fs/ext2/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/fs/ext2/super.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/inode.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller (davem@caip.rutgers.edu), 1995
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/fs.h>
  23 #include <linux/slab.h>
  24 #include <linux/init.h>
  25 #include <linux/blkdev.h>
  26 #include <linux/parser.h>
  27 #include <linux/random.h>
  28 #include <linux/buffer_head.h>
  29 #include <linux/exportfs.h>
  30 #include <linux/vfs.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/mount.h>
  33 #include <linux/log2.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/dax.h>
  37 #include <linux/iversion.h>
  38 #include "ext2.h"
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 static void ext2_write_super(struct super_block *sb);
  43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45 static int ext2_sync_fs(struct super_block *sb, int wait);
  46 static int ext2_freeze(struct super_block *sb);
  47 static int ext2_unfreeze(struct super_block *sb);
  48
  49 void ext2_error(struct super_block *sb, const char *function,
  50                 const char *fmt, ...)
  51 {
  52         struct va_format vaf;
  53         va_list args;
  54         struct ext2_sb_info *sbi = EXT2_SB(sb);
  55         struct ext2_super_block *es = sbi->s_es;
  56
  57         if (!sb_rdonly(sb)) {
  58                 spin_lock(&sbi->s_lock);
  59                 sbi->s_mount_state |= EXT2_ERROR_FS;
  60                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  61                 spin_unlock(&sbi->s_lock);
  62                 ext2_sync_super(sb, es, 1);
  63         }
  64
  65         va_start(args, fmt);
  66
  67         vaf.fmt = fmt;
  68         vaf.va = &args;
  69
  70         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  71                sb->s_id, function, &vaf);
  72
  73         va_end(args);
  74
  75         if (test_opt(sb, ERRORS_PANIC))
  76                 panic("EXT2-fs: panic from previous error\n");
  77         if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {
  78                 ext2_msg(sb, KERN_CRIT,
  79                              "error: remounting filesystem read-only");
  80                 sb->s_flags |= SB_RDONLY;
  81         }
  82 }
  83
  84 void ext2_msg(struct super_block *sb, const char *prefix,
  85                 const char *fmt, ...)
  86 {
  87         struct va_format vaf;
  88         va_list args;
  89
  90         va_start(args, fmt);
  91
  92         vaf.fmt = fmt;
  93         vaf.va = &args;
  94
  95         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  96
  97         va_end(args);
  98 }
  99
 100 /*
 101  * This must be called with sbi->s_lock held.
 102  */
 103 void ext2_update_dynamic_rev(struct super_block *sb)
 104 {
 105         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 106
 107         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 108                 return;
 109
 110         ext2_msg(sb, KERN_WARNING,
 111                      "warning: updating to rev %d because of "
 112                      "new feature flag, running e2fsck is recommended",
 113                      EXT2_DYNAMIC_REV);
 114
 115         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 116         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 117         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 118         /* leave es->s_feature_*compat flags alone */
 119         /* es->s_uuid will be set by e2fsck if empty */
 120
 121         /*
 122          * The rest of the superblock fields should be zero, and if not it
 123          * means they are likely already in use, so leave them alone.  We
 124          * can leave it up to e2fsck to clean up any inconsistencies there.
 125          */
 126 }
 127
 128 #ifdef CONFIG_QUOTA
 129 static int ext2_quota_off(struct super_block *sb, int type);
 130
 131 static void ext2_quota_off_umount(struct super_block *sb)
 132 {
 133         int type;
 134
 135         for (type = 0; type < MAXQUOTAS; type++)
 136                 ext2_quota_off(sb, type);
 137 }
 138 #else
 139 static inline void ext2_quota_off_umount(struct super_block *sb)
 140 {
 141 }
 142 #endif
 143
 144 static void ext2_put_super (struct super_block * sb)
 145 {
 146         int db_count;
 147         int i;
 148         struct ext2_sb_info *sbi = EXT2_SB(sb);
 149
 150         ext2_quota_off_umount(sb);
 151
 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                 brelse(sbi->s_group_desc[i]);
 166         kvfree(sbi->s_group_desc);
 167         kfree(sbi->s_debts);
 168         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 169         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 170         percpu_counter_destroy(&sbi->s_dirs_counter);
 171         brelse (sbi->s_sbh);
 172         sb->s_fs_info = NULL;
 173         kfree(sbi->s_blockgroup_lock);
 174         fs_put_dax(sbi->s_daxdev, NULL);
 175         kfree(sbi);
 176 }
 177
 178 static struct kmem_cache * ext2_inode_cachep;
 179
 180 static struct inode *ext2_alloc_inode(struct super_block *sb)
 181 {
 182         struct ext2_inode_info *ei;
 183         ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
 184         if (!ei)
 185                 return NULL;
 186         ei->i_block_alloc_info = NULL;
 187         inode_set_iversion(&ei->vfs_inode, 1);
 188 #ifdef CONFIG_QUOTA
 189         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 190 #endif
 191
 192         return &ei->vfs_inode;
 193 }
 194
 195 static void ext2_free_in_core_inode(struct inode *inode)
 196 {
 197         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 198 }
 199
 200 static void init_once(void *foo)
 201 {
 202         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 203
 204         rwlock_init(&ei->i_meta_lock);
 205 #ifdef CONFIG_EXT2_FS_XATTR
 206         init_rwsem(&ei->xattr_sem);
 207 #endif
 208         mutex_init(&ei->truncate_mutex);
 209         inode_init_once(&ei->vfs_inode);
 210 }
 211
 212 static int __init init_inodecache(void)
 213 {
 214         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 215                                 sizeof(struct ext2_inode_info), 0,
 216                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 217                                         SLAB_ACCOUNT),
 218                                 offsetof(struct ext2_inode_info, i_data),
 219                                 sizeof_field(struct ext2_inode_info, i_data),
 220                                 init_once);
 221         if (ext2_inode_cachep == NULL)
 222                 return -ENOMEM;
 223         return 0;
 224 }
 225
 226 static void destroy_inodecache(void)
 227 {
 228         /*
 229          * Make sure all delayed rcu free inodes are flushed before we
 230          * destroy cache.
