fs/ext2/super.c

   1 /*
   2  *  linux/fs/ext2/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/slab.h>
  23 #include <linux/init.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/parser.h>
  26 #include <linux/random.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/exportfs.h>
  29 #include <linux/vfs.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/mount.h>
  32 #include <linux/log2.h>
  33 #include <linux/quotaops.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/dax.h>
  36 #include <linux/iversion.h>
  37 #include "ext2.h"
  38 #include "xattr.h"
  39 #include "acl.h"
  40
  41 static void ext2_write_super(struct super_block *sb);
  42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44 static int ext2_sync_fs(struct super_block *sb, int wait);
  45 static int ext2_freeze(struct super_block *sb);
  46 static int ext2_unfreeze(struct super_block *sb);
  47
  48 void ext2_error(struct super_block *sb, const char *function,
  49                 const char *fmt, ...)
  50 {
  51         struct va_format vaf;
  52         va_list args;
  53         struct ext2_sb_info *sbi = EXT2_SB(sb);
  54         struct ext2_super_block *es = sbi->s_es;
  55
  56         if (!sb_rdonly(sb)) {
  57                 spin_lock(&sbi->s_lock);
  58                 sbi->s_mount_state |= EXT2_ERROR_FS;
  59                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  60                 spin_unlock(&sbi->s_lock);
  61                 ext2_sync_super(sb, es, 1);
  62         }
  63
  64         va_start(args, fmt);
  65
  66         vaf.fmt = fmt;
  67         vaf.va = &args;
  68
  69         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  70                sb->s_id, function, &vaf);
  71
  72         va_end(args);
  73
  74         if (test_opt(sb, ERRORS_PANIC))
  75                 panic("EXT2-fs: panic from previous error\n");
  76         if (test_opt(sb, ERRORS_RO)) {
  77                 ext2_msg(sb, KERN_CRIT,
  78                              "error: remounting filesystem read-only");
  79                 sb->s_flags |= SB_RDONLY;
  80         }
  81 }
  82
  83 void ext2_msg(struct super_block *sb, const char *prefix,
  84                 const char *fmt, ...)
  85 {
  86         struct va_format vaf;
  87         va_list args;
  88
  89         va_start(args, fmt);
  90
  91         vaf.fmt = fmt;
  92         vaf.va = &args;
  93
  94         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  95
  96         va_end(args);
  97 }
  98
  99 /*
 100  * This must be called with sbi->s_lock held.
 101  */
 102 void ext2_update_dynamic_rev(struct super_block *sb)
 103 {
 104         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 105
 106         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 107                 return;
 108
 109         ext2_msg(sb, KERN_WARNING,
 110                      "warning: updating to rev %d because of "
 111                      "new feature flag, running e2fsck is recommended",
 112                      EXT2_DYNAMIC_REV);
 113
 114         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 115         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 116         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 117         /* leave es->s_feature_*compat flags alone */
 118         /* es->s_uuid will be set by e2fsck if empty */
 119
 120         /*
 121          * The rest of the superblock fields should be zero, and if not it
 122          * means they are likely already in use, so leave them alone.  We
 123          * can leave it up to e2fsck to clean up any inconsistencies there.
 124          */
 125 }
 126
 127 #ifdef CONFIG_QUOTA
 128 static int ext2_quota_off(struct super_block *sb, int type);
 129
 130 static void ext2_quota_off_umount(struct super_block *sb)
 131 {
 132         int type;
 133
 134         for (type = 0; type < MAXQUOTAS; type++)
 135                 ext2_quota_off(sb, type);
 136 }
 137 #else
 138 static inline void ext2_quota_off_umount(struct super_block *sb)
 139 {
 140 }
 141 #endif
 142
 143 static void ext2_put_super (struct super_block * sb)
 144 {
 145         int db_count;
 146         int i;
 147         struct ext2_sb_info *sbi = EXT2_SB(sb);
 148
 149         ext2_quota_off_umount(sb);
 150
 151         if (sbi->s_ea_block_cache) {
 152                 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
 153                 sbi->s_ea_block_cache = NULL;
 154         }
 155         if (!sb_rdonly(sb)) {
 156                 struct ext2_super_block *es = sbi->s_es;
 157
 158                 spin_lock(&sbi->s_lock);
 159                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 160                 spin_unlock(&sbi->s_lock);
 161                 ext2_sync_super(sb, es, 1);
 162         }
 163         db_count = sbi->s_gdb_count;
 164         for (i = 0; i < db_count; i++)
 165                 if (sbi->s_group_desc[i])
 166                         brelse (sbi->s_group_desc[i]);
 167         kfree(sbi->s_group_desc);
 168         kfree(sbi->s_debts);
 169         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 170         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 171         percpu_counter_destroy(&sbi->s_dirs_counter);
 172         brelse (sbi->s_sbh);
 173         sb->s_fs_info = NULL;
 174         kfree(sbi->s_blockgroup_lock);
 175         fs_put_dax(sbi->s_daxdev);
 176         kfree(sbi);
 177 }
 178
 179 static struct kmem_cache * ext2_inode_cachep;
 180
 181 static struct inode *ext2_alloc_inode(struct super_block *sb)
 182 {
 183         struct ext2_inode_info *ei;
 184         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 185         if (!ei)
 186                 return NULL;
 187         ei->i_block_alloc_info = NULL;
 188         inode_set_iversion(&ei->vfs_inode, 1);
 189 #ifdef CONFIG_QUOTA
 190         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 191 #endif
 192
 193         return &ei->vfs_inode;
 194 }
 195
 196 static void ext2_i_callback(struct rcu_head *head)
 197 {
 198         struct inode *inode = container_of(head, struct inode, i_rcu);
 199         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 200 }
 201
 202 static void ext2_destroy_inode(struct inode *inode)
 203 {
 204         call_rcu(&inode->i_rcu, ext2_i_callback);
 205 }
 206
 207 static void init_once(void *foo)
 208 {
 209         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 210
 211         rwlock_init(&ei->i_meta_lock);
 212 #ifdef CONFIG_EXT2_FS_XATTR
 213         init_rwsem(&ei->xattr_sem);
 214 #endif
 215         mutex_init(&ei->truncate_mutex);
 216 #ifdef CONFIG_FS_DAX
 217         init_rwsem(&ei->dax_sem);
 218 #endif
 219         inode_init_once(&ei->vfs_inode);
 220 }
 221
 222 static int __init init_inodecache(void)
 223 {
 224         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 225                                 sizeof(struct ext2_inode_info), 0,
 226                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 227                                         SLAB_ACCOUNT),
 228                                 offsetof(struct ext2_inode_info, i_data),
 229                                 sizeof_field(struct ext2_inode_info, i_data),
 230                                 init_once);
 231         if (ext2_inode_cachep == NULL)
 232                 return -ENOMEM;
 233         return 0;
 234 }
 235
 236 static void destroy_inodecache(void)
 237 {
 238         /*
 239          * Make sure all delayed rcu free inodes are flushed before we
 240          * destroy cache.
