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 ([email protected])
   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 ([email protected]), 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         .encode_fh = generic_encode_ino32_fh,
 401         .fh_to_dentry = ext2_fh_to_dentry,
 402         .fh_to_parent = ext2_fh_to_parent,
 403         .get_parent = ext2_get_parent,
 404 };
 405
 406 static unsigned long get_sb_block(void **data)
 407 {
 408         unsigned long   sb_block;
 409         char            *options = (char *) *data;
 410
 411         if (!options || strncmp(options, "sb=", 3) != 0)
 412                 return 1;       /* Default location */
 413         options += 3;
 414         sb_block = simple_strtoul(options, &options, 0);
 415         if (*options && *options != ',') {
 416                 printk("EXT2-fs: Invalid sb specification: %s\n",
 417                        (char *) *data);
 418                 return 1;
 419         }
 420         if (*options == ',')
 421                 options++;
 422         *data = (void *) options;
 423         return sb_block;
 424 }
 425
 426 enum {
 427         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 428         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 429         Opt_err_ro, Opt_nouid32, Opt_debug,
 430         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 431         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 432         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 433 };
 434
 435 static const match_table_t tokens = {
 436         {Opt_bsd_df, "bsddf"},
 437         {Opt_minix_df, "minixdf"},
 438         {Opt_grpid, "grpid"},
 439         {Opt_grpid, "bsdgroups"},
 440         {Opt_nogrpid, "nogrpid"},
 441         {Opt_nogrpid, "sysvgroups"},
 442         {Opt_resgid, "resgid=%u"},
 443         {Opt_resuid, "resuid=%u"},
 444         {Opt_sb, "sb=%u"},
 445         {Opt_err_cont, "errors=continue"},
 446         {Opt_err_panic, "errors=panic"},
 447         {Opt_err_ro, "errors=remount-ro"},
 448         {Opt_nouid32, "nouid32"},
 449         {Opt_debug, "debug"},
 450         {Opt_oldalloc, "oldalloc"},
 451         {Opt_orlov, "orlov"},
 452         {Opt_nobh, "nobh"},
 453         {Opt_user_xattr, "user_xattr"},
 454         {Opt_nouser_xattr, "nouser_xattr"},
 455         {Opt_acl, "acl"},
 456         {Opt_noacl, "noacl"},
 457         {Opt_xip, "xip"},
 458         {Opt_dax, "dax"},
 459         {Opt_grpquota, "grpquota"},
 460         {Opt_ignore, "noquota"},
 461         {Opt_quota, "quota"},
 462         {Opt_usrquota, "usrquota"},
 463         {Opt_reservation, "reservation"},
 464         {Opt_noreservation, "noreservation"},
 465         {Opt_err, NULL}
 466 };
 467
 468 static int parse_options(char *options, struct super_block *sb,
 469                          struct ext2_mount_options *opts)
 470 {
 471         char *p;
 472         substring_t args[MAX_OPT_ARGS];
 473         int option;
 474         kuid_t uid;
 475         kgid_t gid;
 476
 477         if (!options)
 478                 return 1;
 479
 480         while ((p = strsep (&options, ",")) != NULL) {
 481                 int token;
 482                 if (!*p)
 483                         continue;
 484
 485                 token = match_token(p, tokens, args);
 486                 switch (token) {
 487                 case Opt_bsd_df:
 488                         clear_opt (opts->s_mount_opt, MINIX_DF);
 489                         break;
 490                 case Opt_minix_df:
 491                         set_opt (opts->s_mount_opt, MINIX_DF);
 492                         break;
 493                 case Opt_grpid:
 494                         set_opt (opts->s_mount_opt, GRPID);
 495                         break;
 496                 case Opt_nogrpid:
 497                         clear_opt (opts->s_mount_opt, GRPID);
 498                         break;
 499                 case Opt_resuid:
 500                         if (match_int(&args[0], &option))
 501                                 return 0;
 502                         uid = make_kuid(current_user_ns(), option);
 503                         if (!uid_valid(uid)) {
 504                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 505                                 return 0;
 506
 507                         }
 508                         opts->s_resuid = uid;
 509                         break;
 510                 case Opt_resgid:
 511                         if (match_int(&args[0], &option))
 512                                 return 0;
 513                         gid = make_kgid(current_user_ns(), option);
 514                         if (!gid_valid(gid)) {
 515                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 516                                 return 0;
 517                         }
 518                         opts->s_resgid = gid;
 519                         break;
 520                 case Opt_sb:
 521                         /* handled by get_sb_block() instead of here */
