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 ext2_xattr_put_super(sb); 118 if (!(sb->s_flags & MS_RDONLY)) { 119 struct ext2_super_block *es = sbi->s_es; 120 121 es->s_state = cpu_to_le16(sbi->s_mount_state); 122 ext2_sync_super(sb, es); 123 } 124 db_count = sbi->s_gdb_count; 125 for (i = 0; i < db_count; i++) 126 if (sbi->s_group_desc[i]) 127 brelse (sbi->s_group_desc[i]); 128 kfree(sbi->s_group_desc); 129 kfree(sbi->s_debts); 130 percpu_counter_destroy(&sbi->s_freeblocks_counter); 131 percpu_counter_destroy(&sbi->s_freeinodes_counter); 132 percpu_counter_destroy(&sbi->s_dirs_counter); 133 brelse (sbi->s_sbh); 134 sb->s_fs_info = NULL; 135 kfree(sbi->s_blockgroup_lock); 136 kfree(sbi); 137 138 return; 139 } 140 141 static struct kmem_cache * ext2_inode_cachep; 142 143 static struct inode *ext2_alloc_inode(struct super_block *sb) 144 { 145 struct ext2_inode_info *ei; 146 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 147 if (!ei) 148 return NULL; 149 #ifdef CONFIG_EXT2_FS_POSIX_ACL 150 ei->i_acl = EXT2_ACL_NOT_CACHED; 151 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 152 #endif 153 ei->i_block_alloc_info = NULL; 154 ei->vfs_inode.i_version = 1; 155 return &ei->vfs_inode; 156 } 157 158 static void ext2_destroy_inode(struct inode *inode) 159 { 160 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 161 } 162 163 static void init_once(void *foo) 164 { 165 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 166 167 rwlock_init(&ei->i_meta_lock); 168 #ifdef CONFIG_EXT2_FS_XATTR 169 init_rwsem(&ei->xattr_sem); 170 #endif 171 mutex_init(&ei->truncate_mutex); 172 inode_init_once(&ei->vfs_inode); 173 } 174 175 static int init_inodecache(void) 176 { 177 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 178 sizeof(struct ext2_inode_info), 179 0, (SLAB_RECLAIM_ACCOUNT| 180 SLAB_MEM_SPREAD), 181 init_once); 182 if (ext2_inode_cachep == NULL) 183 return -ENOMEM; 184 return 0; 185 } 186 187 static void destroy_inodecache(void) 188 { 189 kmem_cache_destroy(ext2_inode_cachep); 190 } 191 192 static void ext2_clear_inode(struct inode *inode) 193 { 194 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 195 #ifdef CONFIG_EXT2_FS_POSIX_ACL 196 struct ext2_inode_info *ei = EXT2_I(inode); 197 198 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 199 posix_acl_release(ei->i_acl); 200 ei->i_acl = EXT2_ACL_NOT_CACHED; 201 } 202 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 203 posix_acl_release(ei->i_default_acl); 204 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 205 } 206 #endif 207 ext2_discard_reservation(inode); 208 EXT2_I(inode)->i_block_alloc_info = NULL; 209 if (unlikely(rsv)) 210 kfree(rsv); 211 } 212 213 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 214 { 215 struct super_block *sb = vfs->mnt_sb; 216 struct ext2_sb_info *sbi = EXT2_SB(sb); 217 struct ext2_super_block *es = sbi->s_es; 218 unsigned long def_mount_opts; 219 220 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 221 222 if (sbi->s_sb_block != 1) 223 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 224 if (test_opt(sb, MINIX_DF)) 225 seq_puts(seq, ",minixdf"); 226 if (test_opt(sb, GRPID)) 227 seq_puts(seq, ",grpid"); 228 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 229 seq_puts(seq, ",nogrpid"); 230 if (sbi->s_resuid != EXT2_DEF_RESUID || 231 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 232 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 233 } 234 if (sbi->s_resgid != EXT2_DEF_RESGID || 235 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 236 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 237 } 238 if (test_opt(sb, ERRORS_RO)) { 239 int def_errors = le16_to_cpu(es->s_errors); 240 241 if (def_errors == EXT2_ERRORS_PANIC || 242 def_errors == EXT2_ERRORS_CONTINUE) { 243 seq_puts(seq, ",errors=remount-ro"); 244 } 245 } 246 if (test_opt(sb, ERRORS_CONT)) 247 seq_puts(seq, ",errors=continue"); 248 if (test_opt(sb, ERRORS_PANIC)) 249 seq_puts(seq, ",errors=panic"); 250 if (test_opt(sb, NO_UID32)) 251 seq_puts(seq, ",nouid32"); 252 if (test_opt(sb, DEBUG)) 253 seq_puts(seq, ",debug"); 254 if (test_opt(sb, OLDALLOC)) 255 seq_puts(seq, ",oldalloc"); 256 257 #ifdef CONFIG_EXT2_FS_XATTR 258 if (test_opt(sb, XATTR_USER)) 259 seq_puts(seq, ",user_xattr"); 260 if (!test_opt(sb, XATTR_USER) && 261 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 262 seq_puts(seq, ",nouser_xattr"); 263 } 264 #endif 265 266 #ifdef CONFIG_EXT2_FS_POSIX_ACL 267 if (test_opt(sb, POSIX_ACL)) 268 seq_puts(seq, ",acl"); 269 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 270 seq_puts(seq, ",noacl"); 271 #endif 272 273 if (test_opt(sb, NOBH)) 274 seq_puts(seq, ",nobh"); 275 276 #if defined(CONFIG_QUOTA) 277 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 278 seq_puts(seq, ",usrquota"); 279 280 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 281 seq_puts(seq, ",grpquota"); 282 #endif 283 284 #if defined(CONFIG_EXT2_FS_XIP) 285 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 286 