fs/ext2/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/fs/ext2/super.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/inode.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller (davem@caip.rutgers.edu), 1995
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/fs.h>
  23 #include <linux/slab.h>
  24 #include <linux/init.h>
  25 #include <linux/blkdev.h>
  26 #include <linux/parser.h>
  27 #include <linux/random.h>
  28 #include <linux/buffer_head.h>
  29 #include <linux/exportfs.h>
  30 #include <linux/vfs.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/mount.h>
  33 #include <linux/log2.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/dax.h>
  37 #include <linux/iversion.h>
  38 #include "ext2.h"
  39 #include "xattr.h"
  40 #include "acl.h"
  41
  42 static void ext2_write_super(struct super_block *sb);
  43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45 static int ext2_sync_fs(struct super_block *sb, int wait);
  46 static int ext2_freeze(struct super_block *sb);
  47 static int ext2_unfreeze(struct super_block *sb);
  48
  49 void ext2_error(struct super_block *sb, const char *function,
  50                 const char *fmt, ...)
  51 {
  52         struct va_format vaf;
  53         va_list args;
  54         struct ext2_sb_info *sbi = EXT2_SB(sb);
  55         struct ext2_super_block *es = sbi->s_es;
  56
  57         if (!sb_rdonly(sb)) {
  58                 spin_lock(&sbi->s_lock);
  59                 sbi->s_mount_state |= EXT2_ERROR_FS;
  60                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  61                 spin_unlock(&sbi->s_lock);
  62                 ext2_sync_super(sb, es, 1);
  63         }
  64
  65         va_start(args, fmt);
  66
  67         vaf.fmt = fmt;
  68         vaf.va = &args;
  69
  70         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  71                sb->s_id, function, &vaf);
  72
  73         va_end(args);
  74
  75         if (test_opt(sb, ERRORS_PANIC))
  76                 panic("EXT2-fs: panic from previous error\n");
  77         if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {
  78                 ext2_msg(sb, KERN_CRIT,
  79                              "error: remounting filesystem read-only");
  80                 sb->s_flags |= SB_RDONLY;
  81         }
  82 }
  83
  84 void ext2_msg(struct super_block *sb, const char *prefix,
  85                 const char *fmt, ...)
  86 {
  87         struct va_format vaf;
  88         va_list args;
  89
  90         va_start(args, fmt);
  91
  92         vaf.fmt = fmt;
  93         vaf.va = &args;
  94
  95         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  96
  97         va_end(args);
  98 }
  99
 100 /*
 101  * This must be called with sbi->s_lock held.
 102  */
 103 void ext2_update_dynamic_rev(struct super_block *sb)
 104 {
 105         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 106
 107         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 108                 return;
 109
 110         ext2_msg(sb, KERN_WARNING,
 111                      "warning: updating to rev %d because of "
 112                      "new feature flag, running e2fsck is recommended",
 113                      EXT2_DYNAMIC_REV);
 114
 115         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 116         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 117         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 118         /* leave es->s_feature_*compat flags alone */
 119         /* es->s_uuid will be set by e2fsck if empty */
 120
 121         /*
 122          * The rest of the superblock fields should be zero, and if not it
 123          * means they are likely already in use, so leave them alone.  We
 124          * can leave it up to e2fsck to clean up any inconsistencies there.
 125          */
 126 }
 127
 128 #ifdef CONFIG_QUOTA
 129 static int ext2_quota_off(struct super_block *sb, int type);
 130
 131 static void ext2_quota_off_umount(struct super_block *sb)
 132 {
 133         int type;
 134
 135         for (type = 0; type < MAXQUOTAS; type++)
 136                 ext2_quota_off(sb, type);
 137 }
 138 #else
 139 static inline void ext2_quota_off_umount(struct super_block *sb)
 140 {
 141 }
 142 #endif
 143
 144 static void ext2_put_super (struct super_block * sb)
 145 {
 146         int db_count;
 147         int i;
 148         struct ext2_sb_info *sbi = EXT2_SB(sb);
 149
 150         ext2_quota_off_umount(sb);
 151
 152         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
 153         sbi->s_ea_block_cache = NULL;
 154
 155         if (!sb_rdonly(sb)) {
 156                 struct ext2_super_block *es = sbi->s_es;
 157
 158                 spin_lock(&sbi->s_lock);
 159                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 160                 spin_unlock(&sbi->s_lock);
 161                 ext2_sync_super(sb, es, 1);
 162         }
 163         db_count = sbi->s_gdb_count;
 164         for (i = 0; i < db_count; i++)
 165                 brelse(sbi->s_group_desc[i]);
 166         kvfree(sbi->s_group_desc);
 167         kfree(sbi->s_debts);
 168         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 169         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 170         percpu_counter_destroy(&sbi->s_dirs_counter);
 171         brelse (sbi->s_sbh);
 172         sb->s_fs_info = NULL;
 173         kfree(sbi->s_blockgroup_lock);
 174         fs_put_dax(sbi->s_daxdev, NULL);
 175         kfree(sbi);
 176 }
 177
 178 static struct kmem_cache * ext2_inode_cachep;
 179
 180 static struct inode *ext2_alloc_inode(struct super_block *sb)
 181 {
 182         struct ext2_inode_info *ei;
 183         ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
 184         if (!ei)
 185                 return NULL;
 186         ei->i_block_alloc_info = NULL;
 187         inode_set_iversion(&ei->vfs_inode, 1);
 188 #ifdef CONFIG_QUOTA
 189         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 190 #endif
 191
 192         return &ei->vfs_inode;
 193 }
 194
 195 static void ext2_free_in_core_inode(struct inode *inode)
 196 {
 197         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 198 }
 199
 200 static void init_once(void *foo)
 201 {
 202         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 203
 204         rwlock_init(&ei->i_meta_lock);
 205 #ifdef CONFIG_EXT2_FS_XATTR
 206         init_rwsem(&ei->xattr_sem);
 207 #endif
 208         mutex_init(&ei->truncate_mutex);
 209         inode_init_once(&ei->vfs_inode);
 210 }
 211
 212 static int __init init_inodecache(void)
 213 {
 214         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 215                                 sizeof(struct ext2_inode_info), 0,
 216                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 217                                         SLAB_ACCOUNT),
 218                                 offsetof(struct ext2_inode_info, i_data),
 219                                 sizeof_field(struct ext2_inode_info, i_data),
 220                                 init_once);
 221         if (ext2_inode_cachep == NULL)
 222                 return -ENOMEM;
 223         return 0;
 224 }
 225
 226 static void destroy_inodecache(void)
 227 {
 228         /*
 229          * Make sure all delayed rcu free inodes are flushed before we
 230          * destroy cache.