 241          */
 242         rcu_barrier();
 243         kmem_cache_destroy(ext2_inode_cachep);
 244 }
 245
 246 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 247 {
 248         struct super_block *sb = root->d_sb;
 249         struct ext2_sb_info *sbi = EXT2_SB(sb);
 250         struct ext2_super_block *es = sbi->s_es;
 251         unsigned long def_mount_opts;
 252
 253         spin_lock(&sbi->s_lock);
 254         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 255
 256         if (sbi->s_sb_block != 1)
 257                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 258         if (test_opt(sb, MINIX_DF))
 259                 seq_puts(seq, ",minixdf");
 260         if (test_opt(sb, GRPID))
 261                 seq_puts(seq, ",grpid");
 262         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 263                 seq_puts(seq, ",nogrpid");
 264         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 265             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 266                 seq_printf(seq, ",resuid=%u",
 267                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 268         }
 269         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 270             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 271                 seq_printf(seq, ",resgid=%u",
 272                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 273         }
 274         if (test_opt(sb, ERRORS_RO)) {
 275                 int def_errors = le16_to_cpu(es->s_errors);
 276
 277                 if (def_errors == EXT2_ERRORS_PANIC ||
 278                     def_errors == EXT2_ERRORS_CONTINUE) {
 279                         seq_puts(seq, ",errors=remount-ro");
 280                 }
 281         }
 282         if (test_opt(sb, ERRORS_CONT))
 283                 seq_puts(seq, ",errors=continue");
 284         if (test_opt(sb, ERRORS_PANIC))
 285                 seq_puts(seq, ",errors=panic");
 286         if (test_opt(sb, NO_UID32))
 287                 seq_puts(seq, ",nouid32");
 288         if (test_opt(sb, DEBUG))
 289                 seq_puts(seq, ",debug");
 290         if (test_opt(sb, OLDALLOC))
 291                 seq_puts(seq, ",oldalloc");
 292
 293 #ifdef CONFIG_EXT2_FS_XATTR
 294         if (test_opt(sb, XATTR_USER))
 295                 seq_puts(seq, ",user_xattr");
 296         if (!test_opt(sb, XATTR_USER) &&
 297             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 298                 seq_puts(seq, ",nouser_xattr");
 299         }
 300 #endif
 301
 302 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 303         if (test_opt(sb, POSIX_ACL))
 304                 seq_puts(seq, ",acl");
 305         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 306                 seq_puts(seq, ",noacl");
 307 #endif
 308
 309         if (test_opt(sb, NOBH))
 310                 seq_puts(seq, ",nobh");
 311
 312 #if defined(CONFIG_QUOTA)
 313         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 314                 seq_puts(seq, ",usrquota");
 315
 316         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 317                 seq_puts(seq, ",grpquota");
 318 #endif
 319
 320 #ifdef CONFIG_FS_DAX
 321         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 322                 seq_puts(seq, ",xip");
 323         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 324                 seq_puts(seq, ",dax");
 325 #endif
 326
 327         if (!test_opt(sb, RESERVATION))
 328                 seq_puts(seq, ",noreservation");
 329
 330         spin_unlock(&sbi->s_lock);
 331         return 0;
 332 }
 333
 334 #ifdef CONFIG_QUOTA
 335 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 336 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 337 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 338                          const struct path *path);
 339 static struct dquot **ext2_get_dquots(struct inode *inode)
 340 {
 341         return EXT2_I(inode)->i_dquot;
 342 }
 343
 344 static const struct quotactl_ops ext2_quotactl_ops = {
 345         .quota_on       = ext2_quota_on,
 346         .quota_off      = ext2_quota_off,
 347         .quota_sync     = dquot_quota_sync,
 348         .get_state      = dquot_get_state,
 349         .set_info       = dquot_set_dqinfo,
 350         .get_dqblk      = dquot_get_dqblk,
 351         .set_dqblk      = dquot_set_dqblk,
 352         .get_nextdqblk  = dquot_get_next_dqblk,
 353 };
 354 #endif
 355
 356 static const struct super_operations ext2_sops = {
 357         .alloc_inode    = ext2_alloc_inode,
 358         .destroy_inode  = ext2_destroy_inode,
 359         .write_inode    = ext2_write_inode,
 360         .evict_inode    = ext2_evict_inode,
 361         .put_super      = ext2_put_super,
 362         .sync_fs        = ext2_sync_fs,
 363         .freeze_fs      = ext2_freeze,
 364         .unfreeze_fs    = ext2_unfreeze,
 365         .statfs         = ext2_statfs,
 366         .remount_fs     = ext2_remount,
 367         .show_options   = ext2_show_options,
 368 #ifdef CONFIG_QUOTA
 369         .quota_read     = ext2_quota_read,
 370         .quota_write    = ext2_quota_write,
 371         .get_dquots     = ext2_get_dquots,
 372 #endif
 373 };
 374
 375 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 376                 u64 ino, u32 generation)
 377 {
 378         struct inode *inode;
 379
 380         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 381                 return ERR_PTR(-ESTALE);
 382         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 383                 return ERR_PTR(-ESTALE);
 384
 385         /*
 386          * ext2_iget isn't quite right if the inode is currently unallocated!
 387          * However ext2_iget currently does appropriate checks to handle stale
 388          * inodes so everything is OK.