 231          */
 232         rcu_barrier();
 233         kmem_cache_destroy(ext2_inode_cachep);
 234 }
 235
 236 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 237 {
 238         struct super_block *sb = root->d_sb;
 239         struct ext2_sb_info *sbi = EXT2_SB(sb);
 240         struct ext2_super_block *es = sbi->s_es;
 241         unsigned long def_mount_opts;
 242
 243         spin_lock(&sbi->s_lock);
 244         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 245
 246         if (sbi->s_sb_block != 1)
 247                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 248         if (test_opt(sb, MINIX_DF))
 249                 seq_puts(seq, ",minixdf");
 250         if (test_opt(sb, GRPID))
 251                 seq_puts(seq, ",grpid");
 252         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 253                 seq_puts(seq, ",nogrpid");
 254         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 255             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 256                 seq_printf(seq, ",resuid=%u",
 257                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 258         }
 259         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 260             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 261                 seq_printf(seq, ",resgid=%u",
 262                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 263         }
 264         if (test_opt(sb, ERRORS_RO)) {
 265                 int def_errors = le16_to_cpu(es->s_errors);
 266
 267                 if (def_errors == EXT2_ERRORS_PANIC ||
 268                     def_errors == EXT2_ERRORS_CONTINUE) {
 269                         seq_puts(seq, ",errors=remount-ro");
 270                 }
 271         }
 272         if (test_opt(sb, ERRORS_CONT))
 273                 seq_puts(seq, ",errors=continue");
 274         if (test_opt(sb, ERRORS_PANIC))
 275                 seq_puts(seq, ",errors=panic");
 276         if (test_opt(sb, NO_UID32))
 277                 seq_puts(seq, ",nouid32");
 278         if (test_opt(sb, DEBUG))
 279                 seq_puts(seq, ",debug");
 280         if (test_opt(sb, OLDALLOC))
 281                 seq_puts(seq, ",oldalloc");
 282
 283 #ifdef CONFIG_EXT2_FS_XATTR
 284         if (test_opt(sb, XATTR_USER))
 285                 seq_puts(seq, ",user_xattr");
 286         if (!test_opt(sb, XATTR_USER) &&
 287             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 288                 seq_puts(seq, ",nouser_xattr");
 289         }
 290 #endif
 291
 292 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 293         if (test_opt(sb, POSIX_ACL))
 294                 seq_puts(seq, ",acl");
 295         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 296                 seq_puts(seq, ",noacl");
 297 #endif
 298
 299         if (test_opt(sb, USRQUOTA))
 300                 seq_puts(seq, ",usrquota");
 301
 302         if (test_opt(sb, GRPQUOTA))
 303                 seq_puts(seq, ",grpquota");
 304
 305         if (test_opt(sb, XIP))
 306                 seq_puts(seq, ",xip");
 307
 308         if (test_opt(sb, DAX))
 309                 seq_puts(seq, ",dax");
 310
 311         if (!test_opt(sb, RESERVATION))
 312                 seq_puts(seq, ",noreservation");
 313
 314         spin_unlock(&sbi->s_lock);
 315         return 0;
 316 }
 317
 318 #ifdef CONFIG_QUOTA
 319 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 320 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 321 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 322                          const struct path *path);
 323 static struct dquot **ext2_get_dquots(struct inode *inode)
 324 {
 325         return EXT2_I(inode)->i_dquot;
 326 }
 327
 328 static const struct quotactl_ops ext2_quotactl_ops = {
 329         .quota_on       = ext2_quota_on,
 330         .quota_off      = ext2_quota_off,
 331         .quota_sync     = dquot_quota_sync,
 332         .get_state      = dquot_get_state,
 333         .set_info       = dquot_set_dqinfo,
 334         .get_dqblk      = dquot_get_dqblk,
 335         .set_dqblk      = dquot_set_dqblk,
 336         .get_nextdqblk  = dquot_get_next_dqblk,
 337 };
 338 #endif
 339
 340 static const struct super_operations ext2_sops = {
 341         .alloc_inode    = ext2_alloc_inode,
 342         .free_inode     = ext2_free_in_core_inode,
 343         .write_inode    = ext2_write_inode,
 344         .evict_inode    = ext2_evict_inode,
 345         .put_super      = ext2_put_super,
 346         .sync_fs        = ext2_sync_fs,
 347         .freeze_fs      = ext2_freeze,
 348         .unfreeze_fs    = ext2_unfreeze,
 349         .statfs         = ext2_statfs,
 350         .remount_fs     = ext2_remount,
 351         .show_options   = ext2_show_options,
 352 #ifdef CONFIG_QUOTA
 353         .quota_read     = ext2_quota_read,
 354         .quota_write    = ext2_quota_write,
 355         .get_dquots     = ext2_get_dquots,
 356 #endif
 357 };
 358
 359 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 360                 u64 ino, u32 generation)
 361 {
 362         struct inode *inode;
 363
 364         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 365                 return ERR_PTR(-ESTALE);
 366         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 367                 return ERR_PTR(-ESTALE);
 368
 369         /*
 370          * ext2_iget isn't quite right if the inode is currently unallocated!
 371          * However ext2_iget currently does appropriate checks to handle stale
 372          * inodes so everything is OK.
 373          */
 374         inode = ext2_iget(sb, ino);
 375         if (IS_ERR(inode))
 376                 return ERR_CAST(inode);
 377         if (generation && inode->i_generation != generation) {
 378                 /* we didn't find the right inode.. */
 379                 iput(inode);
 380                 return ERR_PTR(-ESTALE);
 381         }
 382         return inode;
 383 }
 384
 385 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 386                 int fh_len, int fh_type)
 387 {
 388         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 389                                     ext2_nfs_get_inode);
 390 }
 391
 392 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 393                 int fh_len, int fh_type)
 394 {
 395         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 396                                     ext2_nfs_get_inode);
 397 }
 398
 399 static const struct export_operations ext2_export_ops = {
 400         .fh_to_dentry = ext2_fh_to_dentry,
 401         .fh_to_parent = ext2_fh_to_parent,
 402         .get_parent = ext2_get_parent,
 403 };
 404
 405 static unsigned long get_sb_block(void **data)
 406 {
 407         unsigned long   sb_block;
 408         char            *options = (char *) *data;
 409
 410         if (!options || strncmp(options, "sb=", 3) != 0)
 411                 return 1;       /* Default location */
 412         options += 3;
 413         sb_block = simple_strtoul(options, &options, 0);
 414         if (*options && *options != ',') {
 415                 printk("EXT2-fs: Invalid sb specification: %s\n",
 416                        (char *) *data);
 417                 return 1;
 418         }
 419         if (*options == ',')
 420                 options++;
 421         *data = (void *) options;
 422         return sb_block;
 423 }
 424
 425 enum {
 426         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 427         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 428         Opt_err_ro, Opt_nouid32, Opt_debug,
 429         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 430         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 431         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 432 };
 433
 434 static const match_table_t tokens = {
 435         {Opt_bsd_df, "bsddf"},
 436         {Opt_minix_df, "minixdf"},
 437         {Opt_grpid, "grpid"},
 438         {Opt_grpid, "bsdgroups"},
 439         {Opt_nogrpid, "nogrpid"},
 440         {Opt_nogrpid, "sysvgroups"},
 441         {Opt_resgid, "resgid=%u"},
 442         {Opt_resuid, "resuid=%u"},
 443         {Opt_sb, "sb=%u"},
 444         {Opt_err_cont, "errors=continue"},
 445         {Opt_err_panic, "errors=panic"},
 446         {Opt_err_ro, "errors=remount-ro"},
 447         {Opt_nouid32, "nouid32"},
 448         {Opt_debug, "debug"},
 449         {Opt_oldalloc, "oldalloc"},
 450         {Opt_orlov, "orlov"},
