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                 if (sbi->s_group_desc[i])
 166                         brelse (sbi->s_group_desc[i]);
 167         kfree(sbi->s_group_desc);
 168         kfree(sbi->s_debts);
 169         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 170         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 171         percpu_counter_destroy(&sbi->s_dirs_counter);
 172         brelse (sbi->s_sbh);
 173         sb->s_fs_info = NULL;
 174         kfree(sbi->s_blockgroup_lock);
 175         fs_put_dax(sbi->s_daxdev);
 176         kfree(sbi);
 177 }
 178
 179 static struct kmem_cache * ext2_inode_cachep;
 180
 181 static struct inode *ext2_alloc_inode(struct super_block *sb)
 182 {
 183         struct ext2_inode_info *ei;
 184         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 185         if (!ei)
 186                 return NULL;
 187         ei->i_block_alloc_info = NULL;
 188         inode_set_iversion(&ei->vfs_inode, 1);
 189 #ifdef CONFIG_QUOTA
 190         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 191 #endif
 192
 193         return &ei->vfs_inode;
 194 }
 195
 196 static void ext2_free_in_core_inode(struct inode *inode)
 197 {
 198         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 199 }
 200
 201 static void init_once(void *foo)
 202 {
 203         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 204
 205         rwlock_init(&ei->i_meta_lock);
 206 #ifdef CONFIG_EXT2_FS_XATTR
 207         init_rwsem(&ei->xattr_sem);
 208 #endif
 209         mutex_init(&ei->truncate_mutex);
 210 #ifdef CONFIG_FS_DAX
 211         init_rwsem(&ei->dax_sem);
 212 #endif
 213         inode_init_once(&ei->vfs_inode);
 214 }
 215
 216 static int __init init_inodecache(void)
 217 {
 218         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 219                                 sizeof(struct ext2_inode_info), 0,
 220                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 221                                         SLAB_ACCOUNT),
 222                                 offsetof(struct ext2_inode_info, i_data),
 223                                 sizeof_field(struct ext2_inode_info, i_data),
 224                                 init_once);
 225         if (ext2_inode_cachep == NULL)
 226                 return -ENOMEM;
 227         return 0;
 228 }
 229
 230 static void destroy_inodecache(void)
 231 {
 232         /*
 233          * Make sure all delayed rcu free inodes are flushed before we
 234          * destroy cache.
 235          */
 236         rcu_barrier();
 237         kmem_cache_destroy(ext2_inode_cachep);
 238 }
 239
 240 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 241 {
 242         struct super_block *sb = root->d_sb;
 243         struct ext2_sb_info *sbi = EXT2_SB(sb);
 244         struct ext2_super_block *es = sbi->s_es;
 245         unsigned long def_mount_opts;
 246
 247         spin_lock(&sbi->s_lock);
 248         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 249
 250         if (sbi->s_sb_block != 1)
 251                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 252         if (test_opt(sb, MINIX_DF))
 253                 seq_puts(seq, ",minixdf");
 254         if (test_opt(sb, GRPID))
 255                 seq_puts(seq, ",grpid");
 256         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 257                 seq_puts(seq, ",nogrpid");
 258         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 259             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 260                 seq_printf(seq, ",resuid=%u",
 261                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 262         }
 263         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 264             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 265                 seq_printf(seq, ",resgid=%u",
 266                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 267         }
 268         if (test_opt(sb, ERRORS_RO)) {
 269                 int def_errors = le16_to_cpu(es->s_errors);
 270
 271                 if (def_errors == EXT2_ERRORS_PANIC ||
 272                     def_errors == EXT2_ERRORS_CONTINUE) {
 273                         seq_puts(seq, ",errors=remount-ro");
 274                 }
 275         }
 276         if (test_opt(sb, ERRORS_CONT))
 277                 seq_puts(seq, ",errors=continue");
 278         if (test_opt(sb, ERRORS_PANIC))
 279                 seq_puts(seq, ",errors=panic");
 280         if (test_opt(sb, NO_UID32))
 281                 seq_puts(seq, ",nouid32");
 282         if (test_opt(sb, DEBUG))
 283                 seq_puts(seq, ",debug");
 284         if (test_opt(sb, OLDALLOC))
 285                 seq_puts(seq, ",oldalloc");
 286
 287 #ifdef CONFIG_EXT2_FS_XATTR
 288         if (test_opt(sb, XATTR_USER))
 289                 seq_puts(seq, ",user_xattr");
 290         if (!test_opt(sb, XATTR_USER) &&
 291             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 292                 seq_puts(seq, ",nouser_xattr");
 293         }
 294 #endif
 295
 296 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 297         if (test_opt(sb, POSIX_ACL))
 298                 seq_puts(seq, ",acl");
 299         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 300                 seq_puts(seq, ",noacl");
 301 #endif
 302
 303         if (test_opt(sb, NOBH))
 304                 seq_puts(seq, ",nobh");
 305
 306         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 307                 seq_puts(seq, ",usrquota");
 308
 309         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 310                 seq_puts(seq, ",grpquota");
 311
 312         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 313                 seq_puts(seq, ",xip");
 314
 315         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 316                 seq_puts(seq, ",dax");
 317
 318         if (!test_opt(sb, RESERVATION))
 319                 seq_puts(seq, ",noreservation");
 320
 321         spin_unlock(&sbi->s_lock);
 322         return 0;
 323 }
 324
 325 #ifdef CONFIG_QUOTA
 326 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 327 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 328 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 329                          const struct path *path);
 330 static struct dquot **ext2_get_dquots(struct inode *inode)
 331 {
 332         return EXT2_I(inode)->i_dquot;
 333 }
 334
 335 static const struct quotactl_ops ext2_quotactl_ops = {
 336         .quota_on       = ext2_quota_on,
 337         .quota_off      = ext2_quota_off,
 338         .quota_sync     = dquot_quota_sync,
 339         .get_state      = dquot_get_state,
 340         .set_info       = dquot_set_dqinfo,
 341         .get_dqblk      = dquot_get_dqblk,
 342         .set_dqblk      = dquot_set_dqblk,
 343         .get_nextdqblk  = dquot_get_next_dqblk,
 344 };
 345 #endif
 346
 347 static const struct super_operations ext2_sops = {
 348         .alloc_inode    = ext2_alloc_inode,
 349         .free_inode     = ext2_free_in_core_inode,
 350         .write_inode    = ext2_write_inode,
 351         .evict_inode    = ext2_evict_inode,
 352         .put_super      = ext2_put_super,
 353         .sync_fs        = ext2_sync_fs,
 354         .freeze_fs      = ext2_freeze,
 355         .unfreeze_fs    = ext2_unfreeze,
 356         .statfs         = ext2_statfs,
 357         .remount_fs     = ext2_remount,
 358         .show_options   = ext2_show_options,
 359 #ifdef CONFIG_QUOTA
 360         .quota_read     = ext2_quota_read,
 361         .quota_write    = ext2_quota_write,
 362         .get_dquots     = ext2_get_dquots,
 363 #endif
 364 };
 365
 366 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 367                 u64 ino, u32 generation)
 368 {
 369         struct inode *inode;
 370
 371         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 372                 return ERR_PTR(-ESTALE);
 373         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 374                 return ERR_PTR(-ESTALE);
 375
 376         /*
 377          * ext2_iget isn't quite right if the inode is currently unallocated!
