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 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 sbi->s_mount_state |= EXT2_ERROR_FS; 55 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 56 ext2_sync_super(sb, es); 57 } 58 59 va_start(args, fmt); 60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); 61 vprintk(fmt, args); 62 printk("\n"); 63 va_end(args); 64 65 if (test_opt(sb, ERRORS_PANIC)) 66 panic("EXT2-fs panic from previous error\n"); 67 if (test_opt(sb, ERRORS_RO)) { 68 printk("Remounting filesystem read-only\n"); 69 sb->s_flags |= MS_RDONLY; 70 } 71 } 72 73 void ext2_warning (struct super_block * sb, const char * function, 74 const char * fmt, ...) 75 { 76 va_list args; 77 78 va_start(args, fmt); 79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", 80 sb->s_id, function); 81 vprintk(fmt, args); 82 printk("\n"); 83 va_end(args); 84 } 85 86 void ext2_update_dynamic_rev(struct super_block *sb) 87 { 88 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 89 90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 91 return; 92 93 ext2_warning(sb, __func__, 94 "updating to rev %d because of new feature flag, " 95 "running e2fsck is recommended", 96 EXT2_DYNAMIC_REV); 97 98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 101 /* leave es->s_feature_*compat flags alone */ 102 /* es->s_uuid will be set by e2fsck if empty */ 103 104 /* 105 * The rest of the superblock fields should be zero, and if not it 106 * means they are likely already in use, so leave them alone. We 107 * can leave it up to e2fsck to clean up any inconsistencies there. 108 */ 109 } 110 111 static void ext2_put_super (struct super_block * sb) 112 { 113 int db_count; 114 int i; 115 struct ext2_sb_info *sbi = EXT2_SB(sb); 116 117 lock_kernel(); 118 119 if (sb->s_dirt) 120 ext2_write_super(sb); 121 122 ext2_xattr_put_super(sb); 123 if (!(sb->s_flags & MS_RDONLY)) { 124 struct ext2_super_block *es = sbi->s_es; 125 126 es->s_state = cpu_to_le16(sbi->s_mount_state); 127 ext2_sync_super(sb, es); 128 } 129 db_count = sbi->s_gdb_count; 130 for (i = 0; i < db_count; i++) 131 if (sbi->s_group_desc[i]) 132 brelse (sbi->s_group_desc[i]); 133 kfree(sbi->s_group_desc); 134 kfree(sbi->s_debts); 135 percpu_counter_destroy(&sbi->s_freeblocks_counter); 136 percpu_counter_destroy(&sbi->s_freeinodes_counter); 137 percpu_counter_destroy(&sbi->s_dirs_counter); 138 brelse (sbi->s_sbh); 139 sb->s_fs_info = NULL; 140 kfree(sbi->s_blockgroup_lock); 141 kfree(sbi); 142 143 unlock_kernel(); 144 } 145 146 static struct kmem_cache * ext2_inode_cachep; 147 148 static struct inode *ext2_alloc_inode(struct super_block *sb) 149 { 150 struct ext2_inode_info *ei; 151 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 152 if (!ei) 153 return NULL; 154 #ifdef CONFIG_EXT2_FS_POSIX_ACL 155 ei->i_acl = EXT2_ACL_NOT_CACHED; 156 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 157 #endif 158 ei->i_block_alloc_info = NULL; 159 ei->vfs_inode.i_version = 1; 160 return &ei->vfs_inode; 161 } 162 163 static void ext2_destroy_inode(struct inode *inode) 164 { 165 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 166 } 167 168 static void init_once(void *foo) 169 { 170 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 171 172 rwlock_init(&ei->i_meta_lock); 173 #ifdef CONFIG_EXT2_FS_XATTR 174 init_rwsem(&ei->xattr_sem); 175 #endif 176 mutex_init(&ei->truncate_mutex); 177 inode_init_once(&ei->vfs_inode); 178 } 179 180 static int init_inodecache(void) 181 { 182 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 183 sizeof(struct ext2_inode_info), 184 0, (SLAB_RECLAIM_ACCOUNT| 185 SLAB_MEM_SPREAD), 186 init_once); 187 if (ext2_inode_cachep == NULL) 188 return -ENOMEM; 189 return 0; 190 } 191 192 static void destroy_inodecache(void) 193 { 194 kmem_cache_destroy(ext2_inode_cachep); 195 } 196 197 static void ext2_clear_inode(struct inode *inode) 198 { 199 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 200 #ifdef CONFIG_EXT2_FS_POSIX_ACL 201 struct ext2_inode_info *ei = EXT2_I(inode); 202 203 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 204 posix_acl_release(ei->i_acl); 205 ei->i_acl = EXT2_ACL_NOT_CACHED; 206 } 207 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 208 posix_acl_release(ei->i_default_acl); 209 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 210 } 211 #endif 212 ext2_discard_reservation(inode); 213 EXT2_I(inode)->i_block_alloc_info = NULL; 214 if (unlikely(rsv)) 215 kfree(rsv); 216 } 217 218 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 219 { 220 struct super_block *sb = vfs->mnt_sb; 221 struct ext2_sb_info *sbi = EXT2_SB(sb); 222 struct ext2_super_block *es = sbi->s_es; 223 unsigned long def_mount_opts; 224 225 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 