1 /* 2 * linux/fs/ext2/super.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/inode.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * Big-endian to little-endian byte-swapping/bitmaps by 16 * David S. Miller (davem@caip.rutgers.edu), 1995 17 */ 18 19 #include <linux/module.h> 20 #include <linux/string.h> 21 #include <linux/fs.h> 22 #include <linux/slab.h> 23 #include <linux/init.h> 24 #include <linux/blkdev.h> 25 #include <linux/parser.h> 26 #include <linux/random.h> 27 #include <linux/buffer_head.h> 28 #include <linux/exportfs.h> 29 #include <linux/vfs.h> 30 #include <linux/seq_file.h> 31 #include <linux/mount.h> 32 #include <linux/log2.h> 33 #include <linux/quotaops.h> 34 #include <asm/uaccess.h> 35 #include "ext2.h" 36 #include "xattr.h" 37 #include "acl.h" 38 #include "xip.h" 39 40 static void ext2_sync_super(struct super_block *sb, 41 struct ext2_super_block *es, int wait); 42 static int ext2_remount (struct super_block * sb, int * flags, char * data); 43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); 44 static int ext2_sync_fs(struct super_block *sb, int wait); 45 46 void ext2_error (struct super_block * sb, const char * function, 47 const char * fmt, ...) 48 { 49 va_list args; 50 struct ext2_sb_info *sbi = EXT2_SB(sb); 51 struct ext2_super_block *es = sbi->s_es; 52 53 if (!(sb->s_flags & MS_RDONLY)) { 54 spin_lock(&sbi->s_lock); 55 sbi->s_mount_state |= EXT2_ERROR_FS; 56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS); 57 spin_unlock(&sbi->s_lock); 58 ext2_sync_super(sb, es, 1); 59 } 60 61 va_start(args, fmt); 62 printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function); 63 vprintk(fmt, args); 64 printk("\n"); 65 va_end(args); 66 67 if (test_opt(sb, ERRORS_PANIC)) 68 panic("EXT2-fs: panic from previous error\n"); 69 if (test_opt(sb, ERRORS_RO)) { 70 ext2_msg(sb, KERN_CRIT, 71 "error: remounting filesystem read-only"); 72 sb->s_flags |= MS_RDONLY; 73 } 74 } 75 76 void ext2_msg(struct super_block *sb, const char *prefix, 77 const char *fmt, ...) 78 { 79 va_list args; 80 81 va_start(args, fmt); 82 printk("%sEXT2-fs (%s): ", prefix, sb->s_id); 83 vprintk(fmt, args); 84 printk("\n"); 85 va_end(args); 86 } 87 88 /* 89 * This must be called with sbi->s_lock held. 90 */ 91 void ext2_update_dynamic_rev(struct super_block *sb) 92 { 93 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 94 95 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) 96 return; 97 98 ext2_msg(sb, KERN_WARNING, 99 "warning: updating to rev %d because of " 100 "new feature flag, running e2fsck is recommended", 101 EXT2_DYNAMIC_REV); 102 103 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); 104 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); 105 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); 106 /* leave es->s_feature_*compat flags alone */ 107 /* es->s_uuid will be set by e2fsck if empty */ 108 109 /* 110 * The rest of the superblock fields should be zero, and if not it 111 * means they are likely already in use, so leave them alone. We 112 * can leave it up to e2fsck to clean up any inconsistencies there. 113 */ 114 } 115 116 static void ext2_put_super (struct super_block * sb) 117 { 118 int db_count; 119 int i; 120 struct ext2_sb_info *sbi = EXT2_SB(sb); 121 122 if (sb->s_dirt) 123 ext2_write_super(sb); 124 125 ext2_xattr_put_super(sb); 126 if (!(sb->s_flags & MS_RDONLY)) { 127 struct ext2_super_block *es = sbi->s_es; 128 129 spin_lock(&sbi->s_lock); 130 es->s_state = cpu_to_le16(sbi->s_mount_state); 131 spin_unlock(&sbi->s_lock); 132 ext2_sync_super(sb, es, 1); 133 } 134 db_count = sbi->s_gdb_count; 135 for (i = 0; i < db_count; i++) 136 if (sbi->s_group_desc[i]) 137 brelse (sbi->s_group_desc[i]); 138 kfree(sbi->s_group_desc); 139 kfree(sbi->s_debts); 140 percpu_counter_destroy(&sbi->s_freeblocks_counter); 141 percpu_counter_destroy(&sbi->s_freeinodes_counter); 142 percpu_counter_destroy(&sbi->s_dirs_counter); 143 brelse (sbi->s_sbh); 144 sb->s_fs_info = NULL; 145 kfree(sbi->s_blockgroup_lock); 146 kfree(sbi); 147 } 148 149 static struct kmem_cache * ext2_inode_cachep; 150 151 static struct inode *ext2_alloc_inode(struct super_block *sb) 152 { 153 struct ext2_inode_info *ei; 154 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 155 if (!ei) 156 return NULL; 157 ei->i_block_alloc_info = NULL; 158 ei->vfs_inode.i_version = 1; 159 return &ei->vfs_inode; 160 } 161 162 static void ext2_destroy_inode(struct inode *inode) 163 { 164 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 165 } 166 167 static void init_once(void *foo) 168 { 169 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 170 171 rwlock_init(&ei->i_meta_lock); 172 #ifdef CONFIG_EXT2_FS_XATTR 173 init_rwsem(&ei->xattr_sem); 174 #endif 175 mutex_init(&ei->truncate_mutex); 176 inode_init_once(&ei->vfs_inode); 177 } 178 179 static int init_inodecache(void) 180 { 181 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 182 sizeof(struct ext2_inode_info), 183 0, (SLAB_RECLAIM_ACCOUNT| 184 SLAB_MEM_SPREAD), 185 init_once); 186 if (ext2_inode_cachep == NULL) 187 return -ENOMEM; 188 return 0; 189 } 190 191 static void destroy_inodecache(void) 192 { 193 kmem_cache_destroy(ext2_inode_cachep); 194 } 195 196 static void ext2_clear_inode(struct inode *inode) 197 { 198 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 