 231          */
 232         rcu_barrier();
 233         kmem_cache_destroy(ext2_inode_cachep);
 234 }
 235
 236 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 237 {
 238         struct super_block *sb = root->d_sb;
 239         struct ext2_sb_info *sbi = EXT2_SB(sb);
 240         struct ext2_super_block *es = sbi->s_es;
 241         unsigned long def_mount_opts;
 242
 243         spin_lock(&sbi->s_lock);
 244         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 245
 246         if (sbi->s_sb_block != 1)
 247                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 248         if (test_opt(sb, MINIX_DF))
 249                 seq_puts(seq, ",minixdf");
 250         if (test_opt(sb, GRPID))
 251                 seq_puts(seq, ",grpid");
 252         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 253                 seq_puts(seq, ",nogrpid");
 254         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 255             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 256                 seq_printf(seq, ",resuid=%u",
 257                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 258         }
 259         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 260             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 261                 seq_printf(seq, ",resgid=%u",
 262                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 263         }
 264         if (test_opt(sb, ERRORS_RO)) {
 265                 int def_errors = le16_to_cpu(es->s_errors);
 266
 267                 if (def_errors == EXT2_ERRORS_PANIC ||
 268                     def_errors == EXT2_ERRORS_CONTINUE) {
 269                         seq_puts(seq, ",errors=remount-ro");
 270                 }
 271         }
 272         if (test_opt(sb, ERRORS_CONT))
 273                 seq_puts(seq, ",errors=continue");
 274         if (test_opt(sb, ERRORS_PANIC))
 275                 seq_puts(seq, ",errors=panic");
 276         if (test_opt(sb, NO_UID32))
 277                 seq_puts(seq, ",nouid32");
 278         if (test_opt(sb, DEBUG))
 279                 seq_puts(seq, ",debug");
 280         if (test_opt(sb, OLDALLOC))
 281                 seq_puts(seq, ",oldalloc");
 282
 283 #ifdef CONFIG_EXT2_FS_XATTR
 284         if (test_opt(sb, XATTR_USER))
 285                 seq_puts(seq, ",user_xattr");
 286         if (!test_opt(sb, XATTR_USER) &&
 287             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 288                 seq_puts(seq, ",nouser_xattr");
 289         }
 290 #endif
 291
 292 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 293         if (test_opt(sb, POSIX_ACL))
 294                 seq_puts(seq, ",acl");
 295         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 296                 seq_puts(seq, ",noacl");
 297 #endif
 298
 299         if (test_opt(sb, USRQUOTA))
 300                 seq_puts(seq, ",usrquota");
 301
 302         if (test_opt(sb, GRPQUOTA))
 303                 seq_puts(seq, ",grpquota");
 304
 305         if (test_opt(sb, XIP))
 306                 seq_puts(seq, ",xip");
 307
 308         if (test_opt(sb, DAX))
 309                 seq_puts(seq, ",dax");
 310
 311         if (!test_opt(sb, RESERVATION))
 312                 seq_puts(seq, ",noreservation");
 313
 314         spin_unlock(&sbi->s_lock);
 315         return 0;
 316 }
 317
 318 #ifdef CONFIG_QUOTA
 319 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 320 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 321 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 322                          const struct path *path);
 323 static struct dquot **ext2_get_dquots(struct inode *inode)
 324 {
 325         return EXT2_I(inode)->i_dquot;
 326 }
 327
 328 static const struct quotactl_ops ext2_quotactl_ops = {
 329         .quota_on       = ext2_quota_on,
 330         .quota_off      = ext2_quota_off,
 331         .quota_sync     = dquot_quota_sync,
 332         .get_state      = dquot_get_state,
 333         .set_info       = dquot_set_dqinfo,
 334         .get_dqblk      = dquot_get_dqblk,
 335         .set_dqblk      = dquot_set_dqblk,
 336         .get_nextdqblk  = dquot_get_next_dqblk,
 337 };
 338 #endif
 339
 340 static const struct super_operations ext2_sops = {
 341         .alloc_inode    = ext2_alloc_inode,
 342         .free_inode     = ext2_free_in_core_inode,
 343         .write_inode    = ext2_write_inode,
 344         .evict_inode    = ext2_evict_inode,
 345         .put_super      = ext2_put_super,
 346         .sync_fs        = ext2_sync_fs,
 347         .freeze_fs      = ext2_freeze,
 348         .unfreeze_fs    = ext2_unfreeze,
 349         .statfs         = ext2_statfs,
 350         .remount_fs     = ext2_remount,
 351         .show_options   = ext2_show_options,
 352 #ifdef CONFIG_QUOTA
 353         .quota_read     = ext2_quota_read,
 354         .quota_write    = ext2_quota_write,
 355         .get_dquots     = ext2_get_dquots,
 356 #endif
 357 };
 358
 359 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 360                 u64 ino, u32 generation)
 361 {
 362         struct inode *inode;
 363
 364         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 365                 return ERR_PTR(-ESTALE);
 366         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 367                 return ERR_PTR(-ESTALE);
 368
 369         /*
 370          * ext2_iget isn't quite right if the inode is currently unallocated!
 371          * However ext2_iget currently does appropriate checks to handle stale
 372          * inodes so everything is OK.