 378          * However ext2_iget currently does appropriate checks to handle stale
 379          * inodes so everything is OK.
 380          */
 381         inode = ext2_iget(sb, ino);
 382         if (IS_ERR(inode))
 383                 return ERR_CAST(inode);
 384         if (generation && inode->i_generation != generation) {
 385                 /* we didn't find the right inode.. */
 386                 iput(inode);
 387                 return ERR_PTR(-ESTALE);
 388         }
 389         return inode;
 390 }
 391
 392 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 393                 int fh_len, int fh_type)
 394 {
 395         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 396                                     ext2_nfs_get_inode);
 397 }
 398
 399 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 400                 int fh_len, int fh_type)
 401 {
 402         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 403                                     ext2_nfs_get_inode);
 404 }
 405
 406 static const struct export_operations ext2_export_ops = {
 407         .fh_to_dentry = ext2_fh_to_dentry,
 408         .fh_to_parent = ext2_fh_to_parent,
 409         .get_parent = ext2_get_parent,
 410 };
 411
 412 static unsigned long get_sb_block(void **data)
 413 {
 414         unsigned long   sb_block;
 415         char            *options = (char *) *data;
 416
 417         if (!options || strncmp(options, "sb=", 3) != 0)
 418                 return 1;       /* Default location */
 419         options += 3;
 420         sb_block = simple_strtoul(options, &options, 0);
 421         if (*options && *options != ',') {
 422                 printk("EXT2-fs: Invalid sb specification: %s\n",
 423                        (char *) *data);
 424                 return 1;
 425         }
 426         if (*options == ',')
 427                 options++;
 428         *data = (void *) options;
 429         return sb_block;
 430 }
 431
 432 enum {
 433         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 434         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 435         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 436         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 437         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 438         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 439 };
 440
 441 static const match_table_t tokens = {
 442         {Opt_bsd_df, "bsddf"},
 443         {Opt_minix_df, "minixdf"},
 444         {Opt_grpid, "grpid"},
 445         {Opt_grpid, "bsdgroups"},
 446         {Opt_nogrpid, "nogrpid"},
 447         {Opt_nogrpid, "sysvgroups"},
 448         {Opt_resgid, "resgid=%u"},
 449         {Opt_resuid, "resuid=%u"},
 450         {Opt_sb, "sb=%u"},
 451         {Opt_err_cont, "errors=continue"},
 452         {Opt_err_panic, "errors=panic"},
 453         {Opt_err_ro, "errors=remount-ro"},
 454         {Opt_nouid32, "nouid32"},
 455         {Opt_nocheck, "check=none"},
 456         {Opt_nocheck, "nocheck"},
 457         {Opt_debug, "debug"},
 458         {Opt_oldalloc, "oldalloc"},
 459         {Opt_orlov, "orlov"},
 460         {Opt_nobh, "nobh"},
 461         {Opt_user_xattr, "user_xattr"},
 462         {Opt_nouser_xattr, "nouser_xattr"},
 463         {Opt_acl, "acl"},
 464         {Opt_noacl, "noacl"},
 465         {Opt_xip, "xip"},
 466         {Opt_dax, "dax"},
 467         {Opt_grpquota, "grpquota"},
 468         {Opt_ignore, "noquota"},
 469         {Opt_quota, "quota"},
 470         {Opt_usrquota, "usrquota"},
 471         {Opt_reservation, "reservation"},
 472         {Opt_noreservation, "noreservation"},
 473         {Opt_err, NULL}
 474 };
 475
 476 static int parse_options(char *options, struct super_block *sb,
 477                          struct ext2_mount_options *opts)
 478 {
 479         char *p;
 480         substring_t args[MAX_OPT_ARGS];
 481         int option;
 482         kuid_t uid;
 483         kgid_t gid;
 484
 485         if (!options)
 486                 return 1;
 487
 488         while ((p = strsep (&options, ",")) != NULL) {
 489                 int token;
 490                 if (!*p)
 491                         continue;
 492
 493                 token = match_token(p, tokens, args);
 494                 switch (token) {
 495                 case Opt_bsd_df:
 496                         clear_opt (opts->s_mount_opt, MINIX_DF);
 497                         break;
 498                 case Opt_minix_df:
 499                         set_opt (opts->s_mount_opt, MINIX_DF);
 500                         break;
 501                 case Opt_grpid:
 502                         set_opt (opts->s_mount_opt, GRPID);
 503                         break;
 504                 case Opt_nogrpid:
 505                         clear_opt (opts->s_mount_opt, GRPID);
 506                         break;
 507                 case Opt_resuid:
 508                         if (match_int(&args[0], &option))
 509                                 return 0;
 510                         uid = make_kuid(current_user_ns(), option);
 511                         if (!uid_valid(uid)) {
 512                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 513                                 return 0;
 514
 515                         }
 516                         opts->s_resuid = uid;
 517                         break;
 518                 case Opt_resgid:
 519                         if (match_int(&args[0], &option))
 520                                 return 0;
 521                         gid = make_kgid(current_user_ns(), option);
 522                         if (!gid_valid(gid)) {
 523                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 524                                 return 0;
 525                         }
 526                         opts->s_resgid = gid;
 527                         break;
 528                 case Opt_sb:
 529                         /* handled by get_sb_block() instead of here */
 530                         /* *sb_block = match_int(&args[0]); */
 531                         break;
 532                 case Opt_err_panic:
 533                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 534                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 535                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 536                         break;
 537                 case Opt_err_ro:
 538                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 539                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 540                         set_opt (opts->s_mount_opt, ERRORS_RO);
 541                         break;
 542                 case Opt_err_cont:
 543                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 544                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 545                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 546                         break;
 547                 case Opt_nouid32:
 548                         set_opt (opts->s_mount_opt, NO_UID32);
 549                         break;
 550                 case Opt_nocheck:
 551                         ext2_msg(sb, KERN_WARNING,
 552                                 "Option nocheck/check=none is deprecated and"
 553                                 " will be removed in June 2020.");
 554                         clear_opt (opts->s_mount_opt, CHECK);
 555                         break;
 556                 case Opt_debug:
 557                         set_opt (opts->s_mount_opt, DEBUG);
 558                         break;
 559                 case Opt_oldalloc:
 560                         set_opt (opts->s_mount_opt, OLDALLOC);
 561                         break;
 562                 case Opt_orlov:
 563                         clear_opt (opts->s_mount_opt, OLDALLOC);
 564                         break;
 565                 case Opt_nobh:
 566                         set_opt (opts->s_mount_opt, NOBH);
 567                         break;
 568 #ifdef CONFIG_EXT2_FS_XATTR
 569                 case Opt_user_xattr:
 570                         set_opt (opts->s_mount_opt, XATTR_USER);
