fs/ext2/super.c

   1 /*
   2  *  linux/fs/ext2/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card ([email protected])
   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 ([email protected]), 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 <linux/uaccess.h>
  35 #include <linux/dax.h>
  36 #include <linux/iversion.h>
  37 #include "ext2.h"
  38 #include "xattr.h"
  39 #include "acl.h"
  40
  41 static void ext2_write_super(struct super_block *sb);
  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 static int ext2_freeze(struct super_block *sb);
  46 static int ext2_unfreeze(struct super_block *sb);
  47
  48 void ext2_error(struct super_block *sb, const char *function,
  49                 const char *fmt, ...)
  50 {
  51         struct va_format vaf;
  52         va_list args;
  53         struct ext2_sb_info *sbi = EXT2_SB(sb);
  54         struct ext2_super_block *es = sbi->s_es;
  55
  56         if (!sb_rdonly(sb)) {
  57                 spin_lock(&sbi->s_lock);
  58                 sbi->s_mount_state |= EXT2_ERROR_FS;
  59                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  60                 spin_unlock(&sbi->s_lock);
  61                 ext2_sync_super(sb, es, 1);
  62         }
  63
  64         va_start(args, fmt);
  65
  66         vaf.fmt = fmt;
  67         vaf.va = &args;
  68
  69         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  70                sb->s_id, function, &vaf);
  71
  72         va_end(args);
  73
  74         if (test_opt(sb, ERRORS_PANIC))
  75                 panic("EXT2-fs: panic from previous error\n");
  76         if (test_opt(sb, ERRORS_RO)) {
  77                 ext2_msg(sb, KERN_CRIT,
  78                              "error: remounting filesystem read-only");
  79                 sb->s_flags |= SB_RDONLY;
  80         }
  81 }
  82
  83 void ext2_msg(struct super_block *sb, const char *prefix,
  84                 const char *fmt, ...)
  85 {
  86         struct va_format vaf;
  87         va_list args;
  88
  89         va_start(args, fmt);
  90
  91         vaf.fmt = fmt;
  92         vaf.va = &args;
  93
  94         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  95
  96         va_end(args);
  97 }
  98
  99 /*
 100  * This must be called with sbi->s_lock held.
 101  */
 102 void ext2_update_dynamic_rev(struct super_block *sb)
 103 {
 104         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 105
 106         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 107                 return;
 108
 109         ext2_msg(sb, KERN_WARNING,
 110                      "warning: updating to rev %d because of "
 111                      "new feature flag, running e2fsck is recommended",
 112                      EXT2_DYNAMIC_REV);
 113
 114         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 115         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 116         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 117         /* leave es->s_feature_*compat flags alone */
 118         /* es->s_uuid will be set by e2fsck if empty */
 119
 120         /*
 121          * The rest of the superblock fields should be zero, and if not it
 122          * means they are likely already in use, so leave them alone.  We
 123          * can leave it up to e2fsck to clean up any inconsistencies there.
 124          */
 125 }
 126
 127 #ifdef CONFIG_QUOTA
 128 static int ext2_quota_off(struct super_block *sb, int type);
 129
 130 static void ext2_quota_off_umount(struct super_block *sb)
 131 {
 132         int type;
 133
 134         for (type = 0; type < MAXQUOTAS; type++)
 135                 ext2_quota_off(sb, type);
 136 }
 137 #else
 138 static inline void ext2_quota_off_umount(struct super_block *sb)
 139 {
 140 }
 141 #endif
 142
 143 static void ext2_put_super (struct super_block * sb)
 144 {
 145         int db_count;
 146         int i;
 147         struct ext2_sb_info *sbi = EXT2_SB(sb);
 148
 149         ext2_quota_off_umount(sb);
 150
 151         if (sbi->s_ea_block_cache) {
 152                 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
 153                 sbi->s_ea_block_cache = NULL;
 154         }
 155         if (!sb_rdonly(sb)) {
 156                 struct ext2_super_block *es = sbi->s_es;
 157
 158                 spin_lock(&sbi->s_lock);
 159                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 160                 spin_unlock(&sbi->s_lock);
 161                 ext2_sync_super(sb, es, 1);
 162         }
 163         db_count = sbi->s_gdb_count;
 164         for (i = 0; i < db_count; i++)
 165                 if (sbi->s_group_desc[i])
 166                         brelse (sbi->s_group_desc[i]);
 167         kfree(sbi->s_group_desc);
 168         kfree(sbi->s_debts);
 169         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 170         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 171         percpu_counter_destroy(&sbi->s_dirs_counter);
 172         brelse (sbi->s_sbh);
 173         sb->s_fs_info = NULL;
 174         kfree(sbi->s_blockgroup_lock);
 175         fs_put_dax(sbi->s_daxdev);
 176         kfree(sbi);
 177 }
 178
 179 static struct kmem_cache * ext2_inode_cachep;
 180
 181 static struct inode *ext2_alloc_inode(struct super_block *sb)
 182 {
 183         struct ext2_inode_info *ei;
 184         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 185         if (!ei)
 186                 return NULL;
 187         ei->i_block_alloc_info = NULL;
 188         inode_set_iversion(&ei->vfs_inode, 1);
 189 #ifdef CONFIG_QUOTA
 190         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 191 #endif
 192
 193         return &ei->vfs_inode;
 194 }
 195
 196 static void ext2_i_callback(struct rcu_head *head)
 197 {
 198         struct inode *inode = container_of(head, struct inode, i_rcu);
 199         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 200 }
 201
 202 static void ext2_destroy_inode(struct inode *inode)
 203 {
 204         call_rcu(&inode->i_rcu, ext2_i_callback);
 205 }
 206
 207 static void init_once(void *foo)
 208 {
 209         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 210
 211         rwlock_init(&ei->i_meta_lock);
 212 #ifdef CONFIG_EXT2_FS_XATTR
 213         init_rwsem(&ei->xattr_sem);
 214 #endif
 215         mutex_init(&ei->truncate_mutex);
 216 #ifdef CONFIG_FS_DAX
 217         init_rwsem(&ei->dax_sem);
 218 #endif
 219         inode_init_once(&ei->vfs_inode);
 220 }
 221
 222 static int __init init_inodecache(void)
 223 {
 224         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 225                                 sizeof(struct ext2_inode_info), 0,
 226                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 227                                         SLAB_ACCOUNT),
 228                                 offsetof(struct ext2_inode_info, i_data),
 229                                 sizeof_field(struct ext2_inode_info, i_data),
 230                                 init_once);
 231         if (ext2_inode_cachep == NULL)
 232                 return -ENOMEM;
 233         return 0;
 234 }
 235
 236 static void destroy_inodecache(void)
 237 {
 238         /*
 239          * Make sure all delayed rcu free inodes are flushed before we
 240          * destroy cache.
