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 <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); 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 45 void ext2_error (struct super_block * sb, const char * function, 46 const char * fmt, ...) 47 { 48 va_list args; 49 struct ext2_sb_info *sbi = EXT2_SB(sb); 50 struct ext2_super_block *es = sbi->s_es; 51 52 if (!(sb->s_flags & MS_RDONLY)) { 53 sbi->s_mount_state |= EXT2_ERROR_FS; 54 es->s_state = 55 cpu_to_le16(le16_to_cpu(es->s_state) | 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, __FUNCTION__, 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); 136 137 return; 138 } 139 140 static struct kmem_cache * ext2_inode_cachep; 141 142 static struct inode *ext2_alloc_inode(struct super_block *sb) 143 { 144 struct ext2_inode_info *ei; 145 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL); 146 if (!ei) 147 return NULL; 148 #ifdef CONFIG_EXT2_FS_POSIX_ACL 149 ei->i_acl = EXT2_ACL_NOT_CACHED; 150 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 151 #endif 152 ei->i_block_alloc_info = NULL; 153 ei->vfs_inode.i_version = 1; 154 return &ei->vfs_inode; 155 } 156 157 static void ext2_destroy_inode(struct inode *inode) 158 { 159 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); 160 } 161 162 static void init_once(struct kmem_cache * cachep, void *foo) 163 { 164 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; 165 166 rwlock_init(&ei->i_meta_lock); 167 #ifdef CONFIG_EXT2_FS_XATTR 168 init_rwsem(&ei->xattr_sem); 169 #endif 170 mutex_init(&ei->truncate_mutex); 171 inode_init_once(&ei->vfs_inode); 172 } 173 174 static int init_inodecache(void) 175 { 176 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", 177 sizeof(struct ext2_inode_info), 178 0, (SLAB_RECLAIM_ACCOUNT| 179 SLAB_MEM_SPREAD), 180 init_once); 181 if (ext2_inode_cachep == NULL) 182 return -ENOMEM; 183 return 0; 184 } 185 186 static void destroy_inodecache(void) 187 { 188 kmem_cache_destroy(ext2_inode_cachep); 189 } 190 191 static void ext2_clear_inode(struct inode *inode) 192 { 193 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; 194 #ifdef CONFIG_EXT2_FS_POSIX_ACL 195 struct ext2_inode_info *ei = EXT2_I(inode); 196 197 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { 198 posix_acl_release(ei->i_acl); 199 ei->i_acl = EXT2_ACL_NOT_CACHED; 200 } 201 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { 202 posix_acl_release(ei->i_default_acl); 203 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 204 } 205 #endif 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 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 220 221 if (sbi->s_sb_block != 1) 222 seq_printf(seq, ",sb=%lu", sbi->s_sb_block); 223 if (test_opt(sb, MINIX_DF)) 224 seq_puts(seq, ",minixdf"); 225 if (test_opt(sb, GRPID)) 226 seq_puts(seq, ",grpid"); 227 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS)) 228 seq_puts(seq, ",nogrpid"); 229 if (sbi->s_resuid != EXT2_DEF_RESUID || 230 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) { 231 seq_printf(seq, ",resuid=%u", sbi->s_resuid); 232 } 233 if (sbi->s_resgid != EXT2_DEF_RESGID || 234 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) { 235 seq_printf(seq, ",resgid=%u", sbi->s_resgid); 236 } 237 if (test_opt(sb, ERRORS_RO)) { 238 int def_errors = le16_to_cpu(es->s_errors); 239 240 if (def_errors == EXT2_ERRORS_PANIC || 241 def_errors == EXT2_ERRORS_CONTINUE) { 242 seq_puts(seq, ",errors=remount-ro"); 243 } 244 } 245 if (test_opt(sb, ERRORS_CONT)) 246 seq_puts(seq, ",errors=continue"); 247 if (test_opt(sb, ERRORS_PANIC)) 248 seq_puts(seq, ",errors=panic"); 249 if (test_opt(sb, NO_UID32)) 250 seq_puts(seq, ",nouid32"); 251 if (test_opt(sb, DEBUG)) 252 seq_puts(seq, ",debug"); 253 if (test_opt(sb, OLDALLOC)) 254 seq_puts(seq, ",oldalloc"); 255 256 #ifdef CONFIG_EXT2_FS_XATTR 257 if (test_opt(sb, XATTR_USER)) 258 seq_puts(seq, ",user_xattr"); 259 if (!test_opt(sb, XATTR_USER) && 260 (def_mount_opts & EXT2_DEFM_XATTR_USER)) { 261 seq_puts(seq, ",nouser_xattr"); 262 } 263 #endif 264 265 #ifdef CONFIG_EXT2_FS_POSIX_ACL 266 if (test_opt(sb, POSIX_ACL)) 267 seq_puts(seq, ",acl"); 268 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL)) 269 seq_puts(seq, ",noacl"); 270 #endif 271 272 if (test_opt(sb, NOBH)) 273 seq_puts(seq, ",nobh"); 274 275 #if defined(CONFIG_QUOTA) 276 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) 277 seq_puts(seq, ",usrquota"); 278 279 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) 280 seq_puts(seq, ",grpquota"); 281 #endif 282 283 #if defined(CONFIG_EXT2_FS_XIP) 284 if (sbi->s_mount_opt & EXT2_MOUNT_XIP) 285 seq_puts(seq, ",xip"); 286 #endif 287 288 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 .read_inode = ext2_read_inode, 300 .write_inode = ext2_write_inode, 301 .delete_inode = ext2_delete_inode, 302 .put_super = ext2_put_super, 303 .write_super = ext2_write_super, 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 = iget(sb, ino); 330 if (inode == NULL) 331 return ERR_PTR(-ENOMEM); 332 if (is_bad_inode(inode) || 333 (generation && inode->i_generation != generation)) { 334 /* we didn't find the right inode.. */ 335 iput(inode); 336 return ERR_PTR(-ESTALE); 337 } 338 return inode; 339 } 340 341 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid, 342 int fh_len, int fh_type) 343 { 344 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 345 ext2_nfs_get_inode); 346 } 347 348 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid, 349 int fh_len, int fh_type) 350 { 351 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 352 ext2_nfs_get_inode); 353 } 354 355 /* Yes, most of these are left as NULL!! 356 * A NULL value implies the default, which works with ext2-like file 357 * systems, but can be improved upon. 358 * Currently only get_parent is required. 359 */ 360 static const struct export_operations ext2_export_ops = { 361 .fh_to_dentry = ext2_fh_to_dentry, 362 .fh_to_parent = ext2_fh_to_parent, 363 .get_parent = ext2_get_parent, 364 }; 365 366 static unsigned long get_sb_block(void **data) 367 { 368 unsigned long sb_block; 369 char *options = (char *) *data; 370 371 if (!options || strncmp(options, "sb=", 3) != 0) 372 return 1; /* Default location */ 373 options += 3; 374 sb_block = simple_strtoul(options, &options, 0); 375 if (*options && *options != ',') { 376 printk("EXT2-fs: Invalid sb specification: %s\n", 377 (char *) *data); 378 return 1; 379 } 380 if (*options == ',') 381 options++; 382 *data = (void *) options; 383 return sb_block; 384 } 385 386 enum { 387 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, 388 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, 389 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, 390 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, 391 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, 392 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation 393 }; 394 395 static match_table_t tokens = { 396 {Opt_bsd_df, "bsddf"}, 397 {Opt_minix_df, "minixdf"}, 398 {Opt_grpid, "grpid"}, 399 {Opt_grpid, "bsdgroups"}, 400 {Opt_nogrpid, "nogrpid"}, 401 {Opt_nogrpid, "sysvgroups"}, 402 {Opt_resgid, "resgid=%u"}, 403 {Opt_resuid, "resuid=%u"}, 404 {Opt_sb, "sb=%u"}, 405 {Opt_err_cont, "errors=continue"}, 406 {Opt_err_panic, "errors=panic"}, 407 {Opt_err_ro, "errors=remount-ro"}, 408 {Opt_nouid32, "nouid32"}, 409 {Opt_nocheck, "check=none"}, 410 {Opt_nocheck, "nocheck"}, 411 {Opt_debug, "debug"}, 412 {Opt_oldalloc, "oldalloc"}, 413 {Opt_orlov, "orlov"}, 414 {Opt_nobh, "nobh"}, 415 {Opt_user_xattr, "user_xattr"}, 416 {Opt_nouser_xattr, "nouser_xattr"}, 417 {Opt_acl, "acl"}, 418 {Opt_noacl, "noacl"}, 419 {Opt_xip, "xip"}, 420 {Opt_grpquota, "grpquota"}, 421 {Opt_ignore, "noquota"}, 422 {Opt_quota, "quota"}, 423 {Opt_usrquota, "usrquota"}, 424 {Opt_reservation, "reservation"}, 425 {Opt_noreservation, "noreservation"}, 426 {Opt_err, NULL} 427 }; 428 429 static int parse_options (char * options, 430 struct ext2_sb_info *sbi) 431 { 432 char * p; 433 substring_t args[MAX_OPT_ARGS]; 434 int option; 435 436 if (!options) 437 return 1; 438 439 while ((p = strsep (&options, ",")) != NULL) { 440 int token; 441 if (!*p) 442 continue; 443 444 token = match_token(p, tokens, args); 445 switch (token) { 446 case Opt_bsd_df: 447 clear_opt (sbi->s_mount_opt, MINIX_DF); 448 break; 449 case Opt_minix_df: 450 set_opt (sbi->s_mount_opt, MINIX_DF); 451 break; 452 case Opt_grpid: 453 set_opt (sbi->s_mount_opt, GRPID); 454 break; 455 case Opt_nogrpid: 456 clear_opt (sbi->s_mount_opt, GRPID); 457 break; 458 case Opt_resuid: 459 if (match_int(&args[0], &option)) 460 return 0; 461 sbi->s_resuid = option; 462 break; 463 case Opt_resgid: 464 if (match_int(&args[0], &option)) 465 return 0; 466 sbi->s_resgid = option; 467 break; 468 case Opt_sb: 469 /* handled by get_sb_block() instead of here */ 470 /* *sb_block = match_int(&args[0]); */ 471 break; 472 case Opt_err_panic: 473 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 474 clear_opt (sbi->s_mount_opt, ERRORS_RO); 475 set_opt (sbi->s_mount_opt, ERRORS_PANIC); 476 break; 477 case Opt_err_ro: 478 clear_opt (sbi->s_mount_opt, ERRORS_CONT); 479 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 480 set_opt (sbi->s_mount_opt, ERRORS_RO); 481 break; 482 case Opt_err_cont: 483 clear_opt (sbi->s_mount_opt, ERRORS_RO); 484 clear_opt (sbi->s_mount_opt, ERRORS_PANIC); 485 set_opt (sbi->s_mount_opt, ERRORS_CONT); 486 break; 487 case Opt_nouid32: 488 set_opt (sbi->s_mount_opt, NO_UID32); 489 break; 490 case