199 200 dquot_drop(inode); 201 ext2_discard_reservation(inode); 202 EXT2_I(inode)->i_block_alloc_info = NULL; 203 if (unlikely(rsv)) 204 kfree(rsv); 205 } 206 207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) 208 { 209 struct super_block *sb = vfs->mnt_sb; 210 struct ext2_sb_info *sbi = EXT2_SB(sb); 211 struct ext2_super_block *es = sbi->s_es; 212 unsigned long def_mount_opts; 213 214 spin_lock(&sbi->s_lock); 215 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 216 217 if (sbi->s_sb_block != 1) 218 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 219 if (test_opt(sb, MINIX_DF)) 220 seq_puts(seq, ",minixdf"); 221 if (test_opt(sb, GRPID)) 222 seq_puts(seq, ",grpid"); 223 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 224 seq_puts(seq, ",nogrpid"); 225 if (sbi->s_resuid != EXT2_DEF_RESUID || 226 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 227 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 228 } 229 if (sbi->s_resgid != EXT2_DEF_RESGID || 230 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 231 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 232 } 233 if (test_opt(sb, ERRORS_RO)) { 234 int def_errors = le16_to_cpu(es->s_errors); 235 236 if (def_errors == EXT2_ERRORS_PANIC || 237 def_errors == EXT2_ERRORS_CONTINUE) { 238 seq_puts(seq, ",errors=remount-ro"); 239 } 240 } 241 if (test_opt(sb, ERRORS_CONT)) 242 seq_puts(seq, ",errors=continue"); 243 if (test_opt(sb, ERRORS_PANIC)) 244 seq_puts(seq, ",errors=panic"); 245 if (test_opt(sb, NO_UID32)) 246 seq_puts(seq, ",nouid32"); 247 if (test_opt(sb, DEBUG)) 248 seq_puts(seq, ",debug"); 249 if (test_opt(sb, OLDALLOC)) 250 seq_puts(seq, ",oldalloc"); 251 252 #ifdef CONFIG_EXT2_FS_XATTR 253 if (test_opt(sb, XATTR_USER)) 254 seq_puts(seq, ",user_xattr"); 255 if (!test_opt(sb, XATTR_USER) && 256 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 257 seq_puts(seq, ",nouser_xattr"); 258 } 259 #endif 260 261 #ifdef CONFIG_EXT2_FS_POSIX_ACL 262 if (test_opt(sb, POSIX_ACL)) 263 seq_puts(seq, ",acl"); 264 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 265 seq_puts(seq, ",noacl"); 266 #endif 267 268 if (test_opt(sb, NOBH)) 269 seq_puts(seq, ",nobh"); 270 271 #if defined(CONFIG_QUOTA) 272 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 273 seq_puts(seq, ",usrquota"); 274 275 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 276 seq_puts(seq, ",grpquota"); 277 #endif 278 279 #if defined(CONFIG_EXT2_FS_XIP) 280 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 281 seq_puts(seq, ",xip"); 282 #endif 283 284 if (!test_opt(sb, RESERVATION)) 285 seq_puts(seq, ",noreservation"); 286 287 spin_unlock(&sbi->s_lock); 288 return 0; 289 } 290 291 #ifdef CONFIG_QUOTA 292 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); 293 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); 294 #endif 295 296 static const struct super_operations ext2_sops = { 297 .alloc_inode = ext2_alloc_inode, 298 .destroy_inode = ext2_destroy_inode, 299 .write_inode = ext2_write_inode, 300 .delete_inode = ext2_delete_inode, 301 .put_super = ext2_put_super, 302 .write_super = ext2_write_super, 303 .sync_fs = ext2_sync_fs, 304 .statfs = ext2_statfs, 305 .remount_fs = ext2_remount, 306 .clear_inode = ext2_clear_inode, 307 .show_options = ext2_show_options, 308 #ifdef CONFIG_QUOTA 309 .quota_read = ext2_quota_read, 310 .quota_write = ext2_quota_write, 311 #endif 312 }; 313 314 static struct inode *ext2_nfs_get_inode(struct super_block *sb, 315 u64 ino, u32 generation) 316 { 317 struct inode *inode; 318 319 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO) 320 return ERR_PTR(-ESTALE); 321 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 322 return ERR_PTR(-ESTALE); 323 324 /* iget isn't really right if the inode is currently unallocated!! 325 * ext2_read_inode currently does appropriate checks, but 326 * it might be "neater" to call ext2_get_inode first and check 327 * if the inode is valid..... 328 */ 329 inode = ext2_iget(sb, ino); 330 if (IS_ERR(inode)) 331 return ERR_CAST(inode); 332 if (generation && inode->i_generation != generation) { 333 /* we didn't find the right inode.. */ 334 iput(inode); 335 return ERR_PTR(-ESTALE); 336 } 337 return inode; 338 } 339 340 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 341 int fh_len, int fh_type) 342 { 343 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 344 ext2_nfs_get_inode); 345 } 346 347 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 348 int fh_len, int fh_type) 349 { 350 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 351 ext2_nfs_get_inode); 352 } 353 354 /* Yes, most of these are left as NULL!! 355 * A NULL value implies the default, which works with ext2-like file 356 * systems, but can be improved upon. 357 * Currently only get_parent is required. 