 373          */
 374         inode = ext2_iget(sb, ino);
 375         if (IS_ERR(inode))
 376                 return ERR_CAST(inode);
 377         if (generation && inode->i_generation != generation) {
 378                 /* we didn't find the right inode.. */
 379                 iput(inode);
 380                 return ERR_PTR(-ESTALE);
 381         }
 382         return inode;
 383 }
 384
 385 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 386                 int fh_len, int fh_type)
 387 {
 388         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 389                                     ext2_nfs_get_inode);
 390 }
 391
 392 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 393                 int fh_len, int fh_type)
 394 {
 395         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 396                                     ext2_nfs_get_inode);
 397 }
 398
 399 static const struct export_operations ext2_export_ops = {
 400         .fh_to_dentry = ext2_fh_to_dentry,
 401         .fh_to_parent = ext2_fh_to_parent,
 402         .get_parent = ext2_get_parent,
 403 };
 404
 405 static unsigned long get_sb_block(void **data)
 406 {
 407         unsigned long   sb_block;
 408         char            *options = (char *) *data;
 409
 410         if (!options || strncmp(options, "sb=", 3) != 0)
 411                 return 1;       /* Default location */
 412         options += 3;
 413         sb_block = simple_strtoul(options, &options, 0);
 414         if (*options && *options != ',') {
 415                 printk("EXT2-fs: Invalid sb specification: %s\n",
 416                        (char *) *data);
 417                 return 1;
 418         }
 419         if (*options == ',')
 420                 options++;
 421         *data = (void *) options;
 422         return sb_block;
 423 }
 424
 425 enum {
 426         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 427         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 428         Opt_err_ro, Opt_nouid32, Opt_debug,
 429         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 430         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 431         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 432 };
 433
 434 static const match_table_t tokens = {
 435         {Opt_bsd_df, "bsddf"},
 436         {Opt_minix_df, "minixdf"},
 437         {Opt_grpid, "grpid"},
 438         {Opt_grpid, "bsdgroups"},
 439         {Opt_nogrpid, "nogrpid"},
 440         {Opt_nogrpid, "sysvgroups"},
 441         {Opt_resgid, "resgid=%u"},
 442         {Opt_resuid, "resuid=%u"},
 443         {Opt_sb, "sb=%u"},
 444         {Opt_err_cont, "errors=continue"},
 445         {Opt_err_panic, "errors=panic"},
 446         {Opt_err_ro, "errors=remount-ro"},
 447         {Opt_nouid32, "nouid32"},
 448         {Opt_debug, "debug"},
 449         {Opt_oldalloc, "oldalloc"},
 450         {Opt_orlov, "orlov"},
 451         {Opt_nobh, "nobh"},
 452         {Opt_user_xattr, "user_xattr"},
 453         {Opt_nouser_xattr, "nouser_xattr"},
 454         {Opt_acl, "acl"},
 455         {Opt_noacl, "noacl"},
 456         {Opt_xip, "xip"},
 457         {Opt_dax, "dax"},
 458         {Opt_grpquota, "grpquota"},
 459         {Opt_ignore, "noquota"},
 460         {Opt_quota, "quota"},
 461         {Opt_usrquota, "usrquota"},
 462         {Opt_reservation, "reservation"},
 463         {Opt_noreservation, "noreservation"},
 464         {Opt_err, NULL}
 465 };
 466
 467 static int parse_options(char *options, struct super_block *sb,
 468                          struct ext2_mount_options *opts)
 469 {
 470         char *p;
 471         substring_t args[MAX_OPT_ARGS];
 472         int option;
 473         kuid_t uid;
 474         kgid_t gid;
 475
 476         if (!options)
 477                 return 1;
 478
 479         while ((p = strsep (&options, ",")) != NULL) {
 480                 int token;
 481                 if (!*p)
 482                         continue;
 483
 484                 token = match_token(p, tokens, args);
 485                 switch (token) {
 486                 case Opt_bsd_df:
 487                         clear_opt (opts->s_mount_opt, MINIX_DF);
 488                         break;
 489                 case Opt_minix_df:
 490                         set_opt (opts->s_mount_opt, MINIX_DF);
 491                         break;
 492                 case Opt_grpid:
 493                         set_opt (opts->s_mount_opt, GRPID);
 494                         break;
 495                 case Opt_nogrpid:
 496                         clear_opt (opts->s_mount_opt, GRPID);
 497                         break;
 498                 case Opt_resuid:
 499                         if (match_int(&args[0], &option))
 500                                 return 0;
 501                         uid = make_kuid(current_user_ns(), option);
 502                         if (!uid_valid(uid)) {
 503                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 504                                 return 0;
 505
 506                         }
 507                         opts->s_resuid = uid;
 508                         break;
 509                 case Opt_resgid:
 510                         if (match_int(&args[0], &option))
 511                                 return 0;
 512                         gid = make_kgid(current_user_ns(), option);
 513                         if (!gid_valid(gid)) {
 514                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 515                                 return 0;
 516                         }
 517                         opts->s_resgid = gid;
 518                         break;
 519                 case Opt_sb:
 520                         /* handled by get_sb_block() instead of here */
 521                         /* *sb_block = match_int(&args[0]); */
 522                         break;
 523                 case Opt_err_panic:
 524                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 525                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 526                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 527                         break;
 528                 case Opt_err_ro:
 529                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 530                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 531                         set_opt (opts->s_mount_opt, ERRORS_RO);
 532                         break;
 533                 case Opt_err_cont:
 534                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 535                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 536                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 537                         break;
 538                 case Opt_nouid32:
 539                         set_opt (opts->s_mount_opt, NO_UID32);
 540                         break;
 541                 case Opt_debug:
 542                         set_opt (opts->s_mount_opt, DEBUG);
 543                         break;
 544                 case Opt_oldalloc:
 545                         set_opt (opts->s_mount_opt, OLDALLOC);
 546                         break;
 547                 case Opt_orlov:
 548                         clear_opt (opts->s_mount_opt, OLDALLOC);
 549                         break;
 550                 case Opt_nobh:
 551                         ext2_msg(sb, KERN_INFO,
 552                                 "nobh option not supported");
 553                         break;
 554 #ifdef CONFIG_EXT2_FS_XATTR
 555                 case Opt_user_xattr:
 556                         set_opt (opts->s_mount_opt, XATTR_USER);
 557                         break;
 558                 case Opt_nouser_xattr:
 559                         clear_opt (opts->s_mount_opt, XATTR_USER);
 560                         break;
 561 #else
 562                 case Opt_user_xattr:
 563                 case Opt_nouser_xattr:
 564                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 565                                 "not supported");
 566                         break;
 567 #endif
 568 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 569                 case Opt_acl:
 570                         set_opt(opts->s_mount_opt, POSIX_ACL);
 571                         break;
 572                 case Opt_noacl:
 573                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 574                         break;
 575 #else
 576                 case Opt_acl:
 577                 case Opt_noacl:
 578                         ext2_msg(sb, KERN_INFO,
 579                                 "(no)acl options not supported");
 580                         break;
 581 #endif
 582                 case Opt_xip:
 583                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 584                         set_opt(opts->s_mount_opt, XIP);
 585                         fallthrough;
 586                 case Opt_dax:
 587 #ifdef CONFIG_FS_DAX
 588                         ext2_msg(sb, KERN_WARNING,
 589                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 590                         set_opt(opts->s_mount_opt, DAX);
 591 #else
 592                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 593 #endif
 594                         break;
 595
 596 #if defined(CONFIG_QUOTA)
 597                 case Opt_quota:
 598                 case Opt_usrquota:
 599                         set_opt(opts->s_mount_opt, USRQUOTA);
 600                         break;
 601
 602                 case Opt_grpquota:
 603                         set_opt(opts->s_mount_opt, GRPQUOTA);
 604                         break;
 605 #else
 606                 case Opt_quota:
 607                 case Opt_usrquota:
 608                 case Opt_grpquota:
 609                         ext2_msg(sb, KERN_INFO,
 610                                 "quota operations not supported");
 611                         break;
