linux/fs/ext2/super.c
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   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
  42static void ext2_write_super(struct super_block *sb);
  43static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45static int ext2_sync_fs(struct super_block *sb, int wait);
  46static int ext2_freeze(struct super_block *sb);
  47static int ext2_unfreeze(struct super_block *sb);
  48
  49void 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
  84void 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 */
 103void 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
 129static int ext2_quota_off(struct super_block *sb, int type);
 130
 131static 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
 139static inline void ext2_quota_off_umount(struct super_block *sb)
 140{
 141}
 142#endif
 143
 144static 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        kfree(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);
 175        kfree(sbi);
 176}
 177
 178static struct kmem_cache * ext2_inode_cachep;
 179
 180static struct inode *ext2_alloc_inode(struct super_block *sb)
 181{
 182        struct ext2_inode_info *ei;
 183        ei = kmem_cache_alloc(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
 195static void ext2_free_in_core_inode(struct inode *inode)
 196{
 197        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 198}
 199
 200static 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#ifdef CONFIG_FS_DAX
 210        init_rwsem(&ei->dax_sem);
 211#endif
 212        inode_init_once(&ei->vfs_inode);
 213}
 214
 215static int __init init_inodecache(void)
 216{
 217        ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 218                                sizeof(struct ext2_inode_info), 0,
 219                                (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 220                                        SLAB_ACCOUNT),
 221                                offsetof(struct ext2_inode_info, i_data),
 222                                sizeof_field(struct ext2_inode_info, i_data),
 223                                init_once);
 224        if (ext2_inode_cachep == NULL)
 225                return -ENOMEM;
 226        return 0;
 227}
 228
 229static void destroy_inodecache(void)
 230{
 231        /*
 232         * Make sure all delayed rcu free inodes are flushed before we
 233         * destroy cache.
 234         */
 235        rcu_barrier();
 236        kmem_cache_destroy(ext2_inode_cachep);
 237}
 238
 239static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 240{
 241        struct super_block *sb = root->d_sb;
 242        struct ext2_sb_info *sbi = EXT2_SB(sb);
 243        struct ext2_super_block *es = sbi->s_es;
 244        unsigned long def_mount_opts;
 245
 246        spin_lock(&sbi->s_lock);
 247        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 248
 249        if (sbi->s_sb_block != 1)
 250                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 251        if (test_opt(sb, MINIX_DF))
 252                seq_puts(seq, ",minixdf");
 253        if (test_opt(sb, GRPID))
 254                seq_puts(seq, ",grpid");
 255        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 256                seq_puts(seq, ",nogrpid");
 257        if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 258            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 259                seq_printf(seq, ",resuid=%u",
 260                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
 261        }
 262        if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 263            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 264                seq_printf(seq, ",resgid=%u",
 265                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
 266        }
 267        if (test_opt(sb, ERRORS_RO)) {
 268                int def_errors = le16_to_cpu(es->s_errors);
 269
 270                if (def_errors == EXT2_ERRORS_PANIC ||