Opt_nocheck: 491 clear_opt (sbi->s_mount_opt, CHECK); 492 break; 493 case Opt_debug: 494 set_opt (sbi->s_mount_opt, DEBUG); 495 break; 496 case Opt_oldalloc: 497 set_opt (sbi->s_mount_opt, OLDALLOC); 498 break; 499 case Opt_orlov: 500 clear_opt (sbi->s_mount_opt, OLDALLOC); 501 break; 502 case Opt_nobh: 503 set_opt (sbi->s_mount_opt, NOBH); 504 break; 505 #ifdef CONFIG_EXT2_FS_XATTR 506 case Opt_user_xattr: 507 set_opt (sbi->s_mount_opt, XATTR_USER); 508 break; 509 case Opt_nouser_xattr: 510 clear_opt (sbi->s_mount_opt, XATTR_USER); 511 break; 512 #else 513 case Opt_user_xattr: 514 case Opt_nouser_xattr: 515 printk("EXT2 (no)user_xattr options not supported\n"); 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 printk("EXT2 (no)acl options not supported\n"); 529 break; 530 #endif 531 case Opt_xip: 532 #ifdef CONFIG_EXT2_FS_XIP 533 set_opt (sbi->s_mount_opt, XIP); 534 #else 535 printk("EXT2 xip option not supported\n"); 536 #endif 537 break; 538 539 #if defined(CONFIG_QUOTA) 540 case Opt_quota: 541 case Opt_usrquota: 542 set_opt(sbi->s_mount_opt, USRQUOTA); 543 break; 544 545 case Opt_grpquota: 546 set_opt(sbi->s_mount_opt, GRPQUOTA); 547 break; 548 #else 549 case Opt_quota: 550 case Opt_usrquota: 551 case Opt_grpquota: 552 printk(KERN_ERR 553 "EXT2-fs: quota operations not supported.\n"); 554 555 break; 556 #endif 557 558 case Opt_reservation: 559 set_opt(sbi->s_mount_opt, RESERVATION); 560 printk("reservations ON\n"); 561 break; 562 case Opt_noreservation: 563 clear_opt(sbi->s_mount_opt, RESERVATION); 564 printk("reservations OFF\n"); 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 printk ("EXT2-fs warning: revision level too high, " 584 "forcing read-only mode\n"); 585 res = MS_RDONLY; 586 } 587 if (read_only) 588 return res; 589 if (!(sbi->s_mount_state & EXT2_VALID_FS)) 590 printk ("EXT2-fs warning: mounting unchecked fs, " 591 "running e2fsck is recommended\n"); 592 else if ((sbi->s_mount_state & EXT2_ERROR_FS)) 593 printk ("EXT2-fs warning: mounting fs with errors, " 594 "running e2fsck is recommended\n"); 595 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && 596 le16_to_cpu(es->s_mnt_count) >= 597 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) 598 printk ("EXT2-fs warning: maximal mount count reached, " 599 "running e2fsck is recommended\n"); 600 else if (le32_to_cpu(es->s_checkinterval) && 601 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) 602 printk ("EXT2-fs warning: checktime reached, " 603 "running e2fsck is recommended\n"); 604 if (!le16_to_cpu(es->s_max_mnt_count)) 605 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); 606 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); 607 ext2_write_super(sb); 608 if (test_opt (sb, DEBUG)) 609 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " 610 "bpg=%lu, ipg=%lu, mo=%04lx]\n", 611 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, 612 sbi->s_frag_size, 613 sbi->s_groups_count, 614 EXT2_BLOCKS_PER_GROUP(sb), 615 EXT2_INODES_PER_GROUP(sb), 616 sbi->s_mount_opt); 617 return res; 618 } 619 620 static int ext2_check_descriptors(struct super_block *sb) 621 { 622 int i; 623 struct ext2_sb_info *sbi = EXT2_SB(sb); 624 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block); 625 unsigned long last_block; 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); 631 632 if (i == sbi->s_groups_count - 1) 633 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; 634 else 635 last_block = first_block + 636 (EXT2_BLOCKS_PER_GROUP(sb) - 1); 637 638 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || 639 le32_to_cpu(gdp->bg_block_bitmap) > last_block) 640 { 641 ext2_error (sb, "ext2_check_descriptors", 642 "Block bitmap for group %d" 643 " not in group (block %lu)!", 644 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); 645 return 0; 646 } 647 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || 648 le32_to_cpu(gdp->bg_inode_bitmap) > last_block) 649 { 650 ext2_error (sb, "ext2_check_descriptors", 651 "Inode bitmap for group %d" 652 " not in group (block %lu)!", 653 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); 654 return 0; 655 } 656 if (le32_to_cpu(gdp->bg_inode_table) < first_block || 657 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > 658 last_block) 659 { 660 ext2_error (sb, "ext2_check_descriptors", 661 "Inode table for group %d" 662 " not in group (block %lu)!", 663 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); 664 return 0; 665 } 666 first_block += EXT2_BLOCKS_PER_GROUP(sb); 667 } 668 return 1; 669 } 670 671 /* 672 * Maximal file size. There is a direct, and {,double-,triple-}indirect 673 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. 674 * We need to be 1 filesystem block less than the 2^32 sector limit. 