 389          */
 390         inode = ext2_iget(sb, ino);
 391         if (IS_ERR(inode))
 392                 return ERR_CAST(inode);
 393         if (generation && inode->i_generation != generation) {
 394                 /* we didn't find the right inode.. */
 395                 iput(inode);
 396                 return ERR_PTR(-ESTALE);
 397         }
 398         return inode;
 399 }
 400
 401 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 402                 int fh_len, int fh_type)
 403 {
 404         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 405                                     ext2_nfs_get_inode);
 406 }
 407
 408 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 409                 int fh_len, int fh_type)
 410 {
 411         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 412                                     ext2_nfs_get_inode);
 413 }
 414
 415 static const struct export_operations ext2_export_ops = {
 416         .fh_to_dentry = ext2_fh_to_dentry,
 417         .fh_to_parent = ext2_fh_to_parent,
 418         .get_parent = ext2_get_parent,
 419 };
 420
 421 static unsigned long get_sb_block(void **data)
 422 {
 423         unsigned long   sb_block;
 424         char            *options = (char *) *data;
 425
 426         if (!options || strncmp(options, "sb=", 3) != 0)
 427                 return 1;       /* Default location */
 428         options += 3;
 429         sb_block = simple_strtoul(options, &options, 0);
 430         if (*options && *options != ',') {
 431                 printk("EXT2-fs: Invalid sb specification: %s\n",
 432                        (char *) *data);
 433                 return 1;
 434         }
 435         if (*options == ',')
 436                 options++;
 437         *data = (void *) options;
 438         return sb_block;
 439 }
 440
 441 enum {
 442         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 443         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 444         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 445         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 446         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 447         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 448 };
 449
 450 static const match_table_t tokens = {
 451         {Opt_bsd_df, "bsddf"},
 452         {Opt_minix_df, "minixdf"},
 453         {Opt_grpid, "grpid"},
 454         {Opt_grpid, "bsdgroups"},
 455         {Opt_nogrpid, "nogrpid"},
 456         {Opt_nogrpid, "sysvgroups"},
 457         {Opt_resgid, "resgid=%u"},
 458         {Opt_resuid, "resuid=%u"},
 459         {Opt_sb, "sb=%u"},
 460         {Opt_err_cont, "errors=continue"},
 461         {Opt_err_panic, "errors=panic"},
 462         {Opt_err_ro, "errors=remount-ro"},
 463         {Opt_nouid32, "nouid32"},
 464         {Opt_nocheck, "check=none"},
 465         {Opt_nocheck, "nocheck"},
 466         {Opt_debug, "debug"},
 467         {Opt_oldalloc, "oldalloc"},
 468         {Opt_orlov, "orlov"},
 469         {Opt_nobh, "nobh"},
 470         {Opt_user_xattr, "user_xattr"},
 471         {Opt_nouser_xattr, "nouser_xattr"},
 472         {Opt_acl, "acl"},
 473         {Opt_noacl, "noacl"},
 474         {Opt_xip, "xip"},
 475         {Opt_dax, "dax"},
 476         {Opt_grpquota, "grpquota"},
 477         {Opt_ignore, "noquota"},
 478         {Opt_quota, "quota"},
 479         {Opt_usrquota, "usrquota"},
 480         {Opt_reservation, "reservation"},
 481         {Opt_noreservation, "noreservation"},
 482         {Opt_err, NULL}
 483 };
 484
 485 static int parse_options(char *options, struct super_block *sb,
 486                          struct ext2_mount_options *opts)
 487 {
 488         char *p;
 489         substring_t args[MAX_OPT_ARGS];
 490         int option;
 491         kuid_t uid;
 492         kgid_t gid;
 493
 494         if (!options)
 495                 return 1;
 496
 497         while ((p = strsep (&options, ",")) != NULL) {
 498                 int token;
 499                 if (!*p)
 500                         continue;
 501
 502                 token = match_token(p, tokens, args);
 503                 switch (token) {
 504                 case Opt_bsd_df:
 505                         clear_opt (opts->s_mount_opt, MINIX_DF);
 506                         break;
 507                 case Opt_minix_df:
 508                         set_opt (opts->s_mount_opt, MINIX_DF);
 509                         break;
 510                 case Opt_grpid:
 511                         set_opt (opts->s_mount_opt, GRPID);
 512                         break;
 513                 case Opt_nogrpid:
 514                         clear_opt (opts->s_mount_opt, GRPID);
 515                         break;
 516                 case Opt_resuid:
 517                         if (match_int(&args[0], &option))
 518                                 return 0;
 519                         uid = make_kuid(current_user_ns(), option);
 520                         if (!uid_valid(uid)) {
 521                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 522                                 return 0;
 523
 524                         }
 525                         opts->s_resuid = uid;
 526                         break;
 527                 case Opt_resgid:
 528                         if (match_int(&args[0], &option))
 529                                 return 0;
 530                         gid = make_kgid(current_user_ns(), option);
 531                         if (!gid_valid(gid)) {
 532                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 533                                 return 0;
 534                         }
 535                         opts->s_resgid = gid;
 536                         break;
 537                 case Opt_sb:
 538                         /* handled by get_sb_block() instead of here */
 539                         /* *sb_block = match_int(&args[0]); */
 540                         break;
 541                 case Opt_err_panic:
 542                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 543                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 544                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
 545                         break;
 546                 case Opt_err_ro:
 547                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
 548                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 549                         set_opt (opts->s_mount_opt, ERRORS_RO);
 550                         break;
 551                 case Opt_err_cont:
 552                         clear_opt (opts->s_mount_opt, ERRORS_RO);
 553                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 554                         set_opt (opts->s_mount_opt, ERRORS_CONT);
 555                         break;
 556                 case Opt_nouid32:
 557                         set_opt (opts->s_mount_opt, NO_UID32);
 558                         break;
 559                 case Opt_nocheck:
 560                         ext2_msg(sb, KERN_WARNING,
 561                                 "Option nocheck/check=none is deprecated and"
 562                                 " will be removed in June 2020.");
 563                         clear_opt (opts->s_mount_opt, CHECK);
 564                         break;
 565                 case Opt_debug:
 566                         set_opt (opts->s_mount_opt, DEBUG);
 567                         break;
 568                 case Opt_oldalloc:
 569                         set_opt (opts->s_mount_opt, OLDALLOC);
 570                         break;
 571                 case Opt_orlov:
 572                         clear_opt (opts->s_mount_opt, OLDALLOC);
 573                         break;
 574                 case Opt_nobh:
 575                         set_opt (opts->s_mount_opt, NOBH);
 576                         break;
 577 #ifdef CONFIG_EXT2_FS_XATTR
 578                 case Opt_user_xattr:
 579                         set_opt (opts->s_mount_opt, XATTR_USER);
 580                         break;
 581                 case Opt_nouser_xattr:
 582                         clear_opt (opts->s_mount_opt, XATTR_USER);
 583                         break;
 584 #else
 585                 case Opt_user_xattr:
 586                 case Opt_nouser_xattr:
 587                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 588                                 "not supported");
 589                         break;
 590 #endif
 591 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 592                 case Opt_acl:
 593                         set_opt(opts->s_mount_opt, POSIX_ACL);
 594                         break;
 595                 case Opt_noacl:
 596                         clear_opt(opts->s_mount_opt, POSIX_ACL);
 597                         break;
 598 #else
 599                 case Opt_acl:
 600                 case Opt_noacl:
 601                         ext2_msg(sb, KERN_INFO,
 602                                 "(no)acl options not supported");
 603                         break;
 604 #endif
 605                 case Opt_xip:
 606                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 607                         set_opt(opts->s_mount_opt, XIP);
 608                         /* Fall through */
 609                 case Opt_dax:
 610 #ifdef CONFIG_FS_DAX
 611                         ext2_msg(sb, KERN_WARNING,
 612                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 613                         set_opt(opts->s_mount_opt, DAX);
 614 #else
 615                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 616 #endif
 617                         break;
 618
 619 #if defined(CONFIG_QUOTA)
 620                 case Opt_quota:
 621                 case Opt_usrquota:
 622                         set_opt(opts->s_mount_opt, USRQUOTA);
 623                         break;
 624
 625                 case Opt_grpquota:
 626                         set_opt(opts->s_mount_opt, GRPQUOTA);
 627                         break;
 628 #else
 629                 case Opt_quota:
 630                 case Opt_usrquota:
 631                 case Opt_grpquota:
 632                         ext2_msg(sb, KERN_INFO,