 522                         /* *sb_block = match_int(&args[0]); */
 523                         break;
 524                 case Opt_err_panic:
 525                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 526                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 527                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 528                         break;
 529                 case Opt_err_ro:
 530                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 531                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 532                         set_opt (opts->s_mount_opt, ERRORS_RO);
 533                         break;
 534                 case Opt_err_cont:
 535                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 536                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 537                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 538                         break;
 539                 case Opt_nouid32:
 540                         set_opt (opts->s_mount_opt, NO_UID32);
 541                         break;
 542                 case Opt_debug:
 543                         set_opt (opts->s_mount_opt, DEBUG);
 544                         break;
 545                 case Opt_oldalloc:
 546                         set_opt (opts->s_mount_opt, OLDALLOC);
 547                         break;
 548                 case Opt_orlov:
 549                         clear_opt (opts->s_mount_opt, OLDALLOC);
 550                         break;
 551                 case Opt_nobh:
 552                         ext2_msg(sb, KERN_INFO,
 553                                 "nobh option not supported");
 554                         break;
 555 #ifdef CONFIG_EXT2_FS_XATTR
 556                 case Opt_user_xattr:
 557                         set_opt (opts->s_mount_opt, XATTR_USER);
 558                         break;
 559                 case Opt_nouser_xattr:
 560                         clear_opt (opts->s_mount_opt, XATTR_USER);
 561                         break;
 562 #else
 563                 case Opt_user_xattr:
 564                 case Opt_nouser_xattr:
 565                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 566                                 "not supported");
 567                         break;
 568 #endif
 569 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 570                 case Opt_acl:
 571                         set_opt(opts->s_mount_opt, POSIX_ACL);
 572                         break;
 573                 case Opt_noacl:
 574                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 575                         break;
 576 #else
 577                 case Opt_acl:
 578                 case Opt_noacl:
 579                         ext2_msg(sb, KERN_INFO,
 580                                 "(no)acl options not supported");
 581                         break;
 582 #endif
 583                 case Opt_xip:
 584                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 585                         set_opt(opts->s_mount_opt, XIP);
 586                         fallthrough;
 587                 case Opt_dax:
 588 #ifdef CONFIG_FS_DAX
 589                         ext2_msg(sb, KERN_WARNING,
 590                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 591                         set_opt(opts->s_mount_opt, DAX);
 592 #else
 593                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 594 #endif
 595                         break;
 596
 597 #if defined(CONFIG_QUOTA)
 598                 case Opt_quota:
 599                 case Opt_usrquota:
 600                         set_opt(opts->s_mount_opt, USRQUOTA);
 601                         break;
 602
 603                 case Opt_grpquota:
 604                         set_opt(opts->s_mount_opt, GRPQUOTA);
 605                         break;
 606 #else
 607                 case Opt_quota:
 608                 case Opt_usrquota:
 609                 case Opt_grpquota:
 610                         ext2_msg(sb, KERN_INFO,
 611                                 "quota operations not supported");
 612                         break;
 613 #endif
 614
 615                 case Opt_reservation:
 616                         set_opt(opts->s_mount_opt, RESERVATION);
 617                         ext2_msg(sb, KERN_INFO, "reservations ON");
 618                         break;
 619                 case Opt_noreservation:
 620                         clear_opt(opts->s_mount_opt, RESERVATION);
 621                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 622                         break;
 623                 case Opt_ignore:
 624                         break;
 625                 default:
 626                         return 0;
 627                 }
 628         }
 629         return 1;
 630 }
 631
 632 static int ext2_setup_super (struct super_block * sb,
 633                               struct ext2_super_block * es,
 634                               int read_only)