 612 #endif
 613
 614                 case Opt_reservation:
 615                         set_opt(opts->s_mount_opt, RESERVATION);
 616                         ext2_msg(sb, KERN_INFO, "reservations ON");
 617                         break;
 618                 case Opt_noreservation:
 619                         clear_opt(opts->s_mount_opt, RESERVATION);
 620                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 621                         break;
 622                 case Opt_ignore:
 623                         break;
 624                 default:
 625                         return 0;
 626                 }
 627         }
 628         return 1;
 629 }
 630
 631 static int ext2_setup_super (struct super_block * sb,
 632                               struct ext2_super_block * es,
 633                               int read_only)
 634 {
 635         int res = 0;
 636         struct ext2_sb_info *sbi = EXT2_SB(sb);
 637
 638         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 639                 ext2_msg(sb, KERN_ERR,
 640                         "error: revision level too high, "
 641                         "forcing read-only mode");
 642                 res = SB_RDONLY;
 643         }
 644         if (read_only)
 645                 return res;
 646         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 647                 ext2_msg(sb, KERN_WARNING,
 648                         "warning: mounting unchecked fs, "
 649                         "running e2fsck is recommended");
 650         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 651                 ext2_msg(sb, KERN_WARNING,
 652                         "warning: mounting fs with errors, "
 653                         "running e2fsck is recommended");
 654         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 655                  le16_to_cpu(es->s_mnt_count) >=
 656                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 657                 ext2_msg(sb, KERN_WARNING,
 658                         "warning: maximal mount count reached, "
 659                         "running e2fsck is recommended");
 660         else if (le32_to_cpu(es->s_checkinterval) &&
 661                 (le32_to_cpu(es->s_lastcheck) +
 662                         le32_to_cpu(es->s_checkinterval) <=
 663                         ktime_get_real_seconds()))
 664                 ext2_msg(sb, KERN_WARNING,
 665                         "warning: checktime reached, "
 666                         "running e2fsck is recommended");
 667         if (!le16_to_cpu(es->s_max_mnt_count))
 668                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 669         le16_add_cpu(&es->s_mnt_count, 1);
 670         if (test_opt (sb, DEBUG))
 671                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
 672                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 673                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 674                         sbi->s_groups_count,
 675                         EXT2_BLOCKS_PER_GROUP(sb),
 676                         EXT2_INODES_PER_GROUP(sb),
 677                         sbi->s_mount_opt);
 678         return res;
 679 }
 680
 681 static int ext2_check_descriptors(struct super_block *sb)
 682 {
 683         int i;
 684         struct ext2_sb_info *sbi = EXT2_SB(sb);
 685
 686         ext2_debug ("Checking group descriptors");
 687
 688         for (i = 0; i < sbi->s_groups_count; i++) {
 689                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 690                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 691                 ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
 692
 693                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 694                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 695                 {
 696                         ext2_error (sb, "ext2_check_descriptors",
 697                                     "Block bitmap for group %d"
 698                                     " not in group (block %lu)!",
 699                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 700                         return 0;
 701                 }
 702                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 703                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 704                 {
 705                         ext2_error (sb, "ext2_check_descriptors",
 706                                     "Inode bitmap for group %d"
 707                                     " not in group (block %lu)!",
 708                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 709                         return 0;
 710                 }
 711                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 712                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 713                     last_block)
 714                 {
 715                         ext2_error (sb, "ext2_check_descriptors",
 716                                     "Inode table for group %d"
 717                                     " not in group (block %lu)!",
 718                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 719                         return 0;
 720                 }
 721         }
 722         return 1;
 723 }
 724
 725 /*
 726  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 727  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 728  * We need to be 1 filesystem block less than the 2^32 sector limit.
 729  */
 730 static loff_t ext2_max_size(int bits)
 731 {
 732         loff_t res = EXT2_NDIR_BLOCKS;
 733         int meta_blocks;
 734         unsigned int upper_limit;
 735         unsigned int ppb = 1 << (bits-2);
 736
 737         /* This is calculated to be the largest file size for a
 738          * dense, file such that the total number of
 739          * sectors in the file, including data and all indirect blocks,
 740          * does not exceed 2^32 -1
 741          * __u32 i_blocks representing the total number of
 742          * 512 bytes blocks of the file
 743          */
 744         upper_limit = (1LL << 32) - 1;
 745
 746         /* total blocks in file system block size */
 747         upper_limit >>= (bits - 9);
 748
 749         /* Compute how many blocks we can address by block tree */
 750         res += 1LL << (bits-2);
 751         res += 1LL << (2*(bits-2));
 752         res += 1LL << (3*(bits-2));
 753         /* Compute how many metadata blocks are needed */
 754         meta_blocks = 1;
 755         meta_blocks += 1 + ppb;
 756         meta_blocks += 1 + ppb + ppb * ppb;
 757         /* Does block tree limit file size? */
 758         if (res + meta_blocks <= upper_limit)
 759                 goto check_lfs;
 760
 761         res = upper_limit;
 762         /* How many metadata blocks are needed for addressing upper_limit? */
 763         upper_limit -= EXT2_NDIR_BLOCKS;
 764         /* indirect blocks */
 765         meta_blocks = 1;
 766         upper_limit -= ppb;
 767         /* double indirect blocks */
 768         if (upper_limit < ppb * ppb) {
 769                 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
 770                 res -= meta_blocks;
 771                 goto check_lfs;
 772         }
 773         meta_blocks += 1 + ppb;
 774         upper_limit -= ppb * ppb;
 775         /* tripple indirect blocks for the rest */
 776         meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
 777                 DIV_ROUND_UP(upper_limit, ppb*ppb);
 778         res -= meta_blocks;
 779 check_lfs:
 780         res <<= bits;
 781         if (res > MAX_LFS_FILESIZE)
 782                 res = MAX_LFS_FILESIZE;
 783
 784         return res;
 785 }
 786
 787 static unsigned long descriptor_loc(struct super_block *sb,
 788                                     unsigned long logic_sb_block,
 789                                     int nr)
 790 {
 791         struct ext2_sb_info *sbi = EXT2_SB(sb);
 792         unsigned long bg, first_meta_bg;
 793
 794         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 795
 796         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 797             nr < first_meta_bg)
 798                 return (logic_sb_block + nr + 1);
 799         bg = sbi->s_desc_per_block * nr;
 800
 801         return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
 802 }
 803
 804 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 805 {
 806         struct buffer_head * bh;
 807         struct ext2_sb_info * sbi;
 808         struct ext2_super_block * es;
 809         struct inode *root;
 810         unsigned long block;
 811         unsigned long sb_block = get_sb_block(&data);
 812         unsigned long logic_sb_block;
 813         unsigned long offset = 0;
 814         unsigned long def_mount_opts;
 815         long ret = -ENOMEM;
 816         int blocksize = BLOCK_SIZE;
 817         int db_count;
 818         int i, j;
 819         __le32 features;
 820         int err;
 821         struct ext2_mount_options opts;
 822
 823         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 824         if (!sbi)
 825                 return -ENOMEM;
 826
 827         sbi->s_blockgroup_lock =
 828                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 829         if (!sbi->s_blockgroup_lock) {
 830                 kfree(sbi);
 831                 return -ENOMEM;
 832         }
 833         sb->s_fs_info = sbi;
 834         sbi->s_sb_block = sb_block;
 835         sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
 836                                            NULL, NULL);
 837
 838         spin_lock_init(&sbi->s_lock);
 839         ret = -EINVAL;
 840
 841         /*
 842          * See what the current blocksize for the device is, and
 843          * use that as the blocksize.  Otherwise (or if the blocksize
 844          * is smaller than the default) use the default.