226 227 if (sbi->s_sb_block != 1) 228 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 229 if (test_opt(sb, MINIX_DF)) 230 seq_puts(seq, ",minixdf"); 231 if (test_opt(sb, GRPID)) 232 seq_puts(seq, ",grpid"); 233 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 234 seq_puts(seq, ",nogrpid"); 235 if (sbi->s_resuid != EXT2_DEF_RESUID || 236 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 237 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 238 } 239 if (sbi->s_resgid != EXT2_DEF_RESGID || 240 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 241 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 242 } 243 if (test_opt(sb, ERRORS_RO)) { 244 int def_errors = le16_to_cpu(es->s_errors); 245 246 if (def_errors == EXT2_ERRORS_PANIC || 247 def_errors == EXT2_ERRORS_CONTINUE) { 248 seq_puts(seq, ",errors=remount-ro"); 249 } 250 } 251 if (test_opt(sb, ERRORS_CONT)) 252 seq_puts(seq, ",errors=continue"); 253 if (test_opt(sb, ERRORS_PANIC)) 254 seq_puts(seq, ",errors=panic"); 255 if (test_opt(sb, NO_UID32)) 256 seq_puts(seq, ",nouid32"); 257 if (test_opt(sb, DEBUG)) 258 seq_puts(seq, ",debug"); 259 if (test_opt(sb, OLDALLOC)) 260 seq_puts(seq, ",oldalloc"); 261 262 #ifdef CONFIG_EXT2_FS_XATTR 263 if (test_opt(sb, XATTR_USER)) 264 seq_puts(seq, ",user_xattr"); 265 if (!test_opt(sb, XATTR_USER) && 266 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 267 seq_puts(seq, ",nouser_xattr"); 268 } 269 #endif 270 271 #ifdef CONFIG_EXT2_FS_POSIX_ACL 272 if (test_opt(sb, POSIX_ACL)) 273 seq_puts(seq, ",acl"); 274 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 275 seq_puts(seq, ",noacl"); 276 #endif 277 278 if (test_opt(sb, NOBH)) 279 seq_puts(seq, ",nobh"); 280 281 #if defined(CONFIG_QUOTA) 282 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 283 seq_puts(seq, ",usrquota"); 284 285 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 286 seq_puts(seq, ",grpquota"); 287 #endif 288 289 #if defined(CONFIG_EXT2_FS_XIP) 290 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 291 seq_puts(seq, ",xip"); 292 #endif 293 294 if (!test_opt(sb, RESERVATION)) 295 seq_puts(seq, ",noreservation"); 296 297 return 0; 298 } 299 300 #ifdef CONFIG_QUOTA 301 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 302 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 303 #endif 304 305 static const struct super_operations ext2_sops = { 306 .alloc_inode = ext2_alloc_inode, 307 .destroy_inode = ext2_destroy_inode, 308 .write_inode = ext2_write_inode, 309 .delete_inode = ext2_delete_inode, 310 .put_super = ext2_put_super, 311 .write_super = ext2_write_super, 312 .statfs = ext2_statfs, 313 .remount_fs = ext2_remount, 314 .clear_inode = ext2_clear_inode, 315 .show_options = ext2_show_options, 316 #ifdef CONFIG_QUOTA 317 .quota_read = ext2_quota_read, 318 .quota_write = ext2_quota_write, 319 #endif 320 }; 321 322 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 323 u64 ino, u32 generation) 324 { 325 struct inode *inode; 326 327 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 328 return ERR_PTR(-ESTALE); 329 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 330 return ERR_PTR(-ESTALE); 331 332 /* iget isn't really right if the inode is currently unallocated!! 333 * ext2_read_inode currently does appropriate checks, but 334 * it might be "neater" to call ext2_get_inode first and check 335 * if the inode is valid..... 336 */ 337 inode = ext2_iget(sb, ino); 338 if (IS_ERR(inode)) 339 return ERR_CAST(inode); 340 if (generation && inode->i_generation != generation) { 341 /* we didn't find the right inode.. */ 342 iput(inode); 343 return ERR_PTR(-ESTALE); 344 } 345 return inode; 346 } 347 348 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 349 int fh_len, int fh_type) 350 { 351 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 352 ext2_nfs_get_inode); 353 } 354 355 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 356 int fh_len, int fh_type) 357 { 358 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 359 ext2_nfs_get_inode); 360 } 361 362 /* Yes, most of these are left as NULL!! 363 * A NULL value implies the default, which works with ext2-like file 364 * systems, but can be improved upon. 365 * Currently only get_parent is required. 