 633                                 "quota operations not supported");
 634                         break;
 635 #endif
 636
 637                 case Opt_reservation:
 638                         set_opt(opts->s_mount_opt, RESERVATION);
 639                         ext2_msg(sb, KERN_INFO, "reservations ON");
 640                         break;
 641                 case Opt_noreservation:
 642                         clear_opt(opts->s_mount_opt, RESERVATION);
 643                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 644                         break;
 645                 case Opt_ignore:
 646                         break;
 647                 default:
 648                         return 0;
 649                 }
 650         }
 651         return 1;
 652 }
 653
 654 static int ext2_setup_super (struct super_block * sb,
 655                               struct ext2_super_block * es,
 656                               int read_only)
 657 {
 658         int res = 0;
 659         struct ext2_sb_info *sbi = EXT2_SB(sb);
 660
 661         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 662                 ext2_msg(sb, KERN_ERR,
 663                         "error: revision level too high, "
 664                         "forcing read-only mode");
 665                 res = SB_RDONLY;
 666         }
 667         if (read_only)
 668                 return res;
 669         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 670                 ext2_msg(sb, KERN_WARNING,
 671                         "warning: mounting unchecked fs, "
 672                         "running e2fsck is recommended");
 673         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 674                 ext2_msg(sb, KERN_WARNING,
 675                         "warning: mounting fs with errors, "
 676                         "running e2fsck is recommended");
 677         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 678                  le16_to_cpu(es->s_mnt_count) >=
 679                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 680                 ext2_msg(sb, KERN_WARNING,
 681                         "warning: maximal mount count reached, "
 682                         "running e2fsck is recommended");
 683         else if (le32_to_cpu(es->s_checkinterval) &&
 684                 (le32_to_cpu(es->s_lastcheck) +
 685                         le32_to_cpu(es->s_checkinterval) <=
 686                         ktime_get_real_seconds()))
 687                 ext2_msg(sb, KERN_WARNING,
 688                         "warning: checktime reached, "
 689                         "running e2fsck is recommended");
 690         if (!le16_to_cpu(es->s_max_mnt_count))
 691                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 692         le16_add_cpu(&es->s_mnt_count, 1);
 693         if (test_opt (sb, DEBUG))
 694                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 695                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 696                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 697                         sbi->s_frag_size,
 698                         sbi->s_groups_count,
 699                         EXT2_BLOCKS_PER_GROUP(sb),
 700                         EXT2_INODES_PER_GROUP(sb),
 701                         sbi->s_mount_opt);
 702         return res;
 703 }
 704
 705 static int ext2_check_descriptors(struct super_block *sb)
 706 {
 707         int i;
 708         struct ext2_sb_info *sbi = EXT2_SB(sb);
 709
 710         ext2_debug ("Checking group descriptors");
 711
 712         for (i = 0; i < sbi->s_groups_count; i++) {
 713                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 714                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 715                 ext2_fsblk_t last_block;
 716
 717                 if (i == sbi->s_groups_count - 1)
 718                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 719                 else
 720                         last_block = first_block +
 721                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 722
 723                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 724                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 725                 {
 726                         ext2_error (sb, "ext2_check_descriptors",
 727                                     "Block bitmap for group %d"
 728                                     " not in group (block %lu)!",
 729                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 730                         return 0;
 731                 }
 732                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 733                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 734                 {
 735                         ext2_error (sb, "ext2_check_descriptors",
 736                                     "Inode bitmap for group %d"
 737                                     " not in group (block %lu)!",
 738                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 739                         return 0;
 740                 }
 741                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 742                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 743                     last_block)
 744                 {
 745                         ext2_error (sb, "ext2_check_descriptors",
 746                                     "Inode table for group %d"
 747                                     " not in group (block %lu)!",
 748                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 749                         return 0;
 750                 }
 751         }
 752         return 1;
 753 }
 754
 755 /*
 756  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 757  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 758  * We need to be 1 filesystem block less than the 2^32 sector limit.
 759  */
 760 static loff_t ext2_max_size(int bits)
 761 {
 762         loff_t res = EXT2_NDIR_BLOCKS;
 763         int meta_blocks;
 764         unsigned int upper_limit;
 765         unsigned int ppb = 1 << (bits-2);
 766
 767         /* This is calculated to be the largest file size for a
 768          * dense, file such that the total number of
 769          * sectors in the file, including data and all indirect blocks,
 770          * does not exceed 2^32 -1
 771          * __u32 i_blocks representing the total number of
 772          * 512 bytes blocks of the file
 773          */
 774         upper_limit = (1LL << 32) - 1;
 775
 776         /* total blocks in file system block size */
 777         upper_limit >>= (bits - 9);
 778
 779         /* Compute how many blocks we can address by block tree */
 780         res += 1LL << (bits-2);
 781         res += 1LL << (2*(bits-2));
 782         res += 1LL << (3*(bits-2));
 783         /* Does block tree limit file size? */
 784         if (res < upper_limit)
 785                 goto check_lfs;
 786
 787         res = upper_limit;
 788         /* How many metadata blocks are needed for addressing upper_limit? */
 789         upper_limit -= EXT2_NDIR_BLOCKS;
 790         /* indirect blocks */
 791         meta_blocks = 1;
 792         upper_limit -= ppb;
 793         /* double indirect blocks */
 794         if (upper_limit < ppb * ppb) {
 795                 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
 796                 res -= meta_blocks;
 797                 goto check_lfs;
 798         }
 799         meta_blocks += 1 + ppb;
 800         upper_limit -= ppb * ppb;
 801         /* tripple indirect blocks for the rest */
 802         meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
 803                 DIV_ROUND_UP(upper_limit, ppb*ppb);
 804         res -= meta_blocks;
 805 check_lfs:
 806         res <<= bits;
 807         if (res > MAX_LFS_FILESIZE)
 808                 res = MAX_LFS_FILESIZE;
 809
 810         return res;
 811 }
 812
 813 static unsigned long descriptor_loc(struct super_block *sb,
 814                                     unsigned long logic_sb_block,
 815                                     int nr)
 816 {
 817         struct ext2_sb_info *sbi = EXT2_SB(sb);
 818         unsigned long bg, first_meta_bg;
 819         int has_super = 0;
 820
 821         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 822
 823         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 824             nr < first_meta_bg)
 825                 return (logic_sb_block + nr + 1);
 826         bg = sbi->s_desc_per_block * nr;
 827         if (ext2_bg_has_super(sb, bg))
 828                 has_super = 1;
 829
 830         return ext2_group_first_block_no(sb, bg) + has_super;
 831 }
 832
 833 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 834 {
 835         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 836         struct buffer_head * bh;
 837         struct ext2_sb_info * sbi;
 838         struct ext2_super_block * es;
 839         struct inode *root;
 840         unsigned long block;
 841         unsigned long sb_block = get_sb_block(&data);
 842         unsigned long logic_sb_block;
 843         unsigned long offset = 0;
 844         unsigned long def_mount_opts;
 845         long ret = -ENOMEM;
 846         int blocksize = BLOCK_SIZE;
 847         int db_count;
 848         int i, j;
 849         __le32 features;
 850         int err;
 851         struct ext2_mount_options opts;
 852
 853         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 854         if (!sbi)
 855                 goto failed;
 856
 857         sbi->s_blockgroup_lock =
 858                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 859         if (!sbi->s_blockgroup_lock) {
 860                 kfree(sbi);
 861                 goto failed;
 862         }
 863         sb->s_fs_info = sbi;
 864         sbi->s_sb_block = sb_block;
 865         sbi->s_daxdev = dax_dev;
 866
 867         spin_lock_init(&sbi->s_lock);
 868         ret = -EINVAL;
 869
 870         /*
 871          * See what the current blocksize for the device is, and
 872          * use that as the blocksize.  Otherwise (or if the blocksize
 873          * is smaller than the default) use the default.