 845          * This is important for devices that have a hardware
 846          * sectorsize that is larger than the default.
 847          */
 848         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 849         if (!blocksize) {
 850                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 851                 goto failed_sbi;
 852         }
 853
 854         /*
 855          * If the superblock doesn't start on a hardware sector boundary,
 856          * calculate the offset.
 857          */
 858         if (blocksize != BLOCK_SIZE) {
 859                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 860                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 861         } else {
 862                 logic_sb_block = sb_block;
 863         }
 864
 865         if (!(bh = sb_bread(sb, logic_sb_block))) {
 866                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 867                 goto failed_sbi;
 868         }
 869         /*
 870          * Note: s_es must be initialized as soon as possible because
 871          *       some ext2 macro-instructions depend on its value
 872          */
 873         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 874         sbi->s_es = es;
 875         sb->s_magic = le16_to_cpu(es->s_magic);
 876
 877         if (sb->s_magic != EXT2_SUPER_MAGIC)
 878                 goto cantfind_ext2;
 879
 880         opts.s_mount_opt = 0;
 881         /* Set defaults before we parse the mount options */
 882         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 883         if (def_mount_opts & EXT2_DEFM_DEBUG)
 884                 set_opt(opts.s_mount_opt, DEBUG);
 885         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 886                 set_opt(opts.s_mount_opt, GRPID);
 887         if (def_mount_opts & EXT2_DEFM_UID16)
 888                 set_opt(opts.s_mount_opt, NO_UID32);
 889 #ifdef CONFIG_EXT2_FS_XATTR
 890         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 891                 set_opt(opts.s_mount_opt, XATTR_USER);
 892 #endif
 893 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 894         if (def_mount_opts & EXT2_DEFM_ACL)
 895                 set_opt(opts.s_mount_opt, POSIX_ACL);
 896 #endif
 897
 898         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 899                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
 900         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 901                 set_opt(opts.s_mount_opt, ERRORS_CONT);
 902         else
 903                 set_opt(opts.s_mount_opt, ERRORS_RO);
 904
 905         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 906         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 907
 908         set_opt(opts.s_mount_opt, RESERVATION);
 909
 910         if (!parse_options((char *) data, sb, &opts))
 911                 goto failed_mount;
 912
 913         sbi->s_mount_opt = opts.s_mount_opt;
 914         sbi->s_resuid = opts.s_resuid;
 915         sbi->s_resgid = opts.s_resgid;
 916
 917         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 918                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
 919         sb->s_iflags |= SB_I_CGROUPWB;
 920
 921         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 922             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 923              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 924              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 925                 ext2_msg(sb, KERN_WARNING,
 926                         "warning: feature flags set on rev 0 fs, "
 927                         "running e2fsck is recommended");
 928         /*
 929          * Check feature flags regardless of the revision level, since we
 930          * previously didn't change the revision level when setting the flags,
 931          * so there is a chance incompat flags are set on a rev 0 filesystem.
 932          */
 933         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 934         if (features) {
 935                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 936                        "unsupported optional features (%x)",
 937                         le32_to_cpu(features));
 938                 goto failed_mount;
 939         }
 940         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 941                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 942                        "unsupported optional features (%x)",
 943                        le32_to_cpu(features));
 944                 goto failed_mount;
 945         }
 946
 947         if (le32_to_cpu(es->s_log_block_size) >
 948             (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
 949                 ext2_msg(sb, KERN_ERR,
 950                          "Invalid log block size: %u",
 951                          le32_to_cpu(es->s_log_block_size));
 952                 goto failed_mount;
 953         }
 954         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 955
 956         if (test_opt(sb, DAX)) {
 957                 if (!sbi->s_daxdev) {
 958                         ext2_msg(sb, KERN_ERR,
 959                                 "DAX unsupported by block device. Turning off DAX.");
 960                         clear_opt(sbi->s_mount_opt, DAX);
 961                 } else if (blocksize != PAGE_SIZE) {
 962                         ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
 963                         clear_opt(sbi->s_mount_opt, DAX);
 964                 }
 965         }
 966
 967         /* If the blocksize doesn't match, re-read the thing.. */
 968         if (sb->s_blocksize != blocksize) {
 969                 brelse(bh);
 970
 971                 if (!sb_set_blocksize(sb, blocksize)) {
 972                         ext2_msg(sb, KERN_ERR,
 973                                 "error: bad blocksize %d", blocksize);
 974                         goto failed_sbi;
 975                 }
 976
 977                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 978                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 979                 bh = sb_bread(sb, logic_sb_block);
 980                 if(!bh) {
 981                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 982                                 "superblock on 2nd try");
 983                         goto failed_sbi;
 984                 }
 985                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 986                 sbi->s_es = es;
 987                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 988                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 989                         goto failed_mount;
 990                 }
 991         }
 992
 993         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 994         sb->s_max_links = EXT2_LINK_MAX;
 995         sb->s_time_min = S32_MIN;
 996         sb->s_time_max = S32_MAX;
 997
 998         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 999                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1000                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1001         } else {
1002                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1003                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1004                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1005                     !is_power_of_2(sbi->s_inode_size) ||
1006                     (sbi->s_inode_size > blocksize)) {
1007                         ext2_msg(sb, KERN_ERR,
1008                                 "error: unsupported inode size: %d",
1009                                 sbi->s_inode_size);
1010                         goto failed_mount;
1011                 }
1012         }
1013
1014         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1015         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1016
1017         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1018         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1019                 goto cantfind_ext2;
1020         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1021                                         sbi->s_inodes_per_block;
1022         sbi->s_desc_per_block = sb->s_blocksize /
1023                                         sizeof (struct ext2_group_desc);
1024         sbi->s_sbh = bh;
1025         sbi->s_mount_state = le16_to_cpu(es->s_state);
1026         sbi->s_addr_per_block_bits =
1027                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1028         sbi->s_desc_per_block_bits =
1029                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1030
1031         if (sb->s_magic != EXT2_SUPER_MAGIC)
1032                 goto cantfind_ext2;
1033
1034         if (sb->s_blocksize != bh->b_size) {
1035                 if (!silent)
1036                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1037                 goto failed_mount;
1038         }
