 1162 * In the second extended file system, it is not necessary to 1163 * write the super block since we use a mapping of the 1164 * disk super block in a buffer. 1165 * 1166 * However, this function is still used to set the fs valid 1167 * flags to 0. We need to set this flag to 0 since the fs 1168 * may have been checked while mounted and e2fsck may have 1169 * set s_state to EXT2_VALID_FS after some corrections. 1170 */ 1171 static int ext2_sync_fs(struct super_block *sb, int wait) 1172 { 1173 struct ext2_sb_info *sbi = EXT2_SB(sb); 1174 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 1175 1176 spin_lock(&sbi->s_lock); 1177 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1178 ext2_debug("setting valid to 0\n"); 1179 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1180 } 1181 spin_unlock(&sbi->s_lock); 1182 ext2_sync_super(sb, es, wait); 1183 return 0; 1184 } 1185 1186 1187 void ext2_write_super(struct super_block *sb) 1188 { 1189 if (!(sb->s_flags & MS_RDONLY)) 1190 ext2_sync_fs(sb, 1); 1191 else 1192 sb->s_dirt = 0; 1193 } 1194 1195 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1196 { 1197 struct ext2_sb_info * sbi = EXT2_SB(sb); 1198 struct ext2_super_block * es; 1199 unsigned long old_mount_opt = sbi->s_mount_opt; 1200 struct ext2_mount_options old_opts; 1201 unsigned long old_sb_flags; 1202 int err; 1203 1204 spin_lock(&sbi->s_lock); 1205 1206 /* Store the old options */ 1207 old_sb_flags = sb->s_flags; 1208 old_opts.s_mount_opt = sbi->s_mount_opt; 1209 old_opts.s_resuid = sbi->s_resuid; 1210 old_opts.s_resgid = sbi->s_resgid; 1211 1212 /* 1213 * Allow the "check" option to be passed as a remount option. 1214 */ 1215 if (!parse_options(data, sb)) { 1216 err = -EINVAL; 1217 goto restore_opts; 1218 } 1219 1220 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1221 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1222 1223 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1224 EXT2_MOUNT_XIP if not */ 1225 1226 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1227 ext2_msg(sb, KERN_WARNING, 1228 "warning: unsupported blocksize for xip"); 1229 err = -EINVAL; 1230 goto restore_opts; 1231 } 1232 1233 es = sbi->s_es; 1234 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1235 (old_mount_opt & EXT2_MOUNT_XIP)) && 1236 invalidate_inodes(sb)) { 1237 ext2_msg(sb, KERN_WARNING, "warning: refusing change of " 1238 "xip flag with busy inodes while remounting"); 1239 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1240 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1241 } 1242 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1243 spin_unlock(&sbi->s_lock); 1244 return 0; 1245 } 1246 if (*flags & MS_RDONLY) { 1247 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1248 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1249 spin_unlock(&sbi->s_lock); 1250 return 0; 1251 } 1252 1253 /* 1254 * OK, we are remounting a valid rw partition rdonly, so set 1255 * the rdonly flag and then mark the partition as valid again. 1256 */ 1257 es->s_state = cpu_to_le16(sbi->s_mount_state); 1258 es->s_mtime = cpu_to_le32(get_seconds()); 1259 spin_unlock(&sbi->s_lock); 1260 1261 err = dquot_suspend(sb, -1); 1262 if (err < 0) { 1263 spin_lock(&sbi->s_lock); 1264 goto restore_opts; 1265 } 1266 1267 ext2_sync_super(sb, es, 1); 1268 } else { 1269 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1270 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1271 if (ret) { 1272 ext2_msg(sb, KERN_WARNING, 1273 "warning: couldn't remount RDWR because of " 1274 "unsupported optional features (%x).", 1275 le32_to_cpu(ret)); 1276 err = -EROFS; 1277 goto restore_opts; 1278 } 1279 /* 1280 * Mounting a RDONLY partition read-write, so reread and 1281 * store the current valid flag. (It may have been changed 1282 * by e2fsck since we originally mounted the partition.) 