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, int wait); 43 static int ext2_remount (struct super_block * sb, int * flags, char * data); 44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); 45 static int ext2_sync_fs(struct super_block *sb, int wait); 46 47 void ext2_error (struct super_block * sb, const char * function, 48 const char * fmt, ...) 49 { 50 va_list args; 51 struct ext2_sb_info *sbi = EXT2_SB(sb); 52 struct ext2_super_block *es = sbi->s_es; 53 54 if (!(sb->s_flags & MS_RDONLY)) { 55 spin_lock(&sbi->s_lock); 56 sbi->s_mount_state |= EXT2_ERROR_FS; 57 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 58 spin_unlock(&sbi->s_lock); 59 ext2_sync_super(sb, es, 1); 60 } 61 62 va_start(args, fmt); 63 printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function); 64 vprintk(fmt, args); 65 printk("\n"); 66 va_end(args); 67 68 if (test_opt(sb, ERRORS_PANIC)) 69 panic("EXT2-fs: panic from previous error\n"); 70 if (test_opt(sb, ERRORS_RO)) { 71 ext2_msg(sb, KERN_CRIT, 72 "error: remounting filesystem read-only"); 73 sb->s_flags |= MS_RDONLY; 74 } 75 } 76 77 void ext2_msg(struct super_block *sb, const char *prefix, 78 const char *fmt, ...) 79 { 80 va_list args; 81 82 va_start(args, fmt); 83 printk("%sEXT2-fs (%s): ", prefix, sb->s_id); 84 vprintk(fmt, args); 85 printk("\n"); 86 va_end(args); 87 } 88 89 /* 90 * This must be called with sbi->s_lock held. 91 */ 92 void ext2_update_dynamic_rev(struct super_block *sb) 93 { 94 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 95 96 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 97 return; 98 99 ext2_msg(sb, KERN_WARNING, 100 "warning: updating to rev %d because of " 101 "new feature flag, running e2fsck is recommended", 102 EXT2_DYNAMIC_REV); 103 104 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 105 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 106 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 107 /* leave es->s_feature_*compat flags alone */ 108 /* es->s_uuid will be set by e2fsck if empty */ 109 110 /* 111 * The rest of the superblock fields should be zero, and if not it 112 * means they are likely already in use, so leave them alone. We 113 * can leave it up to e2fsck to clean up any inconsistencies there. 114 */ 115 } 116 117 static void ext2_put_super (struct super_block * sb) 118 { 119 int db_count; 120 int i; 121 struct ext2_sb_info *sbi = EXT2_SB(sb); 122 123 lock_kernel(); 124 125 if (sb->s_dirt) 126 ext2_write_super(sb); 127 128 ext2_xattr_put_super(sb); 129 if (!(sb->s_flags & MS_RDONLY)) { 130 struct ext2_super_block *es = sbi->s_es; 131 132 spin_lock(&sbi->s_lock); 133 es->s_state = cpu_to_le16(sbi->s_mount_state); 134 spin_unlock(&sbi->s_lock); 135 ext2_sync_super(sb, es, 1); 136 } 137 db_count = sbi->s_gdb_count; 138 for (i = 0; i < db_count; i++) 139 if (sbi->s_group_desc[i]) 140 brelse (sbi->s_group_desc[i]); 141 kfree(sbi->s_group_desc); 142 kfree(sbi->s_debts); 143 percpu_counter_destroy(&sbi->s_freeblocks_counter); 144 percpu_counter_destroy(&sbi->s_freeinodes_counter); 145 percpu_counter_destroy(&sbi->s_dirs_counter); 146 brelse (sbi->s_sbh); 147 sb->s_fs_info = NULL; 148 kfree(sbi->s_blockgroup_lock); 149 kfree(sbi); 150 151 unlock_kernel(); 152 } 153 154 static struct kmem_cache * ext2_inode_cachep; 155 156 static struct inode *ext2_alloc_inode(struct super_block *sb) 157 { 158 struct ext2_inode_info *ei; 159 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 160 if (!ei) 161 return NULL; 162 ei->i_block_alloc_info = NULL; 163 ei->vfs_inode.i_version = 1; 164 return &ei->vfs_inode; 165 } 166 167 static void ext2_destroy_inode(struct inode *inode) 168 { 169 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 170 } 171 172 static void init_once(void *foo) 173 { 174 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 175 176 rwlock_init(&ei->i_meta_lock); 177 #ifdef CONFIG_EXT2_FS_XATTR 178 init_rwsem(&ei->xattr_sem); 179 #endif 180 mutex_init(&ei->truncate_mutex); 181 inode_init_once(&ei->vfs_inode); 182 } 183 184 static int init_inodecache(void) 185 { 186 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 187 sizeof(struct ext2_inode_info), 188 0, (SLAB_RECLAIM_ACCOUNT| 189 SLAB_MEM_SPREAD), 190 init_once); 191 if (ext2_inode_cachep == NULL) 192 return -ENOMEM; 193 return 0; 194 } 195 196 static void destroy_inodecache(void) 197 { 198 kmem_cache_destroy(ext2_inode_cachep); 199 } 200 201 static void ext2_clear_inode(struct inode *inode) 202 { 203 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 204 205 dquot_drop(inode); 206 ext2_discard_reservation(inode); 207 EXT2_I(inode)->i_block_alloc_info = NULL; 208 if (unlikely(rsv)) 209 kfree(rsv); 210 } 211 212 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 213 { 214 struct super_block *sb = vfs->mnt_sb; 215 struct ext2_sb_info *sbi = EXT2_SB(sb); 216 struct ext2_super_block *es = sbi->s_es; 217 unsigned long def_mount_opts; 218 219 spin_lock(&sbi->s_lock); 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 spin_unlock(&sbi->s_lock); 293 return 0; 294 } 295 296 #ifdef CONFIG_QUOTA 297 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 298 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 299 #endif 300 301 static const struct