 451         {Opt_nobh, "nobh"},
 452         {Opt_user_xattr, "user_xattr"},
 453         {Opt_nouser_xattr, "nouser_xattr"},
 454         {Opt_acl, "acl"},
 455         {Opt_noacl, "noacl"},
 456         {Opt_xip, "xip"},
 457         {Opt_dax, "dax"},
 458         {Opt_grpquota, "grpquota"},
 459         {Opt_ignore, "noquota"},
 460         {Opt_quota, "quota"},
 461         {Opt_usrquota, "usrquota"},
 462         {Opt_reservation, "reservation"},
 463         {Opt_noreservation, "noreservation"},
 464         {Opt_err, NULL}
 465 };
 466
 467 static int parse_options(char *options, struct super_block *sb,
 468                          struct ext2_mount_options *opts)
 469 {
 470         char *p;
 471         substring_t args[MAX_OPT_ARGS];
 472         int option;
 473         kuid_t uid;
 474         kgid_t gid;
 475
 476         if (!options)
 477                 return 1;
 478
 479         while ((p = strsep (&options, ",")) != NULL) {
 480                 int token;
 481                 if (!*p)
 482                         continue;
 483
 484                 token = match_token(p, tokens, args);
 485                 switch (token) {
 486                 case Opt_bsd_df:
 487                         clear_opt (opts->s_mount_opt, MINIX_DF);
 488                         break;
 489                 case Opt_minix_df:
 490                         set_opt (opts->s_mount_opt, MINIX_DF);
 491                         break;
 492                 case Opt_grpid:
 493                         set_opt (opts->s_mount_opt, GRPID);
 494                         break;
 495                 case Opt_nogrpid:
 496                         clear_opt (opts->s_mount_opt, GRPID);
 497                         break;
 498                 case Opt_resuid:
 499                         if (match_int(&args[0], &option))
 500                                 return 0;
 501                         uid = make_kuid(current_user_ns(), option);
 502                         if (!uid_valid(uid)) {
 503                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 504                                 return 0;
 505
 506                         }
 507                         opts->s_resuid = uid;
 508                         break;
 509                 case Opt_resgid:
 510                         if (match_int(&args[0], &option))
 511                                 return 0;
 512                         gid = make_kgid(current_user_ns(), option);
 513                         if (!gid_valid(gid)) {
 514                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 515                                 return 0;
 516                         }
 517                         opts->s_resgid = gid;
 518                         break;
 519                 case Opt_sb:
 520                         /* handled by get_sb_block() instead of here */
 521                         /* *sb_block = match_int(&args[0]); */
 522                         break;
 523                 case Opt_err_panic:
 524                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 525                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 526                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 527                         break;
 528                 case Opt_err_ro:
 529                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 530                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 531                         set_opt (opts->s_mount_opt, ERRORS_RO);
 532                         break;
 533                 case Opt_err_cont:
 534                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 535                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 536                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 537                         break;
 538                 case Opt_nouid32:
 539                         set_opt (opts->s_mount_opt, NO_UID32);
 540                         break;
 541                 case Opt_debug:
 542                         set_opt (opts->s_mount_opt, DEBUG);
 543                         break;
 544                 case Opt_oldalloc:
 545                         set_opt (opts->s_mount_opt, OLDALLOC);
 546                         break;
 547                 case Opt_orlov:
 548                         clear_opt (opts->s_mount_opt, OLDALLOC);
 549                         break;
 550                 case Opt_nobh:
 551                         ext2_msg(sb, KERN_INFO,
 552                                 "nobh option not supported");
 553                         break;
 554 #ifdef CONFIG_EXT2_FS_XATTR
 555                 case Opt_user_xattr:
 556                         set_opt (opts->s_mount_opt, XATTR_USER);
 557                         break;
 558                 case Opt_nouser_xattr:
 559                         clear_opt (opts->s_mount_opt, XATTR_USER);
 560                         break;
 561 #else
 562                 case Opt_user_xattr:
 563                 case Opt_nouser_xattr:
 564                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 565                                 "not supported");
 566                         break;
 567 #endif
 568 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 569                 case Opt_acl:
 570                         set_opt(opts->s_mount_opt, POSIX_ACL);
 571                         break;
 572                 case Opt_noacl:
 573                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 574                         break;
 575 #else
 576                 case Opt_acl:
 577                 case Opt_noacl:
 578                         ext2_msg(sb, KERN_INFO,
 579                                 "(no)acl options not supported");
 580                         break;
 581 #endif
 582                 case Opt_xip:
 583                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 584                         set_opt(opts->s_mount_opt, XIP);
 585                         fallthrough;
 586                 case Opt_dax:
 587 #ifdef CONFIG_FS_DAX
 588                         ext2_msg(sb, KERN_WARNING,
 589                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 590                         set_opt(opts->s_mount_opt, DAX);
 591 #else
 592                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 593 #endif
 594                         break;
 595
 596 #if defined(CONFIG_QUOTA)
 597                 case Opt_quota:
 598                 case Opt_usrquota:
 599                         set_opt(opts->s_mount_opt, USRQUOTA);
 600                         break;
 601
 602                 case Opt_grpquota:
 603                         set_opt(opts->s_mount_opt, GRPQUOTA);
 604                         break;
 605 #else
 606                 case Opt_quota:
 607                 case Opt_usrquota:
 608                 case Opt_grpquota:
 609                         ext2_msg(sb, KERN_INFO,
 610                                 "quota operations not supported");
 611                         break;
 612 #endif
 613
 614                 case Opt_reservation:
 615                         set_opt(opts->s_mount_opt, RESERVATION);
 616                         ext2_msg(sb, KERN_INFO, "reservations ON");
 617                         break;
 618                 case Opt_noreservation:
 619                         clear_opt(opts->s_mount_opt, RESERVATION);
 620                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 621                         break;
 622                 case Opt_ignore:
 623                         break;
 624                 default:
 625                         return 0;
 626                 }
 627         }
 628         return 1;
 629 }
 630
 631 static int ext2_setup_super (struct super_block * sb,
 632                               struct ext2_super_block * es,
 633                               int read_only)
 634 {
 635         int res = 0;
 636         struct ext2_sb_info *sbi = EXT2_SB(sb);
 637
 638         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 639                 ext2_msg(sb, KERN_ERR,
 640                         "error: revision level too high, "
 641                         "forcing read-only mode");
 642                 res = SB_RDONLY;
 643         }
 644         if (read_only)
 645                 return res;
 646         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 647                 ext2_msg(sb, KERN_WARNING,
 648                         "warning: mounting unchecked fs, "