 271                    def_errors == EXT2_ERRORS_CONTINUE) {
 272                        seq_puts(seq, ",errors=remount-ro");
 273                }
 274        }
 275        if (test_opt(sb, ERRORS_CONT))
 276                seq_puts(seq, ",errors=continue");
 277        if (test_opt(sb, ERRORS_PANIC))
 278                seq_puts(seq, ",errors=panic");
 279        if (test_opt(sb, NO_UID32))
 280                seq_puts(seq, ",nouid32");
 281        if (test_opt(sb, DEBUG))
 282                seq_puts(seq, ",debug");
 283        if (test_opt(sb, OLDALLOC))
 284                seq_puts(seq, ",oldalloc");
 285
 286#ifdef CONFIG_EXT2_FS_XATTR
 287        if (test_opt(sb, XATTR_USER))
 288                seq_puts(seq, ",user_xattr");
 289        if (!test_opt(sb, XATTR_USER) &&
 290            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 291                seq_puts(seq, ",nouser_xattr");
 292        }
 293#endif
 294
 295#ifdef CONFIG_EXT2_FS_POSIX_ACL
 296        if (test_opt(sb, POSIX_ACL))
 297                seq_puts(seq, ",acl");
 298        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 299                seq_puts(seq, ",noacl");
 300#endif
 301
 302        if (test_opt(sb, NOBH))
 303                seq_puts(seq, ",nobh");
 304
 305        if (test_opt(sb, USRQUOTA))
 306                seq_puts(seq, ",usrquota");
 307
 308        if (test_opt(sb, GRPQUOTA))
 309                seq_puts(seq, ",grpquota");
 310
 311        if (test_opt(sb, XIP))
 312                seq_puts(seq, ",xip");
 313
 314        if (test_opt(sb, DAX))
 315                seq_puts(seq, ",dax");
 316
 317        if (!test_opt(sb, RESERVATION))
 318                seq_puts(seq, ",noreservation");
 319
 320        spin_unlock(&sbi->s_lock);
 321        return 0;
 322}
 323
 324#ifdef CONFIG_QUOTA
 325static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 326static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 327static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 328                         const struct path *path);
 329static struct dquot **ext2_get_dquots(struct inode *inode)
 330{
 331        return EXT2_I(inode)->i_dquot;
 332}
 333
 334static const struct quotactl_ops ext2_quotactl_ops = {
 335        .quota_on       = ext2_quota_on,
 336        .quota_off      = ext2_quota_off,
 337        .quota_sync     = dquot_quota_sync,
 338        .get_state      = dquot_get_state,
 339        .set_info       = dquot_set_dqinfo,
 340        .get_dqblk      = dquot_get_dqblk,
 341        .set_dqblk      = dquot_set_dqblk,
 342        .get_nextdqblk  = dquot_get_next_dqblk,
 343};
 344#endif
 345
 346static const struct super_operations ext2_sops = {
 347        .alloc_inode    = ext2_alloc_inode,
 348        .free_inode     = ext2_free_in_core_inode,
 349        .write_inode    = ext2_write_inode,
 350        .evict_inode    = ext2_evict_inode,
 351        .put_super      = ext2_put_super,
 352        .sync_fs        = ext2_sync_fs,
 353        .freeze_fs      = ext2_freeze,
 354        .unfreeze_fs    = ext2_unfreeze,
 355        .statfs         = ext2_statfs,
 356        .remount_fs     = ext2_remount,
 357        .show_options   = ext2_show_options,
 358#ifdef CONFIG_QUOTA
 359        .quota_read     = ext2_quota_read,
 360        .quota_write    = ext2_quota_write,
 361        .get_dquots     = ext2_get_dquots,
 362#endif
 363};
 364
 365static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 366                u64 ino, u32 generation)
 367{
 368        struct inode *inode;
 369
 370        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 371                return ERR_PTR(-ESTALE);
 372        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 373                return ERR_PTR(-ESTALE);
 374
 375        /*
 376         * ext2_iget isn't quite right if the inode is currently unallocated!
 377         * However ext2_iget currently does appropriate checks to handle stale
 378         * inodes so everything is OK.