super_operations ext2_sops = { 302 .alloc_inode = ext2_alloc_inode, 303 .destroy_inode = ext2_destroy_inode, 304 .write_inode = ext2_write_inode, 305 .delete_inode = ext2_delete_inode, 306 .put_super = ext2_put_super, 307 .write_super = ext2_write_super, 308 .sync_fs = ext2_sync_fs, 309 .statfs = ext2_statfs, 310 .remount_fs = ext2_remount, 311 .clear_inode = ext2_clear_inode, 312 .show_options = ext2_show_options, 313 #ifdef CONFIG_QUOTA 314 .quota_read = ext2_quota_read, 315 .quota_write = ext2_quota_write, 316 #endif 317 }; 318 319 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 320 u64 ino, u32 generation) 321 { 322 struct inode *inode; 323 324 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 325 return ERR_PTR(-ESTALE); 326 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 327 return ERR_PTR(-ESTALE); 328 329 /* iget isn't really right if the inode is currently unallocated!! 330 * ext2_read_inode currently does appropriate checks, but 331 * it might be "neater" to call ext2_get_inode first and check 332 * if the inode is valid..... 333 */ 334 inode = ext2_iget(sb, ino); 335 if (IS_ERR(inode)) 336 return ERR_CAST(inode); 337 if (generation && inode->i_generation != generation) { 338 /* we didn't find the right inode.. */ 339 iput(inode); 340 return ERR_PTR(-ESTALE); 341 } 342 return inode; 343 } 344 345 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 346 int fh_len, int fh_type) 347 { 348 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 349 ext2_nfs_get_inode); 350 } 351 352 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 353 int fh_len, int fh_type) 354 { 355 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 356 ext2_nfs_get_inode); 357 } 358 359 /* Yes, most of these are left as NULL!! 360 * A NULL value implies the default, which works with ext2-like file 361 * systems, but can be improved upon. 362 * Currently only get_parent is required. 363 */ 364 static const struct export_operations ext2_export_ops = { 365 .fh_to_dentry = ext2_fh_to_dentry, 366 .fh_to_parent = ext2_fh_to_parent, 367 .get_parent = ext2_get_parent, 368 }; 369 370 static unsigned long get_sb_block(void **data) 371 { 372 unsigned long sb_block; 373 char *options = (char *) *data; 374 375 if (!options || strncmp(options, "sb=", 3) != 0) 376 return 1; /* Default location */ 377 options += 3; 378 sb_block = simple_strtoul(options, &options, 0); 379 if (*options && *options != ',') { 380 printk("EXT2-fs: Invalid sb specification: %s\n", 381 (char *) *data); 382 return 1; 383 } 384 if (*options == ',') 385 options++; 386 *data = (void *) options; 387 return sb_block; 388 } 389 390 enum { 391 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 392 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 393 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 394 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 395 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 396 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 397 }; 398 399 static const match_table_t tokens = { 400 {Opt_bsd_df, "bsddf"}, 401 {Opt_minix_df, "minixdf"}, 402 {Opt_grpid, "grpid"}, 403 {Opt_grpid, "bsdgroups"}, 404 {Opt_nogrpid, "nogrpid"}, 405 {Opt_nogrpid, "sysvgroups"}, 406 {Opt_resgid, "resgid=%u"}, 407 {Opt_resuid, "resuid=%u"}, 408 {Opt_sb, "sb=%u"}, 409 {Opt_err_cont, "errors=continue"}, 410 {Opt_err_panic, "errors=panic"}, 411 {Opt_err_ro, "errors=remount-ro"}, 412 {Opt_nouid32, "nouid32"}, 413 {Opt_nocheck, "check=none"}, 414 {Opt_nocheck, "nocheck"}, 415 {Opt_debug, "debug"}, 416 {Opt_oldalloc, "oldalloc"}, 417 {Opt_orlov, "orlov"}, 418 {Opt_nobh, "nobh"}, 419 {Opt_user_xattr, "user_xattr"}, 420 {Opt_nouser_xattr, "nouser_xattr"}, 421 {Opt_acl, "acl"}, 422 {Opt_noacl, "noacl"}, 423 {Opt_xip, "xip"}, 424 {Opt_grpquota, "grpquota"}, 425 {Opt_ignore, "noquota"}, 426 {Opt_quota, "quota"}, 427 {Opt_usrquota, "usrquota"}, 428 {Opt_reservation, "reservation"}, 429 {Opt_noreservation, "noreservation"}, 430 {Opt_err, NULL} 431 }; 432 433 static int parse_options(char *options, struct super_block *sb) 434 { 435 char *p; 436 struct ext2_sb_info *sbi = EXT2_SB(sb); 437 substring_t args[MAX_OPT_ARGS]; 438 int option; 439 440 if (!options) 441 return 1; 442 443 while ((p = strsep (&options, ",")) != NULL) { 444 int token; 445 if (!*p) 446 continue; 447 448 token = match_token(p, tokens, args); 449 switch (token) { 450 case Opt_bsd_df: 451 clear_opt (sbi->s_mount_opt, MINIX_DF); 452 break; 453 case Opt_minix_df: 454 set_opt (sbi->s_mount_opt, MINIX_DF); 455 break; 456 case Opt_grpid: 457 set_opt (sbi->s_mount_opt, GRPID); 458 break; 459 case Opt_nogrpid: 460 clear_opt (sbi->s_mount_opt, GRPID); 461 break; 462 case Opt_resuid: 463 if (match_int(&args[0], &option)) 464 return 0; 465 sbi->s_resuid = option; 466 break; 467 case Opt_resgid: 468 if (match_int(&args[0], &option)) 469 return 0; 470 sbi->s_resgid = option; 471 break; 472 case Opt_sb: 473 /* handled by get_sb_block() instead of here */ 474 /* *sb_block = match_int(&args[0]); */ 475 break; 476 case Opt_err_panic: 477 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 478 clear_opt (sbi->s_mount_opt, ERRORS_RO); 479 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 480 break; 481 