1039
1040         if (es->s_log_frag_size != es->s_log_block_size) {
1041                 ext2_msg(sb, KERN_ERR,
1042                         "error: fragsize log %u != blocksize log %u",
1043                         le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
1044                 goto failed_mount;
1045         }
1046
1047         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1048                 ext2_msg(sb, KERN_ERR,
1049                         "error: #blocks per group too big: %lu",
1050                         sbi->s_blocks_per_group);
1051                 goto failed_mount;
1052         }
1053         /* At least inode table, bitmaps, and sb have to fit in one group */
1054         if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
1055                 ext2_msg(sb, KERN_ERR,
1056                         "error: #blocks per group smaller than metadata size: %lu <= %lu",
1057                         sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
1058                 goto failed_mount;
1059         }
1060         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
1061             sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1062                 ext2_msg(sb, KERN_ERR,
1063                         "error: invalid #inodes per group: %lu",
1064                         sbi->s_inodes_per_group);
1065                 goto failed_mount;
1066         }
1067         if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
1068                 ext2_msg(sb, KERN_ERR,
1069                          "bad geometry: block count %u exceeds size of device (%u blocks)",
1070                          le32_to_cpu(es->s_blocks_count),
1071                          (unsigned)sb_bdev_nr_blocks(sb));
1072                 goto failed_mount;
1073         }
1074
1075         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1076                                 le32_to_cpu(es->s_first_data_block) - 1)
1077                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1078         if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
1079             le32_to_cpu(es->s_inodes_count)) {
1080                 ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
1081                          le32_to_cpu(es->s_inodes_count),
1082                          (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
1083                 goto failed_mount;
1084         }
1085         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1086                    EXT2_DESC_PER_BLOCK(sb);
1087         sbi->s_group_desc = kvmalloc_array(db_count,
1088                                            sizeof(struct buffer_head *),
1089                                            GFP_KERNEL);
1090         if (sbi->s_group_desc == NULL) {
1091                 ret = -ENOMEM;
1092                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1093                 goto failed_mount;
1094         }
1095         bgl_lock_init(sbi->s_blockgroup_lock);
1096         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1097         if (!sbi->s_debts) {
1098                 ret = -ENOMEM;
1099                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1100                 goto failed_mount_group_desc;
1101         }
1102         for (i = 0; i < db_count; i++) {
1103                 block = descriptor_loc(sb, logic_sb_block, i);
1104                 sbi->s_group_desc[i] = sb_bread(sb, block);
1105                 if (!sbi->s_group_desc[i]) {
1106                         for (j = 0; j < i; j++)
1107                                 brelse (sbi->s_group_desc[j]);
1108                         ext2_msg(sb, KERN_ERR,
1109                                 "error: unable to read group descriptors");
1110                         goto failed_mount_group_desc;
1111                 }
1112         }
1113         if (!ext2_check_descriptors (sb)) {
1114                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1115                 goto failed_mount2;
1116         }
1117         sbi->s_gdb_count = db_count;
1118         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1119         spin_lock_init(&sbi->s_next_gen_lock);
1120
1121         /* per filesystem reservation list head & lock */
1122         spin_lock_init(&sbi->s_rsv_window_lock);
1123         sbi->s_rsv_window_root = RB_ROOT;
1124         /*
1125          * Add a single, static dummy reservation to the start of the
1126          * reservation window list --- it gives us a placeholder for
1127          * append-at-start-of-list which makes the allocation logic
1128          * _much_ simpler.
1129          */
1130         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1131         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1132         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1133         sbi->s_rsv_window_head.rsv_goal_size = 0;
1134         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1135
1136         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1137                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1138         if (!err) {
1139                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1140                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1141         }
1142         if (!err) {
1143                 err = percpu_counter_init(&sbi->s_dirs_counter,
1144                                 ext2_count_dirs(sb), GFP_KERNEL);
1145         }
1146         if (err) {
1147                 ret = err;
1148                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1149                 goto failed_mount3;
1150         }
1151
1152 #ifdef CONFIG_EXT2_FS_XATTR
1153         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1154         if (!sbi->s_ea_block_cache) {
1155                 ret = -ENOMEM;
1156                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1157                 goto failed_mount3;
1158         }
1159 #endif
1160         /*
1161          * set up enough so that it can read an inode
1162          */
1163         sb->s_op = &ext2_sops;
1164         sb->s_export_op = &ext2_export_ops;
1165         sb->s_xattr = ext2_xattr_handlers;
1166
1167 #ifdef CONFIG_QUOTA
1168         sb->dq_op = &dquot_operations;
1169         sb->s_qcop = &ext2_quotactl_ops;
1170         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1171 #endif
1172
1173         root = ext2_iget(sb, EXT2_ROOT_INO);
1174         if (IS_ERR(root)) {
1175                 ret = PTR_ERR(root);
1176                 goto failed_mount3;
1177         }
1178         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1179                 iput(root);
1180                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1181                 goto failed_mount3;
1182         }
1183
1184         sb->s_root = d_make_root(root);
1185         if (!sb->s_root) {
1186                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1187                 ret = -ENOMEM;
1188                 goto failed_mount3;
1189         }
1190         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1191                 ext2_msg(sb, KERN_WARNING,
1192                         "warning: mounting ext3 filesystem as ext2");
1193         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1194                 sb->s_flags |= SB_RDONLY;
1195         ext2_write_super(sb);
1196         return 0;
1197
1198 cantfind_ext2:
1199         if (!silent)
1200                 ext2_msg(sb, KERN_ERR,
1201                         "error: can't find an ext2 filesystem on dev %s.",
1202                         sb->s_id);
1203         goto failed_mount;
1204 failed_mount3:
1205         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1206         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1207         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1208         percpu_counter_destroy(&sbi->s_dirs_counter);
1209 failed_mount2:
1210         for (i = 0; i < db_count; i++)
1211                 brelse(sbi->s_group_desc[i]);
1212 failed_mount_group_desc:
1213         kvfree(sbi->s_group_desc);
1214         kfree(sbi->s_debts);
1215 failed_mount:
1216         brelse(bh);
1217 failed_sbi:
1218         fs_put_dax(sbi->s_daxdev, NULL);
1219         sb->s_fs_info = NULL;
1220         kfree(sbi->s_blockgroup_lock);
1221         kfree(sbi);
1222         return ret;
1223 }
1224
1225 static void ext2_clear_super_error(struct super_block *sb)
1226 {
1227         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1228
1229         if (buffer_write_io_error(sbh)) {
1230                 /*
1231                  * Oh, dear.  A previous attempt to write the
1232                  * superblock failed.  This could happen because the
1233                  * USB device was yanked out.  Or it could happen to
1234                  * be a transient write error and maybe the block will
1235                  * be remapped.  Nothing we can do but to retry the
1236                  * write and hope for the best.