1283 */ 1284 sbi->s_mount_state = le16_to_cpu(es->s_state); 1285 if (!ext2_setup_super (sb, es, 0)) 1286 sb->s_flags &= ~MS_RDONLY; 1287 spin_unlock(&sbi->s_lock); 1288 1289 ext2_write_super(sb); 1290 1291 dquot_resume(sb, -1); 1292 } 1293 1294 return 0; 1295 restore_opts: 1296 sbi->s_mount_opt = old_opts.s_mount_opt; 1297 sbi->s_resuid = old_opts.s_resuid; 1298 sbi->s_resgid = old_opts.s_resgid; 1299 sb->s_flags = old_sb_flags; 1300 spin_unlock(&sbi->s_lock); 1301 return err; 1302 } 1303 1304 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1305 { 1306 struct super_block *sb = dentry->d_sb; 1307 struct ext2_sb_info *sbi = EXT2_SB(sb); 1308 struct ext2_super_block *es = sbi->s_es; 1309 u64 fsid; 1310 1311 spin_lock(&sbi->s_lock); 1312 1313 if (test_opt (sb, MINIX_DF)) 1314 sbi->s_overhead_last = 0; 1315 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1316 unsigned long i, overhead = 0; 1317 smp_rmb(); 1318 1319 /* 1320 * Compute the overhead (FS structures). This is constant 1321 * for a given filesystem unless the number of block groups 1322 * changes so we cache the previous value until it does. 1323 */ 1324 1325 /* 1326 * All of the blocks before first_data_block are 1327 * overhead 1328 */ 1329 overhead = le32_to_cpu(es->s_first_data_block); 1330 1331 /* 1332 * Add the overhead attributed to the superblock and 1333 * block group descriptors. If the sparse superblocks 1334 * feature is turned on, then not all groups have this. 1335 */ 1336 for (i = 0; i < sbi->s_groups_count; i++) 1337 overhead += ext2_bg_has_super(sb, i) + 1338 ext2_bg_num_gdb(sb, i); 1339 1340 /* 1341 * Every block group has an inode bitmap, a block 1342 * bitmap, and an inode table. 1343 */ 1344 overhead += (sbi->s_groups_count * 1345 (2 + sbi->s_itb_per_group)); 1346 sbi->s_overhead_last = overhead; 1347 smp_wmb(); 1348 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1349 } 1350 1351 buf->f_type = EXT2_SUPER_MAGIC; 1352 buf->f_bsize = sb->s_blocksize; 1353 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1354 buf->f_bfree = ext2_count_free_blocks(sb); 1355 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1356 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1357 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1358 buf->f_bavail = 0; 1359 buf->f_files = le32_to_cpu(es->s_inodes_count); 1360 buf->f_ffree = ext2_count_free_inodes(sb); 1361 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1362 buf->f_namelen = EXT2_NAME_LEN; 1363 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1364 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1365 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1366 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1367 spin_unlock(&sbi->s_lock); 1368 return 0; 1369 } 1370 1371 static int ext2_get_sb(struct file_system_type *fs_type, 1372 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1373 { 1374 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1375 } 1376 1377 #ifdef CONFIG_QUOTA 1378 1379 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1380 * acquiring the locks... As quota files are never truncated and quota code 1381 * itself serializes the operations (and noone else should touch the files) 1382 * we don't have to be afraid of races */ 1383 