 241          */
 242         rcu_barrier();
 243         kmem_cache_destroy(ext2_inode_cachep);
 244 }
 245
 246 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 247 {
 248         struct super_block *sb = root->d_sb;
 249         struct ext2_sb_info *sbi = EXT2_SB(sb);
 250         struct ext2_super_block *es = sbi->s_es;
 251         unsigned long def_mount_opts;
 252
 253         spin_lock(&sbi->s_lock);
 254         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 255
 256         if (sbi->s_sb_block != 1)
 257                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 258         if (test_opt(sb, MINIX_DF))
 259                 seq_puts(seq, ",minixdf");
 260         if (test_opt(sb, GRPID))
 261                 seq_puts(seq, ",grpid");
 262         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 263                 seq_puts(seq, ",nogrpid");
 264         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 265             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 266                 seq_printf(seq, ",resuid=%u",
 267                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 268         }
 269         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 270             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 271                 seq_printf(seq, ",resgid=%u",
 272                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 273         }
 274         if (test_opt(sb, ERRORS_RO)) {
 275                 int def_errors = le16_to_cpu(es->s_errors);
 276
 277                 if (def_errors == EXT2_ERRORS_PANIC ||
 278                     def_errors == EXT2_ERRORS_CONTINUE) {
 279                         seq_puts(seq, ",errors=remount-ro");
 280                 }
 281         }
 282         if (test_opt(sb, ERRORS_CONT))
 283                 seq_puts(seq, ",errors=continue");
 284         if (test_opt(sb, ERRORS_PANIC))
 285                 seq_puts(seq, ",errors=panic");
 286         if (test_opt(sb, NO_UID32))
 287                 seq_puts(seq, ",nouid32");
 288         if (test_opt(sb, DEBUG))
 289                 seq_puts(seq, ",debug");
 290         if (test_opt(sb, OLDALLOC))
 291                 seq_puts(seq, ",oldalloc");
 292
 293 #ifdef CONFIG_EXT2_FS_XATTR
 294         if (test_opt(sb, XATTR_USER))
 295                 seq_puts(seq, ",user_xattr");
 296         if (!test_opt(sb, XATTR_USER) &&
 297             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 298                 seq_puts(seq, ",nouser_xattr");
 299         }
 300 #endif
 301
 302 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 303         if (test_opt(sb, POSIX_ACL))
 304                 seq_puts(seq, ",acl");
 305         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 306                 seq_puts(seq, ",noacl");
 307 #endif
 308
 309         if (test_opt(sb, NOBH))
 310                 seq_puts(seq, ",nobh");
 311
 312 #if defined(CONFIG_QUOTA)
 313         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 314                 seq_puts(seq, ",usrquota");
 315
 316         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 317                 seq_puts(seq, ",grpquota");
 318 #endif
 319
 320 #ifdef CONFIG_FS_DAX
 321         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 322                 seq_puts(seq, ",xip");
 323         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 324                 seq_puts(seq, ",dax");
 325 #endif
 326
 327         if (!test_opt(sb, RESERVATION))
 328                 seq_puts(seq, ",noreservation");
 329
 330         spin_unlock(&sbi->s_lock);
 331         return 0;
 332 }
 333
 334 #ifdef CONFIG_QUOTA
 335 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 336 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 337 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 338                          const struct path *path);
 339 static struct dquot **ext2_get_dquots(struct inode *inode)
 340 {
 341         return EXT2_I(inode)->i_dquot;
 342 }
 343
 344 static const struct quotactl_ops ext2_quotactl_ops = {
 345         .quota_on       = ext2_quota_on,
 346         .quota_off      = ext2_quota_off,
 347         .quota_sync     = dquot_quota_sync,
 348         .get_state      = dquot_get_state,
 349         .set_info       = dquot_set_dqinfo,
 350         .get_dqblk      = dquot_get_dqblk,
 351         .set_dqblk      = dquot_set_dqblk,
 352         .get_nextdqblk  = dquot_get_next_dqblk,
 353 };
 354 #endif
 355
 356 static const struct super_operations ext2_sops = {
 357         .alloc_inode    = ext2_alloc_inode,
 358         .destroy_inode  = ext2_destroy_inode,
 359         .write_inode    = ext2_write_inode,
 360         .evict_inode    = ext2_evict_inode,
 361         .put_super      = ext2_put_super,
 362         .sync_fs        = ext2_sync_fs,
 363         .freeze_fs      = ext2_freeze,
 364         .unfreeze_fs    = ext2_unfreeze,
 365         .statfs         = ext2_statfs,
 366         .remount_fs     = ext2_remount,
 367         .show_options   = ext2_show_options,
 368 #ifdef CONFIG_QUOTA
 369         .quota_read     = ext2_quota_read,
 370         .quota_write    = ext2_quota_write,
 371         .get_dquots     = ext2_get_dquots,
 372 #endif
 373 };
 374
 375 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 376                 u64 ino, u32 generation)
 377 {
 378         struct inode *inode;
 379
 380         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 381                 return ERR_PTR(-ESTALE);
 382         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 383                 return ERR_PTR(-ESTALE);
 384
 385         /*
 386          * ext2_iget isn't quite right if the inode is currently unallocated!
 387          * However ext2_iget currently does appropriate checks to handle stale
 388          * inodes so everything is OK.