366 */ 367 static const struct export_operations ext2_export_ops = { 368 .fh_to_dentry = ext2_fh_to_dentry, 369 .fh_to_parent = ext2_fh_to_parent, 370 .get_parent = ext2_get_parent, 371 }; 372 373 static unsigned long get_sb_block(void **data) 374 { 375 unsigned long sb_block; 376 char *options = (char *) *data; 377 378 if (!options || strncmp(options, "sb=", 3) != 0) 379 return 1; /* Default location */ 380 options += 3; 381 sb_block = simple_strtoul(options, &options, 0); 382 if (*options && *options != ',') { 383 printk("EXT2-fs: Invalid sb specification: %s\n", 384 (char *) *data); 385 return 1; 386 } 387 if (*options == ',') 388 options++; 389 *data = (void *) options; 390 return sb_block; 391 } 392 393 enum { 394 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 395 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 396 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 397 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 398 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 399 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 400 }; 401 402 static const match_table_t tokens = { 403 {Opt_bsd_df, "bsddf"}, 404 {Opt_minix_df, "minixdf"}, 405 {Opt_grpid, "grpid"}, 406 {Opt_grpid, "bsdgroups"}, 407 {Opt_nogrpid, "nogrpid"}, 408 {Opt_nogrpid, "sysvgroups"}, 409 {Opt_resgid, "resgid=%u"}, 410 {Opt_resuid, "resuid=%u"}, 411 {Opt_sb, "sb=%u"}, 412 {Opt_err_cont, "errors=continue"}, 413 {Opt_err_panic, "errors=panic"}, 414 {Opt_err_ro, "errors=remount-ro"}, 415 {Opt_nouid32, "nouid32"}, 416 {Opt_nocheck, "check=none"}, 417 {Opt_nocheck, "nocheck"}, 418 {Opt_debug, "debug"}, 419 {Opt_oldalloc, "oldalloc"}, 420 {Opt_orlov, "orlov"}, 421 {Opt_nobh, "nobh"}, 422 {Opt_user_xattr, "user_xattr"}, 423 {Opt_nouser_xattr, "nouser_xattr"}, 424 {Opt_acl, "acl"}, 425 {Opt_noacl, "noacl"}, 426 {Opt_xip, "xip"}, 427 {Opt_grpquota, "grpquota"}, 428 {Opt_ignore, "noquota"}, 429 {Opt_quota, "quota"}, 430 {Opt_usrquota, "usrquota"}, 431 {Opt_reservation, "reservation"}, 432 {Opt_noreservation, "noreservation"}, 433 {Opt_err, NULL} 434 }; 435 436 static int parse_options (char * options, 437 struct ext2_sb_info *sbi) 438 { 439 char * p; 440 substring_t args[MAX_OPT_ARGS]; 441 int option; 442 443 if (!options) 444 return 1; 445 446 while ((p = strsep (&options, ",")) != NULL) { 447 int token; 448 if (!*p) 449 continue; 450 451 token = match_token(p, tokens, args); 452 switch (token) { 453 case Opt_bsd_df: 454 clear_opt (sbi->s_mount_opt, MINIX_DF); 455 break; 456 case Opt_minix_df: 457 set_opt (sbi->s_mount_opt, MINIX_DF); 458 break; 459 case Opt_grpid: 460 set_opt (sbi->s_mount_opt, GRPID); 461 break; 462 case Opt_nogrpid: 463 clear_opt (sbi->s_mount_opt, GRPID); 464 break; 465 case Opt_resuid: 466 if (match_int(&args[0], &option)) 467 return 0; 468 sbi->s_resuid = option; 469 break; 470 case Opt_resgid: 471 if (match_int(&args[0], &option)) 472 return 0; 473 sbi->s_resgid = option; 474 break; 475 case Opt_sb: 476 /* handled by get_sb_block() instead of here */ 477 /* *sb_block = match_int(&args[0]); */ 478 break; 479 case Opt_err_panic: 480 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 481 clear_opt (sbi->s_mount_opt, ERRORS_RO); 482 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 483 break; 484 case Opt_err_ro: 485 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 486 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 487 set_opt (sbi->s_mount_opt, ERRORS_RO); 488 break; 489 case Opt_err_cont: 490 clear_opt (sbi->s_mount_opt, ERRORS_RO); 491 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 492 set_opt (sbi->s_mount_opt, ERRORS_CONT); 493 break; 494 case Opt_nouid32: 495 set_opt (sbi->s_mount_opt, NO_UID32); 496 break; 497 case Opt_nocheck: 498 clear_opt (sbi->s_mount_opt, CHECK); 499 break; 500 case Opt_debug: 501 set_opt (sbi->s_mount_opt, DEBUG); 502 break; 503 case Opt_oldalloc: 504 set_opt (sbi->s_mount_opt, OLDALLOC); 505 break; 506 case Opt_orlov: 507 clear_opt (sbi->s_mount_opt, OLDALLOC); 508 break; 509 case Opt_nobh: 510 set_opt (sbi->s_mount_opt, NOBH); 511 break; 512 #ifdef CONFIG_EXT2_FS_XATTR 513 case Opt_user_xattr: 514 set_opt (sbi->s_mount_opt, XATTR_USER); 515 break; 516 case Opt_nouser_xattr: 517 clear_opt (sbi->s_mount_opt, XATTR_USER); 518 break; 519 #else 520 case Opt_user_xattr: 521 case Opt_nouser_xattr: 522 printk("EXT2 (no)user_xattr options not supported\n"); 523 break; 524 #endif 525 #ifdef CONFIG_EXT2_FS_POSIX_ACL 526 case Opt_acl: 527 set_opt(sbi->s_mount_opt, POSIX_ACL); 528 break; 529 case Opt_noacl: 530 clear_opt(sbi->s_mount_opt, POSIX_ACL); 531 break; 532 #else 533 case Opt_acl: 534 case Opt_noacl: 535 printk("EXT2 (no)acl options not supported\n"); 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 printk("EXT2 xip option not supported\n"); 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 printk(KERN_ERR 560 "EXT2-fs: quota operations not supported.