 649                         "running e2fsck is recommended");
 650         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 651                 ext2_msg(sb, KERN_WARNING,
 652                         "warning: mounting fs with errors, "
 653                         "running e2fsck is recommended");
 654         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 655                  le16_to_cpu(es->s_mnt_count) >=
 656                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 657                 ext2_msg(sb, KERN_WARNING,
 658                         "warning: maximal mount count reached, "
 659                         "running e2fsck is recommended");
 660         else if (le32_to_cpu(es->s_checkinterval) &&
 661                 (le32_to_cpu(es->s_lastcheck) +
 662                         le32_to_cpu(es->s_checkinterval) <=
 663                         ktime_get_real_seconds()))
 664                 ext2_msg(sb, KERN_WARNING,
 665                         "warning: checktime reached, "
 666                         "running e2fsck is recommended");
 667         if (!le16_to_cpu(es->s_max_mnt_count))
 668                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 669         le16_add_cpu(&es->s_mnt_count, 1);
 670         if (test_opt (sb, DEBUG))
 671                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 672                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 673                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 674                         sbi->s_frag_size,
 675                         sbi->s_groups_count,
 676                         EXT2_BLOCKS_PER_GROUP(sb),
 677                         EXT2_INODES_PER_GROUP(sb),
 678                         sbi->s_mount_opt);
 679         return res;
 680 }
 681
 682 static int ext2_check_descriptors(struct super_block *sb)
 683 {
 684         int i;
 685         struct ext2_sb_info *sbi = EXT2_SB(sb);
 686
 687         ext2_debug ("Checking group descriptors");
 688
 689         for (i = 0; i < sbi->s_groups_count; i++) {
 690                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 691                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 692                 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
 693
 694                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 695                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 696                 {
 697                         ext2_error (sb, "ext2_check_descriptors",
 698                                     "Block bitmap for group %d"
 699                                     " not in group (block %lu)!",
 700                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 701                         return 0;
 702                 }
 703                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 704                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 705                 {
 706                         ext2_error (sb, "ext2_check_descriptors",
 707                                     "Inode bitmap for group %d"
 708                                     " not in group (block %lu)!",
 709                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 710                         return 0;
 711                 }
 712                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 713                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 714                     last_block)
 715                 {
 716                         ext2_error (sb, "ext2_check_descriptors",
 717                                     "Inode table for group %d"
 718                                     " not in group (block %lu)!",
 719                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 720                         return 0;
 721                 }
 722         }
 723         return 1;
 724 }
 725
 726 /*
 727  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 728  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 729  * We need to be 1 filesystem block less than the 2^32 sector limit.
 730  */
 731 static loff_t ext2_max_size(int bits)
 732 {
 733         loff_t res = EXT2_NDIR_BLOCKS;
 734         int meta_blocks;
 735         unsigned int upper_limit;
 736         unsigned int ppb = 1 << (bits-2);
 737
 738         /* This is calculated to be the largest file size for a
 739          * dense, file such that the total number of
 740          * sectors in the file, including data and all indirect blocks,
 741          * does not exceed 2^32 -1
 742          * __u32 i_blocks representing the total number of
 743          * 512 bytes blocks of the file
 744          */
 745         upper_limit = (1LL << 32) - 1;
 746
 747         /* total blocks in file system block size */
 748         upper_limit >>= (bits - 9);
 749
 750         /* Compute how many blocks we can address by block tree */
 751         res += 1LL << (bits-2);
 752         res += 1LL << (2*(bits-2));
 753         res += 1LL << (3*(bits-2));
 754         /* Compute how many metadata blocks are needed */
 755         meta_blocks = 1;
 756         meta_blocks += 1 + ppb;
 757         meta_blocks += 1 + ppb + ppb * ppb;
 758         /* Does block tree limit file size? */
 759         if (res + meta_blocks <= upper_limit)
 760                 goto check_lfs;
 761
 762         res = upper_limit;
 763         /* How many metadata blocks are needed for addressing upper_limit? */
 764         upper_limit -= EXT2_NDIR_BLOCKS;
 765         /* indirect blocks */
 766         meta_blocks = 1;
 767         upper_limit -= ppb;
 768         /* double indirect blocks */
 769         if (upper_limit < ppb * ppb) {
 770                 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
 771                 res -= meta_blocks;
 772                 goto check_lfs;
 773         }
 774         meta_blocks += 1 + ppb;
 775         upper_limit -= ppb * ppb;
 776         /* tripple indirect blocks for the rest */
 777         meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
 778                 DIV_ROUND_UP(upper_limit, ppb*ppb);
 779         res -= meta_blocks;
 780 check_lfs:
 781         res <<= bits;
 782         if (res > MAX_LFS_FILESIZE)
 783                 res = MAX_LFS_FILESIZE;
 784
 785         return res;
 786 }
 787
 788 static unsigned long descriptor_loc(struct super_block *sb,
 789                                     unsigned long logic_sb_block,
 790                                     int nr)
 791 {
 792         struct ext2_sb_info *sbi = EXT2_SB(sb);
 793         unsigned long bg, first_meta_bg;
 794
 795         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 796
 797         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 798             nr < first_meta_bg)
 799                 return (logic_sb_block + nr + 1);
 800         bg = sbi->s_desc_per_block * nr;
 801
 802         return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
 803 }
 804
 805 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 806 {
 807         struct buffer_head * bh;
 808         struct ext2_sb_info * sbi;
 809         struct ext2_super_block * es;
 810         struct inode *root;
 811         unsigned long block;
 812         unsigned long sb_block = get_sb_block(&data);
 813         unsigned long logic_sb_block;
 814         unsigned long offset = 0;
 815         unsigned long def_mount_opts;
 816         long ret = -ENOMEM;
 817         int blocksize = BLOCK_SIZE;
 818         int db_count;
 819         int i, j;
 820         __le32 features;
 821         int err;
 822         struct ext2_mount_options opts;
 823
 824         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 825         if (!sbi)
 826                 return -ENOMEM;
 827
 828         sbi->s_blockgroup_lock =
 829                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 830         if (!sbi->s_blockgroup_lock) {
 831                 kfree(sbi);
 832                 return -ENOMEM;
 833         }
 834         sb->s_fs_info = sbi;
 835         sbi->s_sb_block = sb_block;
 836         sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
 837                                            NULL, NULL);
 838
 839         spin_lock_init(&sbi->s_lock);
 840         ret = -EINVAL;
 841
 842         /*
 843          * See what the current blocksize for the device is, and
 844          * use that as the blocksize.  Otherwise (or if the blocksize
 845          * is smaller than the default) use the default.