case Opt_err_ro: 482 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 483 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 484 set_opt (sbi->s_mount_opt, ERRORS_RO); 485 break; 486 case Opt_err_cont: 487 clear_opt (sbi->s_mount_opt, ERRORS_RO); 488 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 489 set_opt (sbi->s_mount_opt, ERRORS_CONT); 490 break; 491 case Opt_nouid32: 492 set_opt (sbi->s_mount_opt, NO_UID32); 493 break; 494 case Opt_nocheck: 495 clear_opt (sbi->s_mount_opt, CHECK); 496 break; 497 case Opt_debug: 498 set_opt (sbi->s_mount_opt, DEBUG); 499 break; 500 case Opt_oldalloc: 501 set_opt (sbi->s_mount_opt, OLDALLOC); 502 break; 503 case Opt_orlov: 504 clear_opt (sbi->s_mount_opt, OLDALLOC); 505 break; 506 case Opt_nobh: 507 set_opt (sbi->s_mount_opt, NOBH); 508 break; 509 #ifdef CONFIG_EXT2_FS_XATTR 510 case Opt_user_xattr: 511 set_opt (sbi->s_mount_opt, XATTR_USER); 512 break; 513 case Opt_nouser_xattr: 514 clear_opt (sbi->s_mount_opt, XATTR_USER); 515 break; 516 #else 517 case Opt_user_xattr: 518 case Opt_nouser_xattr: 519 ext2_msg(sb, KERN_INFO, "(no)user_xattr options" 520 "not supported"); 521 break; 522 #endif 523 #ifdef CONFIG_EXT2_FS_POSIX_ACL 524 case Opt_acl: 525 set_opt(sbi->s_mount_opt, POSIX_ACL); 526 break; 527 case Opt_noacl: 528 clear_opt(sbi->s_mount_opt, POSIX_ACL); 529 break; 530 #else 531 case Opt_acl: 532 case Opt_noacl: 533 ext2_msg(sb, KERN_INFO, 534 "(no)acl options not supported"); 535 break; 536 #endif 537 case Opt_xip: 538 #ifdef CONFIG_EXT2_FS_XIP 539 set_opt (sbi->s_mount_opt, XIP); 540 #else 541 ext2_msg(sb, KERN_INFO, "xip option not supported"); 542 #endif 543 break; 544 545 #if defined(CONFIG_QUOTA) 546 case Opt_quota: 547 case Opt_usrquota: 548 set_opt(sbi->s_mount_opt, USRQUOTA); 549 break; 550 551 case Opt_grpquota: 552 set_opt(sbi->s_mount_opt, GRPQUOTA); 553 break; 554 #else 555 case Opt_quota: 556 case Opt_usrquota: 557 case Opt_grpquota: 558 ext2_msg(sb, KERN_INFO, 559 "quota operations not supported"); 560 break; 561 #endif 562 563 case Opt_reservation: 564 set_opt(sbi->s_mount_opt, RESERVATION); 565 ext2_msg(sb, KERN_INFO, "reservations ON"); 566 break; 567 case Opt_noreservation: 568 clear_opt(sbi->s_mount_opt, RESERVATION); 569 ext2_msg(sb, KERN_INFO, "reservations OFF"); 570 break; 571 case Opt_ignore: 572 break; 573 default: 574 return 0; 575 } 576 } 577 return 1; 578 } 579 580 static int ext2_setup_super (struct super_block * sb, 581 struct ext2_super_block * es, 582 int read_only) 583 { 584 int res = 0; 585 struct ext2_sb_info *sbi = EXT2_SB(sb); 586 587 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 588 ext2_msg(sb, KERN_ERR, 589 "error: revision level too high, " 590 "forcing read-only mode"); 591 res = MS_RDONLY; 592 } 593 if (read_only) 594 return res; 595 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 596 ext2_msg(sb, KERN_WARNING, 597 "warning: mounting unchecked fs, " 598 "running e2fsck is recommended"); 599 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 600 ext2_msg(sb, KERN_WARNING, 601 "warning: mounting fs with errors, " 602 "running e2fsck is recommended"); 603 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 604 le16_to_cpu(es->s_mnt_count) >= 605 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 606 ext2_msg(sb, KERN_WARNING, 607 "warning: maximal mount count reached, " 608 "running e2fsck is recommended"); 609 else if (le32_to_cpu(es->s_checkinterval) && 610 (le32_to_cpu(es->s_lastcheck) + 611 le32_to_cpu(es->s_checkinterval) <= get_seconds())) 612 ext2_msg(sb, KERN_WARNING, 613 "warning: checktime reached, " 614 "running e2fsck is recommended"); 615 if (!le16_to_cpu(es->s_max_mnt_count)) 616 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 617 le16_add_cpu(&es->s_mnt_count, 1); 618 if (test_opt (sb, DEBUG)) 619 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, " 620 "bpg=%lu, ipg=%lu, mo=%04lx]", 621 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 622 sbi->s_frag_size, 623 sbi->s_groups_count, 624 EXT2_BLOCKS_PER_GROUP(sb), 625 EXT2_INODES_PER_GROUP(sb), 626 sbi->s_mount_opt); 627 return res; 628 } 629 630 static int ext2_check_descriptors(struct super_block *sb) 631 { 632 int i; 633 struct ext2_sb_info *sbi = EXT2_SB(sb); 634 635 ext2_debug ("Checking group descriptors"); 636 637 for (i = 0; i < sbi->s_groups_count; i++) { 638 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 639 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 640 ext2_fsblk_t last_block; 641 642 if (i == sbi->s_groups_count - 1) 643 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 644 else 645 last_block = first_block + 646 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 647 648 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 649 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 650 { 651 ext2_error (sb, "ext2_check_descriptors", 652 "Block bitmap for group %d" 653 " not in group (block %lu)!", 654 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 655 return 0; 656 } 657 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 658 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 659 { 660 ext2_error (sb, "ext2_check_descriptors", 661 "Inode bitmap for group %d" 662 " not in group (block %lu)!", 663 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 664 return 0; 665 } 666 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 667 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 668 last_block) 669 { 670 ext2_error (sb, "ext2_check_descriptors", 671 "Inode table for group %d" 672 " not in group (block %lu)!", 673 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 674 return 0; 675 } 676 } 677 return 1; 678 } 679 680 /* 681 * Maximal file size. There is a direct, and {,double-,triple-}indirect 682 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 683 * We need to be 1 filesystem block less than the 2^32 sector limit. 