\n"); 561 562 break; 563 #endif 564 565 case Opt_reservation: 566 set_opt(sbi->s_mount_opt, RESERVATION); 567 printk("reservations ON\n"); 568 break; 569 case Opt_noreservation: 570 clear_opt(sbi->s_mount_opt, RESERVATION); 571 printk("reservations OFF\n"); 572 break; 573 case Opt_ignore: 574 break; 575 default: 576 return 0; 577 } 578 } 579 return 1; 580 } 581 582 static int ext2_setup_super (struct super_block * sb, 583 struct ext2_super_block * es, 584 int read_only) 585 { 586 int res = 0; 587 struct ext2_sb_info *sbi = EXT2_SB(sb); 588 589 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 590 printk ("EXT2-fs warning: revision level too high, " 591 "forcing read-only mode\n"); 592 res = MS_RDONLY; 593 } 594 if (read_only) 595 return res; 596 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 597 printk ("EXT2-fs warning: mounting unchecked fs, " 598 "running e2fsck is recommended\n"); 599 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 600 printk ("EXT2-fs warning: mounting fs with errors, " 601 "running e2fsck is recommended\n"); 602 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 603 le16_to_cpu(es->s_mnt_count) >= 604 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 605 printk ("EXT2-fs warning: maximal mount count reached, " 606 "running e2fsck is recommended\n"); 607 else if (le32_to_cpu(es->s_checkinterval) && 608 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 609 printk ("EXT2-fs warning: checktime reached, " 610 "running e2fsck is recommended\n"); 611 if (!le16_to_cpu(es->s_max_mnt_count)) 612 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 613 le16_add_cpu(&es->s_mnt_count, 1); 614 ext2_write_super(sb); 615 if (test_opt (sb, DEBUG)) 616 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 617 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 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 /* 776 * See what the current blocksize for the device is, and 777 * use that as the blocksize. Otherwise (or if the blocksize 778 * is smaller than the default) use the default. 779 * This is important for devices that have a hardware 780 * sectorsize that is larger than the default. 781 */ 782 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 783 if (!blocksize) { 784 printk ("EXT2-fs: unable to set blocksize\n"); 785 goto failed_sbi; 786 } 787 788 /* 789 * If the superblock doesn't start on a hardware sector boundary, 790 * calculate the offset. 791 */ 792 if (blocksize != BLOCK_SIZE) { 793 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 794 offset = (sb_block*BLOCK_SIZE) % blocksize; 795 } else { 796 logic_sb_block = sb_block; 797 } 798 799 if (!(bh = sb_bread(sb, logic_sb_block))) { 800 printk ("EXT2-fs: unable to read superblock\n"); 801 goto failed_sbi; 802 } 803 /* 804 * Note: s_es must be initialized as soon as possible because 805 * some ext2 macro-instructions depend on its value 806 */ 807 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 808 sbi->s_es = es; 809 sb->s_magic = le16_to_cpu(es->s_magic); 810 811 if (sb->s_magic != EXT2_SUPER_MAGIC) 812 goto cantfind_ext2; 813 814 /* Set defaults before we parse the mount options */ 815 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 816 if (def_mount_opts & EXT2_DEFM_DEBUG) 817 set_opt(sbi->s_mount_opt, DEBUG); 818 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 819 set_opt(sbi->s_mount_opt, GRPID); 820 if (def_mount_opts & EXT2_DEFM_UID16) 821 set_opt(sbi->s_mount_opt, NO_UID32); 822 #ifdef CONFIG_EXT2_FS_XATTR 823 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 824 set_opt(sbi->s_mount_opt, XATTR_USER); 825 #endif 826 #ifdef CONFIG_EXT2_FS_POSIX_ACL 827 if (def_mount_opts & EXT2_DEFM_ACL) 828 set_opt(sbi->s_mount_opt, POSIX_ACL); 829 #endif 830 831 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 832 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 833 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 834 set_opt(sbi->s_mount_opt, ERRORS_CONT); 835 else 836 set_opt(sbi->s_mount_opt, ERRORS_RO); 837 838 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 839 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 840 841 set_opt(sbi->s_mount_opt, RESERVATION); 842 843 if (!parse_options ((char *) data, sbi)) 844 goto failed_mount; 845 846 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 847 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 848 MS_POSIXACL : 0); 849 850 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 851 EXT2_MOUNT_XIP if not */ 852 853 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 854 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 855 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 856 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 857 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 858 "running e2fsck is recommended\n"); 859 /* 860 * Check feature flags regardless of the revision level, since we 861 * previously didn't change the revision level when setting the flags, 862 * so there is a chance incompat flags are set on a rev 0 filesystem. 