 874          * This is important for devices that have a hardware
 875          * sectorsize that is larger than the default.
 876          */
 877         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 878         if (!blocksize) {
 879                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 880                 goto failed_sbi;
 881         }
 882
 883         /*
 884          * If the superblock doesn't start on a hardware sector boundary,
 885          * calculate the offset.
 886          */
 887         if (blocksize != BLOCK_SIZE) {
 888                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 889                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 890         } else {
 891                 logic_sb_block = sb_block;
 892         }
 893
 894         if (!(bh = sb_bread(sb, logic_sb_block))) {
 895                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 896                 goto failed_sbi;
 897         }
 898         /*
 899          * Note: s_es must be initialized as soon as possible because
 900          *       some ext2 macro-instructions depend on its value
 901          */
 902         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 903         sbi->s_es = es;
 904         sb->s_magic = le16_to_cpu(es->s_magic);
 905
 906         if (sb->s_magic != EXT2_SUPER_MAGIC)
 907                 goto cantfind_ext2;
 908
 909         opts.s_mount_opt = 0;
 910         /* Set defaults before we parse the mount options */
 911         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 912         if (def_mount_opts & EXT2_DEFM_DEBUG)
 913                 set_opt(opts.s_mount_opt, DEBUG);
 914         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 915                 set_opt(opts.s_mount_opt, GRPID);
 916         if (def_mount_opts & EXT2_DEFM_UID16)
 917                 set_opt(opts.s_mount_opt, NO_UID32);
 918 #ifdef CONFIG_EXT2_FS_XATTR
 919         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 920                 set_opt(opts.s_mount_opt, XATTR_USER);
 921 #endif
 922 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 923         if (def_mount_opts & EXT2_DEFM_ACL)
 924                 set_opt(opts.s_mount_opt, POSIX_ACL);
 925 #endif
 926
 927         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 928                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
 929         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 930                 set_opt(opts.s_mount_opt, ERRORS_CONT);
 931         else
 932                 set_opt(opts.s_mount_opt, ERRORS_RO);
 933
 934         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 935         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 936
 937         set_opt(opts.s_mount_opt, RESERVATION);
 938
 939         if (!parse_options((char *) data, sb, &opts))
 940                 goto failed_mount;
 941
 942         sbi->s_mount_opt = opts.s_mount_opt;
 943         sbi->s_resuid = opts.s_resuid;
 944         sbi->s_resgid = opts.s_resgid;
 945
 946         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 947                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 948                  SB_POSIXACL : 0);
 949         sb->s_iflags |= SB_I_CGROUPWB;
 950
 951         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 952             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 953              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 954              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 955                 ext2_msg(sb, KERN_WARNING,
 956                         "warning: feature flags set on rev 0 fs, "
 957                         "running e2fsck is recommended");
 958         /*
 959          * Check feature flags regardless of the revision level, since we
 960          * previously didn't change the revision level when setting the flags,
 961          * so there is a chance incompat flags are set on a rev 0 filesystem.
 962          */
 963         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 964         if (features) {
 965                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 966                        "unsupported optional features (%x)",
 967                         le32_to_cpu(features));
 968                 goto failed_mount;
 969         }
 970         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 971                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 972                        "unsupported optional features (%x)",
 973                        le32_to_cpu(features));
 974                 goto failed_mount;
 975         }
 976
 977         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 978
 979         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 980                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
 981                         ext2_msg(sb, KERN_ERR,
 982                                 "DAX unsupported by block device. Turning off DAX.");
 983                         sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
 984                 }
 985         }
 986
 987         /* If the blocksize doesn't match, re-read the thing.. */
 988         if (sb->s_blocksize != blocksize) {
 989                 brelse(bh);
 990
 991                 if (!sb_set_blocksize(sb, blocksize)) {
 992                         ext2_msg(sb, KERN_ERR,
 993                                 "error: bad blocksize %d", blocksize);
 994                         goto failed_sbi;
 995                 }
 996
 997                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 998                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 999                 bh = sb_bread(sb, logic_sb_block);
1000                 if(!bh) {
1001                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
1002                                 "superblock on 2nd try");
1003                         goto failed_sbi;
1004                 }
1005                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
1006                 sbi->s_es = es;
1007                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
1008                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
1009                         goto failed_mount;
1010                 }
1011         }
1012
1013         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1014         sb->s_max_links = EXT2_LINK_MAX;
1015
1016         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1017                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1018                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1019         } else {
1020                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1021                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1022                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1023                     !is_power_of_2(sbi->s_inode_size) ||
1024                     (sbi->s_inode_size > blocksize)) {
1025                         ext2_msg(sb, KERN_ERR,
1026                                 "error: unsupported inode size: %d",
1027                                 sbi->s_inode_size);
1028                         goto failed_mount;
1029                 }
1030         }
1031
1032         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1033                                    le32_to_cpu(es->s_log_frag_size);
1034         if (sbi->s_frag_size == 0)
1035                 goto cantfind_ext2;
1036         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1037
1038         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1039         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1040         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1041
1042         if (EXT2_INODE_SIZE(sb) == 0)
1043                 goto cantfind_ext2;
1044         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1045         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1046                 goto cantfind_ext2;
1047         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1048                                         sbi->s_inodes_per_block;
1049         sbi->s_desc_per_block = sb->s_blocksize /
1050                                         sizeof (struct ext2_group_desc);
1051         sbi->s_sbh = bh;
1052         sbi->s_mount_state = le16_to_cpu(es->s_state);
1053         sbi->s_addr_per_block_bits =