358 */ 359 static const struct export_operations ext2_export_ops = { 360 .fh_to_dentry = ext2_fh_to_dentry, 361 .fh_to_parent = ext2_fh_to_parent, 362 .get_parent = ext2_get_parent, 363 }; 364 365 static unsigned long get_sb_block(void **data) 366 { 367 unsigned long sb_block; 368 char *options = (char *) *data; 369 370 if (!options || strncmp(options, "sb=", 3) != 0) 371 return 1; /* Default location */ 372 options += 3; 373 sb_block = simple_strtoul(options, &options, 0); 374 if (*options && *options != ',') { 375 printk("EXT2-fs: Invalid sb specification: %s\n", 376 (char *) *data); 377 return 1; 378 } 379 if (*options == ',') 380 options++; 381 *data = (void *) options; 382 return sb_block; 383 } 384 385 enum { 386 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 387 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 388 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 389 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 390 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 391 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 392 }; 393 394 static const match_table_t tokens = { 395 {Opt_bsd_df, "bsddf"}, 396 {Opt_minix_df, "minixdf"}, 397 {Opt_grpid, "grpid"}, 398 {Opt_grpid, "bsdgroups"}, 399 {Opt_nogrpid, "nogrpid"}, 400 {Opt_nogrpid, "sysvgroups"}, 401 {Opt_resgid, "resgid=%u"}, 402 {Opt_resuid, "resuid=%u"}, 403 {Opt_sb, "sb=%u"}, 404 {Opt_err_cont, "errors=continue"}, 405 {Opt_err_panic, "errors=panic"}, 406 {Opt_err_ro, "errors=remount-ro"}, 407 {Opt_nouid32, "nouid32"}, 408 {Opt_nocheck, "check=none"}, 409 {Opt_nocheck, "nocheck"}, 410 {Opt_debug, "debug"}, 411 {Opt_oldalloc, "oldalloc"}, 412 {Opt_orlov, "orlov"}, 413 {Opt_nobh, "nobh"}, 414 {Opt_user_xattr, "user_xattr"}, 415 {Opt_nouser_xattr, "nouser_xattr"}, 416 {Opt_acl, "acl"}, 417 {Opt_noacl, "noacl"}, 418 {Opt_xip, "xip"}, 419 {Opt_grpquota, "grpquota"}, 420 {Opt_ignore, "noquota"}, 421 {Opt_quota, "quota"}, 422 {Opt_usrquota, "usrquota"}, 423 {Opt_reservation, "reservation"}, 424 {Opt_noreservation, "noreservation"}, 425 {Opt_err, NULL} 426 }; 427 428 static int parse_options(char *options, struct super_block *sb) 429 { 430 char *p; 431 struct ext2_sb_info *sbi = EXT2_SB(sb); 432 substring_t args[MAX_OPT_ARGS]; 433 int option; 434 435 if (!options) 436 return 1; 437 438 while ((p = strsep (&options, ",")) != NULL) { 439 int token; 440 if (!*p) 441 continue; 442 443 token = match_token(p, tokens, args); 444 switch (token) { 445 case Opt_bsd_df: 446 clear_opt (sbi->s_mount_opt, MINIX_DF); 447 break; 448 case Opt_minix_df: 449 set_opt (sbi->s_mount_opt, MINIX_DF); 450 break; 451 case Opt_grpid: 452 set_opt (sbi->s_mount_opt, GRPID); 453 break; 454 case Opt_nogrpid: 455 clear_opt (sbi->s_mount_opt, GRPID); 456 break; 457 case Opt_resuid: 458 if (match_int(&args[0], &option)) 459 return 0; 460 sbi->s_resuid = option; 461 break; 462 case Opt_resgid: 463 if (match_int(&args[0], &option)) 464 return 0; 465 sbi->s_resgid = option; 466 break; 467 case Opt_sb: 468 /* handled by get_sb_block() instead of here */ 469 /* *sb_block = match_int(&args[0]); */ 470 break; 471 case Opt_err_panic: 472 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 473 clear_opt (sbi->s_mount_opt, ERRORS_RO); 474 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 475 break; 476 case Opt_err_ro: 477 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 478 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 479 set_opt (sbi->s_mount_opt, ERRORS_RO); 480 break; 481 case Opt_err_cont: 482 clear_opt (sbi->s_mount_opt, ERRORS_RO); 483 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 484 set_opt (sbi->s_mount_opt, ERRORS_CONT); 485 break; 486 case Opt_nouid32: 487 set_opt (sbi->s_mount_opt, NO_UID32); 488 break; 489 case Opt_nocheck: 490 clear_opt (sbi->s_mount_opt, CHECK); 491 break; 492 case Opt_debug: 493 set_opt (sbi->s_mount_opt, DEBUG); 494 break; 495 case Opt_oldalloc: 496 set_opt (sbi->s_mount_opt, OLDALLOC); 497 break; 498 case Opt_orlov: 499 clear_opt (sbi->s_mount_opt, OLDALLOC); 500 break; 501 case Opt_nobh: 502 set_opt (sbi->s_mount_opt, NOBH); 503 break; 504 #ifdef CONFIG_EXT2_FS_XATTR 505 case Opt_user_xattr: 506 set_opt (sbi->s_mount_opt, XATTR_USER); 507 break; 508 case Opt_nouser_xattr: 509 clear_opt (sbi->s_mount_opt, XATTR_USER); 510 break; 511 #else 512 case Opt_user_xattr: 513 case Opt_nouser_xattr: 514 ext2_msg(sb, KERN_INFO, "(no)user_xattr options" 515 "not supported"); 516 break; 517 #endif 518 #ifdef CONFIG_EXT2_FS_POSIX_ACL 519 case Opt_acl: 520 set_opt(sbi->s_mount_opt, POSIX_ACL); 521 break; 522 case Opt_noacl: 523 clear_opt(sbi->s_mount_opt, POSIX_ACL); 524 break; 525 #else 526 case Opt_acl: 527 case Opt_noacl: 528 ext2_msg(sb, KERN_INFO, 529 "(no)acl options not supported"); 530 break; 531 #endif 532 case Opt_xip: 533 #ifdef CONFIG_EXT2_FS_XIP 534 set_opt (sbi->s_mount_opt, XIP); 535 #else 536 ext2_msg(sb, KERN_INFO, "xip option not supported"); 537 #endif 538 break; 539 540 #if defined(CONFIG_QUOTA) 541 case Opt_quota: 542 case Opt_usrquota: 543 set_opt(sbi->s_mount_opt, USRQUOTA); 544 break; 545 546 case Opt_grpquota: 547 set_opt(sbi->s_mount_opt, GRPQUOTA); 548 break; 549 #else 550 case Opt_quota: 551 case Opt_usrquota: 552 case Opt_grpquota: 553 ext2_msg(sb, KERN_INFO, 554 "quota operations not supported"); 555 break; 556 #endif 557 558 case Opt_reservation: 559 set_opt(sbi->s_mount_opt, RESERVATION); 560 ext2_msg(sb, KERN_INFO, "reservations ON"); 561 break; 562 case Opt_noreservation: 563 clear_opt(sbi->s_mount_opt, RESERVATION); 564 ext2_msg(sb, KERN_INFO, "reservations OFF"); 565 break; 566 case Opt_ignore: 567 break; 568 default: 569 return 0; 570 } 571 } 572 return 1; 573 } 574 575 static int ext2_setup_super (struct super_block * sb, 576 struct ext2_super_block * es, 577 int read_only) 578 { 579 int res = 0; 580 struct ext2_sb_info *sbi = EXT2_SB(sb); 581 582 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { 583 ext2_msg(sb, KERN_ERR, 584 "error: revision level too high, " 585 "forcing read-only mode"); 586 res = MS_RDONLY; 587 } 588 if (read_only) 589 return res; 590 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 591 ext2_msg(sb, KERN_WARNING, 592 "warning: mounting unchecked fs, " 593 "running e2fsck is recommended"); 594 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 595 ext2_msg(sb, KERN_WARNING, 596 "warning: mounting fs with errors, " 597 "running e2fsck is recommended"); 598 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 599 le16_to_cpu(es->s_mnt_count) >= 600 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 601 ext2_msg(sb, KERN_WARNING, 602 "warning: maximal mount count reached, " 603 "running e2fsck is recommended"); 604 else if (le32_to_cpu(es->s_checkinterval) && 605 (le32_to_cpu(es->s_lastcheck) + 606 le32_to_cpu(es->s_checkinterval) <= get_seconds())) 607 ext2_msg(sb, KERN_WARNING, 608 "warning: checktime reached, " 609 "running e2fsck is recommended"); 610 if (!le16_to_cpu(es->s_max_mnt_count)) 611 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 612 le16_add_cpu(&es->s_mnt_count, 1); 613 if (test_opt (sb, DEBUG)) 614 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, " 615 "bpg=%lu, ipg=%lu, mo=%04lx]", 616 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 617 sbi->s_frag_size, 618 sbi->s_groups_count, 619 EXT2_BLOCKS_PER_GROUP(sb), 620 EXT2_INODES_PER_GROUP(sb), 621 sbi->s_mount_opt); 622 return res; 623 } 624 625 static int ext2_check_descriptors(struct super_block *sb) 626 { 627 int i; 628 struct ext2_sb_info *sbi = EXT2_SB(sb); 629 630 ext2_debug ("Checking group descriptors"); 631 632 for (i = 0; i < sbi->s_groups_count; i++) { 633 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); 634 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); 635 ext2_fsblk_t last_block; 636 637 if (i == sbi->s_groups_count - 1) 638 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 639 else 640 last_block = first_block + 641 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 642 643 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 644 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 645 { 646 ext2_error (sb, "ext2_check_descriptors", 647 "Block bitmap for group %d" 648 " not in group (block %lu)!", 649 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 650 return 0; 651 } 652 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 653 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 654 { 655 ext2_error (sb, "ext2_check_descriptors", 656 "Inode bitmap for group %d" 657 " not in group (block %lu)!", 658 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 659 return 0; 660 } 661 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 662 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 663 last_block) 664 { 665 ext2_error (sb, "ext2_check_descriptors", 666 "Inode table for group %d" 667 " not in group (block %lu)!", 668 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 669 return 0; 670 } 671 } 672 return 1; 673 } 674 675 /* 676 * Maximal file size. There is a direct, and {,double-,triple-}indirect 677 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 678 * We need to be 1 filesystem block less than the 2^32 sector limit. 679 */ 680 static loff_t ext2_max_size(int bits) 681 { 682 loff_t res = EXT2_NDIR_BLOCKS; 683 int meta_blocks; 684 loff_t upper_limit; 685 686 /* This is calculated to be the largest file size for a 687 * dense, file such that the total number of 688 * sectors in the file, including data and all indirect blocks, 689 * does not exceed 2^32 -1 690 * __u32 i_blocks representing the total number of 691 * 512 bytes blocks of the file 692 */ 693 upper_limit = (1LL << 32) - 1; 694 695 /* total blocks in file system block size */ 696 upper_limit >>= (bits - 9); 697 698 699 /* indirect blocks */ 700 meta_blocks = 1; 701 /* double indirect blocks */ 702 meta_blocks += 1 + (1LL << (bits-2)); 703 /* tripple indirect blocks */ 704 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 705 706 upper_limit -= meta_blocks; 707 upper_limit <<= bits; 708 709 res += 1LL << (bits-2); 710 res += 1LL << (2*(bits-2)); 711 res += 1LL << (3*(bits-2)); 712 res <<= bits; 713 if (res > upper_limit) 714 res = upper_limit; 715 716 if (res > MAX_LFS_FILESIZE) 717 res = MAX_LFS_FILESIZE; 718 719 return res; 720 } 721 722 static unsigned long descriptor_loc(struct super_block *sb, 723 unsigned long logic_sb_block, 724 int nr) 725 { 726 struct ext2_sb_info *sbi = EXT2_SB(sb); 727 unsigned long bg, first_meta_bg; 728 int has_super = 0; 729 730 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); 731 732 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || 733 nr < first_meta_bg) 734 return (logic_sb_block + nr + 1); 735 bg = sbi->s_desc_per_block * nr; 736 if (ext2_bg_has_super(sb, bg)) 737 has_super = 1; 738 739 return ext2_group_first_block_no(sb, bg) + has_super; 740 } 741 742 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 743 { 744 struct buffer_head * bh; 745 struct ext2_sb_info * sbi; 746 struct ext2_super_block * es; 747 struct inode *root; 748 unsigned long block; 749 unsigned long sb_block = get_sb_block(&data); 750 