675 */ 676 static loff_t ext2_max_size(int bits) 677 { 678 loff_t res = EXT2_NDIR_BLOCKS; 679 int meta_blocks; 680 loff_t upper_limit; 681 682 /* This is calculated to be the largest file size for a 683 * dense, file such that the total number of 684 * sectors in the file, including data and all indirect blocks, 685 * does not exceed 2^32 -1 686 * __u32 i_blocks representing the total number of 687 * 512 bytes blocks of the file 688 */ 689 upper_limit = (1LL << 32) - 1; 690 691 /* total blocks in file system block size */ 692 upper_limit >>= (bits - 9); 693 694 695 /* indirect blocks */ 696 meta_blocks = 1; 697 /* double indirect blocks */ 698 meta_blocks += 1 + (1LL << (bits-2)); 699 /* tripple indirect blocks */ 700 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2))); 701 702 upper_limit -= meta_blocks; 703 upper_limit <<= bits; 704 705 res += 1LL << (bits-2); 706 res += 1LL << (2*(bits-2)); 707 res += 1LL << (3*(bits-2)); 708 res <<= bits; 709 if (res > upper_limit) 710 res = upper_limit; 711 712 if (res > MAX_LFS_FILESIZE) 713 res = MAX_LFS_FILESIZE; 714 715 return res; 716 } 717 718 static unsigned long descriptor_loc(struct super_block *sb, 719 unsigned long logic_sb_block, 720 int nr) 721 { 722 struct ext2_sb_info *sbi = EXT2_SB(sb); 723 unsigned long bg, first_data_block, first_meta_bg; 724 int has_super = 0; 725 726 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); 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 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); 736 } 737 738 static int ext2_fill_super(struct super_block *sb, void *data, int silent) 739 { 740 struct buffer_head * bh; 741 struct ext2_sb_info * sbi; 742 struct ext2_super_block * es; 743 struct inode *root; 744 unsigned long block; 745 unsigned long sb_block = get_sb_block(&data); 746 unsigned long logic_sb_block; 747 unsigned long offset = 0; 748 unsigned long def_mount_opts; 749 int blocksize = BLOCK_SIZE; 750 int db_count; 751 int i, j; 752 __le32 features; 753 int err; 754 755 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 756 if (!sbi) 757 return -ENOMEM; 758 sb->s_fs_info = sbi; 759 sbi->s_sb_block = sb_block; 760 761 /* 762 * See what the current blocksize for the device is, and 763 * use that as the blocksize. Otherwise (or if the blocksize 764 * is smaller than the default) use the default. 765 * This is important for devices that have a hardware 766 * sectorsize that is larger than the default. 767 */ 768 blocksize = sb_min_blocksize(sb, BLOCK_SIZE); 769 if (!blocksize) { 770 printk ("EXT2-fs: unable to set blocksize\n"); 771 goto failed_sbi; 772 } 773 774 /* 775 * If the superblock doesn't start on a hardware sector boundary, 776 * calculate the offset. 777 */ 778 if (blocksize != BLOCK_SIZE) { 779 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 780 offset = (sb_block*BLOCK_SIZE) % blocksize; 781 } else { 782 logic_sb_block = sb_block; 783 } 784 785 if (!(bh = sb_bread(sb, logic_sb_block))) { 786 printk ("EXT2-fs: unable to read superblock\n"); 787 goto failed_sbi; 788 } 789 /* 790 * Note: s_es must be initialized as soon as possible because 791 * some ext2 macro-instructions depend on its value 792 */ 793 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 794 sbi->s_es = es; 795 sb->s_magic = le16_to_cpu(es->s_magic); 796 797 if (sb->s_magic != EXT2_SUPER_MAGIC) 798 goto cantfind_ext2; 799 800 /* Set defaults before we parse the mount options */ 801 def_mount_opts = le32_to_cpu(es->s_default_mount_opts); 802 if (def_mount_opts & EXT2_DEFM_DEBUG) 803 set_opt(sbi->s_mount_opt, DEBUG); 804 if (def_mount_opts & EXT2_DEFM_BSDGROUPS) 805 set_opt(sbi->s_mount_opt, GRPID); 806 if (def_mount_opts & EXT2_DEFM_UID16) 807 set_opt(sbi->s_mount_opt, NO_UID32); 808 #ifdef CONFIG_EXT2_FS_XATTR 809 if (def_mount_opts & EXT2_DEFM_XATTR_USER) 810 set_opt(sbi->s_mount_opt, XATTR_USER); 811 #endif 812 #ifdef CONFIG_EXT2_FS_POSIX_ACL 813 if (def_mount_opts & EXT2_DEFM_ACL) 814 set_opt(sbi->s_mount_opt, POSIX_ACL); 815 #endif 816 817 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) 818 set_opt(sbi->s_mount_opt, ERRORS_PANIC); 819 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) 820 set_opt(sbi->s_mount_opt, ERRORS_CONT); 821 else 822 set_opt(sbi->s_mount_opt, ERRORS_RO); 823 824 sbi->s_resuid = le16_to_cpu(es->s_def_resuid); 825 sbi->s_resgid = le16_to_cpu(es->s_def_resgid); 826 827 set_opt(sbi->s_mount_opt, RESERVATION); 828 829 if (!parse_options ((char *) data, sbi)) 830 goto failed_mount; 831 832 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 833 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? 