 571                         break;
 572                 case Opt_nouser_xattr:
 573                         clear_opt (opts->s_mount_opt, XATTR_USER);
 574                         break;
 575 #else
 576                 case Opt_user_xattr:
 577                 case Opt_nouser_xattr:
 578                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 579                                 "not supported");
 580                         break;
 581 #endif
 582 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 583                 case Opt_acl:
 584                         set_opt(opts->s_mount_opt, POSIX_ACL);
 585                         break;
 586                 case Opt_noacl:
 587                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 588                         break;
 589 #else
 590                 case Opt_acl:
 591                 case Opt_noacl:
 592                         ext2_msg(sb, KERN_INFO,
 593                                 "(no)acl options not supported");
 594                         break;
 595 #endif
 596                 case Opt_xip:
 597                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 598                         set_opt(opts->s_mount_opt, XIP);
 599                         /* Fall through */
 600                 case Opt_dax:
 601 #ifdef CONFIG_FS_DAX
 602                         ext2_msg(sb, KERN_WARNING,
 603                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 604                         set_opt(opts->s_mount_opt, DAX);
 605 #else
 606                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 607 #endif
 608                         break;
 609
 610 #if defined(CONFIG_QUOTA)
 611                 case Opt_quota:
 612                 case Opt_usrquota:
 613                         set_opt(opts->s_mount_opt, USRQUOTA);
 614                         break;
 615
 616                 case Opt_grpquota:
 617                         set_opt(opts->s_mount_opt, GRPQUOTA);
 618                         break;
 619 #else
 620                 case Opt_quota:
 621                 case Opt_usrquota:
 622                 case Opt_grpquota:
 623                         ext2_msg(sb, KERN_INFO,
 624                                 "quota operations not supported");
 625                         break;
 626 #endif
 627
 628                 case Opt_reservation:
 629                         set_opt(opts->s_mount_opt, RESERVATION);
 630                         ext2_msg(sb, KERN_INFO, "reservations ON");
 631                         break;
 632                 case Opt_noreservation:
 633                         clear_opt(opts->s_mount_opt, RESERVATION);
 634                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 635                         break;
 636                 case Opt_ignore:
 637                         break;
 638                 default:
 639                         return 0;
 640                 }
 641         }
 642         return 1;
 643 }
 644
 645 static int ext2_setup_super (struct super_block * sb,
 646                               struct ext2_super_block * es,
 647                               int read_only)
 648 {
 649         int res = 0;
 650         struct ext2_sb_info *sbi = EXT2_SB(sb);
 651
 652         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 653                 ext2_msg(sb, KERN_ERR,
 654                         "error: revision level too high, "
 655                         "forcing read-only mode");
 656                 res = SB_RDONLY;
 657         }
 658         if (read_only)
 659                 return res;
 660         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 661                 ext2_msg(sb, KERN_WARNING,
 662                         "warning: mounting unchecked fs, "
 663                         "running e2fsck is recommended");
 664         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 665                 ext2_msg(sb, KERN_WARNING,
 666                         "warning: mounting fs with errors, "
 667                         "running e2fsck is recommended");
 668         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 669                  le16_to_cpu(es->s_mnt_count) >=
 670                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 671                 ext2_msg(sb, KERN_WARNING,
 672                         "warning: maximal mount count reached, "
 673                         "running e2fsck is recommended");
 674         else if (le32_to_cpu(es->s_checkinterval) &&
 675                 (le32_to_cpu(es->s_lastcheck) +
 676                         le32_to_cpu(es->s_checkinterval) <=
 677                         ktime_get_real_seconds()))
 678                 ext2_msg(sb, KERN_WARNING,
 679                         "warning: checktime reached, "
 680                         "running e2fsck is recommended");
 681         if (!le16_to_cpu(es->s_max_mnt_count))
 682                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 683         le16_add_cpu(&es->s_mnt_count, 1);
 684         if (test_opt (sb, DEBUG))
 685                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 686                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 687                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 688                         sbi->s_frag_size,
 689                         sbi->s_groups_count,
 690                         EXT2_BLOCKS_PER_GROUP(sb),
 691                         EXT2_INODES_PER_GROUP(sb),
 692                         sbi->s_mount_opt);
 693         return res;
 694 }
 695
 696 static int ext2_check_descriptors(struct super_block *sb)
 697 {
 698         int i;
 699         struct ext2_sb_info *sbi = EXT2_SB(sb);
 700
 701         ext2_debug ("Checking group descriptors");
 702
 703         for (i = 0; i < sbi->s_groups_count; i++) {
 704                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 705                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 706                 ext2_fsblk_t last_block;
 707
 708                 if (i == sbi->s_groups_count - 1)
 709                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 710                 else
 711                         last_block = first_block +
 712                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 713
 714                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 715                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 716                 {
 717                         ext2_error (sb, "ext2_check_descriptors",
 718                                     "Block bitmap for group %d"
 719                                     " not in group (block %lu)!",
 720                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 721                         return 0;
 722                 }
 723                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 724                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 725                 {
 726                         ext2_error (sb, "ext2_check_descriptors",
 727                                     "Inode bitmap for group %d"
 728                                     " not in group (block %lu)!",
 729                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 730                         return 0;
 731                 }
 732                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 733                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 734                     last_block)
 735                 {
 736                         ext2_error (sb, "ext2_check_descriptors",
 737                                     "Inode table for group %d"
 738                                     " not in group (block %lu)!",
 739                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 740                         return 0;
 741                 }
 742         }
 743         return 1;
 744 }
 745
 746 /*
 747  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 748  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 749  * We need to be 1 filesystem block less than the 2^32 sector limit.