 379         */
 380        inode = ext2_iget(sb, ino);
 381        if (IS_ERR(inode))
 382                return ERR_CAST(inode);
 383        if (generation && inode->i_generation != generation) {
 384                /* we didn't find the right inode.. */
 385                iput(inode);
 386                return ERR_PTR(-ESTALE);
 387        }
 388        return inode;
 389}
 390
 391static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 392                int fh_len, int fh_type)
 393{
 394        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 395                                    ext2_nfs_get_inode);
 396}
 397
 398static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 399                int fh_len, int fh_type)
 400{
 401        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 402                                    ext2_nfs_get_inode);
 403}
 404
 405static const struct export_operations ext2_export_ops = {
 406        .fh_to_dentry = ext2_fh_to_dentry,
 407        .fh_to_parent = ext2_fh_to_parent,
 408        .get_parent = ext2_get_parent,
 409};
 410
 411static unsigned long get_sb_block(void **data)
 412{
 413        unsigned long   sb_block;
 414        char            *options = (char *) *data;
 415
 416        if (!options || strncmp(options, "sb=", 3) != 0)
 417                return 1;       /* Default location */
 418        options += 3;
 419        sb_block = simple_strtoul(options, &options, 0);
 420        if (*options && *options != ',') {
 421                printk("EXT2-fs: Invalid sb specification: %s\n",
 422                       (char *) *data);
 423                return 1;
 424        }
 425        if (*options == ',')
 426                options++;
 427        *data = (void *) options;
 428        return sb_block;
 429}
 430
 431enum {
 432        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 433        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 434        Opt_err_ro, Opt_nouid32, Opt_debug,
 435        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 436        Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 437        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 438};
 439
 440static const match_table_t tokens = {
 441        {Opt_bsd_df, "bsddf"},
 442        {Opt_minix_df, "minixdf"},
 443        {Opt_grpid, "grpid"},
 444        {Opt_grpid, "bsdgroups"},
 445        {Opt_nogrpid, "nogrpid"},
 446        {Opt_nogrpid, "sysvgroups"},
 447        {Opt_resgid, "resgid=%u"},
 448        {Opt_resuid, "resuid=%u"},
 449        {Opt_sb, "sb=%u"},
 450        {Opt_err_cont, "errors=continue"},
 451        {Opt_err_panic, "errors=panic"},
 452        {Opt_err_ro, "errors=remount-ro"},
 453        {Opt_nouid32, "nouid32"},
 454        {Opt_debug, "debug"},
 455        {Opt_oldalloc, "oldalloc"},
 456        {Opt_orlov, "orlov"},
 457        {Opt_nobh, "nobh"},
 458        {Opt_user_xattr, "user_xattr"},
 459        {Opt_nouser_xattr, "nouser_xattr"},
 460        {Opt_acl, "acl"},
 461        {Opt_noacl, "noacl"},
 462        {Opt_xip, "xip"},
 463        {Opt_dax, "dax"},
 464        {Opt_grpquota, "grpquota"},
 465        {Opt_ignore, "noquota"},
 466        {Opt_quota, "quota"},
 467        {Opt_usrquota, "usrquota"},
 468        {Opt_reservation, "reservation"},
 469        {Opt_noreservation, "noreservation"},
 470        {Opt_err, NULL}
 471};
 472
 473static int parse_options(char *options, struct super_block *sb,
 474                         struct ext2_mount_options *opts)
 475{
 476        char *p;
 477        substring_t args[MAX_OPT_ARGS];
 478        int option;
 479        kuid_t uid;
 480        kgid_t gid;
 481
 482        if (!options)
 483                return 1;
 484
 485        while ((p = strsep (&options, ",")) != NULL) {
 486                int token;
 487                if (!*p)
 488                        continue;
 489
 490                token = match_token(p, tokens, args);
 491                switch (token) {
 492                case Opt_bsd_df:
 493                        clear_opt (opts->s_mount_opt, MINIX_DF);
 494                        break;
 495                case Opt_minix_df:
 496                        set_opt (opts->s_mount_opt, MINIX_DF);
 497                        break;
 498                case Opt_grpid:
 499                        set_opt (opts->s_mount_opt, GRPID);
 500                        break;
 501                case Opt_nogrpid:
 502                        clear_opt (opts->s_mount_opt, GRPID);
 503                        break;
 504                case Opt_resuid:
 505                        if (match_int(&args[0], &option))
 506                                return 0;
 507                        uid = make_kuid(current_user_ns(), option);
 508                        if (!uid_valid(uid)) {
 509                                ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 510                                return 0;
 511
 512                        }
 513                        opts->s_resuid = uid;
 514                        break;