 389          */
 390         inode = ext2_iget(sb, ino);
 391         if (IS_ERR(inode))
 392                 return ERR_CAST(inode);
 393         if (generation && inode->i_generation != generation) {
 394                 /* we didn't find the right inode.. */
 395                 iput(inode);
 396                 return ERR_PTR(-ESTALE);
 397         }
 398         return inode;
 399 }
 400
 401 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 402                 int fh_len, int fh_type)
 403 {
 404         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 405                                     ext2_nfs_get_inode);
 406 }
 407
 408 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 409                 int fh_len, int fh_type)
 410 {
 411         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 412                                     ext2_nfs_get_inode);
 413 }
 414
 415 static const struct export_operations ext2_export_ops = {
 416         .fh_to_dentry = ext2_fh_to_dentry,
 417         .fh_to_parent = ext2_fh_to_parent,
 418         .get_parent = ext2_get_parent,
 419 };
 420
 421 static unsigned long get_sb_block(void **data)
 422 {
 423         unsigned long   sb_block;
 424         char            *options = (char *) *data;
 425
 426         if (!options || strncmp(options, "sb=", 3) != 0)
 427                 return 1;       /* Default location */
 428         options += 3;
 429         sb_block = simple_strtoul(options, &options, 0);
 430         if (*options && *options != ',') {
 431                 printk("EXT2-fs: Invalid sb specification: %s\n",
 432                        (char *) *data);
 433                 return 1;
 434         }
 435         if (*options == ',')
 436                 options++;
 437         *data = (void *) options;
 438         return sb_block;
 439 }
 440
 441 enum {
 442         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 443         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 444         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 445         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 446         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 447         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 448 };
 449
 450 static const match_table_t tokens = {
 451         {Opt_bsd_df, "bsddf"},
 452         {Opt_minix_df, "minixdf"},
 453         {Opt_grpid, "grpid"},
 454         {Opt_grpid, "bsdgroups"},
 455         {Opt_nogrpid, "nogrpid"},
 456         {Opt_nogrpid, "sysvgroups"},
 457         {Opt_resgid, "resgid=%u"},
 458         {Opt_resuid, "resuid=%u"},
 459         {Opt_sb, "sb=%u"},
 460         {Opt_err_cont, "errors=continue"},
 461         {Opt_err_panic, "errors=panic"},
 462         {Opt_err_ro, "errors=remount-ro"},
 463         {Opt_nouid32, "nouid32"},
 464         {Opt_nocheck, "check=none"},
 465         {Opt_nocheck, "nocheck"},
 466         {Opt_debug, "debug"},
 467         {Opt_oldalloc, "oldalloc"},
 468         {Opt_orlov, "orlov"},
 469         {Opt_nobh, "nobh"},
 470         {Opt_user_xattr, "user_xattr"},
 471         {Opt_nouser_xattr, "nouser_xattr"},
 472         {Opt_acl, "acl"},
 473         {Opt_noacl, "noacl"},
 474         {Opt_xip, "xip"},
 475         {Opt_dax, "dax"},
 476         {Opt_grpquota, "grpquota"},
 477         {Opt_ignore, "noquota"},
 478         {Opt_quota, "quota"},
 479         {Opt_usrquota, "usrquota"},
 480         {Opt_reservation, "reservation"},
 481         {Opt_noreservation, "noreservation"},
 482         {Opt_err, NULL}
 483 };
 484
 485 static int parse_options(char *options, struct super_block *sb,
 486                          struct ext2_mount_options *opts)
 487 {
 488         char *p;
 489         substring_t args[MAX_OPT_ARGS];
 490         int option;
 491         kuid_t uid;
 492         kgid_t gid;
 493
 494         if (!options)
 495                 return 1;
 496
 497         while ((p = strsep (&options, ",")) != NULL) {
 498                 int token;
 499                 if (!*p)
 500                         continue;
 501
 502                 token = match_token(p, tokens, args);
 503                 switch (token) {
 504                 case Opt_bsd_df:
 505                         clear_opt (opts->s_mount_opt, MINIX_DF);
 506                         break;
 507                 case Opt_minix_df:
 508                         set_opt (opts->s_mount_opt, MINIX_DF);
 509                         break;
 510                 case Opt_grpid:
 511                         set_opt (opts->s_mount_opt, GRPID);
 512                         break;
 513                 case Opt_nogrpid:
 514                         clear_opt (opts->s_mount_opt, GRPID);
 515                         break;
 516                 case Opt_resuid:
 517                         if (match_int(&args[0], &option))
 518                                 return 0;
 519                         uid = make_kuid(current_user_ns(), option);
 520                         if (!uid_valid(uid)) {
 521                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 522                                 return 0;
 523
 524                         }
 525                         opts->s_resuid = uid;
 526                         break;
 527                 case Opt_resgid:
 528                         if (match_int(&args[0], &option))
 529                                 return 0;
 530                         gid = make_kgid(current_user_ns(), option);
 531                         if (!gid_valid(gid)) {
 532                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 533                                 return 0;
 534                         }
 535                         opts->s_resgid = gid;
 536                         break;
 537                 case Opt_sb:
 538                         /* handled by get_sb_block() instead of here */
 539                         /* *sb_block = match_int(&args[0]); */
 540                         break;
 541                 case Opt_err_panic:
 542                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 543                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 544                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 545                         break;
 546                 case Opt_err_ro:
 547                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 548                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 549                         set_opt (opts->s_mount_opt, ERRORS_RO);
 550                         break;
 551                 case Opt_err_cont:
 552                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 553                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 554                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 555                         break;
 556                 case Opt_nouid32:
 557                         set_opt (opts->s_mount_opt, NO_UID32);
 558                         break;
 559                 case Opt_nocheck:
 560                         clear_opt (opts->s_mount_opt, CHECK);
 561                         break;
 562                 case Opt_debug:
 563                         set_opt (opts->s_mount_opt, DEBUG);
 564                         break;
 565                 case Opt_oldalloc:
 566                         set_opt (opts->s_mount_opt, OLDALLOC);
 567                         break;
 568                 case Opt_orlov:
 569                         clear_opt (opts->s_mount_opt, OLDALLOC);
 570                         break;
 571                 case Opt_nobh:
 572                         set_opt (opts->s_mount_opt, NOBH);
 573                         break;
 574 #ifdef CONFIG_EXT2_FS_XATTR
 575                 case Opt_user_xattr:
 576                         set_opt (opts->s_mount_opt, XATTR_USER);
 577                         break;
 578                 case Opt_nouser_xattr:
 579                         clear_opt (opts->s_mount_opt, XATTR_USER);
 580                         break;
 581 #else
 582                 case Opt_user_xattr:
 583                 case Opt_nouser_xattr:
 584                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 585                                 "not supported");
 586                         break;
 587 #endif
 588 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 589                 case Opt_acl:
 590                         set_opt(opts->s_mount_opt, POSIX_ACL);
 591                         break;
 592                 case Opt_noacl:
 593                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 594                         break;
 595 #else
 596                 case Opt_acl:
 597                 case Opt_noacl:
 598                         ext2_msg(sb, KERN_INFO,
 599                                 "(no)acl options not supported");
 600                         break;
 601 #endif
 602                 case Opt_xip:
 603                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 604                         set_opt(opts->s_mount_opt, XIP);
 605                         /* Fall through */
 606                 case Opt_dax:
 607 #ifdef CONFIG_FS_DAX
 608                         ext2_msg(sb, KERN_WARNING,
 609                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 610                         set_opt(opts->s_mount_opt, DAX);
 611 #else
 612                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 613 #endif
 614                         break;
 615
 616 #if defined(CONFIG_QUOTA)
 617                 case Opt_quota:
 618                 case Opt_usrquota:
 619                         set_opt(opts->s_mount_opt, USRQUOTA);
 620                         break;
 621
 622                 case Opt_grpquota:
 623                         set_opt(opts->s_mount_opt, GRPQUOTA);