1054                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1055         sbi->s_desc_per_block_bits =
1056                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1057
1058         if (sb->s_magic != EXT2_SUPER_MAGIC)
1059                 goto cantfind_ext2;
1060
1061         if (sb->s_blocksize != bh->b_size) {
1062                 if (!silent)
1063                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1064                 goto failed_mount;
1065         }
1066
1067         if (sb->s_blocksize != sbi->s_frag_size) {
1068                 ext2_msg(sb, KERN_ERR,
1069                         "error: fragsize %lu != blocksize %lu"
1070                         "(not supported yet)",
1071                         sbi->s_frag_size, sb->s_blocksize);
1072                 goto failed_mount;
1073         }
1074
1075         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1076                 ext2_msg(sb, KERN_ERR,
1077                         "error: #blocks per group too big: %lu",
1078                         sbi->s_blocks_per_group);
1079                 goto failed_mount;
1080         }
1081         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1082                 ext2_msg(sb, KERN_ERR,
1083                         "error: #fragments per group too big: %lu",
1084                         sbi->s_frags_per_group);
1085                 goto failed_mount;
1086         }
1087         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1088                 ext2_msg(sb, KERN_ERR,
1089                         "error: #inodes per group too big: %lu",
1090                         sbi->s_inodes_per_group);
1091                 goto failed_mount;
1092         }
1093
1094         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1095                 goto cantfind_ext2;
1096         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1097                                 le32_to_cpu(es->s_first_data_block) - 1)
1098                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1099         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1100                    EXT2_DESC_PER_BLOCK(sb);
1101         sbi->s_group_desc = kmalloc_array (db_count,
1102                                            sizeof(struct buffer_head *),
1103                                            GFP_KERNEL);
1104         if (sbi->s_group_desc == NULL) {
1105                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1106                 goto failed_mount;
1107         }
1108         bgl_lock_init(sbi->s_blockgroup_lock);
1109         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1110         if (!sbi->s_debts) {
1111                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1112                 goto failed_mount_group_desc;
1113         }
1114         for (i = 0; i < db_count; i++) {
1115                 block = descriptor_loc(sb, logic_sb_block, i);
1116                 sbi->s_group_desc[i] = sb_bread(sb, block);
1117                 if (!sbi->s_group_desc[i]) {
1118                         for (j = 0; j < i; j++)
1119                                 brelse (sbi->s_group_desc[j]);
1120                         ext2_msg(sb, KERN_ERR,
1121                                 "error: unable to read group descriptors");
1122                         goto failed_mount_group_desc;
1123                 }
1124         }
1125         if (!ext2_check_descriptors (sb)) {
1126                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1127                 goto failed_mount2;
1128         }
1129         sbi->s_gdb_count = db_count;
1130         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1131         spin_lock_init(&sbi->s_next_gen_lock);
1132
1133         /* per fileystem reservation list head & lock */
1134         spin_lock_init(&sbi->s_rsv_window_lock);
1135         sbi->s_rsv_window_root = RB_ROOT;
1136         /*
1137          * Add a single, static dummy reservation to the start of the
1138          * reservation window list --- it gives us a placeholder for
1139          * append-at-start-of-list which makes the allocation logic
1140          * _much_ simpler.
1141          */
1142         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1143         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1144         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1145         sbi->s_rsv_window_head.rsv_goal_size = 0;
1146         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1147
1148         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1149                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1150         if (!err) {
1151                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1152                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1153         }
1154         if (!err) {
1155                 err = percpu_counter_init(&sbi->s_dirs_counter,
1156                                 ext2_count_dirs(sb), GFP_KERNEL);
1157         }
1158         if (err) {
1159                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1160                 goto failed_mount3;
1161         }
1162
1163 #ifdef CONFIG_EXT2_FS_XATTR
1164         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1165         if (!sbi->s_ea_block_cache) {
1166                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1167                 goto failed_mount3;
1168         }
1169 #endif
1170         /*
1171          * set up enough so that it can read an inode
1172          */
1173         sb->s_op = &ext2_sops;
1174         sb->s_export_op = &ext2_export_ops;
1175         sb->s_xattr = ext2_xattr_handlers;
1176
1177 #ifdef CONFIG_QUOTA
1178         sb->dq_op = &dquot_operations;
1179         sb->s_qcop = &ext2_quotactl_ops;
1180         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1181 #endif
1182
1183         root = ext2_iget(sb, EXT2_ROOT_INO);
1184         if (IS_ERR(root)) {
1185                 ret = PTR_ERR(root);
1186                 goto failed_mount3;
1187         }
1188         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1189                 iput(root);
1190                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1191                 goto failed_mount3;
1192         }
1193
1194         sb->s_root = d_make_root(root);
1195         if (!sb->s_root) {
1196                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1197                 ret = -ENOMEM;
1198                 goto failed_mount3;
1199         }
1200         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1201                 ext2_msg(sb, KERN_WARNING,
1202                         "warning: mounting ext3 filesystem as ext2");
1203         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1204                 sb->s_flags |= SB_RDONLY;
1205         ext2_write_super(sb);
1206         return 0;
1207
1208 cantfind_ext2:
1209         if (!silent)
1210                 ext2_msg(sb, KERN_ERR,
1211                         "error: can't find an ext2 filesystem on dev %s.",
1212                         sb->s_id);
1213         goto failed_mount;
1214 failed_mount3:
1215         if (sbi->s_ea_block_cache)
1216                 ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1217         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1218         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1219         percpu_counter_destroy(&sbi->s_dirs_counter);
1220 failed_mount2:
1221         for (i = 0; i < db_count; i++)
1222                 brelse(sbi->s_group_desc[i]);
1223 failed_mount_group_desc:
1224         kfree(sbi->s_group_desc);
1225         kfree(sbi->s_debts);
1226 failed_mount:
1227         brelse(bh);
1228 failed_sbi:
1229         sb->s_fs_info = NULL;
1230         kfree(sbi->s_blockgroup_lock);
1231         kfree(sbi);
1232 failed:
1233         fs_put_dax(dax_dev);
1234         return ret;
1235 }
1236
1237 static void ext2_clear_super_error(struct super_block *sb)
1238 {
1239         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1240
1241         if (buffer_write_io_error(sbh)) {
1242                 /*
1243                  * Oh, dear.  A previous attempt to write the
1244                  * superblock failed.  This could happen because the
1245                  * USB device was yanked out.  Or it could happen to
1246                  * be a transient write error and maybe the block will
1247                  * be remapped.  Nothing we can do but to retry the
1248                  * write and hope for the best.