unsigned long logic_sb_block; 751 unsigned long offset = 0; 752 unsigned long def_mount_opts; 753 long ret = -EINVAL; 754 int blocksize = BLOCK_SIZE; 755 int db_count; 756 int i, j; 757 __le32 features; 758 int err; 759 760 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 761 if (!sbi) 762 return -ENOMEM; 763 764 sbi->s_blockgroup_lock = 765 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); 766 if (!sbi->s_blockgroup_lock) { 767 kfree(sbi); 768 return -ENOMEM; 769 } 770 sb->s_fs_info = sbi; 771 sbi->s_sb_block = sb_block; 772 773 spin_lock_init(&sbi->s_lock); 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 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize"); 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 ext2_msg(sb, KERN_ERR, "error: unable to read superblock"); 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, sb)) 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 ext2_msg(sb, KERN_WARNING, 858 "warning: feature flags set on rev 0 fs, " 859 "running e2fsck is recommended"); 860 /* 861 * Check feature flags regardless of the revision level, since we 862 * previously didn't change the revision level when setting the flags, 863 * so there is a chance incompat flags are set on a rev 0 filesystem. 864 */ 865 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 866 if (features) { 867 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of " 868 "unsupported optional features (%x)", 869 le32_to_cpu(features)); 870 goto failed_mount; 871 } 872 if (!(sb->s_flags & MS_RDONLY) && 873 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 874 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of " 875 "unsupported optional features (%x)", 876 le32_to_cpu(features)); 877 goto failed_mount; 878 } 879 880 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 881 882 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 883 if (!silent) 884 ext2_msg(sb, KERN_ERR, 885 "error: unsupported blocksize for xip"); 886 goto failed_mount; 887 } 888 889 /* If the blocksize doesn't match, re-read the thing.. */ 890 if (sb->s_blocksize != blocksize) { 891 brelse(bh); 892 893 if (!sb_set_blocksize(sb, blocksize)) { 894 ext2_msg(sb, KERN_ERR, "error: blocksize is too small"); 895 goto failed_sbi; 896 } 897 898 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 899 offset = (sb_block*BLOCK_SIZE) % blocksize; 900 bh = sb_bread(sb, logic_sb_block); 901 if(!bh) { 902 ext2_msg(sb, KERN_ERR, "error: couldn't read" 903 "superblock on 2nd try"); 904 goto failed_sbi; 905 } 906 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 907 sbi->s_es = es; 908 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 909 ext2_msg(sb, KERN_ERR, "error: magic mismatch"); 910 goto failed_mount; 911 } 912 } 913 914 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 915 916 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 917 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 918 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 919 } else { 920 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 921 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 922 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 923 !is_power_of_2(sbi->s_inode_size) || 924 (sbi->s_inode_size > blocksize)) { 925 ext2_msg(sb, KERN_ERR, 926 "error: unsupported inode size: %d", 927 sbi->s_inode_size); 928 goto failed_mount; 929 } 930 } 931 932 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 933 le32_to_cpu(es->s_log_frag_size); 934 if (sbi->s_frag_size == 0) 935 goto cantfind_ext2; 936 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 937 938 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 939 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 940 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 941 942 if (EXT2_INODE_SIZE(sb) == 0) 943 goto cantfind_ext2; 944 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 945 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 946 goto cantfind_ext2; 947 sbi->s_itb_per_group = sbi->s_inodes_per_group / 948 sbi->s_inodes_per_block; 949 sbi->s_desc_per_block = sb->s_blocksize / 950 sizeof (struct ext2_group_desc); 951 sbi->s_sbh = bh; 952 sbi->s_mount_state = le16_to_cpu(es->s_state); 953 sbi->s_addr_per_block_bits = 954 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 955 sbi->s_desc_per_block_bits = 956 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 957 958 if (sb->s_magic != EXT2_SUPER_MAGIC) 959 goto cantfind_ext2; 960 961 if (sb->s_blocksize != bh->b_size) { 962 if (!silent) 963 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize"); 964 goto failed_mount; 965 } 966 967 if (sb->s_blocksize != sbi->s_frag_size) { 968 ext2_msg(sb, KERN_ERR, 969 "error: fragsize %lu != blocksize %lu" 970 "(not supported yet)", 971 sbi->s_frag_size, sb->s_blocksize); 972 goto failed_mount; 973 } 974 975 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 976 ext2_msg(sb, KERN_ERR, 977 "error: #blocks per group too big: %lu", 978 sbi->s_blocks_per_group); 979 goto failed_mount; 980 } 981 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 982 ext2_msg(sb, KERN_ERR, 983 "error: #fragments per group too big: %lu", 984 sbi->s_frags_per_group); 985 goto failed_mount; 986 } 987 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 988 ext2_msg(sb, KERN_ERR, 989 "error: #inodes per group too big: %lu", 990 sbi->s_inodes_per_group); 991 goto failed_mount; 992 } 993 994 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 995 goto cantfind_ext2; 996 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 997 le32_to_cpu(es->s_first_data_block) - 1) 998 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 999 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 1000 EXT2_DESC_PER_BLOCK(sb); 1001 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 1002 if (sbi->s_group_desc == NULL) { 1003 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1004 goto failed_mount; 1005 } 1006 bgl_lock_init(sbi->s_blockgroup_lock); 1007 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 1008 if (!sbi->s_debts) { 1009 ext2_msg(sb, KERN_ERR, "error: not enough memory"); 1010 goto failed_mount_group_desc; 1011 } 1012 for (i = 0; i < db_count; i++) { 1013 block = descriptor_loc(sb, logic_sb_block, i); 1014 sbi->s_group_desc[i] = sb_bread(sb, block); 1015 if (!sbi->s_group_desc[i]) { 1016 for (j = 0; j < i; j++) 1017 brelse (sbi->s_group_desc[j]); 1018 ext2_msg(sb, KERN_ERR, 1019 "error: unable to read group descriptors"); 1020 goto failed_mount_group_desc; 1021 } 1022 } 1023 if (!ext2_check_descriptors (sb)) { 1024 ext2_msg(sb, KERN_ERR, "group descriptors corrupted"); 1025 goto failed_mount2; 1026 } 1027 sbi->s_gdb_count = db_count; 1028 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1029 spin_lock_init(&sbi->s_next_gen_lock); 1030 1031 /* per fileystem reservation list head & lock */ 1032 spin_lock_init(&sbi->s_rsv_window_lock); 1033 sbi->s_rsv_window_root = RB_ROOT; 1034 /* 1035 * Add a single, static dummy reservation to the start of the 1036 * reservation window list --- it gives us a placeholder for 1037 * append-at-start-of-list which makes the allocation logic 1038 * _much_ simpler. 1039 */ 1040 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1041 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1042 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1043 sbi->s_rsv_window_head.rsv_goal_size = 0; 1044 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1045 1046 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1047 ext2_count_free_blocks(sb)); 1048 if (!err) { 1049 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1050 ext2_count_free_inodes(sb)); 1051 } 1052 if (!err) { 1053 err = percpu_counter_init(&sbi->s_dirs_counter, 1054 ext2_count_dirs(sb)); 1055 } 1056 if (err) { 1057 ext2_msg(sb, KERN_ERR, "error: insufficient memory"); 1058 goto failed_mount3; 1059 } 1060 /* 1061 * set up enough so that it can read an inode 1062 */ 1063 sb->s_op = &ext2_sops; 1064 sb->s_export_op = &ext2_export_ops; 1065 sb->s_xattr = ext2_xattr_handlers; 1066 root = ext2_iget(sb, EXT2_ROOT_INO); 1067 if (IS_ERR(root)) { 1068 ret = PTR_ERR(root); 1069 goto failed_mount3; 1070 } 1071 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1072 iput(root); 1073 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck"); 1074 goto failed_mount3; 1075 } 1076 1077 sb->s_root = d_alloc_root(root); 1078 if (!sb->s_root) { 1079 iput(root); 1080 ext2_msg(sb, KERN_ERR, "error: get root inode failed"); 1081 ret = -ENOMEM; 1082 goto failed_mount3; 1083 } 1084 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1085 ext2_msg(sb, KERN_WARNING, 1086 "warning: mounting ext3 filesystem as ext2"); 1087 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY)) 1088 sb->s_flags |= MS_RDONLY; 1089 ext2_write_super(sb); 1090 return 0; 1091 1092 cantfind_ext2: 1093 if (!silent) 1094 ext2_msg(sb, KERN_ERR, 1095 "error: can't find an ext2 filesystem on dev %s.", 1096 sb->s_id); 1097 goto failed_mount; 1098 failed_mount3: 1099 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1100 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1101 percpu_counter_destroy(&sbi->s_dirs_counter); 1102 failed_mount2: 1103 for (i = 0; i < db_count; i++) 1104 brelse(sbi->s_group_desc[i]); 1105 failed_mount_group_desc: 1106 kfree(sbi->s_group_desc); 1107 kfree(sbi->s_debts); 1108 failed_mount: 1109 brelse(bh); 1110 failed_sbi: 1111 sb->s_fs_info = NULL; 1112 kfree(sbi->s_blockgroup_lock); 1113 kfree(sbi); 1114 return ret; 1115 } 1116 1117 static void ext2_clear_super_error(struct super_block *sb) 1118 { 1119 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh; 1120 1121 if (buffer_write_io_error(sbh)) { 1122 /* 1123 * Oh, dear. A previous attempt to write the 1124 * superblock failed. This could happen because the 1125 * USB device was yanked out. Or it could happen to 1126 * be a transient write error and maybe the block will 1127 * be remapped. Nothing we can do but to retry the 1128 * write and hope for the best. 1129 */ 1130 ext2_msg(sb, KERN_ERR, 1131 "previous I/O error to superblock detected\n"); 1132 clear_buffer_write_io_error(sbh); 1133 set_buffer_uptodate(sbh); 1134 } 1135 } 1136 1137 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es, 1138 int wait) 1139 { 1140 ext2_clear_super_error(sb); 1141 spin_lock(&EXT2_SB(sb)->s_lock); 1142 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1143 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1144 es->s_wtime = cpu_to_le32(get_seconds()); 1145 /* unlock before we do IO */ 1146 spin_unlock(&EXT2_SB(sb)->s_lock); 1147 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1148 if (wait) 1149 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1150 sb->s_dirt = 0; 1151 } 1152 1153 /* 1154 * In the second extended file system, it is not necessary to 1155 * write the super block since we use a mapping of the 1156 * disk super block in a buffer. 