seq_puts(seq, ",xip"); 287 #endif 288 289 if (!test_opt(sb, RESERVATION)) 290 seq_puts(seq, ",noreservation"); 291 292 return 0; 293 } 294 295 #ifdef CONFIG_QUOTA 296 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 297 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 298 #endif 299 300 static const struct super_operations ext2_sops = { 301 .alloc_inode = ext2_alloc_inode, 302 .destroy_inode = ext2_destroy_inode, 303 .write_inode = ext2_write_inode, 304 .delete_inode = ext2_delete_inode, 305 .put_super = ext2_put_super, 306 .write_super = ext2_write_super, 307 .statfs = ext2_statfs, 308 .remount_fs = ext2_remount, 309 .clear_inode = ext2_clear_inode, 310 .show_options = ext2_show_options, 311 #ifdef CONFIG_QUOTA 312 .quota_read = ext2_quota_read, 313 .quota_write = ext2_quota_write, 314 #endif 315 }; 316 317 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 318 u64 ino, u32 generation) 319 { 320 struct inode *inode; 321 322 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 323 return ERR_PTR(-ESTALE); 324 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 325 return ERR_PTR(-ESTALE); 326 327 /* iget isn't really right if the inode is currently unallocated!! 328 * ext2_read_inode currently does appropriate checks, but 329 * it might be "neater" to call ext2_get_inode first and check 330 * if the inode is valid..... 331 */ 332 inode = ext2_iget(sb, ino); 333 if (IS_ERR(inode)) 334 return ERR_CAST(inode); 335 if (generation && inode->i_generation != generation) { 336 /* we didn't find the right inode.. */ 337 iput(inode); 338 return ERR_PTR(-ESTALE); 339 } 340 return inode; 341 } 342 343 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 344 int fh_len, int fh_type) 345 { 346 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 347 ext2_nfs_get_inode); 348 } 349 350 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 351 int fh_len, int fh_type) 352 { 353 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 354 ext2_nfs_get_inode); 355 } 356 357 /* Yes, most of these are left as NULL!! 358 * A NULL value implies the default, which works with ext2-like file 359 * systems, but can be improved upon. 360 * Currently only get_parent is required. 361 */ 362 static const struct export_operations ext2_export_ops = { 363 .fh_to_dentry = ext2_fh_to_dentry, 364 .fh_to_parent = ext2_fh_to_parent, 365 .get_parent = ext2_get_parent, 366 }; 367 368 static unsigned long get_sb_block(void **data) 369 { 370 unsigned long sb_block; 371 char *options = (char *) *data; 372 373 if (!options || strncmp(options, "sb=", 3) != 0) 374 return 1; /* Default location */ 375 options += 3; 376 sb_block = simple_strtoul(options, &options, 0); 377 if (*options && *options != ',') { 378 printk("EXT2-fs: Invalid sb specification: %s\n", 379 (char *) *data); 380 return 1; 381 } 382 if (*options == ',') 383 options++; 384 *data = (void *) options; 385 return sb_block; 386 } 387 388 enum { 389 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 390 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 391 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 392 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 393 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 394 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 395 }; 396 397 static const match_table_t tokens = { 398 {Opt_bsd_df, "bsddf"}, 399 {Opt_minix_df, "minixdf"}, 400 {Opt_grpid, "grpid"}, 401 {Opt_grpid, "bsdgroups"}, 402 {Opt_nogrpid, "nogrpid"}, 403 {Opt_nogrpid, "sysvgroups"}, 404 {Opt_resgid, "resgid=%u"}, 405 {Opt_resuid, "resuid=%u"}, 406 {Opt_sb, "sb=%u"}, 407 {Opt_err_cont, "errors=continue"}, 408 {Opt_err_panic, "errors=panic"}, 409 {Opt_err_ro, "errors=remount-ro"}, 410 {Opt_nouid32, "nouid32"}, 411 {Opt_nocheck, "check=none"}, 412 {Opt_nocheck, "nocheck"}, 413 {Opt_debug, "debug"}, 414 {Opt_oldalloc, "oldalloc"}, 415 {Opt_orlov, "orlov"}, 416 {Opt_nobh, "nobh"}, 417 {Opt_user_xattr, "user_xattr"}, 418 {Opt_nouser_xattr, "nouser_xattr"}, 419 {Opt_acl, "acl"}, 420 {Opt_noacl, "noacl"}, 421 {Opt_xip, "xip"}, 422 {Opt_grpquota, "grpquota"}, 423 {Opt_ignore, "noquota"}, 424 {Opt_quota, "quota"}, 425 {Opt_usrquota, "usrquota"}, 426 {Opt_reservation, "reservation"}, 427 {Opt_noreservation, "noreservation"}, 428 {Opt_err, NULL} 429 }; 430 431 static int parse_options (char * options, 432 struct ext2_sb_info *sbi) 433 { 434 char * p; 435 substring_t args[MAX_OPT_ARGS]; 436 int option; 437 438 if (!options) 439 return 1; 440 441 while ((p = strsep (&options, ",")) != NULL) { 442 int token; 443 if (!