 635 {
 636         int res = 0;
 637         struct ext2_sb_info *sbi = EXT2_SB(sb);
 638
 639         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 640                 ext2_msg(sb, KERN_ERR,
 641                         "error: revision level too high, "
 642                         "forcing read-only mode");
 643                 res = SB_RDONLY;
 644         }
 645         if (read_only)
 646                 return res;
 647         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 648                 ext2_msg(sb, KERN_WARNING,
 649                         "warning: mounting unchecked fs, "
 650                         "running e2fsck is recommended");
 651         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 652                 ext2_msg(sb, KERN_WARNING,
 653                         "warning: mounting fs with errors, "
 654                         "running e2fsck is recommended");
 655         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 656                  le16_to_cpu(es->s_mnt_count) >=
 657                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 658                 ext2_msg(sb, KERN_WARNING,
 659                         "warning: maximal mount count reached, "
 660                         "running e2fsck is recommended");
 661         else if (le32_to_cpu(es->s_checkinterval) &&
 662                 (le32_to_cpu(es->s_lastcheck) +
 663                         le32_to_cpu(es->s_checkinterval) <=
 664                         ktime_get_real_seconds()))
 665                 ext2_msg(sb, KERN_WARNING,
 666                         "warning: checktime reached, "
 667                         "running e2fsck is recommended");
 668         if (!le16_to_cpu(es->s_max_mnt_count))
 669                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 670         le16_add_cpu(&es->s_mnt_count, 1);
 671         if (test_opt (sb, DEBUG))
 672                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
 673                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 674                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 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         if (le32_to_cpu(es->s_log_block_size) >
 949             (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
 950                 ext2_msg(sb, KERN_ERR,
 951                          "Invalid log block size: %u",
 952                          le32_to_cpu(es->s_log_block_size));
 953                 goto failed_mount;
 954         }
 955         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 956
 957         if (test_opt(sb, DAX)) {
 958                 if (!sbi->s_daxdev) {
 959                         ext2_msg(sb, KERN_ERR,
 960                                 "DAX unsupported by block device. Turning off DAX.");
 961                         clear_opt(sbi->s_mount_opt, DAX);
 962                 } else if (blocksize != PAGE_SIZE) {
 963                         ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
 964                         clear_opt(sbi->s_mount_opt, DAX);
 965                 }
 966         }
 967
 968         /* If the blocksize doesn't match, re-read the thing.. */
 969         if (sb->s_blocksize != blocksize) {
 970                 brelse(bh);
 971
 972                 if (!sb_set_blocksize(sb, blocksize)) {
 973                         ext2_msg(sb, KERN_ERR,
 974                                 "error: bad blocksize %d", blocksize);
 975                         goto failed_sbi;
 976                 }
 977
 978                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 979                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 980                 bh = sb_bread(sb, logic_sb_block);
 981                 if(!bh) {
 982                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 983                                 "superblock on 2nd try");
 984                         goto failed_sbi;
 985                 }
 986                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 987                 sbi->s_es = es;
 988                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 989                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 990                         goto failed_mount;
 991                 }
 992         }
 993
 994         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 995         sb->s_max_links = EXT2_LINK_MAX;
 996         sb->s_time_min = S32_MIN;
 997         sb->s_time_max = S32_MAX;
 998
 999         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1000                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1001                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1002         } else {
1003                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1004                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1005                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1006                     !is_power_of_2(sbi->s_inode_size) ||