834 MS_POSIXACL : 0); 835 836 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 837 EXT2_MOUNT_XIP if not */ 838 839 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && 840 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || 841 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || 842 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) 843 printk("EXT2-fs warning: feature flags set on rev 0 fs, " 844 "running e2fsck is recommended\n"); 845 /* 846 * Check feature flags regardless of the revision level, since we 847 * previously didn't change the revision level when setting the flags, 848 * so there is a chance incompat flags are set on a rev 0 filesystem. 849 */ 850 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); 851 if (features) { 852 printk("EXT2-fs: %s: couldn't mount because of " 853 "unsupported optional features (%x).\n", 854 sb->s_id, le32_to_cpu(features)); 855 goto failed_mount; 856 } 857 if (!(sb->s_flags & MS_RDONLY) && 858 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ 859 printk("EXT2-fs: %s: couldn't mount RDWR because of " 860 "unsupported optional features (%x).\n", 861 sb->s_id, le32_to_cpu(features)); 862 goto failed_mount; 863 } 864 865 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); 866 867 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) { 868 if (!silent) 869 printk("XIP: Unsupported blocksize\n"); 870 goto failed_mount; 871 } 872 873 /* If the blocksize doesn't match, re-read the thing.. */ 874 if (sb->s_blocksize != blocksize) { 875 brelse(bh); 876 877 if (!sb_set_blocksize(sb, blocksize)) { 878 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); 879 goto failed_sbi; 880 } 881 882 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; 883 offset = (sb_block*BLOCK_SIZE) % blocksize; 884 bh = sb_bread(sb, logic_sb_block); 885 if(!bh) { 886 printk("EXT2-fs: Couldn't read superblock on " 887 "2nd try.\n"); 888 goto failed_sbi; 889 } 890 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); 891 sbi->s_es = es; 892 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { 893 printk ("EXT2-fs: Magic mismatch, very weird !\n"); 894 goto failed_mount; 895 } 896 } 897 898 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); 899 900 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { 901 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 902 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 903 } else { 904 sbi->s_inode_size = le16_to_cpu(es->s_inode_size); 905 sbi->s_first_ino = le32_to_cpu(es->s_first_ino); 906 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || 907 !is_power_of_2(sbi->s_inode_size) || 908 (sbi->s_inode_size > blocksize)) { 909 printk ("EXT2-fs: unsupported inode size: %d\n", 910 sbi->s_inode_size); 911 goto failed_mount; 912 } 913 } 914 915 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << 916 le32_to_cpu(es->s_log_frag_size); 917 if (sbi->s_frag_size == 0) 918 goto cantfind_ext2; 919 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; 920 921 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); 922 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); 923 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); 924 925 if (EXT2_INODE_SIZE(sb) == 0) 926 goto cantfind_ext2; 927 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); 928 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0) 929 goto cantfind_ext2; 930 sbi->s_itb_per_group = sbi->s_inodes_per_group / 931 sbi->s_inodes_per_block; 932 sbi->s_desc_per_block = sb->s_blocksize / 933 sizeof (struct ext2_group_desc); 934 sbi->s_sbh = bh; 935 sbi->s_mount_state = le16_to_cpu(es->s_state); 936 sbi->s_addr_per_block_bits = 937 ilog2 (EXT2_ADDR_PER_BLOCK(sb)); 938 sbi->s_desc_per_block_bits = 939 ilog2 (EXT2_DESC_PER_BLOCK(sb)); 940 941 if (sb->s_magic != EXT2_SUPER_MAGIC) 942 goto cantfind_ext2; 943 944 if (sb->s_blocksize != bh->b_size) { 945 if (!silent) 946 printk ("VFS: Unsupported blocksize on dev " 947 "%s.\n", sb->s_id); 948 goto failed_mount; 949 } 950 951 if (sb->s_blocksize != sbi->s_frag_size) { 952 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", 953 sbi->s_frag_size, sb->s_blocksize); 954 goto failed_mount; 955 } 956 957 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { 958 printk ("EXT2-fs: #blocks per group too big: %lu\n", 959 sbi->s_blocks_per_group); 960 goto failed_mount; 961 } 962 if (sbi->s_frags_per_group > sb->s_blocksize * 8) { 963 printk ("EXT2-fs: #fragments per group too big: %lu\n", 964 sbi->s_frags_per_group); 965 goto failed_mount; 966 } 967 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { 968 printk ("EXT2-fs: #inodes per group too big: %lu\n", 969 sbi->s_inodes_per_group); 970 goto failed_mount; 971 } 972 973 if (EXT2_BLOCKS_PER_GROUP(sb) == 0) 974 goto cantfind_ext2; 975 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - 976 le32_to_cpu(es->s_first_data_block) - 1) 977 / EXT2_BLOCKS_PER_GROUP(sb)) + 