1237                  */
1238                 ext2_msg(sb, KERN_ERR,
1239                        "previous I/O error to superblock detected");
1240                 clear_buffer_write_io_error(sbh);
1241                 set_buffer_uptodate(sbh);
1242         }
1243 }
1244
1245 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1246                      int wait)
1247 {
1248         ext2_clear_super_error(sb);
1249         spin_lock(&EXT2_SB(sb)->s_lock);
1250         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1251         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1252         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1253         /* unlock before we do IO */
1254         spin_unlock(&EXT2_SB(sb)->s_lock);
1255         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1256         if (wait)
1257                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1258 }
1259
1260 /*
1261  * In the second extended file system, it is not necessary to
1262  * write the super block since we use a mapping of the
1263  * disk super block in a buffer.
1264  *
1265  * However, this function is still used to set the fs valid
1266  * flags to 0.  We need to set this flag to 0 since the fs
1267  * may have been checked while mounted and e2fsck may have
1268  * set s_state to EXT2_VALID_FS after some corrections.
1269  */
1270 static int ext2_sync_fs(struct super_block *sb, int wait)
1271 {
1272         struct ext2_sb_info *sbi = EXT2_SB(sb);
1273         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1274
1275         /*
1276          * Write quota structures to quota file, sync_blockdev() will write
1277          * them to disk later
1278          */
1279         dquot_writeback_dquots(sb, -1);
1280
1281         spin_lock(&sbi->s_lock);
1282         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1283                 ext2_debug("setting valid to 0\n");
1284                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1285         }
1286         spin_unlock(&sbi->s_lock);
1287         ext2_sync_super(sb, es, wait);
1288         return 0;
1289 }
1290
1291 static int ext2_freeze(struct super_block *sb)
1292 {
1293         struct ext2_sb_info *sbi = EXT2_SB(sb);
1294
1295         /*
1296          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1297          * because we have unattached inodes and thus filesystem is not fully
1298          * consistent.
1299          */
1300         if (atomic_long_read(&sb->s_remove_count)) {
1301                 ext2_sync_fs(sb, 1);
1302                 return 0;
1303         }
1304         /* Set EXT2_FS_VALID flag */
1305         spin_lock(&sbi->s_lock);
1306         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1307         spin_unlock(&sbi->s_lock);
1308         ext2_sync_super(sb, sbi->s_es, 1);
1309
1310         return 0;
1311 }
1312
1313 static int ext2_unfreeze(struct super_block *sb)
1314 {
1315         /* Just write sb to clear EXT2_VALID_FS flag */
1316         ext2_write_super(sb);
1317
1318         return 0;
1319 }
1320
1321 static void ext2_write_super(struct super_block *sb)
1322 {
1323         if (!sb_rdonly(sb))
1324                 ext2_sync_fs(sb, 1);
1325 }
1326
1327 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1328 {
1329         struct ext2_sb_info * sbi = EXT2_SB(sb);
1330         struct ext2_super_block * es;
1331         struct ext2_mount_options new_opts;
1332         int err;
1333
1334         sync_filesystem(sb);
1335
1336         spin_lock(&sbi->s_lock);
1337         new_opts.s_mount_opt = sbi->s_mount_opt;
1338         new_opts.s_resuid = sbi->s_resuid;
1339         new_opts.s_resgid = sbi->s_resgid;
1340         spin_unlock(&sbi->s_lock);
1341
1342         if (!parse_options(data, sb, &new_opts))
1343                 return -EINVAL;
1344
1345         spin_lock(&sbi->s_lock);
1346         es = sbi->s_es;
1347         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1348                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1349                          "dax flag with busy inodes while remounting");
1350                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1351         }
1352         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1353                 goto out_set;
1354         if (*flags & SB_RDONLY) {
1355                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1356                     !(sbi->s_mount_state & EXT2_VALID_FS))
1357                         goto out_set;
1358
1359                 /*
1360                  * OK, we are remounting a valid rw partition rdonly, so set
1361                  * the rdonly flag and then mark the partition as valid again.
1362                  */
1363                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1364                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1365                 spin_unlock(&sbi->s_lock);
1366
1367                 err = dquot_suspend(sb, -1);
1368                 if (err < 0)
1369                         return err;
1370
1371                 ext2_sync_super(sb, es, 1);
1372         } else {
1373                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1374                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1375                 if (ret) {
1376                         spin_unlock(&sbi->s_lock);
1377                         ext2_msg(sb, KERN_WARNING,
1378                                 "warning: couldn't remount RDWR because of "
1379                                 "unsupported optional features (%x).",
1380                                 le32_to_cpu(ret));
1381                         return -EROFS;
1382                 }
1383                 /*
1384                  * Mounting a RDONLY partition read-write, so reread and
1385                  * store the current valid flag.  (It may have been changed
1386                  * by e2fsck since we originally mounted the partition.)
1387                  */
1388                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1389                 if (!ext2_setup_super (sb, es, 0))
1390                         sb->s_flags &= ~SB_RDONLY;
1391                 spin_unlock(&sbi->s_lock);
1392
1393                 ext2_write_super(sb);
1394
1395                 dquot_resume(sb, -1);
1396         }
1397
1398         spin_lock(&sbi->s_lock);
1399 out_set:
1400         sbi->s_mount_opt = new_opts.s_mount_opt;
1401         sbi->s_resuid = new_opts.s_resuid;
1402         sbi->s_resgid = new_opts.s_resgid;
1403         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1404                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1405         spin_unlock(&sbi->s_lock);
1406
1407         return 0;
1408 }
1409
1410 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1411 {
1412         struct super_block *sb = dentry->d_sb;
1413         struct ext2_sb_info *sbi = EXT2_SB(sb);
1414         struct ext2_super_block *es = sbi->s_es;
1415
1416         spin_lock(&sbi->s_lock);
1417
1418         if (test_opt (sb, MINIX_DF))
1419                 sbi->s_overhead_last = 0;
1420         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1421                 unsigned long i, overhead = 0;
1422                 smp_rmb();
1423
1424                 /*
1425                  * Compute the overhead (FS structures). This is constant
1426                  * for a given filesystem unless the number of block groups
1427                  * changes so we cache the previous value until it does.
1428                  */
1429
1430                 /*
1431                  * All of the blocks before first_data_block are
1432                  * overhead
1433                  */
1434                 overhead = le32_to_cpu(es->s_first_data_block);
1435
1436                 /*
1437                  * Add the overhead attributed to the superblock and
1438                  * block group descriptors.  If the sparse superblocks
1439                  * feature is turned on, then not all groups have this.