 846          * This is important for devices that have a hardware
 847          * sectorsize that is larger than the default.
 848          */
 849         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 850         if (!blocksize) {
 851                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 852                 goto failed_sbi;
 853         }
 854
 855         /*
 856          * If the superblock doesn't start on a hardware sector boundary,
 857          * calculate the offset.
 858          */
 859         if (blocksize != BLOCK_SIZE) {
 860                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 861                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 862         } else {
 863                 logic_sb_block = sb_block;
 864         }
 865
 866         if (!(bh = sb_bread(sb, logic_sb_block))) {
 867                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 868                 goto failed_sbi;
 869         }
 870         /*
 871          * Note: s_es must be initialized as soon as possible because
 872          *       some ext2 macro-instructions depend on its value
 873          */
 874         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 875         sbi->s_es = es;
 876         sb->s_magic = le16_to_cpu(es->s_magic);
 877
 878         if (sb->s_magic != EXT2_SUPER_MAGIC)
 879                 goto cantfind_ext2;
 880
 881         opts.s_mount_opt = 0;
 882         /* Set defaults before we parse the mount options */
 883         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 884         if (def_mount_opts & EXT2_DEFM_DEBUG)
 885                 set_opt(opts.s_mount_opt, DEBUG);
 886         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 887                 set_opt(opts.s_mount_opt, GRPID);
 888         if (def_mount_opts & EXT2_DEFM_UID16)
 889                 set_opt(opts.s_mount_opt, NO_UID32);
 890 #ifdef CONFIG_EXT2_FS_XATTR
 891         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 892                 set_opt(opts.s_mount_opt, XATTR_USER);
 893 #endif
 894 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 895         if (def_mount_opts & EXT2_DEFM_ACL)
 896                 set_opt(opts.s_mount_opt, POSIX_ACL);
 897 #endif
 898
 899         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 900                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
 901         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 902                 set_opt(opts.s_mount_opt, ERRORS_CONT);
 903         else
 904                 set_opt(opts.s_mount_opt, ERRORS_RO);
 905
 906         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 907         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 908
 909         set_opt(opts.s_mount_opt, RESERVATION);
 910
 911         if (!parse_options((char *) data, sb, &opts))
 912                 goto failed_mount;
 913
 914         sbi->s_mount_opt = opts.s_mount_opt;
 915         sbi->s_resuid = opts.s_resuid;
 916         sbi->s_resgid = opts.s_resgid;
 917
 918         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 919                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
 920         sb->s_iflags |= SB_I_CGROUPWB;
 921
 922         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 923             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 924              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 925              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 926                 ext2_msg(sb, KERN_WARNING,
 927                         "warning: feature flags set on rev 0 fs, "
 928                         "running e2fsck is recommended");
 929         /*
 930          * Check feature flags regardless of the revision level, since we
 931          * previously didn't change the revision level when setting the flags,
 932          * so there is a chance incompat flags are set on a rev 0 filesystem.
 933          */
 934         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 935         if (features) {
 936                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 937                        "unsupported optional features (%x)",
 938                         le32_to_cpu(features));
 939                 goto failed_mount;
 940         }
 941         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 942                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 943                        "unsupported optional features (%x)",
 944                        le32_to_cpu(features));
 945                 goto failed_mount;
 946         }
 947
 948         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 949
 950         if (test_opt(sb, DAX)) {
 951                 if (!sbi->s_daxdev) {
 952                         ext2_msg(sb, KERN_ERR,
 953                                 "DAX unsupported by block device. Turning off DAX.");
 954                         clear_opt(sbi->s_mount_opt, DAX);
 955                 } else if (blocksize != PAGE_SIZE) {
 956                         ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
 957                         clear_opt(sbi->s_mount_opt, DAX);
 958                 }
 959         }
 960
 961         /* If the blocksize doesn't match, re-read the thing.. */
 962         if (sb->s_blocksize != blocksize) {
 963                 brelse(bh);
 964
 965                 if (!sb_set_blocksize(sb, blocksize)) {
 966                         ext2_msg(sb, KERN_ERR,
 967                                 "error: bad blocksize %d", blocksize);
 968                         goto failed_sbi;
 969                 }
 970
 971                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 972                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 973                 bh = sb_bread(sb, logic_sb_block);
 974                 if(!bh) {
 975                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 976                                 "superblock on 2nd try");
 977                         goto failed_sbi;
 978                 }
 979                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 980                 sbi->s_es = es;
 981                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 982                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 983                         goto failed_mount;
 984                 }
 985         }
 986
 987         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 988         sb->s_max_links = EXT2_LINK_MAX;
 989         sb->s_time_min = S32_MIN;
 990         sb->s_time_max = S32_MAX;
 991
 992         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 993                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 994                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 995         } else {
 996                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 997                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 998                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 999                     !is_power_of_2(sbi->s_inode_size) ||
1000                     (sbi->s_inode_size > blocksize)) {
1001                         ext2_msg(sb, KERN_ERR,
1002                                 "error: unsupported inode size: %d",
1003                                 sbi->s_inode_size);
1004                         goto failed_mount;
1005                 }
1006         }
1007
1008         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1009                                    le32_to_cpu(es->s_log_frag_size);
1010         if (sbi->s_frag_size == 0)
1011                 goto cantfind_ext2;
1012         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1013
1014         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1015         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1016         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1017
1018         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1019         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1020                 goto cantfind_ext2;
1021         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1022                                         sbi->s_inodes_per_block;
1023         sbi->s_desc_per_block = sb->s_blocksize /
1024                                         sizeof (struct ext2_group_desc);
1025         sbi->s_sbh = bh;
1026         sbi->s_mount_state = le16_to_cpu(es->s_state);
1027         sbi->s_addr_per_block_bits =
1028                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1029         sbi->s_desc_per_block_bits =
1030                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1031
1032         if (sb->s_magic != EXT2_SUPER_MAGIC)
1033                 goto cantfind_ext2;
1034
1035         if (sb->s_blocksize != bh->b_size) {
1036                 if (!silent)
1037                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1038                 goto failed_mount;
1039         }
1040
1041         if (sb->s_blocksize != sbi->s_frag_size) {
1042                 ext2_msg(sb, KERN_ERR,
1043                         "error: fragsize %lu != blocksize %lu"