1249                  */
1250                 ext2_msg(sb, KERN_ERR,
1251                        "previous I/O error to superblock detected");
1252                 clear_buffer_write_io_error(sbh);
1253                 set_buffer_uptodate(sbh);
1254         }
1255 }
1256
1257 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1258                      int wait)
1259 {
1260         ext2_clear_super_error(sb);
1261         spin_lock(&EXT2_SB(sb)->s_lock);
1262         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1263         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1264         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1265         /* unlock before we do IO */
1266         spin_unlock(&EXT2_SB(sb)->s_lock);
1267         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1268         if (wait)
1269                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1270 }
1271
1272 /*
1273  * In the second extended file system, it is not necessary to
1274  * write the super block since we use a mapping of the
1275  * disk super block in a buffer.
1276  *
1277  * However, this function is still used to set the fs valid
1278  * flags to 0.  We need to set this flag to 0 since the fs
1279  * may have been checked while mounted and e2fsck may have
1280  * set s_state to EXT2_VALID_FS after some corrections.
1281  */
1282 static int ext2_sync_fs(struct super_block *sb, int wait)
1283 {
1284         struct ext2_sb_info *sbi = EXT2_SB(sb);
1285         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1286
1287         /*
1288          * Write quota structures to quota file, sync_blockdev() will write
1289          * them to disk later
1290          */
1291         dquot_writeback_dquots(sb, -1);
1292
1293         spin_lock(&sbi->s_lock);
1294         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1295                 ext2_debug("setting valid to 0\n");
1296                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1297         }
1298         spin_unlock(&sbi->s_lock);
1299         ext2_sync_super(sb, es, wait);
1300         return 0;
1301 }
1302
1303 static int ext2_freeze(struct super_block *sb)
1304 {
1305         struct ext2_sb_info *sbi = EXT2_SB(sb);
1306
1307         /*
1308          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1309          * because we have unattached inodes and thus filesystem is not fully
1310          * consistent.
1311          */
1312         if (atomic_long_read(&sb->s_remove_count)) {
1313                 ext2_sync_fs(sb, 1);
1314                 return 0;
1315         }
1316         /* Set EXT2_FS_VALID flag */
1317         spin_lock(&sbi->s_lock);
1318         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1319         spin_unlock(&sbi->s_lock);
1320         ext2_sync_super(sb, sbi->s_es, 1);
1321
1322         return 0;
1323 }
1324
1325 static int ext2_unfreeze(struct super_block *sb)
1326 {
1327         /* Just write sb to clear EXT2_VALID_FS flag */
1328         ext2_write_super(sb);
1329
1330         return 0;
1331 }
1332
1333 static void ext2_write_super(struct super_block *sb)
1334 {
1335         if (!sb_rdonly(sb))
1336                 ext2_sync_fs(sb, 1);
1337 }
1338
1339 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1340 {
1341         struct ext2_sb_info * sbi = EXT2_SB(sb);
1342         struct ext2_super_block * es;
1343         struct ext2_mount_options new_opts;
1344         int err;
1345
1346         sync_filesystem(sb);
1347
1348         spin_lock(&sbi->s_lock);
1349         new_opts.s_mount_opt = sbi->s_mount_opt;
1350         new_opts.s_resuid = sbi->s_resuid;
1351         new_opts.s_resgid = sbi->s_resgid;
1352         spin_unlock(&sbi->s_lock);
1353
1354         if (!parse_options(data, sb, &new_opts))
1355                 return -EINVAL;
1356
1357         spin_lock(&sbi->s_lock);
1358         es = sbi->s_es;
1359         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1360                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1361                          "dax flag with busy inodes while remounting");
1362                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1363         }
1364         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1365                 goto out_set;
1366         if (*flags & SB_RDONLY) {
1367                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1368                     !(sbi->s_mount_state & EXT2_VALID_FS))
1369                         goto out_set;
1370
1371                 /*
1372                  * OK, we are remounting a valid rw partition rdonly, so set
1373                  * the rdonly flag and then mark the partition as valid again.
1374                  */
1375                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1376                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1377                 spin_unlock(&sbi->s_lock);
1378
1379                 err = dquot_suspend(sb, -1);
1380                 if (err < 0)
1381                         return err;
1382
1383                 ext2_sync_super(sb, es, 1);
1384         } else {
1385                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1386                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1387                 if (ret) {
1388                         spin_unlock(&sbi->s_lock);
1389                         ext2_msg(sb, KERN_WARNING,
1390                                 "warning: couldn't remount RDWR because of "
1391                                 "unsupported optional features (%x).",
1392                                 le32_to_cpu(ret));
1393                         return -EROFS;
1394                 }
1395                 /*
1396                  * Mounting a RDONLY partition read-write, so reread and
1397                  * store the current valid flag.  (It may have been changed
1398                  * by e2fsck since we originally mounted the partition.)
1399                  */
1400                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1401                 if (!ext2_setup_super (sb, es, 0))
1402                         sb->s_flags &= ~SB_RDONLY;
1403                 spin_unlock(&sbi->s_lock);
1404
1405                 ext2_write_super(sb);
1406
1407                 dquot_resume(sb, -1);
1408         }
1409
1410         spin_lock(&sbi->s_lock);
1411 out_set:
1412         sbi->s_mount_opt = new_opts.s_mount_opt;
1413         sbi->s_resuid = new_opts.s_resuid;
1414         sbi->s_resgid = new_opts.s_resgid;
1415         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1416                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1417         spin_unlock(&sbi->s_lock);
1418
1419         return 0;
1420 }
1421
1422 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1423 {
1424         struct super_block *sb = dentry->d_sb;
1425         struct ext2_sb_info *sbi = EXT2_SB(sb);
1426         struct ext2_super_block *es = sbi->s_es;
1427         u64 fsid;
1428
1429         spin_lock(&sbi->s_lock);
1430
1431         if (test_opt (sb, MINIX_DF))
1432                 sbi->s_overhead_last = 0;
1433         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1434                 unsigned long i, overhead = 0;
1435                 smp_rmb();
1436
1437                 /*
1438                  * Compute the overhead (FS structures). This is constant
1439                  * for a given filesystem unless the number of block groups
1440                  * changes so we cache the previous value until it does.
1441                  */
1442
1443                 /*
1444                  * All of the blocks before first_data_block are
1445                  * overhead
1446                  */
1447                 overhead = le32_to_cpu(es->s_first_data_block);
1448
1449                 /*
1450                  * Add the overhead attributed to the superblock and
1451                  * block group descriptors.  If the sparse superblocks
1452                  * feature is turned on, then not all groups have this.
1453                  */
1454                 for (i = 0; i < sbi->s_groups_count; i++)
1455                         overhead += ext2_bg_has_super(sb, i) +
1456                                 ext2_bg_num_gdb(sb, i);
1457
1458                 /*
1459                  * Every block group has an inode bitmap, a block
1460                  * bitmap, and an inode table.