684 */ 685 static loff_t ext2_max_size(int bits) 686 { 687 loff_t res = EXT2_NDIR_BLOCKS; 688 int meta_blocks; 689 loff_t upper_limit; 690 691 /* This is calculated to be the largest file size for a 692 * dense, file such that the total number of 693 * sectors in the file, including data and all indirect blocks, 694 * does not exceed 2^32 -1 695 * __u32 i_blocks representing the total number of 696 * 512 bytes blocks of the file 697 */ 698 upper_limit = (1LL << 32) - 1; 699 700 /* total blocks in file system block size */ 701 upper_limit >>= (bits - 9); 702 703 704 /* indirect blocks */ 705 meta_blocks = 1; 706 /* double indirect blocks */ 707 meta_blocks += 1 + (1LL << (bits-2)); 708 /* tripple indirect blocks */ 709 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 710 711 upper_limit -= meta_blocks; 712 upper_limit <<= bits; 713 714 res += 1LL << (bits-2); 715 res += 1LL << (2*(bits-2)); 716 res += 1LL << (3*(bits-2)); 717 res <<= bits; 718 if (res > upper_limit) 719 res = upper_limit; 720 721 if (res > MAX_LFS_FILESIZE) 722 res = MAX_LFS_FILESIZE; 723 724 return res; 725 } 726 727 static unsigned long descriptor_loc(struct super_block *sb, 728 unsigned long logic_sb_block, 729 int nr) 730 { 731 struct ext2_sb_info *sbi = EXT2_SB(sb); 732 unsigned long bg, first_meta_bg; 733 int has_super = 0; 734 735 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 736 737 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 738 nr < first_meta_bg) 739 return (logic_sb_block + nr + 1); 740 bg = sbi->s_desc_per_block * nr; 741 if (ext2_bg_has_super(sb, bg)) 742 has_super = 1; 743 744 return ext2_group_first_block_no(sb, bg) + has_super; 745 } 746 747 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 748 { 749 struct buffer_head * bh; 750 struct ext2_sb_info * sbi; 751 struct ext2_super_block * es; 752 struct inode *root; 753 unsigned long block; 754 unsigned long sb_block = get_sb_block(&data); 755 unsigned long logic_sb_block; 756 unsigned long offset = 0; 757 unsigned long def_mount_opts; 758 long ret = -EINVAL; 759 int blocksize = BLOCK_SIZE; 760 int db_count; 761 int i, j; 762 __le32 features; 763 int err; 764 765 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 766 if (!sbi) 767 return -ENOMEM; 768 769 sbi->s_blockgroup_lock = 770 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 771 if (!sbi->s_blockgroup_lock) { 772 kfree(sbi); 773 return -ENOMEM; 774 } 775 sb->s_fs_info = sbi; 776 sbi->s_sb_block = sb_block; 777 778 spin_lock_init(&sbi->s_lock); 779 780 /* 781 * See what the current blocksize for the device is, and 782 * use that as the blocksize. Otherwise (or if the blocksize 783 * is smaller than the default) use the default. 784 * This is important for devices that have a hardware 785 * sectorsize that is larger than the default. 786 */ 787 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 788 if (!blocksize) { 789 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize"); 790 goto failed_sbi; 791 } 792 793 /* 794 * If the superblock doesn't start on a hardware sector boundary, 795 * calculate the offset. 796 */ 797 if (blocksize != BLOCK_SIZE) { 798 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 799 offset = (sb_block*BLOCK_SIZE) % blocksize; 800 } else { 801 logic_sb_block = sb_block; 802 } 803 804 if (!(bh = sb_bread(sb, logic_sb_block))) { 805 ext2_msg(sb, KERN_ERR, "error: unable to read superblock"); 806 goto failed_sbi; 807 } 808 /* 809 * Note: s_es must be initialized as soon as possible because 810 * some ext2 macro-instructions depend on its value 811 */ 812 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 813 sbi->s_es = es; 814 sb->s_magic = le16_to_cpu(es->s_magic); 815 816 if (sb->s_magic != EXT2_SUPER_MAGIC) 817 goto cantfind_ext2; 818 819 /* Set defaults before we parse the mount options */ 820 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 821 if (def_mount_opts & EXT2_DEFM_DEBUG) 822 set_opt(sbi->s_mount_opt, DEBUG); 823 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 824 set_opt(sbi->s_mount_opt, GRPID); 825 if (def_mount_opts & EXT2_DEFM_UID16) 826 set_opt(sbi->s_mount_opt, NO_UID32); 827 #ifdef CONFIG_EXT2_FS_XATTR 828 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 829 set_opt(sbi->s_mount_opt, XATTR_USER); 830 #endif 831 #ifdef CONFIG_EXT2_FS_POSIX_ACL 832 if (def_mount_opts & EXT2_DEFM_ACL) 833 set_opt(sbi->s_mount_opt, POSIX_ACL); 834 #endif 835 836 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 837 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 838 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 