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1384 size_t len, loff_t off) 1385 { 1386 struct inode *inode = sb_dqopt(sb)->files[type]; 1387 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1388 int err = 0; 1389 int offset = off & (sb->s_blocksize - 1); 1390 int tocopy; 1391 size_t toread; 1392 struct buffer_head tmp_bh; 1393 struct buffer_head *bh; 1394 loff_t i_size = i_size_read(inode); 1395 1396 if (off > i_size) 1397 return 0; 1398 if (off+len > i_size) 1399 len = i_size-off; 1400 toread = len; 1401 while (toread > 0) { 1402 tocopy = sb->s_blocksize - offset < toread ? 1403 sb->s_blocksize - offset : toread; 1404 1405 tmp_bh.b_state = 0; 1406 tmp_bh.b_size = sb->s_blocksize; 1407 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1408 if (err < 0) 1409 return err; 1410 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1411 memset(data, 0, tocopy); 1412 else { 1413 bh = sb_bread(sb, tmp_bh.b_blocknr); 1414 if (!bh) 1415 return -EIO; 1416 memcpy(data, bh->b_data+offset, tocopy); 1417 brelse(bh); 1418 } 1419 offset = 0; 1420 toread -= tocopy; 1421 data += tocopy; 1422 blk++; 1423 } 1424 return len; 1425 } 1426 1427 /* Write to quotafile */ 1428 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1429 const char *data, size_t len, loff_t off) 1430 { 1431 struct inode *inode = sb_dqopt(sb)->files[type]; 1432 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1433 int err = 0; 1434 int offset = off & (sb->s_blocksize - 1); 1435 int tocopy; 1436 size_t towrite = len; 1437 struct buffer_head tmp_bh; 1438 struct buffer_head *bh; 1439 1440 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1441 while (towrite > 0) { 1442 tocopy = sb->s_blocksize - offset < towrite ? 1443 sb->s_blocksize - offset : towrite; 1444 1445 tmp_bh.b_state = 0; 1446 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1447 if (err < 0) 1448 goto out; 1449 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1450 bh = sb_bread(sb, tmp_bh.b_blocknr); 1451 else 1452 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1453 if (!bh) { 1454 err = -EIO; 1455 goto out; 1456 } 1457 lock_buffer(bh); 1458 memcpy(bh->b_data+offset, data, tocopy); 1459 flush_dcache_page(bh->b_page); 1460 set_buffer_uptodate(bh); 1461 mark_buffer_dirty(bh); 1462 unlock_buffer(bh); 1463 brelse(bh); 1464 offset = 0; 1465 towrite -= tocopy; 1466 data += tocopy; 1467 blk++; 1468 } 1469 out: 1470 if (len == towrite) { 1471 mutex_unlock(&inode->i_mutex); 1472 return err; 1473 } 1474 if (inode->i_size < off+len-towrite) 1475 i_size_write(inode, off+len-towrite); 1476 inode->i_version++; 1477 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1478 mark_inode_dirty(inode); 1479 mutex_unlock(&inode->i_mutex); 1480 return len - towrite; 1481 } 1482 1483 #endif 1484 1485 static struct file_system_type ext2_fs_type = { 1486 .owner = THIS_MODULE, 1487 .name = "ext2", 1488 .get_sb = ext2_get_sb, 1489 .kill_sb = kill_block_super, 1490 .fs_flags = FS_REQUIRES_DEV, 1491 }; 1492 1493 static int __init init_ext2_fs(void) 1494 { 1495 int err = init_ext2_xattr(); 1496 if (err) 1497 return err; 1498 err = init_inodecache(); 1499 if (err) 1500 goto out1; 1501 err = register_filesystem(&ext2_fs_type); 1502 if (err) 1503 goto out; 1504 return 0; 1505 out: 1506 destroy_inodecache(); 1507 out1: 1508 exit_ext2_xattr(); 1509 return err; 1510 } 1511 1512 static void __exit exit_ext2_fs(void) 1513 { 1514 unregister_filesystem(&ext2_fs_type); 1515 destroy_inodecache(); 1516 exit_ext2_xattr(); 1517 } 1518 1519 module_init(init_ext2_fs) 1520 module_exit(exit_ext2_fs) 1521