 750  */
 751 static loff_t ext2_max_size(int bits)
 752 {
 753         loff_t res = EXT2_NDIR_BLOCKS;
 754         int meta_blocks;
 755         unsigned int upper_limit;
 756         unsigned int ppb = 1 << (bits-2);
 757
 758         /* This is calculated to be the largest file size for a
 759          * dense, file such that the total number of
 760          * sectors in the file, including data and all indirect blocks,
 761          * does not exceed 2^32 -1
 762          * __u32 i_blocks representing the total number of
 763          * 512 bytes blocks of the file
 764          */
 765         upper_limit = (1LL << 32) - 1;
 766
 767         /* total blocks in file system block size */
 768         upper_limit >>= (bits - 9);
 769
 770         /* Compute how many blocks we can address by block tree */
 771         res += 1LL << (bits-2);
 772         res += 1LL << (2*(bits-2));
 773         res += 1LL << (3*(bits-2));
 774         /* Does block tree limit file size? */
 775         if (res < upper_limit)
 776                 goto check_lfs;
 777
 778         res = upper_limit;
 779         /* How many metadata blocks are needed for addressing upper_limit? */
 780         upper_limit -= EXT2_NDIR_BLOCKS;
 781         /* indirect blocks */
 782         meta_blocks = 1;
 783         upper_limit -= ppb;
 784         /* double indirect blocks */
 785         if (upper_limit < ppb * ppb) {
 786                 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
 787                 res -= meta_blocks;
 788                 goto check_lfs;
 789         }
 790         meta_blocks += 1 + ppb;
 791         upper_limit -= ppb * ppb;
 792         /* tripple indirect blocks for the rest */
 793         meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
 794                 DIV_ROUND_UP(upper_limit, ppb*ppb);
 795         res -= meta_blocks;
 796 check_lfs:
 797         res <<= bits;
 798         if (res > MAX_LFS_FILESIZE)
 799                 res = MAX_LFS_FILESIZE;
 800
 801         return res;
 802 }
 803
 804 static unsigned long descriptor_loc(struct super_block *sb,
 805                                     unsigned long logic_sb_block,
 806                                     int nr)
 807 {
 808         struct ext2_sb_info *sbi = EXT2_SB(sb);
 809         unsigned long bg, first_meta_bg;
 810         int has_super = 0;
 811
 812         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 813
 814         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 815             nr < first_meta_bg)
 816                 return (logic_sb_block + nr + 1);
 817         bg = sbi->s_desc_per_block * nr;
 818         if (ext2_bg_has_super(sb, bg))
 819                 has_super = 1;
 820
 821         return ext2_group_first_block_no(sb, bg) + has_super;
 822 }
 823
 824 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 825 {
 826         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 827         struct buffer_head * bh;
 828         struct ext2_sb_info * sbi;
 829         struct ext2_super_block * es;
 830         struct inode *root;
 831         unsigned long block;
 832         unsigned long sb_block = get_sb_block(&data);
 833         unsigned long logic_sb_block;
 834         unsigned long offset = 0;
 835         unsigned long def_mount_opts;
 836         long ret = -ENOMEM;
 837         int blocksize = BLOCK_SIZE;
 838         int db_count;
 839         int i, j;
 840         __le32 features;
 841         int err;
 842         struct ext2_mount_options opts;
 843
 844         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 845         if (!sbi)
 846                 goto failed;
 847
 848         sbi->s_blockgroup_lock =
 849                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 850         if (!sbi->s_blockgroup_lock) {
 851                 kfree(sbi);
 852                 goto failed;
 853         }
 854         sb->s_fs_info = sbi;
 855         sbi->s_sb_block = sb_block;
 856         sbi->s_daxdev = dax_dev;
 857
 858         spin_lock_init(&sbi->s_lock);
 859         ret = -EINVAL;
 860
 861         /*
 862          * See what the current blocksize for the device is, and
 863          * use that as the blocksize.  Otherwise (or if the blocksize
 864          * is smaller than the default) use the default.
 865          * This is important for devices that have a hardware
 866          * sectorsize that is larger than the default.
 867          */
 868         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 869         if (!blocksize) {
 870                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 871                 goto failed_sbi;
 872         }
 873
 874         /*
 875          * If the superblock doesn't start on a hardware sector boundary,
 876          * calculate the offset.