1007                     (sbi->s_inode_size > blocksize)) {
1008                         ext2_msg(sb, KERN_ERR,
1009                                 "error: unsupported inode size: %d",
1010                                 sbi->s_inode_size);
1011                         goto failed_mount;
1012                 }
1013         }
1014
1015         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_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 (es->s_log_frag_size != es->s_log_block_size) {
1042                 ext2_msg(sb, KERN_ERR,
1043                         "error: fragsize log %u != blocksize log %u",
1044                         le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1045                 goto failed_mount;
1046         }
1047
1048         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1049                 ext2_msg(sb, KERN_ERR,
1050                         "error: #blocks per group too big: %lu",
1051                         sbi->s_blocks_per_group);
1052                 goto failed_mount;
1053         }
1054         /* At least inode table, bitmaps, and sb have to fit in one group */
1055         if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1056                 ext2_msg(sb, KERN_ERR,
1057                         "error: #blocks per group smaller than metadata size: %lu <= %lu",
1058                         sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1059                 goto failed_mount;
1060         }
1061         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1062             sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1063                 ext2_msg(sb, KERN_ERR,
1064                         "error: invalid #inodes per group: %lu",
1065                         sbi->s_inodes_per_group);
1066                 goto failed_mount;
1067         }
1068         if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1069                 ext2_msg(sb, KERN_ERR,
1070                          "bad geometry: block count %u exceeds size of device (%u blocks)",
1071                          le32_to_cpu(es->s_blocks_count),
1072                          (unsigned)sb_bdev_nr_blocks(sb));
1073                 goto failed_mount;
1074         }
1075
1076         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1077                                 le32_to_cpu(es->s_first_data_block) - 1)
1078                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1079         if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1080             le32_to_cpu(es->s_inodes_count)) {
1081                 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1082                          le32_to_cpu(es->s_inodes_count),
1083                          (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1084                 goto failed_mount;
1085         }
1086         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1087                    EXT2_DESC_PER_BLOCK(sb);
1088         sbi->s_group_desc = kvmalloc_array(db_count,
1089                                            sizeof(struct buffer_head *),
1090                                            GFP_KERNEL);
1091         if (sbi->s_group_desc == NULL) {
1092                 ret = -ENOMEM;
1093                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1094                 goto failed_mount;
1095         }
1096         bgl_lock_init(sbi->s_blockgroup_lock);
1097         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1098         if (!sbi->s_debts) {
1099                 ret = -ENOMEM;
1100                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1101                 goto failed_mount_group_desc;
1102         }
1103         for (i = 0; i < db_count; i++) {
1104                 block = descriptor_loc(sb, logic_sb_block, i);
1105                 sbi->s_group_desc[i] = sb_bread(sb, block);
1106                 if (!sbi->s_group_desc[i]) {
1107                         for (j = 0; j < i; j++)
1108                                 brelse (sbi->s_group_desc[j]);
1109                         ext2_msg(sb, KERN_ERR,
1110                                 "error: unable to read group descriptors");
1111                         goto failed_mount_group_desc;
1112                 }
1113         }
1114         if (!ext2_check_descriptors (sb)) {
1115                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1116                 goto failed_mount2;
1117         }
1118         sbi->s_gdb_count = db_count;
1119         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1120         spin_lock_init(&sbi->s_next_gen_lock);
1121
1122         /* per filesystem reservation list head & lock */
1123         spin_lock_init(&sbi->s_rsv_window_lock);
1124         sbi->s_rsv_window_root = RB_ROOT;
1125         /*
1126          * Add a single, static dummy reservation to the start of the
1127          * reservation window list --- it gives us a placeholder for
1128          * append-at-start-of-list which makes the allocation logic
1129          * _much_ simpler.