 515                case Opt_resgid:
 516                        if (match_int(&args[0], &option))
 517                                return 0;
 518                        gid = make_kgid(current_user_ns(), option);
 519                        if (!gid_valid(gid)) {
 520                                ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 521                                return 0;
 522                        }
 523                        opts->s_resgid = gid;
 524                        break;
 525                case Opt_sb:
 526                        /* handled by get_sb_block() instead of here */
 527                        /* *sb_block = match_int(&args[0]); */
 528                        break;
 529                case Opt_err_panic:
 530                        clear_opt (opts->s_mount_opt, ERRORS_CONT);
 531                        clear_opt (opts->s_mount_opt, ERRORS_RO);
 532                        set_opt (opts->s_mount_opt, ERRORS_PANIC);
 533                        break;
 534                case Opt_err_ro:
 535                        clear_opt (opts->s_mount_opt, ERRORS_CONT);
 536                        clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 537                        set_opt (opts->s_mount_opt, ERRORS_RO);
 538                        break;
 539                case Opt_err_cont:
 540                        clear_opt (opts->s_mount_opt, ERRORS_RO);
 541                        clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 542                        set_opt (opts->s_mount_opt, ERRORS_CONT);
 543                        break;
 544                case Opt_nouid32:
 545                        set_opt (opts->s_mount_opt, NO_UID32);
 546                        break;
 547                case Opt_debug:
 548                        set_opt (opts->s_mount_opt, DEBUG);
 549                        break;
 550                case Opt_oldalloc:
 551                        set_opt (opts->s_mount_opt, OLDALLOC);
 552                        break;
 553                case Opt_orlov:
 554                        clear_opt (opts->s_mount_opt, OLDALLOC);
 555                        break;
 556                case Opt_nobh:
 557                        set_opt (opts->s_mount_opt, NOBH);
 558                        break;
 559#ifdef CONFIG_EXT2_FS_XATTR
 560                case Opt_user_xattr:
 561                        set_opt (opts->s_mount_opt, XATTR_USER);
 562                        break;
 563                case Opt_nouser_xattr:
 564                        clear_opt (opts->s_mount_opt, XATTR_USER);
 565                        break;
 566#else
 567                case Opt_user_xattr:
 568                case Opt_nouser_xattr:
 569                        ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 570                                "not supported");
 571                        break;
 572#endif
 573#ifdef CONFIG_EXT2_FS_POSIX_ACL
 574                case Opt_acl:
 575                        set_opt(opts->s_mount_opt, POSIX_ACL);
 576                        break;
 577                case Opt_noacl:
 578                        clear_opt(opts->s_mount_opt, POSIX_ACL);
 579                        break;
 580#else
 581                case Opt_acl:
 582                case Opt_noacl:
 583                        ext2_msg(sb, KERN_INFO,
 584                                "(no)acl options not supported");
 585                        break;
 586#endif
 587                case Opt_xip:
 588                        ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 589                        set_opt(opts->s_mount_opt, XIP);
 590                        fallthrough;
 591                case Opt_dax:
 592#ifdef CONFIG_FS_DAX
 593                        ext2_msg(sb, KERN_WARNING,
 594                "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 595                        set_opt(opts->s_mount_opt, DAX);
 596#else
 597                        ext2_msg(sb, KERN_INFO, "dax option not supported");
 598#endif
 599                        break;
 600
 601#if defined(CONFIG_QUOTA)
 602                case Opt_quota:
 603                case Opt_usrquota:
 604                        set_opt(opts->s_mount_opt, USRQUOTA);
 605                        break;
 606
 607                case Opt_grpquota:
 608                        set_opt(opts->s_mount_opt, GRPQUOTA);
 609                        break;
 610#else
 611                case Opt_quota:
 612                case Opt_usrquota:
 613                case Opt_grpquota:
 614                        ext2_msg(sb, KERN_INFO,
 615                                "quota operations not supported");
 616                        break;
 617#endif
 618
 619                case Opt_reservation:
 620                        set_opt(opts->s_mount_opt, RESERVATION);
 621                        ext2_msg(sb, KERN_INFO, "reservations ON");
 622                        break;
 623                case Opt_noreservation:
 624                        clear_opt(opts->s_mount_opt, RESERVATION);
 625                        ext2_msg(sb, KERN_INFO, "reservations OFF");