863 */ 864 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 865 if (features) { 866 printk("EXT2-fs: %s: couldn't mount because of " 867 "unsupported optional features (%x).\n", 868 sb->s_id, le32_to_cpu(features)); 869 goto failed_mount; 870 } 871 if (!(sb->s_flags & MS_RDONLY) && 872 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 873 printk("EXT2-fs: %s: couldn't mount RDWR because of " 874 "unsupported optional features (%x).\n", 875 sb->s_id, le32_to_cpu(features)); 876 goto failed_mount; 877 } 878 879 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 880 881 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 882 if (!silent) 883 printk("XIP: Unsupported blocksize\n"); 884 goto failed_mount; 885 } 886 887 /* If the blocksize doesn't match, re-read the thing.. */ 888 if (sb->s_blocksize != blocksize) { 889 brelse(bh); 890 891 if (!sb_set_blocksize(sb, blocksize)) { 892 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 893 goto failed_sbi; 894 } 895 896 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 897 offset = (sb_block*BLOCK_SIZE) % blocksize; 898 bh = sb_bread(sb, logic_sb_block); 899 if(!bh) { 900 printk("EXT2-fs: Couldn't read superblock on " 901 "2nd try.\n"); 902 goto failed_sbi; 903 } 904 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 905 sbi->s_es = es; 906 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 907 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 908 goto failed_mount; 909 } 910 } 911 912 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 913 914 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 915 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 916 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 917 } else { 918 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 919 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 920 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 921 !is_power_of_2(sbi->s_inode_size) || 922 (sbi->s_inode_size > blocksize)) { 923 printk ("EXT2-fs: unsupported inode size: %d\n", 924 sbi->s_inode_size); 925 goto failed_mount; 926 } 927 } 928 929 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 930 le32_to_cpu(es->s_log_frag_size); 931 if (sbi->s_frag_size == 0) 932 goto cantfind_ext2; 933 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 934 935 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 936 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 937 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 938 939 if (EXT2_INODE_SIZE(sb) == 0) 940 goto cantfind_ext2; 941 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 942 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 943 goto cantfind_ext2; 944 sbi->s_itb_per_group = sbi->s_inodes_per_group / 945 sbi->s_inodes_per_block; 946 sbi->s_desc_per_block = sb->s_blocksize / 947 sizeof (struct ext2_group_desc); 948 sbi->s_sbh = bh; 949 sbi->s_mount_state = le16_to_cpu(es->s_state); 950 sbi->s_addr_per_block_bits = 951 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 952 sbi->s_desc_per_block_bits = 953 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 954 955 if (sb->s_magic != EXT2_SUPER_MAGIC) 956 goto cantfind_ext2; 957 958 if (sb->s_blocksize != bh->b_size) { 959 if (!silent) 960 printk ("VFS: Unsupported blocksize on dev " 961 "%s.\n", sb->s_id); 962 goto failed_mount; 963 } 964 965 if (sb->s_blocksize != sbi->s_frag_size) { 966 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 967 sbi->s_frag_size, sb->s_blocksize); 968 goto failed_mount; 969 } 970 971 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 972 printk ("EXT2-fs: #blocks per group too big: %lu\n", 973 sbi->s_blocks_per_group); 974 goto failed_mount; 975 } 976 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 977 printk ("EXT2-fs: #fragments per group too big: %lu\n", 978 sbi->s_frags_per_group); 979 goto failed_mount; 980 } 981 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 982 printk ("EXT2-fs: #inodes per group too big: %lu\n", 983 sbi->s_inodes_per_group); 984 goto failed_mount; 985 } 986 987 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 988 goto cantfind_ext2; 989 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 990 le32_to_cpu(es->s_first_data_block) - 1) 991 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 992 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 993 EXT2_DESC_PER_BLOCK(sb); 994 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 995 if (sbi->s_group_desc == NULL) { 996 printk ("EXT2-fs: not enough memory\n"); 997 goto failed_mount; 998 } 999 bgl_lock_init(sbi->s_blockgroup_lock); 1000 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 1001 if (!sbi->s_debts) { 1002 printk ("EXT2-fs: not enough memory\n"); 1003 goto failed_mount_group_desc; 1004 } 1005 for (i = 0; i < db_count; i++) { 1006 block = descriptor_loc(sb, logic_sb_block, i); 1007 sbi->s_group_desc[i] = sb_bread(sb, block); 1008 if (!sbi->s_group_desc[i]) { 1009 for (j = 0; j < i; j++) 1010 brelse (sbi->s_group_desc[j]); 1011 printk ("EXT2-fs: unable to read group descriptors\n"); 1012 goto failed_mount_group_desc; 1013 } 1014 } 1015 if (!ext2_check_descriptors (sb)) { 1016 printk ("EXT2-fs: group descriptors corrupted!