*p) 444 continue; 445 446 token = match_token(p, tokens, args); 447 switch (token) { 448 case Opt_bsd_df: 449 clear_opt (sbi->s_mount_opt, MINIX_DF); 450 break; 451 case Opt_minix_df: 452 set_opt (sbi->s_mount_opt, MINIX_DF); 453 break; 454 case Opt_grpid: 455 set_opt (sbi->s_mount_opt, GRPID); 456 break; 457 case Opt_nogrpid: 458 clear_opt (sbi->s_mount_opt, GRPID); 459 break; 460 case Opt_resuid: 461 if (match_int(&args[0], &option)) 462 return 0; 463 sbi->s_resuid = option; 464 break; 465 case Opt_resgid: 466 if (match_int(&args[0], &option)) 467 return 0; 468 sbi->s_resgid = option; 469 break; 470 case Opt_sb: 471 /* handled by get_sb_block() instead of here */ 472 /* *sb_block = match_int(&args[0]); */ 473 break; 474 case Opt_err_panic: 475 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 476 clear_opt (sbi->s_mount_opt, ERRORS_RO); 477 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 478 break; 479 case Opt_err_ro: 480 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 481 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 482 set_opt (sbi->s_mount_opt, ERRORS_RO); 483 break; 484 case Opt_err_cont: 485 clear_opt (sbi->s_mount_opt, ERRORS_RO); 486 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 487 set_opt (sbi->s_mount_opt, ERRORS_CONT); 488 break; 489 case Opt_nouid32: 490 set_opt (sbi->s_mount_opt, NO_UID32); 491 break; 492 case Opt_nocheck: 493 clear_opt (sbi->s_mount_opt, CHECK); 494 break; 495 case Opt_debug: 496 set_opt (sbi->s_mount_opt, DEBUG); 497 break; 498 case Opt_oldalloc: 499 set_opt (sbi->s_mount_opt, OLDALLOC); 500 break; 501 case Opt_orlov: 502 clear_opt (sbi->s_mount_opt, OLDALLOC); 503 break; 504 case Opt_nobh: 505 set_opt (sbi->s_mount_opt, NOBH); 506 break; 507 #ifdef CONFIG_EXT2_FS_XATTR 508 case Opt_user_xattr: 509 set_opt (sbi->s_mount_opt, XATTR_USER); 510 break; 511 case Opt_nouser_xattr: 512 clear_opt (sbi->s_mount_opt, XATTR_USER); 513 break; 514 #else 515 case Opt_user_xattr: 516 case Opt_nouser_xattr: 517 printk("EXT2 (no)user_xattr options not supported\n"); 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 printk("EXT2 (no)acl options not supported\n"); 531 break; 532 #endif 533 case Opt_xip: 534 #ifdef CONFIG_EXT2_FS_XIP 535 set_opt (sbi->s_mount_opt, XIP); 536 #else 537 printk("EXT2 xip option not supported\n"); 538 #endif 539 break; 540 541 #if defined(CONFIG_QUOTA) 542 case Opt_quota: 543 case Opt_usrquota: 544 set_opt(sbi->s_mount_opt, USRQUOTA); 545 break; 546 547 case Opt_grpquota: 548 set_opt(sbi->s_mount_opt, GRPQUOTA); 549 break; 550 #else 551 case Opt_quota: 552 case Opt_usrquota: 553 case Opt_grpquota: 554 printk(KERN_ERR 555 "EXT2-fs: quota operations not supported.\n"); 556 557 break; 558 #endif 559 560 case Opt_reservation: 561 set_opt(sbi->s_mount_opt, RESERVATION); 562 printk("reservations ON\n"); 563 break; 564 case Opt_noreservation: 565 clear_opt(sbi->s_mount_opt, RESERVATION); 566 printk("reservations OFF\n"); 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 printk ("EXT2-fs warning: revision level too high, " 586 "forcing read-only mode\n"); 587 res = MS_RDONLY; 588 } 589 if (read_only) 590 return res; 591 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 592 printk ("EXT2-fs warning: mounting unchecked fs, " 593 "running e2fsck is recommended\n"); 594 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 595 printk ("EXT2-fs warning: mounting fs with errors, " 596 "running e2fsck is recommended\n"); 597 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 598 le16_to_cpu(es->s_mnt_count) >= 599 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 600 printk ("EXT2-fs warning: maximal mount count reached, " 601 "running e2fsck is recommended\n"); 602 else if (le32_to_cpu(es->s_checkinterval) && 603 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 604 printk ("EXT2-fs warning: checktime reached, " 605 "running e2fsck is recommended\n"); 606 if (!le16_to_cpu(es->s_max_mnt_count)) 607 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 608 le16_add_cpu(&es->s_mnt_count, 1); 609 ext2_write_super(sb); 610 if (test_opt (sb, DEBUG)) 611 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 612 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 613 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 614 sbi->s_frag_size, 615 sbi->s_groups_count, 616 EXT2_BLOCKS_PER_GROUP(sb), 617 EXT2_INODES_PER_GROUP(sb), 618 sbi->s_mount_opt); 619 return res; 620 } 621 622 static int ext2_check_descriptors(struct super_block *sb) 623 { 624 int i; 625 struct ext2_sb_info *sbi = EXT2_SB(sb); 626 627 ext2_debug ("Checking group descriptors"); 628 629 for (i = 0; i < sbi->s_groups_count; i++) { 630 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 631 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 632 ext2_fsblk_t last_block; 633 634 if (i == sbi->s_groups_count - 1) 635 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 636 else 637 last_block = first_block + 638 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 639 640 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 641 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 642 { 643 ext2_error (sb, "ext2_check_descriptors", 644 "Block bitmap for group %d" 645 " not in group (block %lu)!", 646 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 647 return 0; 648 } 649 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 650 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 651 { 652 ext2_error (sb, "ext2_check_descriptors", 653 "Inode bitmap for group %d" 654 " not in group (block %lu)!", 655 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 656 return 0; 657 } 658 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 659 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 660 last_block) 661 { 662 ext2_error (sb, "ext2_check_descriptors", 663 "Inode table for group %d" 664 " not in group (block %lu)!", 665 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 666 return 0; 667 } 668 } 669 return 1; 670 } 671 672 /* 673 * Maximal file size. There is a direct, and {,double-,triple-}indirect 674 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 675 * We need to be 1 filesystem block less than the 2^32 sector limit. 