 877          */
 878         if (blocksize != BLOCK_SIZE) {
 879                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 880                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 881         } else {
 882                 logic_sb_block = sb_block;
 883         }
 884
 885         if (!(bh = sb_bread(sb, logic_sb_block))) {
 886                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 887                 goto failed_sbi;
 888         }
 889         /*
 890          * Note: s_es must be initialized as soon as possible because
 891          *       some ext2 macro-instructions depend on its value
 892          */
 893         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 894         sbi->s_es = es;
 895         sb->s_magic = le16_to_cpu(es->s_magic);
 896
 897         if (sb->s_magic != EXT2_SUPER_MAGIC)
 898                 goto cantfind_ext2;
 899
 900         opts.s_mount_opt = 0;
 901         /* Set defaults before we parse the mount options */
 902         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 903         if (def_mount_opts & EXT2_DEFM_DEBUG)
 904                 set_opt(opts.s_mount_opt, DEBUG);
 905         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 906                 set_opt(opts.s_mount_opt, GRPID);
 907         if (def_mount_opts & EXT2_DEFM_UID16)
 908                 set_opt(opts.s_mount_opt, NO_UID32);
 909 #ifdef CONFIG_EXT2_FS_XATTR
 910         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 911                 set_opt(opts.s_mount_opt, XATTR_USER);
 912 #endif
 913 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 914         if (def_mount_opts & EXT2_DEFM_ACL)
 915                 set_opt(opts.s_mount_opt, POSIX_ACL);
 916 #endif
 917
 918         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 919                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
 920         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 921                 set_opt(opts.s_mount_opt, ERRORS_CONT);
 922         else
 923                 set_opt(opts.s_mount_opt, ERRORS_RO);
 924
 925         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 926         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 927
 928         set_opt(opts.s_mount_opt, RESERVATION);
 929
 930         if (!parse_options((char *) data, sb, &opts))
 931                 goto failed_mount;
 932
 933         sbi->s_mount_opt = opts.s_mount_opt;
 934         sbi->s_resuid = opts.s_resuid;
 935         sbi->s_resgid = opts.s_resgid;
 936
 937         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 938                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 939                  SB_POSIXACL : 0);
 940         sb->s_iflags |= SB_I_CGROUPWB;
 941
 942         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 943             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 944              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 945              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 946                 ext2_msg(sb, KERN_WARNING,
 947                         "warning: feature flags set on rev 0 fs, "
 948                         "running e2fsck is recommended");
 949         /*
 950          * Check feature flags regardless of the revision level, since we
 951          * previously didn't change the revision level when setting the flags,
 952          * so there is a chance incompat flags are set on a rev 0 filesystem.
 953          */
 954         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 955         if (features) {
 956                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 957                        "unsupported optional features (%x)",
 958                         le32_to_cpu(features));
 959                 goto failed_mount;
 960         }
 961         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 962                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 963                        "unsupported optional features (%x)",
 964                        le32_to_cpu(features));
 965                 goto failed_mount;
 966         }
 967
 968         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 969
 970         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 971                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
 972                         ext2_msg(sb, KERN_ERR,
 973                                 "DAX unsupported by block device. Turning off DAX.");
 974                         sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
 975                 }
 976         }
 977
 978         /* If the blocksize doesn't match, re-read the thing.. */
 979         if (sb->s_blocksize != blocksize) {
 980                 brelse(bh);
 981
 982                 if (!sb_set_blocksize(sb, blocksize)) {
 983                         ext2_msg(sb, KERN_ERR,
 984                                 "error: bad blocksize %d", blocksize);
 985                         goto failed_sbi;
 986                 }
 987
 988                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 989                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 990                 bh = sb_bread(sb, logic_sb_block);
 991                 if(!bh) {
 992                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 993                                 "superblock on 2nd try");
 994                         goto failed_sbi;
 995                 }
 996                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 997                 sbi->s_es = es;
 998                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 999                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
1000                         goto failed_mount;
1001                 }
1002         }
1003
1004         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1005         sb->s_max_links = EXT2_LINK_MAX;
1006
1007         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1008                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1009                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1010         } else {
1011                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1012                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1013                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1014                     !is_power_of_2(sbi->s_inode_size) ||
1015                     (sbi->s_inode_size > blocksize)) {
1016                         ext2_msg(sb, KERN_ERR,
1017                                 "error: unsupported inode size: %d",
1018                                 sbi->s_inode_size);
1019                         goto failed_mount;
1020                 }
1021         }
1022
1023         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1024                                    le32_to_cpu(es->s_log_frag_size);
1025         if (sbi->s_frag_size == 0)
1026                 goto cantfind_ext2;
1027         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1028
1029         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1030         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1031         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1032
1033         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1034         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1035                 goto cantfind_ext2;
1036         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1037                                         sbi->s_inodes_per_block;
1038         sbi->s_desc_per_block = sb->s_blocksize /
1039                                         sizeof (struct ext2_group_desc);
1040         sbi->s_sbh = bh;
1041         sbi->s_mount_state = le16_to_cpu(es->s_state);
1042         sbi->s_addr_per_block_bits =
1043                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1044         sbi->s_desc_per_block_bits =
1045                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1046
1047         if (sb->s_magic != EXT2_SUPER_MAGIC)
1048                 goto cantfind_ext2;
1049
1050         if (sb->s_blocksize != bh->b_size) {
1051                 if (!silent)
1052                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1053                 goto failed_mount;
1054         }
1055
1056         if (sb->s_blocksize != sbi->s_frag_size) {
1057                 ext2_msg(sb, KERN_ERR,
1058                         "error: fragsize %lu != blocksize %lu"
1059                         "(not supported yet)",
1060                         sbi->s_frag_size, sb->s_blocksize);
1061                 goto failed_mount;
1062         }
1063
1064         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1065                 ext2_msg(sb, KERN_ERR,