1157 * 1158 * However, this function is still used to set the fs valid 1159 * flags to 0. We need to set this flag to 0 since the fs 1160 * may have been checked while mounted and e2fsck may have 1161 * set s_state to EXT2_VALID_FS after some corrections. 1162 */ 1163 static int ext2_sync_fs(struct super_block *sb, int wait) 1164 { 1165 struct ext2_sb_info *sbi = EXT2_SB(sb); 1166 struct ext2_super_block *es = EXT2_SB(sb)->s_es; 1167 1168 spin_lock(&sbi->s_lock); 1169 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { 1170 ext2_debug("setting valid to 0\n"); 1171 es->s_state &= cpu_to_le16(~EXT2_VALID_FS); 1172 } 1173 spin_unlock(&sbi->s_lock); 1174 ext2_sync_super(sb, es, wait); 1175 return 0; 1176 } 1177 1178 1179 void ext2_write_super(struct super_block *sb) 1180 { 1181 if (!(sb->s_flags & MS_RDONLY)) 1182 ext2_sync_fs(sb, 1); 1183 else 1184 sb->s_dirt = 0; 1185 } 1186 1187 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1188 { 1189 struct ext2_sb_info * sbi = EXT2_SB(sb); 1190 struct ext2_super_block * es; 1191 unsigned long old_mount_opt = sbi->s_mount_opt; 1192 struct ext2_mount_options old_opts; 1193 unsigned long old_sb_flags; 1194 int err; 1195 1196 spin_lock(&sbi->s_lock); 1197 1198 /* Store the old options */ 1199 old_sb_flags = sb->s_flags; 1200 old_opts.s_mount_opt = sbi->s_mount_opt; 1201 old_opts.s_resuid = sbi->s_resuid; 1202 old_opts.s_resgid = sbi->s_resgid; 1203 1204 /* 1205 * Allow the "check" option to be passed as a remount option. 1206 */ 1207 if (!parse_options(data, sb)) { 1208 err = -EINVAL; 1209 goto restore_opts; 1210 } 1211 1212 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1213 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1214 1215 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1216 EXT2_MOUNT_XIP if not */ 1217 1218 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1219 ext2_msg(sb, KERN_WARNING, 1220 "warning: unsupported blocksize for xip"); 1221 err = -EINVAL; 1222 goto restore_opts; 1223 } 1224 1225 es = sbi->s_es; 1226 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1227 (old_mount_opt & EXT2_MOUNT_XIP)) && 1228 invalidate_inodes(sb)) { 1229 ext2_msg(sb, KERN_WARNING, "warning: refusing change of " 1230 "xip flag with busy inodes while remounting"); 1231 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP; 1232 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; 1233 } 1234 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { 1235 spin_unlock(&sbi->s_lock); 1236 return 0; 1237 } 1238 if (*flags & MS_RDONLY) { 1239 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1240 !(sbi->s_mount_state & EXT2_VALID_FS)) { 1241 spin_unlock(&sbi->s_lock); 1242 return 0; 1243 } 1244 /* 1245 * OK, we are remounting a valid rw partition rdonly, so set 1246 * the rdonly flag and then mark the partition as valid again. 1247 */ 1248 es->s_state = cpu_to_le16(sbi->s_mount_state); 1249 es->s_mtime = cpu_to_le32(get_seconds()); 1250 spin_unlock(&sbi->s_lock); 1251 ext2_sync_super(sb, es, 1); 1252 } else { 1253 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1254 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1255 if (ret) { 1256 ext2_msg(sb, KERN_WARNING, 1257 "warning: couldn't remount RDWR because of " 1258 "unsupported optional features (%x).", 1259 le32_to_cpu(ret)); 1260 err = -EROFS; 1261 goto restore_opts; 1262 } 1263 /* 1264 * Mounting a RDONLY partition read-write, so reread and 1265 * store the current valid flag. (It may have been changed 1266 * by e2fsck since we originally mounted the partition.) 1267 */ 1268 sbi->s_mount_state = le16_to_cpu(es->s_state); 1269 if (!ext2_setup_super (sb, es, 0)) 1270 sb->s_flags &= ~MS_RDONLY; 1271 spin_unlock(&sbi->s_lock); 1272 ext2_write_super(sb); 1273 } 1274 return 0; 1275 restore_opts: 1276 sbi->s_mount_opt = old_opts.s_mount_opt; 1277 sbi->s_resuid = old_opts.s_resuid; 1278 sbi->s_resgid = old_opts.s_resgid; 1279 sb->s_flags = old_sb_flags; 1280 spin_unlock(&sbi->s_lock); 1281 return err; 1282 } 1283 1284 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1285 { 1286 struct super_block *sb = dentry->d_sb; 1287 struct ext2_sb_info *sbi = EXT2_SB(sb); 1288 struct ext2_super_block *es = sbi->s_es; 1289 u64 fsid; 1290 1291 spin_lock(&sbi->s_lock); 1292 1293 if (test_opt (sb, MINIX_DF)) 1294 sbi->s_overhead_last = 0; 1295 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1296 unsigned long i, overhead = 0; 1297 smp_rmb(); 1298 1299 /* 1300 * Compute the overhead (FS structures). This is constant 1301 * for a given filesystem unless the number of block groups 1302 * changes so we cache the previous value until it does. 1303 */ 1304 1305 /* 1306 * All of the blocks before first_data_block are 1307 * overhead 1308 */ 1309 overhead = le32_to_cpu(es->s_first_data_block); 1310 1311 /* 1312 * Add the overhead attributed to the superblock and 1313 * block group descriptors. If the sparse superblocks 1314 * feature is turned on, then not all groups have this. 1315 */ 1316 for (i = 0; i < sbi->s_groups_count; i++) 1317 overhead += ext2_bg_has_super(sb, i) + 1318 ext2_bg_num_gdb(sb, i); 1319 1320 /* 1321 * Every block group has an inode bitmap, a block 1322 * bitmap, and an inode table. 