676 */ 677 static loff_t ext2_max_size(int bits) 678 { 679 loff_t res = EXT2_NDIR_BLOCKS; 680 int meta_blocks; 681 loff_t upper_limit; 682 683 /* This is calculated to be the largest file size for a 684 * dense, file such that the total number of 685 * sectors in the file, including data and all indirect blocks, 686 * does not exceed 2^32 -1 687 * __u32 i_blocks representing the total number of 688 * 512 bytes blocks of the file 689 */ 690 upper_limit = (1LL << 32) - 1; 691 692 /* total blocks in file system block size */ 693 upper_limit >>= (bits - 9); 694 695 696 /* indirect blocks */ 697 meta_blocks = 1; 698 /* double indirect blocks */ 699 meta_blocks += 1 + (1LL << (bits-2)); 700 /* tripple indirect blocks */ 701 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 702 703 upper_limit -= meta_blocks; 704 upper_limit <<= bits; 705 706 res += 1LL << (bits-2); 707 res += 1LL << (2*(bits-2)); 708 res += 1LL << (3*(bits-2)); 709 res <<= bits; 710 if (res > upper_limit) 711 res = upper_limit; 712 713 if (res > MAX_LFS_FILESIZE) 714 res = MAX_LFS_FILESIZE; 715 716 return res; 717 } 718 719 static unsigned long descriptor_loc(struct super_block *sb, 720 unsigned long logic_sb_block, 721 int nr) 722 { 723 struct ext2_sb_info *sbi = EXT2_SB(sb); 724 unsigned long bg, first_meta_bg; 725 int has_super = 0; 726 727 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 728 729 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 730 nr < first_meta_bg) 731 return (logic_sb_block + nr + 1); 732 bg = sbi->s_desc_per_block * nr; 733 if (ext2_bg_has_super(sb, bg)) 734 has_super = 1; 735 736 return ext2_group_first_block_no(sb, bg) + has_super; 737 } 738 739 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 740 { 741 struct buffer_head * bh; 742 struct ext2_sb_info * sbi; 743 struct ext2_super_block * es; 744 struct inode *root; 745 unsigned long block; 746 unsigned long sb_block = get_sb_block(&data); 747 unsigned long logic_sb_block; 748 unsigned long offset = 0; 749 unsigned long def_mount_opts; 750 long ret = -EINVAL; 751 int blocksize = BLOCK_SIZE; 752 int db_count; 753 int i, j; 754 __le32 features; 755 int err; 756 757 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 758 if (!sbi) 759 return -ENOMEM; 760 761 sbi->s_blockgroup_lock = 762 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 763 if (!sbi->s_blockgroup_lock) { 764 kfree(sbi); 765 return -ENOMEM; 766 } 767 sb->s_fs_info = sbi; 768 sbi->s_sb_block = sb_block; 769 770 /* 771 * See what the current blocksize for the device is, and 772 * use that as the blocksize. Otherwise (or if the blocksize 773 * is smaller than the default) use the default. 774 * This is important for devices that have a hardware 775 * sectorsize that is larger than the default. 776 */ 777 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 778 if (!blocksize) { 779 printk ("EXT2-fs: unable to set blocksize\n"); 780 goto failed_sbi; 781 } 782 783 /* 784 * If the superblock doesn't start on a hardware sector boundary, 785 * calculate the offset. 786 */ 787 if (blocksize != BLOCK_SIZE) { 788 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 789 offset = (sb_block*BLOCK_SIZE) % blocksize; 790 } else { 791 logic_sb_block = sb_block; 792 } 793 794 if (!(bh = sb_bread(sb, logic_sb_block))) { 795 printk ("EXT2-fs: unable to read superblock\n"); 796 goto failed_sbi; 797 } 798 /* 799 * Note: s_es must be initialized as soon as possible because 800 * some ext2 macro-instructions depend on its value 801 */ 802 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 803 sbi->s_es = es; 804 sb->s_magic = le16_to_cpu(es->s_magic); 805 806 if (sb->s_magic != EXT2_SUPER_MAGIC) 807 goto cantfind_ext2; 808 809 /* Set defaults before we parse the mount options */ 810 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 811 if (def_mount_opts & EXT2_DEFM_DEBUG) 812 set_opt(sbi->s_mount_opt, DEBUG); 813 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 814 set_opt(sbi->s_mount_opt, GRPID); 815 if (def_mount_opts & EXT2_DEFM_UID16) 816 set_opt(sbi->s_mount_opt, NO_UID32); 817 #ifdef CONFIG_EXT2_FS_XATTR 818 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 819 set_opt(sbi->s_mount_opt, XATTR_USER); 820 #endif 821 #ifdef CONFIG_EXT2_FS_POSIX_ACL 822 if (def_mount_opts & EXT2_DEFM_ACL) 823 