 626                        break;
 627                case Opt_ignore:
 628                        break;
 629                default:
 630                        return 0;
 631                }
 632        }
 633        return 1;
 634}
 635
 636static int ext2_setup_super (struct super_block * sb,
 637                              struct ext2_super_block * es,
 638                              int read_only)
 639{
 640        int res = 0;
 641        struct ext2_sb_info *sbi = EXT2_SB(sb);
 642
 643        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 644                ext2_msg(sb, KERN_ERR,
 645                        "error: revision level too high, "
 646                        "forcing read-only mode");
 647                res = SB_RDONLY;
 648        }
 649        if (read_only)
 650                return res;
 651        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 652                ext2_msg(sb, KERN_WARNING,
 653                        "warning: mounting unchecked fs, "
 654                        "running e2fsck is recommended");
 655        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 656                ext2_msg(sb, KERN_WARNING,
 657                        "warning: mounting fs with errors, "
 658                        "running e2fsck is recommended");
 659        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 660                 le16_to_cpu(es->s_mnt_count) >=
 661                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 662                ext2_msg(sb, KERN_WARNING,
 663                        "warning: maximal mount count reached, "
 664                        "running e2fsck is recommended");
 665        else if (le32_to_cpu(es->s_checkinterval) &&
 666                (le32_to_cpu(es->s_lastcheck) +
 667                        le32_to_cpu(es->s_checkinterval) <=
 668                        ktime_get_real_seconds()))
 669                ext2_msg(sb, KERN_WARNING,
 670                        "warning: checktime reached, "
 671                        "running e2fsck is recommended");
 672        if (!le16_to_cpu(es->s_max_mnt_count))
 673                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 674        le16_add_cpu(&es->s_mnt_count, 1);
 675        if (test_opt (sb, DEBUG))
 676                ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 677                        "bpg=%lu, ipg=%lu, mo=%04lx]",
 678                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 679                        sbi->s_frag_size,
 680                        sbi->s_groups_count,
 681                        EXT2_BLOCKS_PER_GROUP(sb),
 682                        EXT2_INODES_PER_GROUP(sb),
 683                        sbi->s_mount_opt);
 684        return res;
 685}
 686
 687static int ext2_check_descriptors(struct super_block *sb)
 688{
 689        int i;
 690        struct ext2_sb_info *sbi = EXT2_SB(sb);
 691
 692        ext2_debug ("Checking group descriptors");
 693
 694        for (i = 0; i < sbi->s_groups_count; i++) {
 695                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 696                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 697                ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
 698
 699                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 700                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 701                {
 702                        ext2_error (sb, "ext2_check_descriptors",
 703                                    "Block bitmap for group %d"
 704                                    " not in group (block %lu)!",
 705                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 706                        return 0;
 707                }
 708                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 709                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 710                {
 711                        ext2_error (sb, "ext2_check_descriptors",
 712                                    "Inode bitmap for group %d"
 713                                    " not in group (block %lu)!",
 714                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 715                        return 0;
 716                }
 717                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 718                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 719                    last_block)
 720                {
 721                        ext2_error (sb, "ext2_check_descriptors",
 722                                    "Inode table for group %d"
 723                                    " not in group (block %lu)!",
 724                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 725                        return 0;
 726                }
 727        }
 728        return 1;
 729}
 730
 731/*
 732 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 733 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 734 * We need to be 1 filesystem block less than the 2^32 sector limit.