1130          */
1131         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1132         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1133         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1134         sbi->s_rsv_window_head.rsv_goal_size = 0;
1135         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1136
1137         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1138                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1139         if (!err) {
1140                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1141                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1142         }
1143         if (!err) {
1144                 err = percpu_counter_init(&sbi->s_dirs_counter,
1145                                 ext2_count_dirs(sb), GFP_KERNEL);
1146         }
1147         if (err) {
1148                 ret = err;
1149                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1150                 goto failed_mount3;
1151         }
1152
1153 #ifdef CONFIG_EXT2_FS_XATTR
1154         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1155         if (!sbi->s_ea_block_cache) {
1156                 ret = -ENOMEM;
1157                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1158                 goto failed_mount3;
1159         }
1160 #endif
1161         /*
1162          * set up enough so that it can read an inode
1163          */
1164         sb->s_op = &ext2_sops;
1165         sb->s_export_op = &ext2_export_ops;
1166         sb->s_xattr = ext2_xattr_handlers;
1167
1168 #ifdef CONFIG_QUOTA
1169         sb->dq_op = &dquot_operations;
1170         sb->s_qcop = &ext2_quotactl_ops;
1171         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1172 #endif
1173
1174         root = ext2_iget(sb, EXT2_ROOT_INO);
1175         if (IS_ERR(root)) {
1176                 ret = PTR_ERR(root);
1177                 goto failed_mount3;
1178         }
1179         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1180                 iput(root);
1181                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1182                 goto failed_mount3;
1183         }
1184
1185         sb->s_root = d_make_root(root);
1186         if (!sb->s_root) {
1187                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1188                 ret = -ENOMEM;
1189                 goto failed_mount3;
1190         }
1191         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1192                 ext2_msg(sb, KERN_WARNING,
1193                         "warning: mounting ext3 filesystem as ext2");
1194         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1195                 sb->s_flags |= SB_RDONLY;
1196         ext2_write_super(sb);
1197         return 0;
1198
1199 cantfind_ext2:
1200         if (!silent)
1201                 ext2_msg(sb, KERN_ERR,
1202                         "error: can't find an ext2 filesystem on dev %s.",
1203                         sb->s_id);
1204         goto failed_mount;
1205 failed_mount3:
1206         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1207         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1208         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1209         percpu_counter_destroy(&sbi->s_dirs_counter);
1210 failed_mount2:
1211         for (i = 0; i < db_count; i++)
1212                 brelse(sbi->s_group_desc[i]);
1213 failed_mount_group_desc:
1214         kvfree(sbi->s_group_desc);
1215         kfree(sbi->s_debts);
1216 failed_mount:
1217         brelse(bh);
1218 failed_sbi:
1219         fs_put_dax(sbi->s_daxdev, NULL);
1220         sb->s_fs_info = NULL;
1221         kfree(sbi->s_blockgroup_lock);
1222         kfree(sbi);
1223         return ret;
1224 }
1225
1226 static void ext2_clear_super_error(struct super_block *sb)
1227 {
1228         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1229
1230         if (buffer_write_io_error(sbh)) {
1231                 /*
1232                  * Oh, dear.  A previous attempt to write the
1233                  * superblock failed.  This could happen because the
1234                  * USB device was yanked out.  Or it could happen to
1235                  * be a transient write error and maybe the block will
1236                  * be remapped.  Nothing we can do but to retry the
1237                  * write and hope for the best.
1238                  */
1239                 ext2_msg(sb, KERN_ERR,
1240                        "previous I/O error to superblock detected");
1241                 clear_buffer_write_io_error(sbh);
1242                 set_buffer_uptodate(sbh);
1243         }
1244 }
1245
1246 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1247                      int wait)
1248 {
1249         ext2_clear_super_error(sb);
1250         spin_lock(&EXT2_SB(sb)->s_lock);
1251         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1252         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1253         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1254         /* unlock before we do IO */
1255         spin_unlock(&EXT2_SB(sb)->s_lock);
1256         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1257         if (wait)
1258                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1259 }
1260
1261 /*
1262  * In the second extended file system, it is not necessary to
1263  * write the super block since we use a mapping of the
1264  * disk super block in a buffer.