set_opt(sbi->s_mount_opt, POSIX_ACL); 824 #endif 825 826 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 827 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 828 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 829 set_opt(sbi->s_mount_opt, ERRORS_CONT); 830 else 831 set_opt(sbi->s_mount_opt, ERRORS_RO); 832 833 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 834 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 835 836 set_opt(sbi->s_mount_opt, RESERVATION); 837 838 if (!parse_options ((char *) data, sbi)) 839 goto failed_mount; 840 841 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 842 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 843 MS_POSIXACL : 0); 844 845 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 846 EXT2_MOUNT_XIP if not */ 847 848 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 849 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 850 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 851 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 852 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 853 "running e2fsck is recommended\n"); 854 /* 855 * Check feature flags regardless of the revision level, since we 856 * previously didn't change the revision level when setting the flags, 857 * so there is a chance incompat flags are set on a rev 0 filesystem. 858 */ 859 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 860 if (features) { 861 printk("EXT2-fs: %s: couldn't mount because of " 862 "unsupported optional features (%x).\n", 863 sb->s_id, le32_to_cpu(features)); 864 goto failed_mount; 865 } 866 if (!(sb->s_flags & MS_RDONLY) && 867 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 868 printk("EXT2-fs: %s: couldn't mount RDWR because of " 869 "unsupported optional features (%x).\n", 870 sb->s_id, le32_to_cpu(features)); 871 goto failed_mount; 872 } 873 874 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 875 876 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 877 if (!silent) 878 printk("XIP: Unsupported blocksize\n"); 879 goto failed_mount; 880 } 881 882 /* If the blocksize doesn't match, re-read the thing.. */ 883 if (sb->s_blocksize != blocksize) { 884 brelse(bh); 885 886 if (!sb_set_blocksize(sb, blocksize)) { 887 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 888 goto failed_sbi; 889 } 890 891 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 892 offset = (sb_block*BLOCK_SIZE) % blocksize; 893 bh = sb_bread(sb, logic_sb_block); 894 if(!bh) { 895 printk("EXT2-fs: Couldn't read superblock on " 896 "2nd try.\n"); 897 goto failed_sbi; 898 } 899 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 900 sbi->s_es = es; 901 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 902 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 903 goto failed_mount; 904 } 905 } 906 907 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 908 909 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 910 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 911 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 912 } else { 913 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 914 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 915 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 916 !is_power_of_2(sbi->s_inode_size) || 917 (sbi->s_inode_size > blocksize)) { 918 printk ("EXT2-fs: unsupported inode size: %d\n", 919 sbi->s_inode_size); 920 goto failed_mount; 921 } 922 } 923 924 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 925 le32_to_cpu(es->s_log_frag_size); 926 if (sbi->s_frag_size == 0) 927 goto cantfind_ext2; 928 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 929 930 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 931 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 932 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 933 934 if (EXT2_INODE_SIZE(sb) == 0) 935 goto cantfind_ext2; 936 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 937 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 938 goto cantfind_ext2; 939 sbi->s_itb_per_group = sbi->s_inodes_per_group / 940 sbi->s_inodes_per_block; 941 sbi->s_desc_per_block = sb->s_blocksize / 942 sizeof (struct ext2_group_desc); 943 sbi->s_sbh = bh; 944 sbi->s_mount_state = le16_to_cpu(es->s_state); 945 sbi->s_addr_per_block_bits = 946 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 947 sbi->s_desc_per_block_bits = 948 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 949 950 if (sb->s_magic != EXT2_SUPER_MAGIC) 951 goto cantfind_ext2; 952 953 if (sb->s_blocksize != bh->b_size) { 954 if (!silent) 955 printk ("VFS: Unsupported blocksize on dev " 956 "%s.