839 set_opt(sbi->s_mount_opt, ERRORS_CONT); 840 else 841 set_opt(sbi->s_mount_opt, ERRORS_RO); 842 843 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 844 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 845 846 set_opt(sbi->s_mount_opt, RESERVATION); 847 848 if (!parse_options((char *) data, sb)) 849 goto failed_mount; 850 851 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 852 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 853 MS_POSIXACL : 0); 854 855 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 856 EXT2_MOUNT_XIP if not */ 857 858 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 859 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 860 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 861 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 862 ext2_msg(sb, KERN_WARNING, 863 "warning: feature flags set on rev 0 fs, " 864 "running e2fsck is recommended"); 865 /* 866 * Check feature flags regardless of the revision level, since we 867 * previously didn't change the revision level when setting the flags, 868 * so there is a chance incompat flags are set on a rev 0 filesystem. 869 */ 870 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 871 if (features) { 872 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of " 873 "unsupported optional features (%x)", 874 le32_to_cpu(features)); 875 goto failed_mount; 876 } 877 if (!(sb->s_flags & MS_RDONLY) && 878 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 879 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of " 880 "unsupported optional features (%x)", 881 le32_to_cpu(features)); 882 goto failed_mount; 883 } 884 885 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 886 887 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 888 if (!silent) 889 ext2_msg(sb, KERN_ERR, 890 "error: unsupported blocksize for xip"); 891 goto failed_mount; 892 } 893 894 /* If the blocksize doesn't match, re-read the thing.. */ 895 if (sb->s_blocksize != blocksize) { 896 brelse(bh); 897 898 if (!sb_set_blocksize(sb, blocksize)) { 899 ext2_msg(sb, KERN_ERR, "error: blocksize is too small"); 900 goto failed_sbi; 901 } 902 903 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 904 offset = (sb_block*BLOCK_SIZE) % blocksize; 905 bh = sb_bread(sb, logic_sb_block); 906 if(!bh) { 907 ext2_msg(sb, KERN_ERR, "error: couldn't read" 908 "superblock on 2nd try"); 909 goto failed_sbi; 910 } 911 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 912 sbi->s_es = es; 913 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 914 ext2_msg(sb, KERN_ERR, "error: magic mismatch"); 915 goto failed_mount; 916 } 917 } 918 919 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 920 921 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 922 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 923 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 924 } else { 925 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 926 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 927 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 928 !is_power_of_2(sbi->s_inode_size) || 929 (sbi->s_inode_size > blocksize)) { 930 ext2_msg(sb, KERN_ERR, 931 "error: unsupported inode size: %d", 932 sbi->s_inode_size); 933 goto failed_mount; 934 } 935 } 936 937 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 938 le32_to_cpu(es->s_log_frag_size); 939 if (sbi->s_frag_size == 0) 940 goto cantfind_ext2; 941 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 942 943 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 944 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 945 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 946 947 if (EXT2_INODE_SIZE(sb) == 0) 948 goto cantfind_ext2; 949 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 950 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 951 goto cantfind_ext2; 952 sbi->s_itb_per_group = sbi->s_inodes_per_group / 953 sbi->s_inodes_per_block; 954 sbi->s_desc_per_block = sb->s_blocksize / 955 sizeof (struct ext2_group_desc); 956 sbi->s_sbh = bh; 957 sbi->s_mount_state = le16_to_cpu(es->s_state); 958 sbi->s_addr_per_block_bits = 959 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 960 sbi->s_desc_per_block_bits = 961 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 962 963 if (sb->s_magic != EXT2_SUPER_MAGIC) 964 goto cantfind_ext2; 965 966 if (sb->s_blocksize != bh->b_size) { 967 if (!silent) 968 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize"); 969 goto failed_mount; 970 } 971 972 if (sb->s_blocksize != sbi->s_frag_size) { 973 ext2_msg(sb, KERN_ERR, 974 "error: fragsize %lu != blocksize %lu" 975 "(not supported yet)", 976 sbi->s_frag_size, sb->s_blocksize); 977 goto failed_mount; 978 } 979 980 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 981 ext2_msg(sb, KERN_ERR, 982 "error: #blocks per group too big: %lu", 983 sbi->s_blocks_per_group); 984 goto failed_mount; 985 } 986 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 987 ext2_msg(sb, KERN_ERR, 988 "error: #fragments per group too big: %lu", 989 sbi->s_frags_per_group); 990 goto failed_mount; 991 } 992 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 993 ext2_msg(sb, KERN_ERR, 994 "error: #inodes per group too big: %lu", 995 sbi->s_inodes_per_group); 996 goto failed_mount; 997 } 998 999 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 1000 goto cantfind_ext2; 1001 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 1002 le32_to_cpu(es->s_first_data_block) - 1) 1003 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 1004 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 1005 EXT2_DESC_PER_BLOCK(sb); 1006 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 1007 if (sbi->s_group_desc == NULL) { 1008 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1009 goto failed_mount; 1010 } 1011 bgl_lock_init(sbi->s_blockgroup_lock); 1012 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 1013 if (!sbi->s_debts) { 1014 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1015 goto failed_mount_group_desc; 1016 } 1017 for (i = 0; i < db_count; i++) { 1018 block = descriptor_loc(sb, logic_sb_block, i); 1019 sbi->s_group_desc[i] = sb_bread(sb, block); 1020 if (!sbi->s_group_desc[i]) { 1021 for (j = 0; j < i; j++) 1022 brelse (sbi->s_group_desc[j]); 1023 ext2_msg(sb, KERN_ERR, 1024 "error: unable to read group descriptors"); 1025 goto failed_mount_group_desc; 1026 } 1027 } 1028 if (!ext2_check_descriptors (sb)) { 1029 ext2_msg(sb, KERN_ERR, "group descriptors corrupted"); 1030 goto failed_mount2; 1031 } 1032 sbi->s_gdb_count = db_count; 1033 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1034 spin_lock_init(&sbi->s_next_gen_lock); 1035 1036 /* per fileystem reservation list head & lock */ 1037 spin_lock_init(&sbi->s_rsv_window_lock); 1038 sbi->s_rsv_window_root = RB_ROOT; 1039 /* 1040 * Add a single, static dummy reservation to the start of the 1041 * reservation window list --- it gives us a placeholder for 1042 * append-at-start-of-list which makes the allocation logic 1043 * _much_ simpler. 1044 */ 1045 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1046 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1047 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1048 sbi->s_rsv_window_head.rsv_goal_size = 0; 1049 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1050 1051 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1052 ext2_count_free_blocks(sb)); 1053 if (!err) { 1054 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1055 ext2_count_free_inodes(sb)); 1056 } 1057 if (!err) { 1058 err = percpu_counter_init(&sbi->s_dirs_counter, 1059 ext2_count_dirs(sb)); 1060 } 1061 if (err) { 1062 ext2_msg(sb, KERN_ERR, "error: insufficient memory"); 1063 goto failed_mount3; 1064 } 1065 /* 1066 * set up enough so that it can read an inode 1067 */ 1068 sb->s_op = &ext2_sops; 1069 sb->s_export_op = &ext2_export_ops; 1070 sb->s_xattr = ext2_xattr_handlers; 1071 root = ext2_iget(sb, EXT2_ROOT_INO); 1072 if (IS_ERR(root)) { 1073 ret = PTR_ERR(root); 1074 goto failed_mount3; 1075 } 1076 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1077 iput(root); 1078 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck"); 1079 goto failed_mount3; 1080 } 1081 1082 sb->s_root = d_alloc_root(root); 1083 if (!sb->s_root) { 1084 iput(root); 1085 ext2_msg(sb, KERN_ERR, "error: get root inode failed"); 1086 ret = -ENOMEM; 1087 goto failed_mount3; 1088 } 1089 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1090 ext2_msg(sb, KERN_WARNING, 1091 "warning: mounting ext3 filesystem as ext2"); 1092 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY)) 1093 sb->s_flags |= MS_RDONLY; 1094 ext2_write_super(sb); 1095 return 0; 1096 1097 cantfind_ext2: 1098 if (!silent) 1099 ext2_msg(sb, KERN_ERR, 1100 "error: can't find an ext2 filesystem on dev %s.", 1101 sb->s_id); 1102 goto failed_mount; 1103 failed_mount3: 1104 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1105 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1106 percpu_counter_destroy(&sbi->s_dirs_counter); 1107 failed_mount2: 1108 for (i = 0; i < db_count; i++) 1109 brelse(sbi->s_group_desc[i]); 1110 failed_mount_group_desc: 1111 kfree(sbi->s_group_desc); 1112 kfree(sbi->s_debts); 1113 failed_mount: 1114 brelse(bh); 1115 failed_sbi: 1116 sb->s_fs_info = NULL; 1117 kfree(sbi->s_blockgroup_lock); 1118 kfree(sbi); 1119 return ret; 1120 } 1121 1122 static void ext2_clear_super_error(struct super_block *sb) 1123 { 1124 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh; 1125 1126 if (buffer_write_io_error(sbh)) { 1127 /* 1128 * Oh, dear. A previous attempt to write the 1129 * superblock failed. This could happen because the 1130 * USB device was yanked out. Or it could happen to 1131 * be a transient write error and maybe the block will 1132 * be remapped. Nothing we can do but to retry the 1133 * write and hope for the best. 1134 */ 1135 ext2_msg(sb, KERN_ERR, 1136 "previous I/O error to superblock detected\n"); 1137 clear_buffer_write_io_error(sbh); 1138 set_buffer_uptodate(sbh); 1139 } 1140 } 1141 1142 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es, 1143 int wait) 1144 { 1145 ext2_clear_super_error(sb); 1146 spin_lock(&EXT2_SB(sb)->s_lock); 1147 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1148 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1149 es->s_wtime = cpu_to_le32(get_seconds()); 1150 /* unlock before we do IO */ 1151 spin_unlock(&EXT2_SB(sb)->s_lock); 1152 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1153 if (wait) 1154 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1155 sb->s_dirt = 0; 1156 } 1157 1158 /* 1159 * In the second extended file system, it is not necessary to 1160 * write the super block since we use a mapping of the 1161 * disk super block in a buffer. 