1066                         "error: #blocks per group too big: %lu",
1067                         sbi->s_blocks_per_group);
1068                 goto failed_mount;
1069         }
1070         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1071                 ext2_msg(sb, KERN_ERR,
1072                         "error: #fragments per group too big: %lu",
1073                         sbi->s_frags_per_group);
1074                 goto failed_mount;
1075         }
1076         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1077                 ext2_msg(sb, KERN_ERR,
1078                         "error: #inodes per group too big: %lu",
1079                         sbi->s_inodes_per_group);
1080                 goto failed_mount;
1081         }
1082
1083         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1084                 goto cantfind_ext2;
1085         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1086                                 le32_to_cpu(es->s_first_data_block) - 1)
1087                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1088         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1089                    EXT2_DESC_PER_BLOCK(sb);
1090         sbi->s_group_desc = kmalloc_array (db_count,
1091                                            sizeof(struct buffer_head *),
1092                                            GFP_KERNEL);
1093         if (sbi->s_group_desc == NULL) {
1094                 ret = -ENOMEM;
1095                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1096                 goto failed_mount;
1097         }
1098         bgl_lock_init(sbi->s_blockgroup_lock);
1099         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1100         if (!sbi->s_debts) {
1101                 ret = -ENOMEM;
1102                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1103                 goto failed_mount_group_desc;
1104         }
1105         for (i = 0; i < db_count; i++) {
1106                 block = descriptor_loc(sb, logic_sb_block, i);
1107                 sbi->s_group_desc[i] = sb_bread(sb, block);
1108                 if (!sbi->s_group_desc[i]) {
1109                         for (j = 0; j < i; j++)
1110                                 brelse (sbi->s_group_desc[j]);
1111                         ext2_msg(sb, KERN_ERR,
1112                                 "error: unable to read group descriptors");
1113                         goto failed_mount_group_desc;
1114                 }
1115         }
1116         if (!ext2_check_descriptors (sb)) {
1117                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1118                 goto failed_mount2;
1119         }
1120         sbi->s_gdb_count = db_count;
1121         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1122         spin_lock_init(&sbi->s_next_gen_lock);
1123
1124         /* per fileystem reservation list head & lock */
1125         spin_lock_init(&sbi->s_rsv_window_lock);
1126         sbi->s_rsv_window_root = RB_ROOT;
1127         /*
1128          * Add a single, static dummy reservation to the start of the
1129          * reservation window list --- it gives us a placeholder for
1130          * append-at-start-of-list which makes the allocation logic
1131          * _much_ simpler.
1132          */
1133         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1134         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1135         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1136         sbi->s_rsv_window_head.rsv_goal_size = 0;
1137         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1138
1139         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1140                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1141         if (!err) {
1142                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1143                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1144         }
1145         if (!err) {
1146                 err = percpu_counter_init(&sbi->s_dirs_counter,
1147                                 ext2_count_dirs(sb), GFP_KERNEL);
1148         }
1149         if (err) {
1150                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1151                 goto failed_mount3;
1152         }
1153
1154 #ifdef CONFIG_EXT2_FS_XATTR
1155         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1156         if (!sbi->s_ea_block_cache) {
1157                 ret = -ENOMEM;
1158                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1159                 goto failed_mount3;
1160         }
1161 #endif
1162         /*
1163          * set up enough so that it can read an inode
1164          */
1165         sb->s_op = &ext2_sops;
1166         sb->s_export_op = &ext2_export_ops;
1167         sb->s_xattr = ext2_xattr_handlers;
1168
1169 #ifdef CONFIG_QUOTA
1170         sb->dq_op = &dquot_operations;
1171         sb->s_qcop = &ext2_quotactl_ops;
1172         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1173 #endif
1174
1175         root = ext2_iget(sb, EXT2_ROOT_INO);
1176         if (IS_ERR(root)) {
1177                 ret = PTR_ERR(root);
1178                 goto failed_mount3;
1179         }
1180         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1181                 iput(root);
1182                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1183                 goto failed_mount3;
1184         }
1185
1186         sb->s_root = d_make_root(root);
1187         if (!sb->s_root) {
1188                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1189                 ret = -ENOMEM;
1190                 goto failed_mount3;
1191         }
1192         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1193                 ext2_msg(sb, KERN_WARNING,
1194                         "warning: mounting ext3 filesystem as ext2");
1195         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1196                 sb->s_flags |= SB_RDONLY;
1197         ext2_write_super(sb);
1198         return 0;
1199
1200 cantfind_ext2:
1201         if (!silent)
1202                 ext2_msg(sb, KERN_ERR,
1203                         "error: can't find an ext2 filesystem on dev %s.",
1204                         sb->s_id);
1205         goto failed_mount;
1206 failed_mount3:
1207         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1208         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1209         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1210         percpu_counter_destroy(&sbi->s_dirs_counter);
1211 failed_mount2:
1212         for (i = 0; i < db_count; i++)
1213                 brelse(sbi->s_group_desc[i]);
1214 failed_mount_group_desc:
1215         kfree(sbi->s_group_desc);
1216         kfree(sbi->s_debts);
1217 failed_mount:
1218         brelse(bh);
1219 failed_sbi:
1220         sb->s_fs_info = NULL;
1221         kfree(sbi->s_blockgroup_lock);
1222         kfree(sbi);
1223 failed:
1224         fs_put_dax(dax_dev);
1225         return ret;
1226 }
1227
1228 static void ext2_clear_super_error(struct super_block *sb)
1229 {
1230         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1231
1232         if (buffer_write_io_error(sbh)) {
1233                 /*
1234                  * Oh, dear.  A previous attempt to write the
1235                  * superblock failed.  This could happen because the
1236                  * USB device was yanked out.  Or it could happen to
1237                  * be a transient write error and maybe the block will
1238                  * be remapped.  Nothing we can do but to retry the
1239                  * write and hope for the best.
1240                  */
1241                 ext2_msg(sb, KERN_ERR,
1242                        "previous I/O error to superblock detected");
1243                 clear_buffer_write_io_error(sbh);
1244                 set_buffer_uptodate(sbh);
1245         }
1246 }
1247
1248 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1249                      int wait)
1250 {
1251         ext2_clear_super_error(sb);
1252         spin_lock(&EXT2_SB(sb)->s_lock);
1253         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1254         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1255         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1256         /* unlock before we do IO */
1257         spin_unlock(&EXT2_SB(sb)->s_lock);
1258         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1259         if (wait)
1260                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1261 }
1262
1263 /*
1264  * In the second extended file system, it is not necessary to
1265  * write the super block since we use a mapping of the
1266  * disk super block in a buffer.