1; 978 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / 979 EXT2_DESC_PER_BLOCK(sb); 980 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); 981 if (sbi->s_group_desc == NULL) { 982 printk ("EXT2-fs: not enough memory\n"); 983 goto failed_mount; 984 } 985 bgl_lock_init(&sbi->s_blockgroup_lock); 986 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL); 987 if (!sbi->s_debts) { 988 printk ("EXT2-fs: not enough memory\n"); 989 goto failed_mount_group_desc; 990 } 991 for (i = 0; i < db_count; i++) { 992 block = descriptor_loc(sb, logic_sb_block, i); 993 sbi->s_group_desc[i] = sb_bread(sb, block); 994 if (!sbi->s_group_desc[i]) { 995 for (j = 0; j < i; j++) 996 brelse (sbi->s_group_desc[j]); 997 printk ("EXT2-fs: unable to read group descriptors\n"); 998 goto failed_mount_group_desc; 999 } 1000 } 1001 if (!ext2_check_descriptors (sb)) { 1002 printk ("EXT2-fs: group descriptors corrupted!\n"); 1003 goto failed_mount2; 1004 } 1005 sbi->s_gdb_count = db_count; 1006 get_random_bytes(&sbi->s_next_generation, sizeof(u32)); 1007 spin_lock_init(&sbi->s_next_gen_lock); 1008 1009 /* per fileystem reservation list head & lock */ 1010 spin_lock_init(&sbi->s_rsv_window_lock); 1011 sbi->s_rsv_window_root = RB_ROOT; 1012 /* 1013 * Add a single, static dummy reservation to the start of the 1014 * reservation window list --- it gives us a placeholder for 1015 * append-at-start-of-list which makes the allocation logic 1016 * _much_ simpler. 1017 */ 1018 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1019 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; 1020 sbi->s_rsv_window_head.rsv_alloc_hit = 0; 1021 sbi->s_rsv_window_head.rsv_goal_size = 0; 1022 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); 1023 1024 err = percpu_counter_init(&sbi->s_freeblocks_counter, 1025 ext2_count_free_blocks(sb)); 1026 if (!err) { 1027 err = percpu_counter_init(&sbi->s_freeinodes_counter, 1028 ext2_count_free_inodes(sb)); 1029 } 1030 if (!err) { 1031 err = percpu_counter_init(&sbi->s_dirs_counter, 1032 ext2_count_dirs(sb)); 1033 } 1034 if (err) { 1035 printk(KERN_ERR "EXT2-fs: insufficient memory\n"); 1036 goto failed_mount3; 1037 } 1038 /* 1039 * set up enough so that it can read an inode 1040 */ 1041 sb->s_op = &ext2_sops; 1042 sb->s_export_op = &ext2_export_ops; 1043 sb->s_xattr = ext2_xattr_handlers; 1044 root = iget(sb, EXT2_ROOT_INO); 1045 sb->s_root = d_alloc_root(root); 1046 if (!sb->s_root) { 1047 iput(root); 1048 printk(KERN_ERR "EXT2-fs: get root inode failed\n"); 1049 goto failed_mount3; 1050 } 1051 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { 1052 dput(sb->s_root); 1053 sb->s_root = NULL; 1054 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); 1055 goto failed_mount3; 1056 } 1057 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1058 ext2_warning(sb, __FUNCTION__, 1059 "mounting ext3 filesystem as ext2"); 1060 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); 1061 return 0; 1062 1063 cantfind_ext2: 1064 if (!silent) 1065 printk("VFS: Can't find an ext2 filesystem on dev %s.\n", 1066 sb->s_id); 1067 goto failed_mount; 1068 failed_mount3: 1069 percpu_counter_destroy(&sbi->s_freeblocks_counter); 1070 percpu_counter_destroy(&sbi->s_freeinodes_counter); 1071 percpu_counter_destroy(&sbi->s_dirs_counter); 1072 failed_mount2: 1073 for (i = 0; i < db_count; i++) 1074 brelse(sbi->s_group_desc[i]); 1075 failed_mount_group_desc: 1076 kfree(sbi->s_group_desc); 1077 kfree(sbi->s_debts); 1078 failed_mount: 1079 brelse(bh); 1080 failed_sbi: 1081 sb->s_fs_info = NULL; 1082 kfree(sbi); 1083 return -EINVAL; 1084 } 1085 1086 static void ext2_commit_super (struct super_block * sb, 1087 struct ext2_super_block * es) 1088 { 1089 es->s_wtime = cpu_to_le32(get_seconds()); 1090 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1091 sb->s_dirt = 0; 1092 } 1093 1094 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) 1095 { 1096 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1097 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1098 es->s_wtime = cpu_to_le32(get_seconds()); 1099 mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 1100 sync_dirty_buffer(EXT2_SB(sb)->s_sbh); 1101 sb->s_dirt = 0; 1102 } 1103 1104 /* 1105 * In the second extended file system, it is not necessary to 1106 * write the super block since we use a mapping of the 1107 * disk super block in a buffer. 1108 * 1109 * However, this function is still used to set the fs valid 1110 * flags to 0. We need to set this flag to 0 since the fs 1111 * may have been checked while mounted and e2fsck may have 1112 * set s_state to EXT2_VALID_FS after some corrections. 1113 */ 1114 1115 void ext2_write_super (struct super_block * sb) 1116 { 1117 struct ext2_super_block * es; 1118 lock_kernel(); 1119 if (!