\n", sb->s_id); 957 goto failed_mount; 958 } 959 960 if (sb->s_blocksize != sbi->s_frag_size) { 961 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 962 sbi->s_frag_size, sb->s_blocksize); 963 goto failed_mount; 964 } 965 966 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 967 printk ("EXT2-fs: #blocks per group too big: %lu\n", 968 sbi->s_blocks_per_group); 969 goto failed_mount; 970 } 971 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 972 printk ("EXT2-fs: #fragments per group too big: %lu\n", 973 sbi->s_frags_per_group); 974 goto failed_mount; 975 } 976 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 977 printk ("EXT2-fs: #inodes per group too big: %lu\n", 978 sbi->s_inodes_per_group); 979 goto failed_mount; 980 } 981 982 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 983 goto cantfind_ext2; 984 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 985 le32_to_cpu(es->s_first_data_block) - 1) 986 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 987 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 988 EXT2_DESC_PER_BLOCK(sb); 989 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 990 if (sbi->s_group_desc == NULL) { 991 printk ("EXT2-fs: not enough memory\n"); 992 goto failed_mount; 993 } 994 bgl_lock_init(sbi->s_blockgroup_lock); 995 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 996 if (!sbi->s_debts) { 997 printk ("EXT2-fs: not enough memory\n"); 998 goto failed_mount_group_desc; 999 } 1000 for (i = 0; i < db_count; i++) { 1001 block = descriptor_loc(sb, logic_sb_block, i); 1002 sbi->s_group_desc[i] = sb_bread(sb, block); 1003 if (!sbi->s_group_desc[i]) { 1004 for (j = 0; j < i; j++) 1005 brelse (sbi->s_group_desc[j]); 1006 printk ("EXT2-fs: unable to read group descriptors\n"); 1007 goto failed_mount_group_desc; 1008 } 1009 } 1010 if (!ext2_check_descriptors (sb)) { 1011 printk ("EXT2-fs: group descriptors corrupted!\n"); 1012 goto failed_mount2; 1013 } 1014 sbi->s_gdb_count = db_count; 1015 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1016 spin_lock_init(&sbi->s_next_gen_lock); 1017 1018 /* per fileystem reservation list head & lock */ 1019 spin_lock_init(&sbi->s_rsv_window_lock); 1020 sbi->s_rsv_window_root = RB_ROOT; 1021 /* 1022 * Add a single, static dummy reservation to the start of the 1023 * reservation window list --- it gives us a placeholder for 1024 * append-at-start-of-list which makes the allocation logic 1025 * _much_ simpler. 1026 */ 1027 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1028 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1029 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1030 sbi->s_rsv_window_head.rsv_goal_size = 0; 1031 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1032 1033 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1034 ext2_count_free_blocks(sb)); 1035 if (!err) { 1036 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1037 ext2_count_free_inodes(sb)); 1038 } 1039 if (!err) { 1040 err = percpu_counter_init(&sbi->s_dirs_counter, 1041 ext2_count_dirs(sb)); 1042 } 1043 if (err) { 1044 printk(KERN_ERR "EXT2-fs: insufficient memory\n"); 1045 goto failed_mount3; 1046 } 1047 /* 1048 * set up enough so that it can read an inode 1049 */ 1050 sb->s_op = &ext2_sops; 1051 sb->s_export_op = &ext2_export_ops; 1052 sb->s_xattr = ext2_xattr_handlers; 1053 root = ext2_iget(sb, EXT2_ROOT_INO); 1054 if (IS_ERR(root)) { 1055 ret = PTR_ERR(root); 1056 goto failed_mount3; 1057 } 1058 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1059 iput(root); 1060 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 1061 goto failed_mount3; 1062 } 1063 1064 sb->s_root = d_alloc_root(root); 1065 if (!sb->s_root) { 1066 iput(root); 1067 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 1068 ret = -ENOMEM; 1069 goto failed_mount3; 1070 } 1071 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1072 ext2_warning(sb, __func__, 1073 "mounting ext3 filesystem as ext2"); 1074 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 1075 return 0; 1076 1077 cantfind_ext2: 1078 if (!silent) 1079 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 1080 sb->s_id); 1081 goto failed_mount; 1082 failed_mount3: 1083 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1084 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1085 percpu_counter_destroy(&sbi->s_dirs_counter); 1086 failed_mount2: 1087 for (i = 0; i < db_count; i++) 1088 brelse(sbi->s_group_desc[i]); 1089 failed_mount_group_desc: 1090 kfree(sbi->s_group_desc); 1091 kfree(sbi->s_debts); 1092 failed_mount: 1093 brelse(bh); 1094 failed_sbi: 1095 sb->s_fs_info = NULL; 1096 kfree(sbi); 1097 return ret; 1098 } 1099 1100 static void ext2_commit_super (struct super_block * sb, 1101 struct ext2_super_block * es) 1102 { 1103 es->s_wtime = cpu_to_le32(get_seconds()); 1104 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1105 sb->s_dirt = 0; 1106 } 1107 1108 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1109 { 1110 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1111 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1112 es->s_wtime = cpu_to_le32(get_seconds()); 1113 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1114 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1115 sb->s_dirt = 0; 1116 } 1117 1118 /* 1119 * In the second extended file system, it is not necessary to 1120 * write the super block since we use a mapping of the 1121 * disk super block in a buffer. 