 624                         break;
 625 #else
 626                 case Opt_quota:
 627                 case Opt_usrquota:
 628                 case Opt_grpquota:
 629                         ext2_msg(sb, KERN_INFO,
 630                                 "quota operations not supported");
 631                         break;
 632 #endif
 633
 634                 case Opt_reservation:
 635                         set_opt(opts->s_mount_opt, RESERVATION);
 636                         ext2_msg(sb, KERN_INFO, "reservations ON");
 637                         break;
 638                 case Opt_noreservation:
 639                         clear_opt(opts->s_mount_opt, RESERVATION);
 640                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 641                         break;
 642                 case Opt_ignore:
 643                         break;
 644                 default:
 645                         return 0;
 646                 }
 647         }
 648         return 1;
 649 }
 650
 651 static int ext2_setup_super (struct super_block * sb,
 652                               struct ext2_super_block * es,
 653                               int read_only)
 654 {
 655         int res = 0;
 656         struct ext2_sb_info *sbi = EXT2_SB(sb);
 657
 658         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 659                 ext2_msg(sb, KERN_ERR,
 660                         "error: revision level too high, "
 661                         "forcing read-only mode");
 662                 res = SB_RDONLY;
 663         }
 664         if (read_only)
 665                 return res;
 666         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 667                 ext2_msg(sb, KERN_WARNING,
 668                         "warning: mounting unchecked fs, "
 669                         "running e2fsck is recommended");
 670         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 671                 ext2_msg(sb, KERN_WARNING,
 672                         "warning: mounting fs with errors, "
 673                         "running e2fsck is recommended");
 674         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 675                  le16_to_cpu(es->s_mnt_count) >=
 676                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 677                 ext2_msg(sb, KERN_WARNING,
 678                         "warning: maximal mount count reached, "
 679                         "running e2fsck is recommended");
 680         else if (le32_to_cpu(es->s_checkinterval) &&
 681                 (le32_to_cpu(es->s_lastcheck) +
 682                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 683                 ext2_msg(sb, KERN_WARNING,
 684                         "warning: checktime reached, "
 685                         "running e2fsck is recommended");
 686         if (!le16_to_cpu(es->s_max_mnt_count))
 687                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 688         le16_add_cpu(&es->s_mnt_count, 1);
 689         if (test_opt (sb, DEBUG))
 690                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 691                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 692                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 693                         sbi->s_frag_size,
 694                         sbi->s_groups_count,
 695                         EXT2_BLOCKS_PER_GROUP(sb),
 696                         EXT2_INODES_PER_GROUP(sb),
 697                         sbi->s_mount_opt);
 698         return res;
 699 }
 700
 701 static int ext2_check_descriptors(struct super_block *sb)
 702 {
 703         int i;
 704         struct ext2_sb_info *sbi = EXT2_SB(sb);
 705
 706         ext2_debug ("Checking group descriptors");
 707
 708         for (i = 0; i < sbi->s_groups_count; i++) {
 709                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 710                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 711                 ext2_fsblk_t last_block;
 712
 713                 if (i == sbi->s_groups_count - 1)
 714                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 715                 else
 716                         last_block = first_block +
 717                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 718
 719                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 720                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 721                 {
 722                         ext2_error (sb, "ext2_check_descriptors",
 723                                     "Block bitmap for group %d"
 724                                     " not in group (block %lu)!",
 725                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 726                         return 0;
 727                 }
 728                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 729                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 730                 {
 731                         ext2_error (sb, "ext2_check_descriptors",
 732                                     "Inode bitmap for group %d"
 733                                     " not in group (block %lu)!",
 734                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 735                         return 0;
 736                 }
 737                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 738                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 739                     last_block)
 740                 {
 741                         ext2_error (sb, "ext2_check_descriptors",
 742                                     "Inode table for group %d"
 743                                     " not in group (block %lu)!",
 744                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 745                         return 0;
 746                 }
 747         }
 748         return 1;
 749 }
 750
 751 /*
 752  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 753  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 754  * We need to be 1 filesystem block less than the 2^32 sector limit.
 755  */
 756 static loff_t ext2_max_size(int bits)
 757 {
 758         loff_t res = EXT2_NDIR_BLOCKS;
 759         int meta_blocks;
 760         loff_t upper_limit;
 761
 762         /* This is calculated to be the largest file size for a
 763          * dense, file such that the total number of
 764          * sectors in the file, including data and all indirect blocks,
 765          * does not exceed 2^32 -1
 766          * __u32 i_blocks representing the total number of
 767          * 512 bytes blocks of the file
 768          */
 769         upper_limit = (1LL << 32) - 1;
 770
 771         /* total blocks in file system block size */
 772         upper_limit >>= (bits - 9);
 773
 774
 775         /* indirect blocks */
 776         meta_blocks = 1;
 777         /* double indirect blocks */
 778         meta_blocks += 1 + (1LL << (bits-2));
 779         /* tripple indirect blocks */
 780         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 781
 782         upper_limit -= meta_blocks;
 783         upper_limit <<= bits;
 784
 785         res += 1LL << (bits-2);
 786         res += 1LL << (2*(bits-2));
 787         res += 1LL << (3*(bits-2));
 788         res <<= bits;
 789         if (res > upper_limit)
 790                 res = upper_limit;
 791
 792         if (res > MAX_LFS_FILESIZE)
 793                 res = MAX_LFS_FILESIZE;
 794
 795         return res;
 796 }
 797
 798 static unsigned long descriptor_loc(struct super_block *sb,
 799                                     unsigned long logic_sb_block,
 800                                     int nr)
 801 {
 802         struct ext2_sb_info *sbi = EXT2_SB(sb);
 803         unsigned long bg, first_meta_bg;
 804         int has_super = 0;
 805
 806         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 807
 808         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 809             nr < first_meta_bg)
 810                 return (logic_sb_block + nr + 1);
 811         bg = sbi->s_desc_per_block * nr;
 812         if (ext2_bg_has_super(sb, bg))
 813                 has_super = 1;
 814
 815         return ext2_group_first_block_no(sb, bg) + has_super;
 816 }
 817
 818 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 819 {
 820         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 821         struct buffer_head * bh;
 822         struct ext2_sb_info * sbi;
 823         struct ext2_super_block * es;
 824         struct inode *root;
 825         unsigned long block;
 826         unsigned long sb_block = get_sb_block(&data);
 827         unsigned long logic_sb_block;
 828         unsigned long offset = 0;
 829         unsigned long def_mount_opts;
 830         long ret = -ENOMEM;
 831         int blocksize = BLOCK_SIZE;
 832         int db_count;
 833         int i, j;
 834         __le32 features;
 835         int err;
 836         struct ext2_mount_options opts;
 837
 838         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 839         if (!sbi)
 840                 goto failed;
 841
 842         sbi->s_blockgroup_lock =
 843                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 844         if (!sbi->s_blockgroup_lock) {
 845                 kfree(sbi);
 846                 goto failed;
 847         }
 848         sb->s_fs_info = sbi;
 849         sbi->s_sb_block = sb_block;
 850         sbi->s_daxdev = dax_dev;
 851
 852         spin_lock_init(&sbi->s_lock);
 853         ret = -EINVAL;
 854
 855         /*
 856          * See what the current blocksize for the device is, and
 857          * use that as the blocksize.  Otherwise (or if the blocksize
 858          * is smaller than the default) use the default.