(sb->s_flags & MS_RDONLY)) { 1120 es = EXT2_SB(sb)->s_es; 1121 1122 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { 1123 ext2_debug ("setting valid to 0\n"); 1124 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & 1125 ~EXT2_VALID_FS); 1126 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); 1127 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); 1128 es->s_mtime = cpu_to_le32(get_seconds()); 1129 ext2_sync_super(sb, es); 1130 } else 1131 ext2_commit_super (sb, es); 1132 } 1133 sb->s_dirt = 0; 1134 unlock_kernel(); 1135 } 1136 1137 static int ext2_remount (struct super_block * sb, int * flags, char * data) 1138 { 1139 struct ext2_sb_info * sbi = EXT2_SB(sb); 1140 struct ext2_super_block * es; 1141 unsigned long old_mount_opt = sbi->s_mount_opt; 1142 struct ext2_mount_options old_opts; 1143 unsigned long old_sb_flags; 1144 int err; 1145 1146 /* Store the old options */ 1147 old_sb_flags = sb->s_flags; 1148 old_opts.s_mount_opt = sbi->s_mount_opt; 1149 old_opts.s_resuid = sbi->s_resuid; 1150 old_opts.s_resgid = sbi->s_resgid; 1151 1152 /* 1153 * Allow the "check" option to be passed as a remount option. 1154 */ 1155 if (!parse_options (data, sbi)) { 1156 err = -EINVAL; 1157 goto restore_opts; 1158 } 1159 1160 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | 1161 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); 1162 1163 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset 1164 EXT2_MOUNT_XIP if not */ 1165 1166 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) { 1167 printk("XIP: Unsupported blocksize\n"); 1168 err = -EINVAL; 1169 goto restore_opts; 1170 } 1171 1172 es = sbi->s_es; 1173 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != 1174 (old_mount_opt & EXT2_MOUNT_XIP)) && 1175 invalidate_inodes(sb)) 1176 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ 1177 "xip remain in cache (no functional problem)"); 1178 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1179 return 0; 1180 if (*flags & MS_RDONLY) { 1181 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || 1182 !(sbi->s_mount_state & EXT2_VALID_FS)) 1183 return 0; 1184 /* 1185 * OK, we are remounting a valid rw partition rdonly, so set 1186 * the rdonly flag and then mark the partition as valid again. 1187 */ 1188 es->s_state = cpu_to_le16(sbi->s_mount_state); 1189 es->s_mtime = cpu_to_le32(get_seconds()); 1190 } else { 1191 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, 1192 ~EXT2_FEATURE_RO_COMPAT_SUPP); 1193 if (ret) { 1194 printk("EXT2-fs: %s: couldn't remount RDWR because of " 1195 "unsupported optional features (%x).\n", 1196 sb->s_id, le32_to_cpu(ret)); 1197 err = -EROFS; 1198 goto restore_opts; 1199 } 1200 /* 1201 * Mounting a RDONLY partition read-write, so reread and 1202 * store the current valid flag. (It may have been changed 1203 * by e2fsck since we originally mounted the partition.) 1204 */ 1205 sbi->s_mount_state = le16_to_cpu(es->s_state); 1206 if (!ext2_setup_super (sb, es, 0)) 1207 sb->s_flags &= ~MS_RDONLY; 1208 } 1209 ext2_sync_super(sb, es); 1210 return 0; 1211 restore_opts: 1212 sbi->s_mount_opt = old_opts.s_mount_opt; 1213 sbi->s_resuid = old_opts.s_resuid; 1214 sbi->s_resgid = old_opts.s_resgid; 1215 sb->s_flags = old_sb_flags; 1216 return err; 1217 } 1218 1219 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 1220 { 1221 struct super_block *sb = dentry->d_sb; 1222 struct ext2_sb_info *sbi = EXT2_SB(sb); 1223 struct ext2_super_block *es = sbi->s_es; 1224 u64 fsid; 1225 1226 if (test_opt (sb, MINIX_DF)) 1227 sbi->s_overhead_last = 0; 1228 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { 1229 unsigned long i, overhead = 0; 1230 smp_rmb(); 1231 1232 /* 1233 * Compute the overhead (FS structures). This is constant 1234 * for a given filesystem unless the number of block groups 1235 * changes so we cache the previous value until it does. 1236 */ 1237 1238 /* 1239 * All of the blocks before first_data_block are 1240 * overhead 1241 */ 1242 overhead = le32_to_cpu(es->s_first_data_block); 1243 1244 /* 1245 * Add the overhead attributed to the superblock and 1246 * block group descriptors. If the sparse superblocks 1247 * feature is turned on, then not all groups have this. 1248 */ 1249 for (i = 0; i < sbi->s_groups_count; i++) 1250 overhead += ext2_bg_has_super(sb, i) + 1251 ext2_bg_num_gdb(sb, i); 1252 1253 /* 1254 * Every block group has an inode bitmap, a block 1255 * bitmap, and an inode table. 