1440                  */
1441                 for (i = 0; i < sbi->s_groups_count; i++)
1442                         overhead += ext2_bg_has_super(sb, i) +
1443                                 ext2_bg_num_gdb(sb, i);
1444
1445                 /*
1446                  * Every block group has an inode bitmap, a block
1447                  * bitmap, and an inode table.
1448                  */
1449                 overhead += (sbi->s_groups_count *
1450                              (2 + sbi->s_itb_per_group));
1451                 sbi->s_overhead_last = overhead;
1452                 smp_wmb();
1453                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1454         }
1455
1456         buf->f_type = EXT2_SUPER_MAGIC;
1457         buf->f_bsize = sb->s_blocksize;
1458         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1459         buf->f_bfree = ext2_count_free_blocks(sb);
1460         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1461         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1462         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1463                 buf->f_bavail = 0;
1464         buf->f_files = le32_to_cpu(es->s_inodes_count);
1465         buf->f_ffree = ext2_count_free_inodes(sb);
1466         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1467         buf->f_namelen = EXT2_NAME_LEN;
1468         buf->f_fsid = uuid_to_fsid(es->s_uuid);
1469         spin_unlock(&sbi->s_lock);
1470         return 0;
1471 }
1472
1473 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1474         int flags, const char *dev_name, void *data)
1475 {
1476         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1477 }
1478
1479 #ifdef CONFIG_QUOTA
1480
1481 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1482  * acquiring the locks... As quota files are never truncated and quota code
1483  * itself serializes the operations (and no one else should touch the files)
1484  * we don't have to be afraid of races */
1485 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1486                                size_t len, loff_t off)
1487 {
1488         struct inode *inode = sb_dqopt(sb)->files[type];
1489         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1490         int err = 0;
1491         int offset = off & (sb->s_blocksize - 1);
1492         int tocopy;
1493         size_t toread;
1494         struct buffer_head tmp_bh;
1495         struct buffer_head *bh;
1496         loff_t i_size = i_size_read(inode);
1497
1498         if (off > i_size)
1499                 return 0;
1500         if (off+len > i_size)
1501                 len = i_size-off;
1502         toread = len;
1503         while (toread > 0) {
1504                 tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
1505
1506                 tmp_bh.b_state = 0;
1507                 tmp_bh.b_size = sb->s_blocksize;
1508                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1509                 if (err < 0)
1510                         return err;
1511                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1512                         memset(data, 0, tocopy);
1513                 else {
1514                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1515                         if (!bh)
1516                                 return -EIO;
1517                         memcpy(data, bh->b_data+offset, tocopy);
1518                         brelse(bh);
1519                 }
1520                 offset = 0;
1521                 toread -= tocopy;
1522                 data += tocopy;
1523                 blk++;
1524         }
1525         return len;
1526 }
1527
1528 /* Write to quotafile */
1529 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1530                                 const char *data, size_t len, loff_t off)
1531 {
1532         struct inode *inode = sb_dqopt(sb)->files[type];
1533         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1534         int err = 0;
1535         int offset = off & (sb->s_blocksize - 1);
1536         int tocopy;
1537         size_t towrite = len;
1538         struct buffer_head tmp_bh;
1539         struct buffer_head *bh;
1540
1541         while (towrite > 0) {
1542                 tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
1543
1544                 tmp_bh.b_state = 0;
1545                 tmp_bh.b_size = sb->s_blocksize;
1546                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1547                 if (err < 0)
1548                         goto out;
1549                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1550                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1551                 else
1552                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1553                 if (unlikely(!bh)) {
1554                         err = -EIO;
1555                         goto out;
1556                 }
1557                 lock_buffer(bh);
1558                 memcpy(bh->b_data+offset, data, tocopy);
1559                 flush_dcache_page(bh->b_page);
1560                 set_buffer_uptodate(bh);
1561                 mark_buffer_dirty(bh);
1562                 unlock_buffer(bh);
1563                 brelse(bh);
1564                 offset = 0;
1565                 towrite -= tocopy;
1566                 data += tocopy;
1567                 blk++;
1568         }
1569 out:
1570         if (len == towrite)
1571                 return err;
1572         if (inode->i_size < off+len-towrite)
1573                 i_size_write(inode, off+len-towrite);
1574         inode_inc_iversion(inode);
1575         inode->i_mtime = inode_set_ctime_current(inode);
1576         mark_inode_dirty(inode);
1577         return len - towrite;
1578 }
1579
1580 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1581                          const struct path *path)
1582 {
1583         int err;
1584         struct inode *inode;
1585
1586         err = dquot_quota_on(sb, type, format_id, path);
1587         if (err)
1588                 return err;
1589
1590         inode = d_inode(path->dentry);
1591         inode_lock(inode);
1592         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1593         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1594                         S_NOATIME | S_IMMUTABLE);
1595         inode_unlock(inode);
1596         mark_inode_dirty(inode);
1597
1598         return 0;
1599 }
1600
1601 static int ext2_quota_off(struct super_block *sb, int type)
1602 {
1603         struct inode *inode = sb_dqopt(sb)->files[type];
1604         int err;
1605
1606         if (!inode || !igrab(inode))
1607                 goto out;
1608
1609         err = dquot_quota_off(sb, type);
1610         if (err)
1611                 goto out_put;
1612
1613         inode_lock(inode);
1614         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1615         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1616         inode_unlock(inode);
1617         mark_inode_dirty(inode);
1618 out_put:
1619         iput(inode);
1620         return err;
1621 out:
1622         return dquot_quota_off(sb, type);
1623 }
1624
1625 #endif
1626
1627 static struct file_system_type ext2_fs_type = {
1628         .owner          = THIS_MODULE,
1629         .name           = "ext2",
1630         .mount          = ext2_mount,
1631         .kill_sb        = kill_block_super,
1632         .fs_flags       = FS_REQUIRES_DEV,
1633 };
1634 MODULE_ALIAS_FS("ext2");
1635
1636 static int __init init_ext2_fs(void)
1637 {
1638         int err;
1639
1640         err = init_inodecache();
1641         if (err)
1642                 return err;
1643         err = register_filesystem(&ext2_fs_type);
1644         if (err)
1645                 goto out;
1646         return 0;
1647 out:
1648         destroy_inodecache();
1649         return err;
1650 }
1651
1652 static void __exit exit_ext2_fs(void)
1653 {
1654         unregister_filesystem(&ext2_fs_type);
1655         destroy_inodecache();
1656 }
1657
1658 MODULE_AUTHOR("Remy Card and others");
1659 MODULE_DESCRIPTION("Second Extended Filesystem");
1660 MODULE_LICENSE("GPL");
1661 module_init(init_ext2_fs)
1662 module_exit(exit_ext2_fs)