\n"); 1017 goto failed_mount2; 1018 } 1019 sbi->s_gdb_count = db_count; 1020 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1021 spin_lock_init(&sbi->s_next_gen_lock); 1022 1023 /* per fileystem reservation list head & lock */ 1024 spin_lock_init(&sbi->s_rsv_window_lock); 1025 sbi->s_rsv_window_root = RB_ROOT; 1026 /* 1027 * Add a single, static dummy reservation to the start of the 1028 * reservation window list --- it gives us a placeholder for 1029 * append-at-start-of-list which makes the allocation logic 1030 * _much_ simpler. 1031 */ 1032 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1033 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1034 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1035 sbi->s_rsv_window_head.rsv_goal_size = 0; 1036 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1037 1038 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1039 ext2_count_free_blocks(sb)); 1040 if (!err) { 1041 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1042 ext2_count_free_inodes(sb)); 1043 } 1044 if (!err) { 1045 err = percpu_counter_init(&sbi->s_dirs_counter, 1046 ext2_count_dirs(sb)); 1047 } 1048 if (err) { 1049 printk(KERN_ERR "EXT2-fs: insufficient memory\n"); 1050 goto failed_mount3; 1051 } 1052 /* 1053 * set up enough so that it can read an inode 1054 */ 1055 sb->s_op = &ext2_sops; 1056 sb->s_export_op = &ext2_export_ops; 1057 sb->s_xattr = ext2_xattr_handlers; 1058 root = ext2_iget(sb, EXT2_ROOT_INO); 1059 if (IS_ERR(root)) { 1060 ret = PTR_ERR(root); 1061 goto failed_mount3; 1062 } 1063 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1064 iput(root); 1065 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 1066 goto failed_mount3; 1067 } 1068 1069 sb->s_root = d_alloc_root(root); 1070 if (!sb->s_root) { 1071 iput(root); 1072 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 1073 ret = -ENOMEM; 1074 goto failed_mount3; 1075 } 1076 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1077 ext2_warning(sb, __func__, 1078 "mounting ext3 filesystem as ext2"); 1079 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 1080 return 0; 1081 1082 cantfind_ext2: 1083 if (!silent) 1084 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 1085 sb->s_id); 1086 goto failed_mount; 1087 failed_mount3: 1088 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1089 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1090 percpu_counter_destroy(&sbi->s_dirs_counter); 1091 failed_mount2: 1092 for (i = 0; i < db_count; i++) 1093 brelse(sbi->s_group_desc[i]); 1094 failed_mount_group_desc: 1095 kfree(sbi->s_group_desc); 1096 kfree(sbi->s_debts); 1097 failed_mount: 1098 brelse(bh); 1099 failed_sbi: 1100 sb->s_fs_info = NULL; 1101 kfree(sbi->s_blockgroup_lock); 1102 kfree(sbi); 1103 return ret; 1104 } 1105 1106 static void ext2_commit_super (struct super_block * sb, 1107 struct ext2_super_block * es) 1108 { 1109 es->s_wtime = cpu_to_le32(get_seconds()); 1110 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1111 sb->s_dirt = 0; 1112 } 1113 1114 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1115 { 1116 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1117 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1118 es->s_wtime = cpu_to_le32(get_seconds()); 1119 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1120 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1121 sb->s_dirt = 0; 1122 } 1123 1124 /* 1125 * In the second extended file system, it is not necessary to 1126 * write the super block since we use a mapping of the 1127 * disk super block in a buffer. 1128 * 1129 * However, this function is still used to set the fs valid 1130 * flags to 0. We need to set this flag to 0 since the fs 1131 * may have been checked while mounted and e2fsck may have 1132 * set s_state to EXT2_VALID_FS after some corrections. 1133 */ 1134 1135 void ext2_write_super (struct super_block * sb) 1136 { 1137 struct ext2_super_block * es; 1138 lock_kernel(); 1139 if (!