 859          * This is important for devices that have a hardware
 860          * sectorsize that is larger than the default.
 861          */
 862         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 863         if (!blocksize) {
 864                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 865                 goto failed_sbi;
 866         }
 867
 868         /*
 869          * If the superblock doesn't start on a hardware sector boundary,
 870          * calculate the offset.
 871          */
 872         if (blocksize != BLOCK_SIZE) {
 873                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 874                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 875         } else {
 876                 logic_sb_block = sb_block;
 877         }
 878
 879         if (!(bh = sb_bread(sb, logic_sb_block))) {
 880                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 881                 goto failed_sbi;
 882         }
 883         /*
 884          * Note: s_es must be initialized as soon as possible because
 885          *       some ext2 macro-instructions depend on its value
 886          */
 887         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 888         sbi->s_es = es;
 889         sb->s_magic = le16_to_cpu(es->s_magic);
 890
 891         if (sb->s_magic != EXT2_SUPER_MAGIC)
 892                 goto cantfind_ext2;
 893
 894         /* Set defaults before we parse the mount options */
 895         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 896         if (def_mount_opts & EXT2_DEFM_DEBUG)
 897                 set_opt(opts.s_mount_opt, DEBUG);
 898         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 899                 set_opt(opts.s_mount_opt, GRPID);
 900         if (def_mount_opts & EXT2_DEFM_UID16)
 901                 set_opt(opts.s_mount_opt, NO_UID32);
 902 #ifdef CONFIG_EXT2_FS_XATTR
 903         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 904                 set_opt(opts.s_mount_opt, XATTR_USER);
 905 #endif
 906 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 907         if (def_mount_opts & EXT2_DEFM_ACL)
 908                 set_opt(opts.s_mount_opt, POSIX_ACL);
 909 #endif
 910
 911         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 912                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
 913         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 914                 set_opt(opts.s_mount_opt, ERRORS_CONT);
 915         else
 916                 set_opt(opts.s_mount_opt, ERRORS_RO);
 917
 918         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 919         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 920
 921         set_opt(opts.s_mount_opt, RESERVATION);
 922
 923         if (!parse_options((char *) data, sb, &opts))
 924                 goto failed_mount;
 925
 926         sbi->s_mount_opt = opts.s_mount_opt;
 927         sbi->s_resuid = opts.s_resuid;
 928         sbi->s_resgid = opts.s_resgid;
 929
 930         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 931                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 932                  SB_POSIXACL : 0);
 933         sb->s_iflags |= SB_I_CGROUPWB;
 934
 935         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 936             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 937              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 938              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 939                 ext2_msg(sb, KERN_WARNING,
 940                         "warning: feature flags set on rev 0 fs, "
 941                         "running e2fsck is recommended");
 942         /*
 943          * Check feature flags regardless of the revision level, since we
 944          * previously didn't change the revision level when setting the flags,
 945          * so there is a chance incompat flags are set on a rev 0 filesystem.
 946          */
 947         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 948         if (features) {
 949                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 950                        "unsupported optional features (%x)",
 951                         le32_to_cpu(features));
 952                 goto failed_mount;
 953         }
 954         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 955                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 956                        "unsupported optional features (%x)",
 957                        le32_to_cpu(features));
 958                 goto failed_mount;
 959         }
 960
 961         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 962
 963         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 964                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
 965                         ext2_msg(sb, KERN_ERR,
 966                                 "DAX unsupported by block device. Turning off DAX.");
 967                         sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
 968                 }
 969         }
 970
 971         /* If the blocksize doesn't match, re-read the thing.. */
 972         if (sb->s_blocksize != blocksize) {
 973                 brelse(bh);
 974
 975                 if (!sb_set_blocksize(sb, blocksize)) {
 976                         ext2_msg(sb, KERN_ERR,
 977                                 "error: bad blocksize %d", blocksize);
 978                         goto failed_sbi;
 979                 }
 980
 981                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 982                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 983                 bh = sb_bread(sb, logic_sb_block);
 984                 if(!bh) {
 985                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 986                                 "superblock on 2nd try");
 987                         goto failed_sbi;
 988                 }
 989                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 990                 sbi->s_es = es;
 991                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 992                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 993                         goto failed_mount;
 994                 }
 995         }
 996
 997         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 998         sb->s_max_links = EXT2_LINK_MAX;
 999
1000         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1001                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1002                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1003         } else {
1004                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1005                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1006                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1007                     !is_power_of_2(sbi->s_inode_size) ||
1008                     (sbi->s_inode_size > blocksize)) {
1009                         ext2_msg(sb, KERN_ERR,
1010                                 "error: unsupported inode size: %d",
1011                                 sbi->s_inode_size);
1012                         goto failed_mount;
1013                 }
1014         }
1015
1016         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1017                                    le32_to_cpu(es->s_log_frag_size);
1018         if (sbi->s_frag_size == 0)
1019                 goto cantfind_ext2;
1020         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1021
1022         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1023         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1024         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1025
1026         if (EXT2_INODE_SIZE(sb) == 0)
1027                 goto cantfind_ext2;
1028         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1029         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1030                 goto cantfind_ext2;
1031         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1032                                         sbi->s_inodes_per_block;
1033         sbi->s_desc_per_block = sb->s_blocksize /
1034                                         sizeof (struct ext2_group_desc);
1035         sbi->s_sbh = bh;
1036         sbi->s_mount_state = le16_to_cpu(es->s_state);
1037         sbi->s_addr_per_block_bits =
1038                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1039         sbi->s_desc_per_block_bits =
1040                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1041
1042         if (sb->s_magic != EXT2_SUPER_MAGIC)
1043                 goto cantfind_ext2;
1044
1045         if (sb->s_blocksize != bh->b_size) {
1046                 if (!silent)
1047                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1048                 goto failed_mount;
1049         }
1050
1051         if (sb->s_blocksize != sbi->s_frag_size) {