1461                  */
1462                 overhead += (sbi->s_groups_count *
1463                              (2 + sbi->s_itb_per_group));
1464                 sbi->s_overhead_last = overhead;
1465                 smp_wmb();
1466                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1467         }
1468
1469         buf->f_type = EXT2_SUPER_MAGIC;
1470         buf->f_bsize = sb->s_blocksize;
1471         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1472         buf->f_bfree = ext2_count_free_blocks(sb);
1473         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1474         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1475         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1476                 buf->f_bavail = 0;
1477         buf->f_files = le32_to_cpu(es->s_inodes_count);
1478         buf->f_ffree = ext2_count_free_inodes(sb);
1479         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1480         buf->f_namelen = EXT2_NAME_LEN;
1481         fsid = le64_to_cpup((void *)es->s_uuid) ^
1482                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1483         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1484         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1485         spin_unlock(&sbi->s_lock);
1486         return 0;
1487 }
1488
1489 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1490         int flags, const char *dev_name, void *data)
1491 {
1492         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1493 }
1494
1495 #ifdef CONFIG_QUOTA
1496
1497 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1498  * acquiring the locks... As quota files are never truncated and quota code
1499  * itself serializes the operations (and no one else should touch the files)
1500  * we don't have to be afraid of races */
1501 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1502                                size_t len, loff_t off)
1503 {
1504         struct inode *inode = sb_dqopt(sb)->files[type];
1505         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1506         int err = 0;
1507         int offset = off & (sb->s_blocksize - 1);
1508         int tocopy;
1509         size_t toread;
1510         struct buffer_head tmp_bh;
1511         struct buffer_head *bh;
1512         loff_t i_size = i_size_read(inode);
1513
1514         if (off > i_size)
1515                 return 0;
1516         if (off+len > i_size)
1517                 len = i_size-off;
1518         toread = len;
1519         while (toread > 0) {
1520                 tocopy = sb->s_blocksize - offset < toread ?
1521                                 sb->s_blocksize - offset : toread;
1522
1523                 tmp_bh.b_state = 0;
1524                 tmp_bh.b_size = sb->s_blocksize;
1525                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1526                 if (err < 0)
1527                         return err;
1528                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1529                         memset(data, 0, tocopy);
1530                 else {
1531                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1532                         if (!bh)
1533                                 return -EIO;
1534                         memcpy(data, bh->b_data+offset, tocopy);
1535                         brelse(bh);
1536                 }
1537                 offset = 0;
1538                 toread -= tocopy;
1539                 data += tocopy;
1540                 blk++;
1541         }
1542         return len;
1543 }
1544
1545 /* Write to quotafile */
1546 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1547                                 const char *data, size_t len, loff_t off)
1548 {
1549         struct inode *inode = sb_dqopt(sb)->files[type];
1550         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1551         int err = 0;
1552         int offset = off & (sb->s_blocksize - 1);
1553         int tocopy;
1554         size_t towrite = len;
1555         struct buffer_head tmp_bh;
1556         struct buffer_head *bh;
1557
1558         while (towrite > 0) {
1559                 tocopy = sb->s_blocksize - offset < towrite ?
1560                                 sb->s_blocksize - offset : towrite;
1561
1562                 tmp_bh.b_state = 0;
1563                 tmp_bh.b_size = sb->s_blocksize;
1564                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1565                 if (err < 0)
1566                         goto out;
1567                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1568                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1569                 else
1570                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1571                 if (unlikely(!bh)) {
1572                         err = -EIO;
1573                         goto out;
1574                 }
1575                 lock_buffer(bh);
1576                 memcpy(bh->b_data+offset, data, tocopy);
1577                 flush_dcache_page(bh->b_page);
1578                 set_buffer_uptodate(bh);
1579                 mark_buffer_dirty(bh);
1580                 unlock_buffer(bh);
1581                 brelse(bh);
1582                 offset = 0;
1583                 towrite -= tocopy;
1584                 data += tocopy;
1585                 blk++;
1586         }
1587 out:
1588         if (len == towrite)
1589                 return err;
1590         if (inode->i_size < off+len-towrite)
1591                 i_size_write(inode, off+len-towrite);
1592         inode_inc_iversion(inode);
1593         inode->i_mtime = inode->i_ctime = current_time(inode);
1594         mark_inode_dirty(inode);
1595         return len - towrite;
1596 }
1597
1598 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1599                          const struct path *path)
1600 {
1601         int err;
1602         struct inode *inode;
1603
1604         err = dquot_quota_on(sb, type, format_id, path);
1605         if (err)
1606                 return err;
1607
1608         inode = d_inode(path->dentry);
1609         inode_lock(inode);
1610         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1611         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1612                         S_NOATIME | S_IMMUTABLE);
1613         inode_unlock(inode);
1614         mark_inode_dirty(inode);
1615
1616         return 0;
1617 }
1618
1619 static int ext2_quota_off(struct super_block *sb, int type)
1620 {
1621         struct inode *inode = sb_dqopt(sb)->files[type];
1622         int err;
1623
1624         if (!inode || !igrab(inode))
1625                 goto out;
1626
1627         err = dquot_quota_off(sb, type);
1628         if (err)
1629                 goto out_put;
1630
1631         inode_lock(inode);
1632         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1633         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1634         inode_unlock(inode);
1635         mark_inode_dirty(inode);
1636 out_put:
1637         iput(inode);
1638         return err;
1639 out:
1640         return dquot_quota_off(sb, type);
1641 }
1642
1643 #endif
1644
1645 static struct file_system_type ext2_fs_type = {
1646         .owner          = THIS_MODULE,
1647         .name           = "ext2",
1648         .mount          = ext2_mount,
1649         .kill_sb        = kill_block_super,
1650         .fs_flags       = FS_REQUIRES_DEV,
1651 };
1652 MODULE_ALIAS_FS("ext2");
1653
1654 static int __init init_ext2_fs(void)
1655 {
1656         int err;
1657
1658         err = init_inodecache();
1659         if (err)
1660                 return err;
1661         err = register_filesystem(&ext2_fs_type);
1662         if (err)
1663                 goto out;
1664         return 0;
1665 out:
1666         destroy_inodecache();
1667         return err;
1668 }
1669
1670 static void __exit exit_ext2_fs(void)
1671 {
1672         unregister_filesystem(&ext2_fs_type);
1673         destroy_inodecache();
1674 }
1675
1676 MODULE_AUTHOR("Remy Card and others");
1677 MODULE_DESCRIPTION("Second Extended Filesystem");
1678 MODULE_LICENSE("GPL");
1679 module_init(init_ext2_fs)
1680 module_exit(exit_ext2_fs)