(sb->s_flags & MS_RDONLY)) { 1140 es = EXT2_SB(sb)->s_es; 1141 1142 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1143 ext2_debug ("setting valid to 0\n"); 1144 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1145 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1146 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1147 es->s_mtime = cpu_to_le32(get_seconds()); 1148 ext2_sync_super(sb, es); 1149 } else 1150 ext2_commit_super (sb, es); 1151 } 1152 sb->s_dirt = 0; 1153 unlock_kernel(); 1154 } 1155 1156 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1157 { 1158 struct ext2_sb_info * sbi = EXT2_SB(sb); 1159 struct ext2_super_block * es; 1160 unsigned long old_mount_opt = sbi->s_mount_opt; 1161 struct ext2_mount_options old_opts; 1162 unsigned long old_sb_flags; 1163 int err; 1164 1165 lock_kernel(); 1166 1167 /* Store the old options */ 1168 old_sb_flags = sb->s_flags; 1169 old_opts.s_mount_opt = sbi->s_mount_opt; 1170 old_opts.s_resuid = sbi->s_resuid; 1171 old_opts.s_resgid = sbi->s_resgid; 1172 1173 /* 1174 * Allow the "check" option to be passed as a remount option. 1175 */ 1176 if (!parse_options (data, sbi)) { 1177 err = -EINVAL; 1178 goto restore_opts; 1179 } 1180 1181 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1182 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1183 1184 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1185 EXT2_MOUNT_XIP if not */ 1186 1187 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1188 printk("XIP: Unsupported blocksize\n"); 1189 err = -EINVAL; 1190 goto restore_opts; 1191 } 1192 1193 es = sbi->s_es; 1194 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1195 (old_mount_opt & EXT2_MOUNT_XIP)) && 1196 invalidate_inodes(sb)) { 1197 ext2_warning(sb, __func__, "refusing change of xip flag " 1198 "with busy inodes while remounting"); 1199 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1200 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1201 } 1202 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1203 unlock_kernel(); 1204 return 0; 1205 } 1206 if (*flags & MS_RDONLY) { 1207 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1208 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1209 unlock_kernel(); 1210 return 0; 1211 } 1212 /* 1213 * OK, we are remounting a valid rw partition rdonly, so set 1214 * the rdonly flag and then mark the partition as valid again. 1215 */ 1216 es->s_state = cpu_to_le16(sbi->s_mount_state); 1217 es->s_mtime = cpu_to_le32(get_seconds()); 1218 } else { 1219 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1220 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1221 if (ret) { 1222 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1223 "unsupported optional features (%x).\n", 1224 sb->s_id, le32_to_cpu(ret)); 1225 err = -EROFS; 1226 goto restore_opts; 1227 } 1228 /* 1229 * Mounting a RDONLY partition read-write, so reread and 1230 * store the current valid flag. (It may have been changed 1231 * by e2fsck since we originally mounted the partition.) 1232 */ 1233 sbi->s_mount_state = le16_to_cpu(es->s_state); 1234 if (!ext2_setup_super (sb, es, 0)) 1235 sb->s_flags &= ~MS_RDONLY; 1236 } 1237 ext2_sync_super(sb, es); 1238 unlock_kernel(); 1239 return 0; 1240 restore_opts: 1241 sbi->s_mount_opt = old_opts.s_mount_opt; 1242 sbi->s_resuid = old_opts.s_resuid; 1243 sbi->s_resgid = old_opts.s_resgid; 1244 sb->s_flags = old_sb_flags; 1245 unlock_kernel(); 1246 return err; 1247 } 1248 1249 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1250 { 1251 struct super_block *sb = dentry->d_sb; 1252 struct ext2_sb_info *sbi = EXT2_SB(sb); 1253 struct ext2_super_block *es = sbi->s_es; 1254 u64 fsid; 1255 1256 if (test_opt (sb, MINIX_DF)) 1257 sbi->s_overhead_last = 0; 1258 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1259 unsigned long i, overhead = 0; 1260 smp_rmb(); 1261 1262 /* 1263 * Compute the overhead (FS structures). This is constant 1264 * for a given filesystem unless the number of block groups 1265 * changes so we cache the previous value until it does. 1266 */ 1267 1268 /* 1269 * All of the blocks before first_data_block are 1270 * overhead 1271 */ 1272 overhead = le32_to_cpu(es->s_first_data_block); 1273 1274 /* 1275 * Add the overhead attributed to the superblock and 1276 * block group descriptors. If the sparse superblocks 1277 * feature is turned on, then not all groups have this. 1278 */ 1279 for (i = 0; i < sbi->s_groups_count; i++) 1280 overhead += ext2_bg_has_super(sb, i) + 1281 ext2_bg_num_gdb(sb, i); 1282 1283 /* 1284 * Every block group has an inode bitmap, a block 1285 * bitmap, and an inode table. 