1267  *
1268  * However, this function is still used to set the fs valid
1269  * flags to 0.  We need to set this flag to 0 since the fs
1270  * may have been checked while mounted and e2fsck may have
1271  * set s_state to EXT2_VALID_FS after some corrections.
1272  */
1273 static int ext2_sync_fs(struct super_block *sb, int wait)
1274 {
1275         struct ext2_sb_info *sbi = EXT2_SB(sb);
1276         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1277
1278         /*
1279          * Write quota structures to quota file, sync_blockdev() will write
1280          * them to disk later
1281          */
1282         dquot_writeback_dquots(sb, -1);
1283
1284         spin_lock(&sbi->s_lock);
1285         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1286                 ext2_debug("setting valid to 0\n");
1287                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1288         }
1289         spin_unlock(&sbi->s_lock);
1290         ext2_sync_super(sb, es, wait);
1291         return 0;
1292 }
1293
1294 static int ext2_freeze(struct super_block *sb)
1295 {
1296         struct ext2_sb_info *sbi = EXT2_SB(sb);
1297
1298         /*
1299          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1300          * because we have unattached inodes and thus filesystem is not fully
1301          * consistent.
1302          */
1303         if (atomic_long_read(&sb->s_remove_count)) {
1304                 ext2_sync_fs(sb, 1);
1305                 return 0;
1306         }
1307         /* Set EXT2_FS_VALID flag */
1308         spin_lock(&sbi->s_lock);
1309         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1310         spin_unlock(&sbi->s_lock);
1311         ext2_sync_super(sb, sbi->s_es, 1);
1312
1313         return 0;
1314 }
1315
1316 static int ext2_unfreeze(struct super_block *sb)
1317 {
1318         /* Just write sb to clear EXT2_VALID_FS flag */
1319         ext2_write_super(sb);
1320
1321         return 0;
1322 }
1323
1324 static void ext2_write_super(struct super_block *sb)
1325 {
1326         if (!sb_rdonly(sb))
1327                 ext2_sync_fs(sb, 1);
1328 }
1329
1330 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1331 {
1332         struct ext2_sb_info * sbi = EXT2_SB(sb);
1333         struct ext2_super_block * es;
1334         struct ext2_mount_options new_opts;
1335         int err;
1336
1337         sync_filesystem(sb);
1338
1339         spin_lock(&sbi->s_lock);
1340         new_opts.s_mount_opt = sbi->s_mount_opt;
1341         new_opts.s_resuid = sbi->s_resuid;
1342         new_opts.s_resgid = sbi->s_resgid;
1343         spin_unlock(&sbi->s_lock);
1344
1345         if (!parse_options(data, sb, &new_opts))
1346                 return -EINVAL;
1347
1348         spin_lock(&sbi->s_lock);
1349         es = sbi->s_es;
1350         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1351                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1352                          "dax flag with busy inodes while remounting");
1353                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1354         }
1355         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1356                 goto out_set;
1357         if (*flags & SB_RDONLY) {
1358                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1359                     !(sbi->s_mount_state & EXT2_VALID_FS))
1360                         goto out_set;
1361
1362                 /*
1363                  * OK, we are remounting a valid rw partition rdonly, so set
1364                  * the rdonly flag and then mark the partition as valid again.
1365                  */
1366                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1367                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1368                 spin_unlock(&sbi->s_lock);
1369
1370                 err = dquot_suspend(sb, -1);
1371                 if (err < 0)
1372                         return err;
1373
1374                 ext2_sync_super(sb, es, 1);
1375         } else {
1376                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1377                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1378                 if (ret) {
1379                         spin_unlock(&sbi->s_lock);
1380                         ext2_msg(sb, KERN_WARNING,
1381                                 "warning: couldn't remount RDWR because of "
1382                                 "unsupported optional features (%x).",
1383                                 le32_to_cpu(ret));
1384                         return -EROFS;
1385                 }
1386                 /*
1387                  * Mounting a RDONLY partition read-write, so reread and
1388                  * store the current valid flag.  (It may have been changed
1389                  * by e2fsck since we originally mounted the partition.)
1390                  */
1391                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1392                 if (!ext2_setup_super (sb, es, 0))
1393                         sb->s_flags &= ~SB_RDONLY;
1394                 spin_unlock(&sbi->s_lock);
1395
1396                 ext2_write_super(sb);
1397
1398                 dquot_resume(sb, -1);
1399         }
1400
1401         spin_lock(&sbi->s_lock);
1402 out_set:
1403         sbi->s_mount_opt = new_opts.s_mount_opt;
1404         sbi->s_resuid = new_opts.s_resuid;
1405         sbi->s_resgid = new_opts.s_resgid;
1406         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1407                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1408         spin_unlock(&sbi->s_lock);
1409
1410         return 0;
1411 }
1412
1413 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1414 {
1415         struct super_block *sb = dentry->d_sb;
1416         struct ext2_sb_info *sbi = EXT2_SB(sb);
1417         struct ext2_super_block *es = sbi->s_es;
1418         u64 fsid;
1419
1420         spin_lock(&sbi->s_lock);
1421
1422         if (test_opt (sb, MINIX_DF))
1423                 sbi->s_overhead_last = 0;
1424         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1425                 unsigned long i, overhead = 0;
1426                 smp_rmb();
1427
1428                 /*
1429                  * Compute the overhead (FS structures). This is constant
1430                  * for a given filesystem unless the number of block groups
1431                  * changes so we cache the previous value until it does.
1432                  */
1433
1434                 /*
1435                  * All of the blocks before first_data_block are
1436                  * overhead
1437                  */
1438                 overhead = le32_to_cpu(es->s_first_data_block);
1439
1440                 /*
1441                  * Add the overhead attributed to the superblock and
1442                  * block group descriptors.  If the sparse superblocks
1443                  * feature is turned on, then not all groups have this.