 735 */
 736static loff_t ext2_max_size(int bits)
 737{
 738        loff_t res = EXT2_NDIR_BLOCKS;
 739        int meta_blocks;
 740        unsigned int upper_limit;
 741        unsigned int ppb = 1 << (bits-2);
 742
 743        /* This is calculated to be the largest file size for a
 744         * dense, file such that the total number of
 745         * sectors in the file, including data and all indirect blocks,
 746         * does not exceed 2^32 -1
 747         * __u32 i_blocks representing the total number of
 748         * 512 bytes blocks of the file
 749         */
 750        upper_limit = (1LL << 32) - 1;
 751
 752        /* total blocks in file system block size */
 753        upper_limit >>= (bits - 9);
 754
 755        /* Compute how many blocks we can address by block tree */
 756        res += 1LL << (bits-2);
 757        res += 1LL << (2*(bits-2));
 758        res += 1LL << (3*(bits-2));
 759        /* Does block tree limit file size? */
 760        if (res < upper_limit)
 761                goto check_lfs;
 762
 763        res = upper_limit;
 764        /* How many metadata blocks are needed for addressing upper_limit? */
 765        upper_limit -= EXT2_NDIR_BLOCKS;
 766        /* indirect blocks */
 767        meta_blocks = 1;
 768        upper_limit -= ppb;
 769        /* double indirect blocks */
 770        if (upper_limit < ppb * ppb) {
 771                meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
 772                res -= meta_blocks;
 773                goto check_lfs;
 774        }
 775        meta_blocks += 1 + ppb;
 776        upper_limit -= ppb * ppb;
 777        /* tripple indirect blocks for the rest */
 778        meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
 779                DIV_ROUND_UP(upper_limit, ppb*ppb);
 780        res -= meta_blocks;
 781check_lfs:
 782        res <<= bits;
 783        if (res > MAX_LFS_FILESIZE)
 784                res = MAX_LFS_FILESIZE;
 785
 786        return res;
 787}
 788
 789static unsigned long descriptor_loc(struct super_block *sb,
 790                                    unsigned long logic_sb_block,
 791                                    int nr)
 792{
 793        struct ext2_sb_info *sbi = EXT2_SB(sb);
 794        unsigned long bg, first_meta_bg;
 795        
 796        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 797
 798        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 799            nr < first_meta_bg)
 800                return (logic_sb_block + nr + 1);
 801        bg = sbi->s_desc_per_block * nr;
 802
 803        return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
 804}
 805
 806static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 807{
 808        struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 809        struct buffer_head * bh;
 810        struct ext2_sb_info * sbi;
 811        struct ext2_super_block * es;
 812        struct inode *root;
 813        unsigned long block;
 814        unsigned long sb_block = get_sb_block(&data);
 815        unsigned long logic_sb_block;
 816        unsigned long offset = 0;
 817        unsigned long def_mount_opts;
 818        long ret = -ENOMEM;
 819        int blocksize = BLOCK_SIZE;
 820        int db_count;
 821        int i, j;
 822        __le32 features;
 823        int err;
 824        struct ext2_mount_options opts;
 825
 826        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 827        if (!sbi)
 828                goto failed;
 829
 830        sbi->s_blockgroup_lock =
 831                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 832        if (!sbi->s_blockgroup_lock) {
 833                kfree(sbi);
 834                goto failed;
 835        }
 836        sb->s_fs_info = sbi;
 837        sbi->s_sb_block = sb_block;
 838        sbi->s_daxdev = dax_dev;
 839
 840        spin_lock_init(&sbi->s_lock);
 841        ret = -EINVAL;
 842
 843        /*
 844         * See what the current blocksize for the device is, and
 845         * use that as the blocksize.  Otherwise (or if the blocksize
 846         * is smaller than the default) use the default.
 847         * This is important for devices that have a hardware
 848         * sectorsize that is larger than the default.
 849         */
 850        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 851        if (!blocksize) {
 852                ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 853                goto failed_sbi;
 854        }
 855
 856        /*
 857         * If the superblock doesn't start on a hardware sector boundary,
 858         * calculate the offset.  