1052                 ext2_msg(sb, KERN_ERR,
1053                         "error: fragsize %lu != blocksize %lu"
1054                         "(not supported yet)",
1055                         sbi->s_frag_size, sb->s_blocksize);
1056                 goto failed_mount;
1057         }
1058
1059         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1060                 ext2_msg(sb, KERN_ERR,
1061                         "error: #blocks per group too big: %lu",
1062                         sbi->s_blocks_per_group);
1063                 goto failed_mount;
1064         }
1065         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1066                 ext2_msg(sb, KERN_ERR,
1067                         "error: #fragments per group too big: %lu",
1068                         sbi->s_frags_per_group);
1069                 goto failed_mount;
1070         }
1071         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1072                 ext2_msg(sb, KERN_ERR,
1073                         "error: #inodes per group too big: %lu",
1074                         sbi->s_inodes_per_group);
1075                 goto failed_mount;
1076         }
1077
1078         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1079                 goto cantfind_ext2;
1080         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1081                                 le32_to_cpu(es->s_first_data_block) - 1)
1082                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1083         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1084                    EXT2_DESC_PER_BLOCK(sb);
1085         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1086         if (sbi->s_group_desc == NULL) {
1087                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1088                 goto failed_mount;
1089         }
1090         bgl_lock_init(sbi->s_blockgroup_lock);
1091         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1092         if (!sbi->s_debts) {
1093                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1094                 goto failed_mount_group_desc;
1095         }
1096         for (i = 0; i < db_count; i++) {
1097                 block = descriptor_loc(sb, logic_sb_block, i);
1098                 sbi->s_group_desc[i] = sb_bread(sb, block);
1099                 if (!sbi->s_group_desc[i]) {
1100                         for (j = 0; j < i; j++)
1101                                 brelse (sbi->s_group_desc[j]);
1102                         ext2_msg(sb, KERN_ERR,
1103                                 "error: unable to read group descriptors");
1104                         goto failed_mount_group_desc;
1105                 }
1106         }
1107         if (!ext2_check_descriptors (sb)) {
1108                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1109                 goto failed_mount2;
1110         }
1111         sbi->s_gdb_count = db_count;
1112         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1113         spin_lock_init(&sbi->s_next_gen_lock);
1114
1115         /* per fileystem reservation list head & lock */
1116         spin_lock_init(&sbi->s_rsv_window_lock);
1117         sbi->s_rsv_window_root = RB_ROOT;
1118         /*
1119          * Add a single, static dummy reservation to the start of the
1120          * reservation window list --- it gives us a placeholder for
1121          * append-at-start-of-list which makes the allocation logic
1122          * _much_ simpler.
1123          */
1124         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1125         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1126         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1127         sbi->s_rsv_window_head.rsv_goal_size = 0;
1128         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1129
1130         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1131                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1132         if (!err) {
1133                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1134                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1135         }
1136         if (!err) {
1137                 err = percpu_counter_init(&sbi->s_dirs_counter,
1138                                 ext2_count_dirs(sb), GFP_KERNEL);
1139         }
1140         if (err) {
1141                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1142                 goto failed_mount3;
1143         }
1144
1145 #ifdef CONFIG_EXT2_FS_XATTR
1146         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1147         if (!sbi->s_ea_block_cache) {
1148                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1149                 goto failed_mount3;
1150         }
1151 #endif
1152         /*
1153          * set up enough so that it can read an inode
1154          */
1155         sb->s_op = &ext2_sops;
1156         sb->s_export_op = &ext2_export_ops;
1157         sb->s_xattr = ext2_xattr_handlers;
1158
1159 #ifdef CONFIG_QUOTA
1160         sb->dq_op = &dquot_operations;
1161         sb->s_qcop = &ext2_quotactl_ops;
1162         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1163 #endif
1164
1165         root = ext2_iget(sb, EXT2_ROOT_INO);
1166         if (IS_ERR(root)) {
1167                 ret = PTR_ERR(root);
1168                 goto failed_mount3;
1169         }
1170         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1171                 iput(root);
1172                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1173                 goto failed_mount3;
1174         }
1175
1176         sb->s_root = d_make_root(root);
1177         if (!sb->s_root) {
1178                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1179                 ret = -ENOMEM;
1180                 goto failed_mount3;
1181         }
1182         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1183                 ext2_msg(sb, KERN_WARNING,
1184                         "warning: mounting ext3 filesystem as ext2");
1185         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1186                 sb->s_flags |= SB_RDONLY;
1187         ext2_write_super(sb);
1188         return 0;
1189
1190 cantfind_ext2:
1191         if (!silent)
1192                 ext2_msg(sb, KERN_ERR,
1193                         "error: can't find an ext2 filesystem on dev %s.",
1194                         sb->s_id);
1195         goto failed_mount;
1196 failed_mount3:
1197         if (sbi->s_ea_block_cache)
1198                 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1199         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1200         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1201         percpu_counter_destroy(&sbi->s_dirs_counter);
1202 failed_mount2:
1203         for (i = 0; i < db_count; i++)
1204                 brelse(sbi->s_group_desc[i]);
1205 failed_mount_group_desc:
1206         kfree(sbi->s_group_desc);
1207         kfree(sbi->s_debts);
1208 failed_mount:
1209         brelse(bh);
1210 failed_sbi:
1211         sb->s_fs_info = NULL;
1212         kfree(sbi->s_blockgroup_lock);
1213         kfree(sbi);
1214 failed:
1215         fs_put_dax(dax_dev);
1216         return ret;
1217 }
1218
1219 static void ext2_clear_super_error(struct super_block *sb)
1220 {
1221         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1222
1223         if (buffer_write_io_error(sbh)) {
1224                 /*
1225                  * Oh, dear.  A previous attempt to write the
1226                  * superblock failed.  This could happen because the
1227                  * USB device was yanked out.  Or it could happen to
1228                  * be a transient write error and maybe the block will
1229                  * be remapped.  Nothing we can do but to retry the
1230                  * write and hope for the best.
1231                  */
1232                 ext2_msg(sb, KERN_ERR,
1233                        "previous I/O error to superblock detected");
1234                 clear_buffer_write_io_error(sbh);
1235                 set_buffer_uptodate(sbh);
1236         }
1237 }
1238
1239 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1240                      int wait)
1241 {
1242         ext2_clear_super_error(sb);
1243         spin_lock(&EXT2_SB(sb)->s_lock);
1244         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1245         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1246         es->s_wtime = cpu_to_le32(get_seconds());
1247         /* unlock before we do IO */
1248         spin_unlock(&EXT2_SB(sb)->s_lock);
1249         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1250         if (wait)
1251                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1252 }
1253
1254 /*
1255  * In the second extended file system, it is not necessary to
1256  * write the super block since we use a mapping of the
1257  * disk super block in a buffer.