1265  *
1266  * However, this function is still used to set the fs valid
1267  * flags to 0.  We need to set this flag to 0 since the fs
1268  * may have been checked while mounted and e2fsck may have
1269  * set s_state to EXT2_VALID_FS after some corrections.
1270  */
1271 static int ext2_sync_fs(struct super_block *sb, int wait)
1272 {
1273         struct ext2_sb_info *sbi = EXT2_SB(sb);
1274         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1275
1276         /*
1277          * Write quota structures to quota file, sync_blockdev() will write
1278          * them to disk later
1279          */
1280         dquot_writeback_dquots(sb, -1);
1281
1282         spin_lock(&sbi->s_lock);
1283         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1284                 ext2_debug("setting valid to 0\n");
1285                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1286         }
1287         spin_unlock(&sbi->s_lock);
1288         ext2_sync_super(sb, es, wait);
1289         return 0;
1290 }
1291
1292 static int ext2_freeze(struct super_block *sb)
1293 {
1294         struct ext2_sb_info *sbi = EXT2_SB(sb);
1295
1296         /*
1297          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1298          * because we have unattached inodes and thus filesystem is not fully
1299          * consistent.
1300          */
1301         if (atomic_long_read(&sb->s_remove_count)) {
1302                 ext2_sync_fs(sb, 1);
1303                 return 0;
1304         }
1305         /* Set EXT2_FS_VALID flag */
1306         spin_lock(&sbi->s_lock);
1307         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1308         spin_unlock(&sbi->s_lock);
1309         ext2_sync_super(sb, sbi->s_es, 1);
1310
1311         return 0;
1312 }
1313
1314 static int ext2_unfreeze(struct super_block *sb)
1315 {
1316         /* Just write sb to clear EXT2_VALID_FS flag */
1317         ext2_write_super(sb);
1318
1319         return 0;
1320 }
1321
1322 static void ext2_write_super(struct super_block *sb)
1323 {
1324         if (!sb_rdonly(sb))
1325                 ext2_sync_fs(sb, 1);
1326 }
1327
1328 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1329 {
1330         struct ext2_sb_info * sbi = EXT2_SB(sb);
1331         struct ext2_super_block * es;
1332         struct ext2_mount_options new_opts;
1333         int err;
1334
1335         sync_filesystem(sb);
1336
1337         spin_lock(&sbi->s_lock);
1338         new_opts.s_mount_opt = sbi->s_mount_opt;
1339         new_opts.s_resuid = sbi->s_resuid;
1340         new_opts.s_resgid = sbi->s_resgid;
1341         spin_unlock(&sbi->s_lock);
1342
1343         if (!parse_options(data, sb, &new_opts))
1344                 return -EINVAL;
1345
1346         spin_lock(&sbi->s_lock);
1347         es = sbi->s_es;
1348         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1349                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1350                          "dax flag with busy inodes while remounting");
1351                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1352         }
1353         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1354                 goto out_set;
1355         if (*flags & SB_RDONLY) {
1356                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1357                     !(sbi->s_mount_state & EXT2_VALID_FS))
1358                         goto out_set;
1359
1360                 /*
1361                  * OK, we are remounting a valid rw partition rdonly, so set
1362                  * the rdonly flag and then mark the partition as valid again.
1363                  */
1364                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1365                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1366                 spin_unlock(&sbi->s_lock);
1367
1368                 err = dquot_suspend(sb, -1);
1369                 if (err < 0)
1370                         return err;
1371
1372                 ext2_sync_super(sb, es, 1);
1373         } else {
1374                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1375                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1376                 if (ret) {
1377                         spin_unlock(&sbi->s_lock);
1378                         ext2_msg(sb, KERN_WARNING,
1379                                 "warning: couldn't remount RDWR because of "
1380                                 "unsupported optional features (%x).",
1381                                 le32_to_cpu(ret));
1382                         return -EROFS;
1383                 }
1384                 /*
1385                  * Mounting a RDONLY partition read-write, so reread and
1386                  * store the current valid flag.  (It may have been changed
1387                  * by e2fsck since we originally mounted the partition.)