1256 */ 1257 overhead += (sbi->s_groups_count * 1258 (2 + sbi->s_itb_per_group)); 1259 sbi->s_overhead_last = overhead; 1260 smp_wmb(); 1261 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count); 1262 } 1263 1264 buf->f_type = EXT2_SUPER_MAGIC; 1265 buf->f_bsize = sb->s_blocksize; 1266 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last; 1267 buf->f_bfree = ext2_count_free_blocks(sb); 1268 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree); 1269 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count); 1270 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count)) 1271 buf->f_bavail = 0; 1272 buf->f_files = le32_to_cpu(es->s_inodes_count); 1273 buf->f_ffree = ext2_count_free_inodes(sb); 1274 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree); 1275 buf->f_namelen = EXT2_NAME_LEN; 1276 fsid = le64_to_cpup((void *)es->s_uuid) ^ 1277 le64_to_cpup((void *)es->s_uuid + sizeof(u64)); 1278 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; 1279 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; 1280 return 0; 1281 } 1282 1283 static int ext2_get_sb(struct file_system_type *fs_type, 1284 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 1285 { 1286 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); 1287 } 1288 1289 #ifdef CONFIG_QUOTA 1290 1291 /* Read data from quotafile - avoid pagecache and such because we cannot afford 1292 * acquiring the locks... As quota files are never truncated and quota code 1293 * itself serializes the operations (and noone else should touch the files) 1294 * we don't have to be afraid of races */ 1295 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, 1296 size_t len, loff_t off) 1297 { 1298 struct inode *inode = sb_dqopt(sb)->files[type]; 1299 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1300 int err = 0; 1301 int offset = off & (sb->s_blocksize - 1); 1302 int tocopy; 1303 size_t toread; 1304 struct buffer_head tmp_bh; 1305 struct buffer_head *bh; 1306 loff_t i_size = i_size_read(inode); 1307 1308 if (off > i_size) 1309 return 0; 1310 if (off+len > i_size) 1311 len = i_size-off; 1312 toread = len; 1313 while (toread > 0) { 1314 tocopy = sb->s_blocksize - offset < toread ? 1315 sb->s_blocksize - offset : toread; 1316 1317 tmp_bh.b_state = 0; 1318 err = ext2_get_block(inode, blk, &tmp_bh, 0); 1319 if (err < 0) 1320 return err; 1321 if (!buffer_mapped(&tmp_bh)) /* A hole? */ 1322 memset(data, 0, tocopy); 1323 else { 1324 bh = sb_bread(sb, tmp_bh.b_blocknr); 1325 if (!bh) 1326 return -EIO; 1327 memcpy(data, bh->b_data+offset, tocopy); 1328 brelse(bh); 1329 } 1330 offset = 0; 1331 toread -= tocopy; 1332 data += tocopy; 1333 blk++; 1334 } 1335 return len; 1336 } 1337 1338 /* Write to quotafile */ 1339 static ssize_t ext2_quota_write(struct super_block *sb, int type, 1340 const char *data, size_t len, loff_t off) 1341 { 1342 struct inode *inode = sb_dqopt(sb)->files[type]; 1343 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); 1344 int err = 0; 1345 int offset = off & (sb->s_blocksize - 1); 1346 int tocopy; 1347 size_t towrite = len; 1348 struct buffer_head tmp_bh; 1349 struct buffer_head *bh; 1350 1351 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 1352 while (towrite > 0) { 1353 tocopy = sb->s_blocksize - offset < towrite ? 1354 sb->s_blocksize - offset : towrite; 1355 1356 tmp_bh.b_state = 0; 1357 err = ext2_get_block(inode, blk, &tmp_bh, 1); 1358 if (err < 0) 1359 goto out; 1360 if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) 1361 bh = sb_bread(sb, tmp_bh.b_blocknr); 1362 else 1363 bh = sb_getblk(sb, tmp_bh.b_blocknr); 1364 if (!bh) { 1365 err = -EIO; 1366 goto out; 1367 } 1368 lock_buffer(bh); 1369 memcpy(bh->b_data+offset, data, tocopy); 1370 flush_dcache_page(bh->b_page); 1371 set_buffer_uptodate(bh); 1372 mark_buffer_dirty(bh); 1373 unlock_buffer(bh); 1374 brelse(bh); 1375 offset = 0; 1376 towrite -= tocopy; 1377 data += tocopy; 1378 blk++; 1379 } 1380 out: 1381 if (len == towrite) 1382 return err; 1383 if (inode->i_size < off+len-towrite) 1384 i_size_write(inode, off+len-towrite); 1385 inode->i_version++; 1386 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1387 mark_inode_dirty(inode); 1388 mutex_unlock(&inode->i_mutex); 1389 return len - towrite; 1390 } 1391 1392 #endif 1393 1394 static struct file_system_type ext2_fs_type = { 1395 .owner = THIS_MODULE, 1396 .name = "ext2", 1397 .get_sb = ext2_get_sb, 1398 .kill_sb = kill_block_super, 1399 .fs_flags = FS_REQUIRES_DEV, 1400 }; 1401 1402 static int __init init_ext2_fs(void) 1403 { 1404 int err = init_ext2_xattr(); 1405 if (err) 1406 return err; 1407 err = init_inodecache(); 1408 if (err) 1409 goto out1; 1410 err = register_filesystem(&ext2_fs_type); 1411 if (err) 1412 goto out; 1413 return 0; 1414 out: 1415 destroy_inodecache(); 1416 out1: 1417 exit_ext2_xattr(); 1418 return err; 1419 } 1420 1421 static void __exit exit_ext2_fs(void) 1422 { 1423 unregister_filesystem(&ext2_fs_type); 1424 destroy_inodecache(); 1425 exit_ext2_xattr(); 1426 } 1427 1428 module_init(init_ext2_fs) 1429 module_exit(exit_ext2_fs) 1430