1044                         "(not supported yet)",
1045                         sbi->s_frag_size, sb->s_blocksize);
1046                 goto failed_mount;
1047         }
1048
1049         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1050                 ext2_msg(sb, KERN_ERR,
1051                         "error: #blocks per group too big: %lu",
1052                         sbi->s_blocks_per_group);
1053                 goto failed_mount;
1054         }
1055         /* At least inode table, bitmaps, and sb have to fit in one group */
1056         if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1057                 ext2_msg(sb, KERN_ERR,
1058                         "error: #blocks per group smaller than metadata size: %lu <= %lu",
1059                         sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1060                 goto failed_mount;
1061         }
1062         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1063                 ext2_msg(sb, KERN_ERR,
1064                         "error: #fragments per group too big: %lu",
1065                         sbi->s_frags_per_group);
1066                 goto failed_mount;
1067         }
1068         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1069             sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1070                 ext2_msg(sb, KERN_ERR,
1071                         "error: invalid #inodes per group: %lu",
1072                         sbi->s_inodes_per_group);
1073                 goto failed_mount;
1074         }
1075         if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1076                 ext2_msg(sb, KERN_ERR,
1077                          "bad geometry: block count %u exceeds size of device (%u blocks)",
1078                          le32_to_cpu(es->s_blocks_count),
1079                          (unsigned)sb_bdev_nr_blocks(sb));
1080                 goto failed_mount;
1081         }
1082
1083         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1084                                 le32_to_cpu(es->s_first_data_block) - 1)
1085                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1086         if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1087             le32_to_cpu(es->s_inodes_count)) {
1088                 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1089                          le32_to_cpu(es->s_inodes_count),
1090                          (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1091                 goto failed_mount;
1092         }
1093         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1094                    EXT2_DESC_PER_BLOCK(sb);
1095         sbi->s_group_desc = kvmalloc_array(db_count,
1096                                            sizeof(struct buffer_head *),
1097                                            GFP_KERNEL);
1098         if (sbi->s_group_desc == NULL) {
1099                 ret = -ENOMEM;
1100                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1101                 goto failed_mount;
1102         }
1103         bgl_lock_init(sbi->s_blockgroup_lock);
1104         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1105         if (!sbi->s_debts) {
1106                 ret = -ENOMEM;
1107                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1108                 goto failed_mount_group_desc;
1109         }
1110         for (i = 0; i < db_count; i++) {
1111                 block = descriptor_loc(sb, logic_sb_block, i);
1112                 sbi->s_group_desc[i] = sb_bread(sb, block);
1113                 if (!sbi->s_group_desc[i]) {
1114                         for (j = 0; j < i; j++)
1115                                 brelse (sbi->s_group_desc[j]);
1116                         ext2_msg(sb, KERN_ERR,
1117                                 "error: unable to read group descriptors");
1118                         goto failed_mount_group_desc;
1119                 }
1120         }
1121         if (!ext2_check_descriptors (sb)) {
1122                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1123                 goto failed_mount2;
1124         }
1125         sbi->s_gdb_count = db_count;
1126         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1127         spin_lock_init(&sbi->s_next_gen_lock);
1128
1129         /* per filesystem reservation list head & lock */
1130         spin_lock_init(&sbi->s_rsv_window_lock);
1131         sbi->s_rsv_window_root = RB_ROOT;
1132         /*
1133          * Add a single, static dummy reservation to the start of the
1134          * reservation window list --- it gives us a placeholder for
1135          * append-at-start-of-list which makes the allocation logic
1136          * _much_ simpler.
1137          */
1138         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1139         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1140         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1141         sbi->s_rsv_window_head.rsv_goal_size = 0;
1142         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1143
1144         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1145                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1146         if (!err) {
1147                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1148                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1149         }
1150         if (!err) {
1151                 err = percpu_counter_init(&sbi->s_dirs_counter,
1152                                 ext2_count_dirs(sb), GFP_KERNEL);
1153         }
1154         if (err) {
1155                 ret = err;
1156                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1157                 goto failed_mount3;
1158         }
1159
1160 #ifdef CONFIG_EXT2_FS_XATTR
1161         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1162         if (!sbi->s_ea_block_cache) {
1163                 ret = -ENOMEM;
1164                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1165                 goto failed_mount3;
1166         }
1167 #endif
1168         /*
1169          * set up enough so that it can read an inode
1170          */
1171         sb->s_op = &ext2_sops;
1172         sb->s_export_op = &ext2_export_ops;
1173         sb->s_xattr = ext2_xattr_handlers;
1174
1175 #ifdef CONFIG_QUOTA
1176         sb->dq_op = &dquot_operations;
1177         sb->s_qcop = &ext2_quotactl_ops;
1178         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1179 #endif
1180
1181         root = ext2_iget(sb, EXT2_ROOT_INO);
1182         if (IS_ERR(root)) {
1183                 ret = PTR_ERR(root);
1184                 goto failed_mount3;
1185         }
1186         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1187                 iput(root);
1188                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1189                 goto failed_mount3;
1190         }
1191
1192         sb->s_root = d_make_root(root);
1193         if (!sb->s_root) {
1194                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1195                 ret = -ENOMEM;
1196                 goto failed_mount3;
1197         }
1198         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1199                 ext2_msg(sb, KERN_WARNING,
1200                         "warning: mounting ext3 filesystem as ext2");
1201         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1202                 sb->s_flags |= SB_RDONLY;
1203         ext2_write_super(sb);
1204         return 0;
1205
1206 cantfind_ext2:
1207         if (!silent)
1208                 ext2_msg(sb, KERN_ERR,
1209                         "error: can't find an ext2 filesystem on dev %s.",
1210                         sb->s_id);
1211         goto failed_mount;
1212 failed_mount3:
1213         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1214         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1215         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1216         percpu_counter_destroy(&sbi->s_dirs_counter);
1217 failed_mount2:
1218         for (i = 0; i < db_count; i++)
1219                 brelse(sbi->s_group_desc[i]);
1220 failed_mount_group_desc:
1221         kvfree(sbi->s_group_desc);
1222         kfree(sbi->s_debts);
1223 failed_mount:
1224         brelse(bh);
1225 failed_sbi:
1226         fs_put_dax(sbi->s_daxdev, NULL);
1227         sb->s_fs_info = NULL;
1228         kfree(sbi->s_blockgroup_lock);
1229         kfree(sbi);
1230         return ret;
1231 }
1232
1233 static void ext2_clear_super_error(struct super_block *sb)
1234 {
1235         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1236
1237         if (buffer_write_io_error(sbh)) {
1238                 /*
1239                  * Oh, dear.  A previous attempt to write the
1240                  * superblock failed.  This could happen because the
1241                  * USB device was yanked out.  Or it could happen to
1242                  * be a transient write error and maybe the block will
1243                  * be remapped.  Nothing we can do but to retry the
1244                  * write and hope for the best.