1258  *
1259  * However, this function is still used to set the fs valid
1260  * flags to 0.  We need to set this flag to 0 since the fs
1261  * may have been checked while mounted and e2fsck may have
1262  * set s_state to EXT2_VALID_FS after some corrections.
1263  */
1264 static int ext2_sync_fs(struct super_block *sb, int wait)
1265 {
1266         struct ext2_sb_info *sbi = EXT2_SB(sb);
1267         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1268
1269         /*
1270          * Write quota structures to quota file, sync_blockdev() will write
1271          * them to disk later
1272          */
1273         dquot_writeback_dquots(sb, -1);
1274
1275         spin_lock(&sbi->s_lock);
1276         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1277                 ext2_debug("setting valid to 0\n");
1278                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1279         }
1280         spin_unlock(&sbi->s_lock);
1281         ext2_sync_super(sb, es, wait);
1282         return 0;
1283 }
1284
1285 static int ext2_freeze(struct super_block *sb)
1286 {
1287         struct ext2_sb_info *sbi = EXT2_SB(sb);
1288
1289         /*
1290          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1291          * because we have unattached inodes and thus filesystem is not fully
1292          * consistent.
1293          */
1294         if (atomic_long_read(&sb->s_remove_count)) {
1295                 ext2_sync_fs(sb, 1);
1296                 return 0;
1297         }
1298         /* Set EXT2_FS_VALID flag */
1299         spin_lock(&sbi->s_lock);
1300         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1301         spin_unlock(&sbi->s_lock);
1302         ext2_sync_super(sb, sbi->s_es, 1);
1303
1304         return 0;
1305 }
1306
1307 static int ext2_unfreeze(struct super_block *sb)
1308 {
1309         /* Just write sb to clear EXT2_VALID_FS flag */
1310         ext2_write_super(sb);
1311
1312         return 0;
1313 }
1314
1315 static void ext2_write_super(struct super_block *sb)
1316 {
1317         if (!sb_rdonly(sb))
1318                 ext2_sync_fs(sb, 1);
1319 }
1320
1321 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1322 {
1323         struct ext2_sb_info * sbi = EXT2_SB(sb);
1324         struct ext2_super_block * es;
1325         struct ext2_mount_options new_opts;
1326         int err;
1327
1328         sync_filesystem(sb);
1329
1330         spin_lock(&sbi->s_lock);
1331         new_opts.s_mount_opt = sbi->s_mount_opt;
1332         new_opts.s_resuid = sbi->s_resuid;
1333         new_opts.s_resgid = sbi->s_resgid;
1334         spin_unlock(&sbi->s_lock);
1335
1336         /*
1337          * Allow the "check" option to be passed as a remount option.
1338          */
1339         if (!parse_options(data, sb, &new_opts))
1340                 return -EINVAL;
1341
1342         spin_lock(&sbi->s_lock);
1343         es = sbi->s_es;
1344         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1345                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1346                          "dax flag with busy inodes while remounting");
1347                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1348         }
1349         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1350                 goto out_set;
1351         if (*flags & SB_RDONLY) {
1352                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1353                     !(sbi->s_mount_state & EXT2_VALID_FS))
1354                         goto out_set;
1355
1356                 /*
1357                  * OK, we are remounting a valid rw partition rdonly, so set
1358                  * the rdonly flag and then mark the partition as valid again.
1359                  */
1360                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1361                 es->s_mtime = cpu_to_le32(get_seconds());
1362                 spin_unlock(&sbi->s_lock);
1363
1364                 err = dquot_suspend(sb, -1);
1365                 if (err < 0)
1366                         return err;
1367
1368                 ext2_sync_super(sb, es, 1);
1369         } else {
1370                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1371                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1372                 if (ret) {
1373                         spin_unlock(&sbi->s_lock);
1374                         ext2_msg(sb, KERN_WARNING,
1375                                 "warning: couldn't remount RDWR because of "
1376                                 "unsupported optional features (%x).",
1377                                 le32_to_cpu(ret));
1378                         return -EROFS;
1379                 }
1380                 /*
1381                  * Mounting a RDONLY partition read-write, so reread and
1382                  * store the current valid flag.  (It may have been changed
1383                  * by e2fsck since we originally mounted the partition.)
1384                  */
1385                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1386                 if (!ext2_setup_super (sb, es, 0))
1387                         sb->s_flags &= ~SB_RDONLY;
1388                 spin_unlock(&sbi->s_lock);
1389
1390                 ext2_write_super(sb);
1391
1392                 dquot_resume(sb, -1);
1393         }
1394
1395         spin_lock(&sbi->s_lock);
1396 out_set:
1397         sbi->s_mount_opt = new_opts.s_mount_opt;
1398         sbi->s_resuid = new_opts.s_resuid;
1399         sbi->s_resgid = new_opts.s_resgid;
1400         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1401                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1402         spin_unlock(&sbi->s_lock);
1403
1404         return 0;
1405 }
1406
1407 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1408 {
1409         struct super_block *sb = dentry->d_sb;
1410         struct ext2_sb_info *sbi = EXT2_SB(sb);
1411         struct ext2_super_block *es = sbi->s_es;
1412         u64 fsid;
1413
1414         spin_lock(&sbi->s_lock);
1415
1416         if (test_opt (sb, MINIX_DF))
1417                 sbi->s_overhead_last = 0;
1418         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1419                 unsigned long i, overhead = 0;
1420                 smp_rmb();
1421
1422                 /*
1423                  * Compute the overhead (FS structures). This is constant
1424                  * for a given filesystem unless the number of block groups
1425                  * changes so we cache the previous value until it does.
1426                  */
1427
1428                 /*
1429                  * All of the blocks before first_data_block are
1430                  * overhead
1431                  */
1432                 overhead = le32_to_cpu(es->s_first_data_block);
1433
1434                 /*
1435                  * Add the overhead attributed to the superblock and
1436                  * block group descriptors.  If the sparse superblocks
1437                  * feature is turned on, then not all groups have this.
1438                  */
1439                 for (i = 0; i < sbi->s_groups_count; i++)
1440                         overhead += ext2_bg_has_super(sb, i) +
1441                                 ext2_bg_num_gdb(sb, i);
1442
1443                 /*
1444                  * Every block group has an inode bitmap, a block
1445                  * bitmap, and an inode table.