1388                  */
1389                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1390                 if (!ext2_setup_super (sb, es, 0))
1391                         sb->s_flags &= ~SB_RDONLY;
1392                 spin_unlock(&sbi->s_lock);
1393
1394                 ext2_write_super(sb);
1395
1396                 dquot_resume(sb, -1);
1397         }
1398
1399         spin_lock(&sbi->s_lock);
1400 out_set:
1401         sbi->s_mount_opt = new_opts.s_mount_opt;
1402         sbi->s_resuid = new_opts.s_resuid;
1403         sbi->s_resgid = new_opts.s_resgid;
1404         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1405                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1406         spin_unlock(&sbi->s_lock);
1407
1408         return 0;
1409 }
1410
1411 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1412 {
1413         struct super_block *sb = dentry->d_sb;
1414         struct ext2_sb_info *sbi = EXT2_SB(sb);
1415         struct ext2_super_block *es = sbi->s_es;
1416
1417         spin_lock(&sbi->s_lock);
1418
1419         if (test_opt (sb, MINIX_DF))
1420                 sbi->s_overhead_last = 0;
1421         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1422                 unsigned long i, overhead = 0;
1423                 smp_rmb();
1424
1425                 /*
1426                  * Compute the overhead (FS structures). This is constant
1427                  * for a given filesystem unless the number of block groups
1428                  * changes so we cache the previous value until it does.
1429                  */
1430
1431                 /*
1432                  * All of the blocks before first_data_block are
1433                  * overhead
1434                  */
1435                 overhead = le32_to_cpu(es->s_first_data_block);
1436
1437                 /*
1438                  * Add the overhead attributed to the superblock and
1439                  * block group descriptors.  If the sparse superblocks
1440                  * feature is turned on, then not all groups have this.
1441                  */
1442                 for (i = 0; i < sbi->s_groups_count; i++)
1443                         overhead += ext2_bg_has_super(sb, i) +
1444                                 ext2_bg_num_gdb(sb, i);
1445
1446                 /*
1447                  * Every block group has an inode bitmap, a block
1448                  * bitmap, and an inode table.
1449                  */
1450                 overhead += (sbi->s_groups_count *
1451                              (2 + sbi->s_itb_per_group));
1452                 sbi->s_overhead_last = overhead;
1453                 smp_wmb();
1454                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1455         }
1456
1457         buf->f_type = EXT2_SUPER_MAGIC;
1458         buf->f_bsize = sb->s_blocksize;
1459         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1460         buf->f_bfree = ext2_count_free_blocks(sb);
1461         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1462         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1463         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1464                 buf->f_bavail = 0;
1465         buf->f_files = le32_to_cpu(es->s_inodes_count);
1466         buf->f_ffree = ext2_count_free_inodes(sb);
1467         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1468         buf->f_namelen = EXT2_NAME_LEN;
1469         buf->f_fsid = uuid_to_fsid(es->s_uuid);
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 = min_t(size_t, sb->s_blocksize - offset, toread);
1506
1507                 tmp_bh.b_state = 0;
1508                 tmp_bh.b_size = sb->s_blocksize;
1509                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1510                 if (err < 0)
1511                         return err;
1512                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1513                         memset(data, 0, tocopy);
1514                 else {
1515                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1516                         if (!bh)
1517                                 return -EIO;
1518                         memcpy(data, bh->b_data+offset, tocopy);
1519                         brelse(bh);
1520                 }
1521                 offset = 0;
1522                 toread -= tocopy;
1523                 data += tocopy;
1524                 blk++;
1525         }
1526         return len;
1527 }
1528
1529 /* Write to quotafile */