1245                  */
1246                 ext2_msg(sb, KERN_ERR,
1247                        "previous I/O error to superblock detected");
1248                 clear_buffer_write_io_error(sbh);
1249                 set_buffer_uptodate(sbh);
1250         }
1251 }
1252
1253 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1254                      int wait)
1255 {
1256         ext2_clear_super_error(sb);
1257         spin_lock(&EXT2_SB(sb)->s_lock);
1258         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1259         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1260         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1261         /* unlock before we do IO */
1262         spin_unlock(&EXT2_SB(sb)->s_lock);
1263         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1264         if (wait)
1265                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1266 }
1267
1268 /*
1269  * In the second extended file system, it is not necessary to
1270  * write the super block since we use a mapping of the
1271  * disk super block in a buffer.
1272  *
1273  * However, this function is still used to set the fs valid
1274  * flags to 0.  We need to set this flag to 0 since the fs
1275  * may have been checked while mounted and e2fsck may have
1276  * set s_state to EXT2_VALID_FS after some corrections.
1277  */
1278 static int ext2_sync_fs(struct super_block *sb, int wait)
1279 {
1280         struct ext2_sb_info *sbi = EXT2_SB(sb);
1281         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1282
1283         /*
1284          * Write quota structures to quota file, sync_blockdev() will write
1285          * them to disk later
1286          */
1287         dquot_writeback_dquots(sb, -1);
1288
1289         spin_lock(&sbi->s_lock);
1290         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1291                 ext2_debug("setting valid to 0\n");
1292                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1293         }
1294         spin_unlock(&sbi->s_lock);
1295         ext2_sync_super(sb, es, wait);
1296         return 0;
1297 }
1298
1299 static int ext2_freeze(struct super_block *sb)
1300 {
1301         struct ext2_sb_info *sbi = EXT2_SB(sb);
1302
1303         /*
1304          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1305          * because we have unattached inodes and thus filesystem is not fully
1306          * consistent.
1307          */
1308         if (atomic_long_read(&sb->s_remove_count)) {
1309                 ext2_sync_fs(sb, 1);
1310                 return 0;
1311         }
1312         /* Set EXT2_FS_VALID flag */
1313         spin_lock(&sbi->s_lock);
1314         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1315         spin_unlock(&sbi->s_lock);
1316         ext2_sync_super(sb, sbi->s_es, 1);
1317
1318         return 0;
1319 }
1320
1321 static int ext2_unfreeze(struct super_block *sb)
1322 {
1323         /* Just write sb to clear EXT2_VALID_FS flag */
1324         ext2_write_super(sb);
1325
1326         return 0;
1327 }
1328
1329 static void ext2_write_super(struct super_block *sb)
1330 {
1331         if (!sb_rdonly(sb))
1332                 ext2_sync_fs(sb, 1);
1333 }
1334
1335 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1336 {
1337         struct ext2_sb_info * sbi = EXT2_SB(sb);
1338         struct ext2_super_block * es;
1339         struct ext2_mount_options new_opts;
1340         int err;
1341
1342         sync_filesystem(sb);
1343
1344         spin_lock(&sbi->s_lock);
1345         new_opts.s_mount_opt = sbi->s_mount_opt;
1346         new_opts.s_resuid = sbi->s_resuid;
1347         new_opts.s_resgid = sbi->s_resgid;
1348         spin_unlock(&sbi->s_lock);
1349
1350         if (!parse_options(data, sb, &new_opts))
1351                 return -EINVAL;
1352
1353         spin_lock(&sbi->s_lock);
1354         es = sbi->s_es;
1355         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1356                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1357                          "dax flag with busy inodes while remounting");
1358                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1359         }
1360         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1361                 goto out_set;
1362         if (*flags & SB_RDONLY) {
1363                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1364                     !(sbi->s_mount_state & EXT2_VALID_FS))
1365                         goto out_set;
1366
1367                 /*
1368                  * OK, we are remounting a valid rw partition rdonly, so set
1369                  * the rdonly flag and then mark the partition as valid again.
1370                  */
1371                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1372                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1373                 spin_unlock(&sbi->s_lock);
1374
1375                 err = dquot_suspend(sb, -1);
1376                 if (err < 0)
1377                         return err;
1378
1379                 ext2_sync_super(sb, es, 1);
1380         } else {
1381                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1382                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1383                 if (ret) {
1384                         spin_unlock(&sbi->s_lock);
1385                         ext2_msg(sb, KERN_WARNING,
1386                                 "warning: couldn't remount RDWR because of "
1387                                 "unsupported optional features (%x).",
1388                                 le32_to_cpu(ret));
1389                         return -EROFS;
1390                 }
1391                 /*
1392                  * Mounting a RDONLY partition read-write, so reread and
1393                  * store the current valid flag.  (It may have been changed
1394                  * by e2fsck since we originally mounted the partition.)
1395                  */
1396                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1397                 if (!ext2_setup_super (sb, es, 0))
1398                         sb->s_flags &= ~SB_RDONLY;
1399                 spin_unlock(&sbi->s_lock);
1400
1401                 ext2_write_super(sb);
1402
1403                 dquot_resume(sb, -1);
1404         }
1405
1406         spin_lock(&sbi->s_lock);
1407 out_set:
1408         sbi->s_mount_opt = new_opts.s_mount_opt;
1409         sbi->s_resuid = new_opts.s_resuid;
1410         sbi->s_resgid = new_opts.s_resgid;
1411         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1412                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1413         spin_unlock(&sbi->s_lock);
1414
1415         return 0;
1416 }
1417
1418 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1419 {
1420         struct super_block *sb = dentry->d_sb;
1421         struct ext2_sb_info *sbi = EXT2_SB(sb);
1422         struct ext2_super_block *es = sbi->s_es;
1423
1424         spin_lock(&sbi->s_lock);
1425
1426         if (test_opt (sb, MINIX_DF))
1427                 sbi->s_overhead_last = 0;
1428         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1429                 unsigned long i, overhead = 0;
1430                 smp_rmb();
1431
1432                 /*
1433                  * Compute the overhead (FS structures). This is constant
1434                  * for a given filesystem unless the number of block groups
1435                  * changes so we cache the previous value until it does.
1436                  */
1437
1438                 /*
1439                  * All of the blocks before first_data_block are
1440                  * overhead
1441                  */
1442                 overhead = le32_to_cpu(es->s_first_data_block);
1443
1444                 /*
1445                  * Add the overhead attributed to the superblock and
1446                  * block group descriptors.  If the sparse superblocks
1447                  * feature is turned on, then not all groups have this.