1122 * 1123 * However, this function is still used to set the fs valid 1124 * flags to 0. We need to set this flag to 0 since the fs 1125 * may have been checked while mounted and e2fsck may have 1126 * set s_state to EXT2_VALID_FS after some corrections. 1127 */ 1128 1129 void ext2_write_super (struct super_block * sb) 1130 { 1131 struct ext2_super_block * es; 1132 lock_kernel(); 1133 if (!(sb->s_flags & MS_RDONLY)) { 1134 es = EXT2_SB(sb)->s_es; 1135 1136 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1137 ext2_debug ("setting valid to 0\n"); 1138 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1139 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1140 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1141 es->s_mtime = cpu_to_le32(get_seconds()); 1142 ext2_sync_super(sb, es); 1143 } else 1144 ext2_commit_super (sb, es); 1145 } 1146 sb->s_dirt = 0; 1147 unlock_kernel(); 1148 } 1149 1150 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1151 { 1152 struct ext2_sb_info * sbi = EXT2_SB(sb); 1153 struct ext2_super_block * es; 1154 unsigned long old_mount_opt = sbi->s_mount_opt; 1155 struct ext2_mount_options old_opts; 1156 unsigned long old_sb_flags; 1157 int err; 1158 1159 /* Store the old options */ 1160 old_sb_flags = sb->s_flags; 1161 old_opts.s_mount_opt = sbi->s_mount_opt; 1162 old_opts.s_resuid = sbi->s_resuid; 1163 old_opts.s_resgid = sbi->s_resgid; 1164 1165 /* 1166 * Allow the "check" option to be passed as a remount option. 1167 */ 1168 if (!parse_options (data, sbi)) { 1169 err = -EINVAL; 1170 goto restore_opts; 1171 } 1172 1173 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1174 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1175 1176 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1177 EXT2_MOUNT_XIP if not */ 1178 1179 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1180 printk("XIP: Unsupported blocksize\n"); 1181 err = -EINVAL; 1182 goto restore_opts; 1183 } 1184 1185 es = sbi->s_es; 1186 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1187 (old_mount_opt & EXT2_MOUNT_XIP)) && 1188 invalidate_inodes(sb)) { 1189 ext2_warning(sb, __func__, "refusing change of xip flag " 1190 "with busy inodes while remounting"); 1191 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1192 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1193 } 1194 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1195 return 0; 1196 if (*flags & MS_RDONLY) { 1197 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1198 !(sbi->s_mount_state & EXT2_VALID_FS)) 1199 return 0; 1200 /* 1201 * OK, we are remounting a valid rw partition rdonly, so set 1202 * the rdonly flag and then mark the partition as valid again. 1203 */ 1204 es->s_state = cpu_to_le16(sbi->s_mount_state); 1205 es->s_mtime = cpu_to_le32(get_seconds()); 1206 } else { 1207 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1208 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1209 if (ret) { 1210 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1211 "unsupported optional features (%x).\n", 1212 sb->s_id, le32_to_cpu(ret)); 1213 err = -EROFS; 1214 goto restore_opts; 1215 } 1216 /* 1217 * Mounting a RDONLY partition read-write, so reread and 1218 * store the current valid flag. (It may have been changed 1219 * by e2fsck since we originally mounted the partition.) 1220 */ 1221 sbi->s_mount_state = le16_to_cpu(es->s_state); 1222 if (!ext2_setup_super (sb, es, 0)) 1223 sb->s_flags &= ~MS_RDONLY; 1224 } 1225 ext2_sync_super(sb, es); 1226 return 0; 1227 restore_opts: 1228 sbi->s_mount_opt = old_opts.s_mount_opt; 1229 sbi->s_resuid = old_opts.s_resuid; 1230 sbi->s_resgid = old_opts.s_resgid; 1231 sb->s_flags = old_sb_flags; 1232 return err; 1233 } 1234 1235 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1236 { 1237 struct super_block *sb = dentry->d_sb; 1238 struct ext2_sb_info *sbi = EXT2_SB(sb); 1239 struct ext2_super_block *es = sbi->s_es; 1240 u64 fsid; 1241 1242 if (test_opt (sb, MINIX_DF)) 1243 sbi->s_overhead_last = 0; 1244 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1245 unsigned long i, overhead = 0; 1246 smp_rmb(); 1247 1248 /* 1249 * Compute the overhead (FS structures). This is constant 1250 * for a given filesystem unless the number of block groups 1251 * changes so we cache the previous value until it does. 1252 */ 1253 1254 /* 1255 * All of the blocks before first_data_block are 1256 * overhead 1257 */ 1258 overhead = le32_to_cpu(es->s_first_data_block); 1259 1260 /* 1261 * Add the overhead attributed to the superblock and 1262 * block group descriptors. If the sparse superblocks 1263 * feature is turned on, then not all groups have this. 1264 */ 1265 for (i = 0; i < sbi->s_groups_count; i++) 1266 overhead += ext2_bg_has_super(sb, i) + 1267 ext2_bg_num_gdb(sb, i); 1268 1269 /* 1270 * Every block group has an inode bitmap, a block 1271 * bitmap, and an inode table. 