1446                  */
1447                 overhead += (sbi->s_groups_count *
1448                              (2 + sbi->s_itb_per_group));
1449                 sbi->s_overhead_last = overhead;
1450                 smp_wmb();
1451                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1452         }
1453
1454         buf->f_type = EXT2_SUPER_MAGIC;
1455         buf->f_bsize = sb->s_blocksize;
1456         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1457         buf->f_bfree = ext2_count_free_blocks(sb);
1458         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1459         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1460         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1461                 buf->f_bavail = 0;
1462         buf->f_files = le32_to_cpu(es->s_inodes_count);
1463         buf->f_ffree = ext2_count_free_inodes(sb);
1464         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1465         buf->f_namelen = EXT2_NAME_LEN;
1466         fsid = le64_to_cpup((void *)es->s_uuid) ^
1467                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1468         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1469         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1470         spin_unlock(&sbi->s_lock);
1471         return 0;
1472 }
1473
1474 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1475         int flags, const char *dev_name, void *data)
1476 {
1477         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1478 }
1479
1480 #ifdef CONFIG_QUOTA
1481
1482 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1483  * acquiring the locks... As quota files are never truncated and quota code
1484  * itself serializes the operations (and no one else should touch the files)
1485  * we don't have to be afraid of races */
1486 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1487                                size_t len, loff_t off)
1488 {
1489         struct inode *inode = sb_dqopt(sb)->files[type];
1490         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1491         int err = 0;
1492         int offset = off & (sb->s_blocksize - 1);
1493         int tocopy;
1494         size_t toread;
1495         struct buffer_head tmp_bh;
1496         struct buffer_head *bh;
1497         loff_t i_size = i_size_read(inode);
1498
1499         if (off > i_size)
1500                 return 0;
1501         if (off+len > i_size)
1502                 len = i_size-off;
1503         toread = len;
1504         while (toread > 0) {
1505                 tocopy = sb->s_blocksize - offset < toread ?
1506                                 sb->s_blocksize - offset : toread;
1507
1508                 tmp_bh.b_state = 0;
1509                 tmp_bh.b_size = sb->s_blocksize;
1510                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1511                 if (err < 0)
1512                         return err;
1513                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1514                         memset(data, 0, tocopy);
1515                 else {
1516                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1517                         if (!bh)
1518                                 return -EIO;
1519                         memcpy(data, bh->b_data+offset, tocopy);
1520                         brelse(bh);
1521                 }
1522                 offset = 0;
1523                 toread -= tocopy;
1524                 data += tocopy;
1525                 blk++;
1526         }
1527         return len;
1528 }
1529
1530 /* Write to quotafile */
1531 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1532                                 const char *data, size_t len, loff_t off)
1533 {
1534         struct inode *inode = sb_dqopt(sb)->files[type];
1535         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1536         int err = 0;
1537         int offset = off & (sb->s_blocksize - 1);
1538         int tocopy;
1539         size_t towrite = len;
1540         struct buffer_head tmp_bh;
1541         struct buffer_head *bh;
1542
1543         while (towrite > 0) {
1544                 tocopy = sb->s_blocksize - offset < towrite ?
1545                                 sb->s_blocksize - offset : towrite;
1546
1547                 tmp_bh.b_state = 0;
1548                 tmp_bh.b_size = sb->s_blocksize;
1549                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1550                 if (err < 0)
1551                         goto out;
1552                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1553                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1554                 else
1555                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1556                 if (unlikely(!bh)) {
1557                         err = -EIO;
1558                         goto out;
1559                 }
1560                 lock_buffer(bh);
1561                 memcpy(bh->b_data+offset, data, tocopy);
1562                 flush_dcache_page(bh->b_page);
1563                 set_buffer_uptodate(bh);
1564                 mark_buffer_dirty(bh);
1565                 unlock_buffer(bh);
1566                 brelse(bh);
1567                 offset = 0;
1568                 towrite -= tocopy;
1569                 data += tocopy;
1570                 blk++;
1571         }
1572 out:
1573         if (len == towrite)
1574                 return err;
1575         if (inode->i_size < off+len-towrite)
1576                 i_size_write(inode, off+len-towrite);
1577         inode_inc_iversion(inode);
1578         inode->i_mtime = inode->i_ctime = current_time(inode);
1579         mark_inode_dirty(inode);
1580         return len - towrite;
1581 }
1582
1583 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1584                          const struct path *path)
1585 {
1586         int err;
1587         struct inode *inode;
1588
1589         err = dquot_quota_on(sb, type, format_id, path);
1590         if (err)
1591                 return err;
1592
1593         inode = d_inode(path->dentry);
1594         inode_lock(inode);
1595         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1596         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1597                         S_NOATIME | S_IMMUTABLE);
1598         inode_unlock(inode);
1599         mark_inode_dirty(inode);
1600
1601         return 0;
1602 }
1603
1604 static int ext2_quota_off(struct super_block *sb, int type)
1605 {
1606         struct inode *inode = sb_dqopt(sb)->files[type];
1607         int err;
1608
1609         if (!inode || !igrab(inode))
1610                 goto out;
1611
1612         err = dquot_quota_off(sb, type);
1613         if (err)
1614                 goto out_put;
1615
1616         inode_lock(inode);
1617         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1618         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1619         inode_unlock(inode);
1620         mark_inode_dirty(inode);
1621 out_put:
1622         iput(inode);
1623         return err;
1624 out:
1625         return dquot_quota_off(sb, type);
1626 }
1627
1628 #endif
1629
1630 static struct file_system_type ext2_fs_type = {
1631         .owner          = THIS_MODULE,
1632         .name           = "ext2",
1633         .mount          = ext2_mount,
1634         .kill_sb        = kill_block_super,
1635         .fs_flags       = FS_REQUIRES_DEV,
1636 };
1637 MODULE_ALIAS_FS("ext2");
1638
1639 static int __init init_ext2_fs(void)
1640 {
1641         int err;
1642
1643         err = init_inodecache();
1644         if (err)
1645                 return err;
1646         err = register_filesystem(&ext2_fs_type);
1647         if (err)
1648                 goto out;
1649         return 0;
1650 out:
1651         destroy_inodecache();
1652         return err;
1653 }
1654
1655 static void __exit exit_ext2_fs(void)
1656 {
1657         unregister_filesystem(&ext2_fs_type);
1658         destroy_inodecache();
1659 }
1660
1661 MODULE_AUTHOR("Remy Card and others");
1662 MODULE_DESCRIPTION("Second Extended Filesystem");
1663 MODULE_LICENSE("GPL");
1664 module_init(init_ext2_fs)
1665 module_exit(exit_ext2_fs)