1162 * 1163 * However, this function is still used to set the fs valid 1164 * flags to 0. We need to set this flag to 0 since the fs 1165 * may have been checked while mounted and e2fsck may have 1166 * set s_state to EXT2_VALID_FS after some corrections. 1167 */ 1168 static int ext2_sync_fs(struct super_block *sb, int wait) 1169 { 1170 struct ext2_sb_info *sbi = EXT2_SB(sb); 1171 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 1172 1173 lock_kernel(); 1174 spin_lock(&sbi->s_lock); 1175 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1176 ext2_debug("setting valid to 0\n"); 1177 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1178 } 1179 spin_unlock(&sbi->s_lock); 1180 ext2_sync_super(sb, es, wait); 1181 unlock_kernel(); 1182 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 lock_kernel(); 1205 spin_lock(&sbi->s_lock); 1206 1207 /* Store the old options */ 1208 old_sb_flags = sb->s_flags; 1209 old_opts.s_mount_opt = sbi->s_mount_opt; 1210 old_opts.s_resuid = sbi->s_resuid; 1211 old_opts.s_resgid = sbi->s_resgid; 1212 1213 /* 1214 * Allow the "check" option to be passed as a remount option. 1215 */ 1216 if (!parse_options(data, sb)) { 1217 err = -EINVAL; 1218 goto restore_opts; 1219 } 1220 1221 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1222 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1223 1224 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1225 EXT2_MOUNT_XIP if not */ 1226 1227 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1228 ext2_msg(sb, KERN_WARNING, 1229 "warning: unsupported blocksize for xip"); 1230 err = -EINVAL; 1231 goto restore_opts; 1232 } 1233 1234 es = sbi->s_es; 1235 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1236 (old_mount_opt & EXT2_MOUNT_XIP)) && 1237 invalidate_inodes(sb)) { 1238 ext2_msg(sb, KERN_WARNING, "warning: refusing change of " 1239 "xip flag with busy inodes while remounting"); 1240 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1241 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1242 } 1243 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1244 spin_unlock(&sbi->s_lock); 1245 unlock_kernel(); 1246 return 0; 1247 } 1248 if (*flags & MS_RDONLY) { 1249 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1250 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1251 spin_unlock(&sbi->s_lock); 1252 unlock_kernel(); 1253 return 0; 1254 } 1255 /* 1256 * OK, we are remounting a valid rw partition rdonly, so set 1257 * the rdonly flag and then mark the partition as valid again. 1258 */ 1259 es->s_state = cpu_to_le16(sbi->s_mount_state); 1260 es->s_mtime = cpu_to_le32(get_seconds()); 1261 spin_unlock(&sbi->s_lock); 1262 ext2_sync_super(sb, es, 1); 1263 } else { 1264 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1265 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1266 if (ret) { 1267 ext2_msg(sb, KERN_WARNING, 1268 "warning: couldn't remount RDWR because of " 1269 "unsupported optional features (%x).", 1270 le32_to_cpu(ret)); 1271 err = -EROFS; 1272 goto restore_opts; 1273 } 1274 /* 1275 * Mounting a RDONLY partition read-write, so reread and 1276 * store the current valid flag. (It may have been changed 1277 * by e2fsck since we originally mounted the partition.) 1278 */ 1279 sbi->s_mount_state = le16_to_cpu(es->s_state); 1280 if (!ext2_setup_super (sb, es, 0)) 1281 sb->s_flags &= ~MS_RDONLY; 1282 spin_unlock(&sbi->s_lock); 1283 ext2_write_super(sb); 1284 } 1285 unlock_kernel(); 1286 return 0; 1287 restore_opts: 1288 sbi->s_mount_opt = old_opts.s_mount_opt; 1289 sbi->s_resuid = old_opts.s_resuid; 1290 sbi->s_resgid = old_opts.s_resgid; 1291 sb->s_flags = old_sb_flags; 1292 spin_unlock(&sbi->s_lock); 1293 unlock_kernel(); 1294 return err; 1295 } 1296 1297 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1298 { 1299 struct super_block *sb = dentry->d_sb; 1300 struct ext2_sb_info *sbi = EXT2_SB(sb); 1301 struct ext2_super_block *es = sbi->s_es; 1302 u64 fsid; 1303 1304 spin_lock(&sbi->s_lock); 1305 1306 if (test_opt (sb, MINIX_DF)) 1307 sbi->s_overhead_last = 0; 1308 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1309 unsigned long i, overhead = 0; 1310 smp_rmb(); 1311 1312 /* 1313 * Compute the overhead (FS structures). This is constant 1314 * for a given filesystem unless the number of block groups 1315 * changes so we cache the previous value until it does. 1316 */ 1317 1318 /* 1319 * All of the blocks before first_data_block are 1320 * overhead 1321 */ 1322 overhead = le32_to_cpu(es->s_first_data_block); 1323 1324 /* 1325 * Add the overhead attributed to the superblock and 1326 * block group descriptors. If the sparse superblocks 1327 * feature is turned on, then not all groups have this. 1328 */ 1329 for (i = 0; i < sbi->s_groups_count; i++) 1330 overhead += ext2_bg_has_super(sb, i) + 1331 ext2_bg_num_gdb(sb, i); 1332 1333 /* 1334 * Every block group has an inode bitmap, a block 1335 * bitmap, and an inode table. 