1272 */ 1273 overhead += (sbi->s_groups_count * 1274 (2 + sbi->s_itb_per_group)); 1275 sbi->s_overhead_last = overhead; 1276 smp_wmb(); 1277 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1278 } 1279 1280 buf->f_type = EXT2_SUPER_MAGIC; 1281 buf->f_bsize = sb->s_blocksize; 1282 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1283 buf->f_bfree = ext2_count_free_blocks(sb); 1284 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1285 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1286 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1287 buf->f_bavail = 0; 1288 buf->f_files = le32_to_cpu(es->s_inodes_count); 1289 buf->f_ffree = ext2_count_free_inodes(sb); 1290 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1291 buf->f_namelen = EXT2_NAME_LEN; 1292 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1293 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1294 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1295 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1296 return 0; 1297 } 1298 1299 static int ext2_get_sb(struct file_system_type *fs_type, 1300 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1301 { 1302 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1303 } 1304 1305 #ifdef CONFIG_QUOTA 1306 1307 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1308 * acquiring the locks... As quota files are never truncated and quota code 1309 * itself serializes the operations (and noone else should touch the files) 1310 * we don't have to be afraid of races */ 1311 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1312 size_t len, loff_t off) 1313 { 1314 struct inode *inode = sb_dqopt(sb)->files[type]; 1315 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1316 int err = 0; 1317 int offset = off & (sb->s_blocksize - 1); 1318 int tocopy; 1319 size_t toread; 1320 struct buffer_head tmp_bh; 1321 struct buffer_head *bh; 1322 loff_t i_size = i_size_read(inode); 1323 1324 if (off > i_size) 1325 return 0; 1326 if (off+len > i_size) 1327 len = i_size-off; 1328 toread = len; 1329 while (toread > 0) { 1330 tocopy = sb->s_blocksize - offset < toread ? 1331 sb->s_blocksize - offset : toread; 1332 1333 tmp_bh.b_state = 0; 1334 tmp_bh.b_size = sb->s_blocksize; 1335 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1336 if (err < 0) 1337 return err; 1338 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1339 memset(data, 0, tocopy); 1340 else { 1341 bh = sb_bread(sb, tmp_bh.b_blocknr); 1342 if (!bh) 1343 return -EIO; 1344 memcpy(data, bh->b_data+offset, tocopy); 1345 brelse(bh); 1346 } 1347 offset = 0; 1348 toread -= tocopy; 1349 data += tocopy; 1350 blk++; 1351 } 1352 return len; 1353 } 1354 1355 /* Write to quotafile */ 1356 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1357 const char *data, size_t len, loff_t off) 1358 { 1359 struct inode *inode = sb_dqopt(sb)->files[type]; 1360 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1361 int err = 0; 1362 int offset = off & (sb->s_blocksize - 1); 1363 int tocopy; 1364 size_t towrite = len; 1365 struct buffer_head tmp_bh; 1366 struct buffer_head *bh; 1367 1368 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1369 while (towrite > 0) { 1370 tocopy = sb->s_blocksize - offset < towrite ? 1371 sb->s_blocksize - offset : towrite; 1372 1373 tmp_bh.b_state = 0; 1374 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1375 if (err < 0) 1376 goto out; 1377 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1378 bh = sb_bread(sb, tmp_bh.b_blocknr); 1379 else 1380 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1381 if (!bh) { 1382 err = -EIO; 1383 goto out; 1384 } 1385 lock_buffer(bh); 1386 memcpy(bh->b_data+offset, data, tocopy); 1387 flush_dcache_page(bh->b_page); 1388 set_buffer_uptodate(bh); 1389 mark_buffer_dirty(bh); 1390 unlock_buffer(bh); 1391 brelse(bh); 1392 offset = 0; 1393 towrite -= tocopy; 1394 data += tocopy; 1395 blk++; 1396 } 1397 out: 1398 if (len == towrite) { 1399 mutex_unlock(&inode->i_mutex); 1400 return err; 1401 } 1402 if (inode->i_size < off+len-towrite) 1403 i_size_write(inode, off+len-towrite); 1404 inode->i_version++; 1405 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1406 mark_inode_dirty(inode); 1407 mutex_unlock(&inode->i_mutex); 1408 return len - towrite; 1409 } 1410 1411 #endif 1412 1413 static struct file_system_type ext2_fs_type = { 1414 .owner = THIS_MODULE, 1415 .name = "ext2", 1416 .get_sb = ext2_get_sb, 1417 .kill_sb = kill_block_super, 1418 .fs_flags = FS_REQUIRES_DEV, 1419 }; 1420 1421 static int __init init_ext2_fs(void) 1422 { 1423 int err = init_ext2_xattr(); 1424 if (err) 1425 return err; 1426 err = init_inodecache(); 1427 if (err) 1428 goto out1; 1429 err = register_filesystem(&ext2_fs_type); 1430 if (err) 1431 goto out; 1432 return 0; 1433 out: 1434 destroy_inodecache(); 1435 out1: 1436 exit_ext2_xattr(); 1437 return err; 1438 } 1439 1440 static void __exit exit_ext2_fs(void) 1441 { 1442 unregister_filesystem(&ext2_fs_type); 1443 destroy_inodecache(); 1444 exit_ext2_xattr(); 1445 } 1446 1447 module_init(init_ext2_fs) 1448 module_exit(exit_ext2_fs) 1449