1530 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1531                                 const char *data, size_t len, loff_t off)
1532 {
1533         struct inode *inode = sb_dqopt(sb)->files[type];
1534         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1535         int err = 0;
1536         int offset = off & (sb->s_blocksize - 1);
1537         int tocopy;
1538         size_t towrite = len;
1539         struct buffer_head tmp_bh;
1540         struct buffer_head *bh;
1541
1542         while (towrite > 0) {
1543                 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1544
1545                 tmp_bh.b_state = 0;
1546                 tmp_bh.b_size = sb->s_blocksize;
1547                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1548                 if (err < 0)
1549                         goto out;
1550                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1551                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1552                 else
1553                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1554                 if (unlikely(!bh)) {
1555                         err = -EIO;
1556                         goto out;
1557                 }
1558                 lock_buffer(bh);
1559                 memcpy(bh->b_data+offset, data, tocopy);
1560                 flush_dcache_page(bh->b_page);
1561                 set_buffer_uptodate(bh);
1562                 mark_buffer_dirty(bh);
1563                 unlock_buffer(bh);
1564                 brelse(bh);
1565                 offset = 0;
1566                 towrite -= tocopy;
1567                 data += tocopy;
1568                 blk++;
1569         }
1570 out:
1571         if (len == towrite)
1572                 return err;
1573         if (inode->i_size < off+len-towrite)
1574                 i_size_write(inode, off+len-towrite);
1575         inode_inc_iversion(inode);
1576         inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1577         mark_inode_dirty(inode);
1578         return len - towrite;
1579 }
1580
1581 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1582                          const struct path *path)
1583 {
1584         int err;
1585         struct inode *inode;
1586
1587         err = dquot_quota_on(sb, type, format_id, path);
1588         if (err)
1589                 return err;
1590
1591         inode = d_inode(path->dentry);
1592         inode_lock(inode);
1593         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1594         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1595                         S_NOATIME | S_IMMUTABLE);
1596         inode_unlock(inode);
1597         mark_inode_dirty(inode);
1598
1599         return 0;
1600 }
1601
1602 static int ext2_quota_off(struct super_block *sb, int type)
1603 {
1604         struct inode *inode = sb_dqopt(sb)->files[type];
1605         int err;
1606
1607         if (!inode || !igrab(inode))
1608                 goto out;
1609
1610         err = dquot_quota_off(sb, type);
1611         if (err)
1612                 goto out_put;
1613
1614         inode_lock(inode);
1615         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1616         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1617         inode_unlock(inode);
1618         mark_inode_dirty(inode);
1619 out_put:
1620         iput(inode);
1621         return err;
1622 out:
1623         return dquot_quota_off(sb, type);
1624 }
1625
1626 #endif
1627
1628 static struct file_system_type ext2_fs_type = {
1629         .owner          = THIS_MODULE,
1630         .name           = "ext2",
1631         .mount          = ext2_mount,
1632         .kill_sb        = kill_block_super,
1633         .fs_flags       = FS_REQUIRES_DEV,
1634 };
1635 MODULE_ALIAS_FS("ext2");
1636
1637 static int __init init_ext2_fs(void)
1638 {
1639         int err;
1640
1641         err = init_inodecache();
1642         if (err)
1643                 return err;
1644         err = register_filesystem(&ext2_fs_type);
1645         if (err)
1646                 goto out;
1647         return 0;
1648 out:
1649         destroy_inodecache();
1650         return err;
1651 }
1652
1653 static void __exit exit_ext2_fs(void)
1654 {
1655         unregister_filesystem(&ext2_fs_type);
1656         destroy_inodecache();
1657 }
1658
1659 MODULE_AUTHOR("Remy Card and others");
1660 MODULE_DESCRIPTION("Second Extended Filesystem");
1661 MODULE_LICENSE("GPL");
1662 module_init(init_ext2_fs)
1663 module_exit(exit_ext2_fs)