1336 */ 1337 overhead += (sbi->s_groups_count * 1338 (2 + sbi->s_itb_per_group)); 1339 sbi->s_overhead_last = overhead; 1340 smp_wmb(); 1341 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1342 } 1343 1344 buf->f_type = EXT2_SUPER_MAGIC; 1345 buf->f_bsize = sb->s_blocksize; 1346 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1347 buf->f_bfree = ext2_count_free_blocks(sb); 1348 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1349 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1350 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1351 buf->f_bavail = 0; 1352 buf->f_files = le32_to_cpu(es->s_inodes_count); 1353 buf->f_ffree = ext2_count_free_inodes(sb); 1354 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1355 buf->f_namelen = EXT2_NAME_LEN; 1356 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1357 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1358 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1359 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1360 spin_unlock(&sbi->s_lock); 1361 return 0; 1362 } 1363 1364 static int ext2_get_sb(struct file_system_type *fs_type, 1365 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1366 { 1367 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1368 } 1369 1370 #ifdef CONFIG_QUOTA 1371 1372 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1373 * acquiring the locks... As quota files are never truncated and quota code 1374 * itself serializes the operations (and noone else should touch the files) 1375 * we don't have to be afraid of races */ 1376 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1377 size_t len, loff_t off) 1378 { 1379 struct inode *inode = sb_dqopt(sb)->files[type]; 1380 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1381 int err = 0; 1382 int offset = off & (sb->s_blocksize - 1); 1383 int tocopy; 1384 size_t toread; 1385 struct buffer_head tmp_bh; 1386 struct buffer_head *bh; 1387 loff_t i_size = i_size_read(inode); 1388 1389 if (off > i_size) 1390 return 0; 1391 if (off+len > i_size) 1392 len = i_size-off; 1393 toread = len; 1394 while (toread > 0) { 1395 tocopy = sb->s_blocksize - offset < toread ? 1396 sb->s_blocksize - offset : toread; 1397 1398 tmp_bh.b_state = 0; 1399 tmp_bh.b_size = sb->s_blocksize; 1400 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1401 if (err < 0) 1402 return err; 1403 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1404 memset(data, 0, tocopy); 1405 else { 1406 bh = sb_bread(sb, tmp_bh.b_blocknr); 1407 if (!bh) 1408 return -EIO; 1409 memcpy(data, bh->b_data+offset, tocopy); 1410 brelse(bh); 1411 } 1412 offset = 0; 1413 toread -= tocopy; 1414 data += tocopy; 1415 blk++; 1416 } 1417 return len; 1418 } 1419 1420 /* Write to quotafile */ 1421 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1422 const char *data, size_t len, loff_t off) 1423 { 1424 struct inode *inode = sb_dqopt(sb)->files[type]; 1425 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1426 int err = 0; 1427 int offset = off & (sb->s_blocksize - 1); 1428 int tocopy; 1429 size_t towrite = len; 1430 struct buffer_head tmp_bh; 1431 struct buffer_head *bh; 1432 1433 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1434 while (towrite > 0) { 1435 tocopy = sb->s_blocksize - offset < towrite ? 1436 sb->s_blocksize - offset : towrite; 1437 1438 tmp_bh.b_state = 0; 1439 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1440 if (err < 0) 1441 goto out; 1442 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1443 bh = sb_bread(sb, tmp_bh.b_blocknr); 1444 else 1445 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1446 if (!bh) { 1447 err = -EIO; 1448 goto out; 1449 } 1450 lock_buffer(bh); 1451 memcpy(bh->b_data+offset, data, tocopy); 1452 flush_dcache_page(bh->b_page); 1453 set_buffer_uptodate(bh); 1454 mark_buffer_dirty(bh); 1455 unlock_buffer(bh); 1456 brelse(bh); 1457 offset = 0; 1458 towrite -= tocopy; 1459 data += tocopy; 1460 blk++; 1461 } 1462 out: 1463 if (len == towrite) { 1464 mutex_unlock(&inode->i_mutex); 1465 return err; 1466 } 1467 if (inode->i_size < off+len-towrite) 1468 i_size_write(inode, off+len-towrite); 1469 inode->i_version++; 1470 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1471 mark_inode_dirty(inode); 1472 mutex_unlock(&inode->i_mutex); 1473 return len - towrite; 1474 } 1475 1476 #endif 1477 1478 static struct file_system_type ext2_fs_type = { 1479 .owner = THIS_MODULE, 1480 .name = "ext2", 1481 .get_sb = ext2_get_sb, 1482 .kill_sb = kill_block_super, 1483 .fs_flags = FS_REQUIRES_DEV, 1484 }; 1485 1486 static int __init init_ext2_fs(void) 1487 { 1488 int err = init_ext2_xattr(); 1489 if (err) 1490 return err; 1491 err = init_inodecache(); 1492 if (err) 1493 goto out1; 1494 err = register_filesystem(&ext2_fs_type); 1495 if (err) 1496 goto out; 1497 return 0; 1498 out: 1499 destroy_inodecache(); 1500 out1: 1501 exit_ext2_xattr(); 1502 return err; 1503 } 1504 1505 static void __exit exit_ext2_fs(void) 1506 { 1507 unregister_filesystem(&ext2_fs_type); 1508 destroy_inodecache(); 1509 exit_ext2_xattr(); 1510 } 1511 1512 module_init(init_ext2_fs) 1513 module_exit(exit_ext2_fs) 1514