1448                  */
1449                 for (i = 0; i < sbi->s_groups_count; i++)
1450                         overhead += ext2_bg_has_super(sb, i) +
1451                                 ext2_bg_num_gdb(sb, i);
1452
1453                 /*
1454                  * Every block group has an inode bitmap, a block
1455                  * bitmap, and an inode table.
1456                  */
1457                 overhead += (sbi->s_groups_count *
1458                              (2 + sbi->s_itb_per_group));
1459                 sbi->s_overhead_last = overhead;
1460                 smp_wmb();
1461                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1462         }
1463
1464         buf->f_type = EXT2_SUPER_MAGIC;
1465         buf->f_bsize = sb->s_blocksize;
1466         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1467         buf->f_bfree = ext2_count_free_blocks(sb);
1468         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1469         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1470         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1471                 buf->f_bavail = 0;
1472         buf->f_files = le32_to_cpu(es->s_inodes_count);
1473         buf->f_ffree = ext2_count_free_inodes(sb);
1474         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1475         buf->f_namelen = EXT2_NAME_LEN;
1476         buf->f_fsid = uuid_to_fsid(es->s_uuid);
1477         spin_unlock(&sbi->s_lock);
1478         return 0;
1479 }
1480
1481 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1482         int flags, const char *dev_name, void *data)
1483 {
1484         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1485 }
1486
1487 #ifdef CONFIG_QUOTA
1488
1489 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1490  * acquiring the locks... As quota files are never truncated and quota code
1491  * itself serializes the operations (and no one else should touch the files)
1492  * we don't have to be afraid of races */
1493 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1494                                size_t len, loff_t off)
1495 {
1496         struct inode *inode = sb_dqopt(sb)->files[type];
1497         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1498         int err = 0;
1499         int offset = off & (sb->s_blocksize - 1);
1500         int tocopy;
1501         size_t toread;
1502         struct buffer_head tmp_bh;
1503         struct buffer_head *bh;
1504         loff_t i_size = i_size_read(inode);
1505
1506         if (off > i_size)
1507                 return 0;
1508         if (off+len > i_size)
1509                 len = i_size-off;
1510         toread = len;
1511         while (toread > 0) {
1512                 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1513
1514                 tmp_bh.b_state = 0;
1515                 tmp_bh.b_size = sb->s_blocksize;
1516                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1517                 if (err < 0)
1518                         return err;
1519                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1520                         memset(data, 0, tocopy);
1521                 else {
1522                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1523                         if (!bh)
1524                                 return -EIO;
1525                         memcpy(data, bh->b_data+offset, tocopy);
1526                         brelse(bh);
1527                 }
1528                 offset = 0;
1529                 toread -= tocopy;
1530                 data += tocopy;
1531                 blk++;
1532         }
1533         return len;
1534 }
1535
1536 /* Write to quotafile */
1537 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1538                                 const char *data, size_t len, loff_t off)
1539 {
1540         struct inode *inode = sb_dqopt(sb)->files[type];
1541         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1542         int err = 0;
1543         int offset = off & (sb->s_blocksize - 1);
1544         int tocopy;
1545         size_t towrite = len;
1546         struct buffer_head tmp_bh;
1547         struct buffer_head *bh;
1548
1549         while (towrite > 0) {
1550                 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1551
1552                 tmp_bh.b_state = 0;
1553                 tmp_bh.b_size = sb->s_blocksize;
1554                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1555                 if (err < 0)
1556                         goto out;
1557                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1558                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1559                 else
1560                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1561                 if (unlikely(!bh)) {
1562                         err = -EIO;
1563                         goto out;
1564                 }
1565                 lock_buffer(bh);
1566                 memcpy(bh->b_data+offset, data, tocopy);
1567                 flush_dcache_page(bh->b_page);
1568                 set_buffer_uptodate(bh);
1569                 mark_buffer_dirty(bh);
1570                 unlock_buffer(bh);
1571                 brelse(bh);
1572                 offset = 0;
1573                 towrite -= tocopy;
1574                 data += tocopy;
1575                 blk++;
1576         }
1577 out:
1578         if (len == towrite)
1579                 return err;
1580         if (inode->i_size < off+len-towrite)
1581                 i_size_write(inode, off+len-towrite);
1582         inode_inc_iversion(inode);
1583         inode->i_mtime = inode->i_ctime = current_time(inode);
1584         mark_inode_dirty(inode);
1585         return len - towrite;
1586 }
1587
1588 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1589                          const struct path *path)
1590 {
1591         int err;
1592         struct inode *inode;
1593
1594         err = dquot_quota_on(sb, type, format_id, path);
1595         if (err)
1596                 return err;
1597
1598         inode = d_inode(path->dentry);
1599         inode_lock(inode);
1600         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1601         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1602                         S_NOATIME | S_IMMUTABLE);
1603         inode_unlock(inode);
1604         mark_inode_dirty(inode);
1605
1606         return 0;
1607 }
1608
1609 static int ext2_quota_off(struct super_block *sb, int type)
1610 {
1611         struct inode *inode = sb_dqopt(sb)->files[type];
1612         int err;
1613
1614         if (!inode || !igrab(inode))
1615                 goto out;
1616
1617         err = dquot_quota_off(sb, type);
1618         if (err)
1619                 goto out_put;
1620
1621         inode_lock(inode);
1622         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1623         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1624         inode_unlock(inode);
1625         mark_inode_dirty(inode);
1626 out_put:
1627         iput(inode);
1628         return err;
1629 out:
1630         return dquot_quota_off(sb, type);
1631 }
1632
1633 #endif
1634
1635 static struct file_system_type ext2_fs_type = {
1636         .owner          = THIS_MODULE,
1637         .name           = "ext2",
1638         .mount          = ext2_mount,
1639         .kill_sb        = kill_block_super,
1640         .fs_flags       = FS_REQUIRES_DEV,
1641 };
1642 MODULE_ALIAS_FS("ext2");
1643
1644 static int __init init_ext2_fs(void)
1645 {
1646         int err;
1647
1648         err = init_inodecache();
1649         if (err)
1650                 return err;
1651         err = register_filesystem(&ext2_fs_type);
1652         if (err)
1653                 goto out;
1654         return 0;
1655 out:
1656         destroy_inodecache();
1657         return err;
1658 }
1659
1660 static void __exit exit_ext2_fs(void)
1661 {
1662         unregister_filesystem(&ext2_fs_type);
1663         destroy_inodecache();
1664 }
1665
1666 MODULE_AUTHOR("Remy Card and others");
1667 MODULE_DESCRIPTION("Second Extended Filesystem");
1668 MODULE_LICENSE("GPL");
1669 module_init(init_ext2_fs)
1670 module_exit(exit_ext2_fs)