1444                  */
1445                 for (i = 0; i < sbi->s_groups_count; i++)
1446                         overhead += ext2_bg_has_super(sb, i) +
1447                                 ext2_bg_num_gdb(sb, i);
1448
1449                 /*
1450                  * Every block group has an inode bitmap, a block
1451                  * bitmap, and an inode table.
1452                  */
1453                 overhead += (sbi->s_groups_count *
1454                              (2 + sbi->s_itb_per_group));
1455                 sbi->s_overhead_last = overhead;
1456                 smp_wmb();
1457                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1458         }
1459
1460         buf->f_type = EXT2_SUPER_MAGIC;
1461         buf->f_bsize = sb->s_blocksize;
1462         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1463         buf->f_bfree = ext2_count_free_blocks(sb);
1464         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1465         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1466         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1467                 buf->f_bavail = 0;
1468         buf->f_files = le32_to_cpu(es->s_inodes_count);
1469         buf->f_ffree = ext2_count_free_inodes(sb);
1470         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1471         buf->f_namelen = EXT2_NAME_LEN;
1472         fsid = le64_to_cpup((void *)es->s_uuid) ^
1473                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1474         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1475         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1476         spin_unlock(&sbi->s_lock);
1477         return 0;
1478 }
1479
1480 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1481         int flags, const char *dev_name, void *data)
1482 {
1483         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1484 }
1485
1486 #ifdef CONFIG_QUOTA
1487
1488 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1489  * acquiring the locks... As quota files are never truncated and quota code
1490  * itself serializes the operations (and no one else should touch the files)
1491  * we don't have to be afraid of races */
1492 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1493                                size_t len, loff_t off)
1494 {
1495         struct inode *inode = sb_dqopt(sb)->files[type];
1496         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1497         int err = 0;
1498         int offset = off & (sb->s_blocksize - 1);
1499         int tocopy;
1500         size_t toread;
1501         struct buffer_head tmp_bh;
1502         struct buffer_head *bh;
1503         loff_t i_size = i_size_read(inode);
1504
1505         if (off > i_size)
1506                 return 0;
1507         if (off+len > i_size)
1508                 len = i_size-off;
1509         toread = len;
1510         while (toread > 0) {
1511                 tocopy = sb->s_blocksize - offset < toread ?
1512                                 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 = sb->s_blocksize - offset < towrite ?
1551                                 sb->s_blocksize - offset : towrite;
1552
1553                 tmp_bh.b_state = 0;
1554                 tmp_bh.b_size = sb->s_blocksize;
1555                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1556                 if (err < 0)
1557                         goto out;
1558                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1559                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1560                 else
1561                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1562                 if (unlikely(!bh)) {
1563                         err = -EIO;
1564                         goto out;
1565                 }
1566                 lock_buffer(bh);
1567                 memcpy(bh->b_data+offset, data, tocopy);
1568                 flush_dcache_page(bh->b_page);
1569                 set_buffer_uptodate(bh);
1570                 mark_buffer_dirty(bh);
1571                 unlock_buffer(bh);
1572                 brelse(bh);
1573                 offset = 0;
1574                 towrite -= tocopy;
1575                 data += tocopy;
1576                 blk++;
1577         }
1578 out:
1579         if (len == towrite)
1580                 return err;
1581         if (inode->i_size < off+len-towrite)
1582                 i_size_write(inode, off+len-towrite);
1583         inode_inc_iversion(inode);
1584         inode->i_mtime = inode->i_ctime = current_time(inode);
1585         mark_inode_dirty(inode);
1586         return len - towrite;
1587 }
1588
1589 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1590                          const struct path *path)
1591 {
1592         int err;
1593         struct inode *inode;
1594
1595         err = dquot_quota_on(sb, type, format_id, path);
1596         if (err)
1597                 return err;
1598
1599         inode = d_inode(path->dentry);
1600         inode_lock(inode);
1601         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1602         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1603                         S_NOATIME | S_IMMUTABLE);
1604         inode_unlock(inode);
1605         mark_inode_dirty(inode);
1606
1607         return 0;
1608 }
1609
1610 static int ext2_quota_off(struct super_block *sb, int type)
1611 {
1612         struct inode *inode = sb_dqopt(sb)->files[type];
1613         int err;
1614
1615         if (!inode || !igrab(inode))
1616                 goto out;
1617
1618         err = dquot_quota_off(sb, type);
1619         if (err)
1620                 goto out_put;
1621
1622         inode_lock(inode);
1623         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1624         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1625         inode_unlock(inode);
1626         mark_inode_dirty(inode);
1627 out_put:
1628         iput(inode);
1629         return err;
1630 out:
1631         return dquot_quota_off(sb, type);
1632 }
1633
1634 #endif
1635
1636 static struct file_system_type ext2_fs_type = {
1637         .owner          = THIS_MODULE,
1638         .name           = "ext2",
1639         .mount          = ext2_mount,
1640         .kill_sb        = kill_block_super,
1641         .fs_flags       = FS_REQUIRES_DEV,
1642 };
1643 MODULE_ALIAS_FS("ext2");
1644
1645 static int __init init_ext2_fs(void)
1646 {
1647         int err;
1648
1649         err = init_inodecache();
1650         if (err)
1651                 return err;
1652         err = register_filesystem(&ext2_fs_type);
1653         if (err)
1654                 goto out;
1655         return 0;
1656 out:
1657         destroy_inodecache();
1658         return err;
1659 }
1660
1661 static void __exit exit_ext2_fs(void)
1662 {
1663         unregister_filesystem(&ext2_fs_type);
1664         destroy_inodecache();
1665 }
1666
1667 MODULE_AUTHOR("Remy Card and others");
1668 MODULE_DESCRIPTION("Second Extended Filesystem");
1669 MODULE_LICENSE("GPL");
1670 module_init(init_ext2_fs)
1671 module_exit(exit_ext2_fs)