1323 */ 1324 overhead += (sbi->s_groups_count * 1325 (2 + sbi->s_itb_per_group)); 1326 sbi->s_overhead_last = overhead; 1327 smp_wmb(); 1328 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1329 } 1330 1331 buf->f_type = EXT2_SUPER_MAGIC; 1332 buf->f_bsize = sb->s_blocksize; 1333 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1334 buf->f_bfree = ext2_count_free_blocks(sb); 1335 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1336 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1337 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1338 buf->f_bavail = 0; 1339 buf->f_files = le32_to_cpu(es->s_inodes_count); 1340 buf->f_ffree = ext2_count_free_inodes(sb); 1341 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1342 buf->f_namelen = EXT2_NAME_LEN; 1343 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1344 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1345 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1346 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1347 spin_unlock(&sbi->s_lock); 1348 return 0; 1349 } 1350 1351 static int ext2_get_sb(struct file_system_type *fs_type, 1352 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1353 { 1354 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1355 } 1356 1357 #ifdef CONFIG_QUOTA 1358 1359 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1360 * acquiring the locks... As quota files are never truncated and quota code 1361 * itself serializes the operations (and noone else should touch the files) 1362 * we don't have to be afraid of races */ 1363 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1364 size_t len, loff_t off) 1365 { 1366 struct inode *inode = sb_dqopt(sb)->files[type]; 1367 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1368 int err = 0; 1369 int offset = off & (sb->s_blocksize - 1); 1370 int tocopy; 1371 size_t toread; 1372 struct buffer_head tmp_bh; 1373 struct buffer_head *bh; 1374 loff_t i_size = i_size_read(inode); 1375 1376 if (off > i_size) 1377 return 0; 1378 if (off+len > i_size) 1379 len = i_size-off; 1380 toread = len; 1381 while (toread > 0) { 1382 tocopy = sb->s_blocksize - offset < toread ? 1383 sb->s_blocksize - offset : toread; 1384 1385 tmp_bh.b_state = 0; 1386 tmp_bh.b_size = sb->s_blocksize; 1387 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1388 if (err < 0) 1389 return err; 1390 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1391 memset(data, 0, tocopy); 1392 else { 1393 bh = sb_bread(sb, tmp_bh.b_blocknr); 1394 if (!bh) 1395 return -EIO; 1396 memcpy(data, bh->b_data+offset, tocopy); 1397 brelse(bh); 1398 } 1399 offset = 0; 1400 toread -= tocopy; 1401 data += tocopy; 1402 blk++; 1403 } 1404 return len; 1405 } 1406 1407 /* Write to quotafile */ 1408 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1409 const char *data, size_t len, loff_t off) 1410 { 1411 struct inode *inode = sb_dqopt(sb)->files[type]; 1412 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1413 int err = 0; 1414 int offset = off & (sb->s_blocksize - 1); 1415 int tocopy; 1416 size_t towrite = len; 1417 struct buffer_head tmp_bh; 1418 struct buffer_head *bh; 1419 1420 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1421 while (towrite > 0) { 1422 tocopy = sb->s_blocksize - offset < towrite ? 1423 sb->s_blocksize - offset : towrite; 1424 1425 tmp_bh.b_state = 0; 1426 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1427 if (err < 0) 1428 goto out; 1429 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1430 bh = sb_bread(sb, tmp_bh.b_blocknr); 1431 else 1432 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1433 if (!bh) { 1434 err = -EIO; 1435 goto out; 1436 } 1437 lock_buffer(bh); 1438 memcpy(bh->b_data+offset, data, tocopy); 1439 flush_dcache_page(bh->b_page); 1440 set_buffer_uptodate(bh); 1441 mark_buffer_dirty(bh); 1442 unlock_buffer(bh); 1443 brelse(bh); 1444 offset = 0; 1445 towrite -= tocopy; 1446 data += tocopy; 1447 blk++; 1448 } 1449 out: 1450 if (len == towrite) { 1451 mutex_unlock(&inode->i_mutex); 1452 return err; 1453 } 1454 if (inode->i_size < off+len-towrite) 1455 i_size_write(inode, off+len-towrite); 1456 inode->i_version++; 1457 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1458 mark_inode_dirty(inode); 1459 mutex_unlock(&inode->i_mutex); 1460 return len - towrite; 1461 } 1462 1463 #endif 1464 1465 static struct file_system_type ext2_fs_type = { 1466 .owner = THIS_MODULE, 1467 .name = "ext2", 1468 .get_sb = ext2_get_sb, 1469 .kill_sb = kill_block_super, 1470 .fs_flags = FS_REQUIRES_DEV, 1471 }; 1472 1473 static int __init init_ext2_fs(void) 1474 { 1475 int err = init_ext2_xattr(); 1476 if (err) 1477 return err; 1478 err = init_inodecache(); 1479 if (err) 1480 goto out1; 1481 err = register_filesystem(&ext2_fs_type); 1482 if (err) 1483 goto out; 1484 return 0; 1485 out: 1486 destroy_inodecache(); 1487 out1: 1488 exit_ext2_xattr(); 1489 return err; 1490 } 1491 1492 static void __exit exit_ext2_fs(void) 1493 { 1494 unregister_filesystem(&ext2_fs_type); 1495 destroy_inodecache(); 1496 exit_ext2_xattr(); 1497 } 1498 1499 module_init(init_ext2_fs) 1500 module_exit(exit_ext2_fs) 1501