1286 */ 1287 overhead += (sbi->s_groups_count * 1288 (2 + sbi->s_itb_per_group)); 1289 sbi->s_overhead_last = overhead; 1290 smp_wmb(); 1291 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1292 } 1293 1294 buf->f_type = EXT2_SUPER_MAGIC; 1295 buf->f_bsize = sb->s_blocksize; 1296 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1297 buf->f_bfree = ext2_count_free_blocks(sb); 1298 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1299 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1300 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1301 buf->f_bavail = 0; 1302 buf->f_files = le32_to_cpu(es->s_inodes_count); 1303 buf->f_ffree = ext2_count_free_inodes(sb); 1304 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1305 buf->f_namelen = EXT2_NAME_LEN; 1306 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1307 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1308 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1309 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1310 return 0; 1311 } 1312 1313 static int ext2_get_sb(struct file_system_type *fs_type, 1314 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1315 { 1316 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1317 } 1318 1319 #ifdef CONFIG_QUOTA 1320 1321 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1322 * acquiring the locks... As quota files are never truncated and quota code 1323 * itself serializes the operations (and noone else should touch the files) 1324 * we don't have to be afraid of races */ 1325 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1326 size_t len, loff_t off) 1327 { 1328 struct inode *inode = sb_dqopt(sb)->files[type]; 1329 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1330 int err = 0; 1331 int offset = off & (sb->s_blocksize - 1); 1332 int tocopy; 1333 size_t toread; 1334 struct buffer_head tmp_bh; 1335 struct buffer_head *bh; 1336 loff_t i_size = i_size_read(inode); 1337 1338 if (off > i_size) 1339 return 0; 1340 if (off+len > i_size) 1341 len = i_size-off; 1342 toread = len; 1343 while (toread > 0) { 1344 tocopy = sb->s_blocksize - offset < toread ? 1345 sb->s_blocksize - offset : toread; 1346 1347 tmp_bh.b_state = 0; 1348 tmp_bh.b_size = sb->s_blocksize; 1349 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1350 if (err < 0) 1351 return err; 1352 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1353 memset(data, 0, tocopy); 1354 else { 1355 bh = sb_bread(sb, tmp_bh.b_blocknr); 1356 if (!bh) 1357 return -EIO; 1358 memcpy(data, bh->b_data+offset, tocopy); 1359 brelse(bh); 1360 } 1361 offset = 0; 1362 toread -= tocopy; 1363 data += tocopy; 1364 blk++; 1365 } 1366 return len; 1367 } 1368 1369 /* Write to quotafile */ 1370 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1371 const char *data, size_t len, loff_t off) 1372 { 1373 struct inode *inode = sb_dqopt(sb)->files[type]; 1374 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1375 int err = 0; 1376 int offset = off & (sb->s_blocksize - 1); 1377 int tocopy; 1378 size_t towrite = len; 1379 struct buffer_head tmp_bh; 1380 struct buffer_head *bh; 1381 1382 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1383 while (towrite > 0) { 1384 tocopy = sb->s_blocksize - offset < towrite ? 1385 sb->s_blocksize - offset : towrite; 1386 1387 tmp_bh.b_state = 0; 1388 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1389 if (err < 0) 1390 goto out; 1391 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1392 bh = sb_bread(sb, tmp_bh.b_blocknr); 1393 else 1394 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1395 if (!bh) { 1396 err = -EIO; 1397 goto out; 1398 } 1399 lock_buffer(bh); 1400 memcpy(bh->b_data+offset, data, tocopy); 1401 flush_dcache_page(bh->b_page); 1402 set_buffer_uptodate(bh); 1403 mark_buffer_dirty(bh); 1404 unlock_buffer(bh); 1405 brelse(bh); 1406 offset = 0; 1407 towrite -= tocopy; 1408 data += tocopy; 1409 blk++; 1410 } 1411 out: 1412 if (len == towrite) { 1413 mutex_unlock(&inode->i_mutex); 1414 return err; 1415 } 1416 if (inode->i_size < off+len-towrite) 1417 i_size_write(inode, off+len-towrite); 1418 inode->i_version++; 1419 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1420 mark_inode_dirty(inode); 1421 mutex_unlock(&inode->i_mutex); 1422 return len - towrite; 1423 } 1424 1425 #endif 1426 1427 static struct file_system_type ext2_fs_type = { 1428 .owner = THIS_MODULE, 1429 .name = "ext2", 1430 .get_sb = ext2_get_sb, 1431 .kill_sb = kill_block_super, 1432 .fs_flags = FS_REQUIRES_DEV, 1433 }; 1434 1435 static int __init init_ext2_fs(void) 1436 { 1437 int err = init_ext2_xattr(); 1438 if (err) 1439 return err; 1440 err = init_inodecache(); 1441 if (err) 1442 goto out1; 1443 err = register_filesystem(&ext2_fs_type); 1444 if (err) 1445 goto out; 1446 return 0; 1447 out: 1448 destroy_inodecache(); 1449 out1: 1450 exit_ext2_xattr(); 1451 return err; 1452 } 1453 1454 static void __exit exit_ext2_fs(void) 1455 { 1456 unregister_filesystem(&ext2_fs_type); 1457 destroy_inodecache(); 1458 exit_ext2_xattr(); 1459 } 1460 1461 module_init(init_ext2_fs) 1462 module_exit(exit_ext2_fs) 1463