 859         */
 860        if (blocksize != BLOCK_SIZE) {
 861                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 862                offset = (sb_block*BLOCK_SIZE) % blocksize;
 863        } else {
 864                logic_sb_block = sb_block;
 865        }
 866
 867        if (!(bh = sb_bread(sb, logic_sb_block))) {
 868                ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 869                goto failed_sbi;
 870        }
 871        /*
 872         * Note: s_es must be initialized as soon as possible because
 873         *       some ext2 macro-instructions depend on its value
 874         */
 875        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 876        sbi->s_es = es;
 877        sb->s_magic = le16_to_cpu(es->s_magic);
 878
 879        if (sb->s_magic != EXT2_SUPER_MAGIC)
 880                goto cantfind_ext2;
 881
 882        opts.s_mount_opt = 0;
 883        /* Set defaults before we parse the mount options */
 884        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 885        if (def_mount_opts & EXT2_DEFM_DEBUG)
 886                set_opt(opts.s_mount_opt, DEBUG);
 887        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 888                set_opt(opts.s_mount_opt, GRPID);
 889        if (def_mount_opts & EXT2_DEFM_UID16)
 890                set_opt(opts.s_mount_opt, NO_UID32);
 891#ifdef CONFIG_EXT2_FS_XATTR
 892        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 893                set_opt(opts.s_mount_opt, XATTR_USER);
 894#endif
 895#ifdef CONFIG_EXT2_FS_POSIX_ACL
 896        if (def_mount_opts & EXT2_DEFM_ACL)
 897                set_opt(opts.s_mount_opt, POSIX_ACL);
 898#endif
 899        
 900        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 901                set_opt(opts.s_mount_opt, ERRORS_PANIC);
 902        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 903                set_opt(opts.s_mount_opt, ERRORS_CONT);
 904        else
 905                set_opt(opts.s_mount_opt, ERRORS_RO);
 906
 907        opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 908        opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 909        
 910        set_opt(opts.s_mount_opt, RESERVATION);
 911
 912        if (!parse_options((char *) data, sb, &opts))
 913                goto failed_mount;
 914
 915        sbi->s_mount_opt = opts.s_mount_opt;
 916        sbi->s_resuid = opts.s_resuid;
 917        sbi->s_resgid = opts.s_resgid;
 918
 919        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 920                (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
 921        sb->s_iflags |= SB_I_CGROUPWB;
 922
 923        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 924            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 925             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 926             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 927                ext2_msg(sb, KERN_WARNING,
 928                        "warning: feature flags set on rev 0 fs, "
 929                        "running e2fsck is recommended");
 930        /*
 931         * Check feature flags regardless of the revision level, since we
 932         * previously didn't change the revision level when setting the flags,
 933         * so there is a chance incompat flags are set on a rev 0 filesystem.
 934         */
 935        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 936        if (features) {
 937                ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 938                       "unsupported optional features (%x)",
 939                        le32_to_cpu(features));
 940                goto failed_mount;
 941        }
 942        if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 943                ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 944                       "unsupported optional features (%x)",
 945                       le32_to_cpu(features));
 946                goto failed_mount;
 947        }
 948
 949        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 950
 951        if (test_opt(sb, DAX)) {
 952                if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
 953                        ext2_msg(sb, KERN_ERR,
 954                                "DAX unsupported by block device. Turning off DAX.");
 955                        clear_opt(sbi->s_mount_opt, DAX);
 956                }
 957        }
 958
 959        /* If the blocksize doesn't match, re-read the thing.. */
 960        if (sb->s_blocksize != blocksize) {
 961                brelse(bh);
 962
 963                if (!sb_set_blocksize(sb, blocksize)) {
 964                        ext2_msg(sb, KERN_ERR,
 965                                "error: bad blocksize %d", blocksize);
 966                        goto failed_sbi;
 967                }
 968
 969                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 970                offset = (sb_block*BLOCK_SIZE) % blocksize;
 971                bh = sb_bread(sb, logic_sb_block);
 972                if(!bh) {
 973                        ext2_msg(sb, KERN_ERR, "error: couldn't read"
 974                                "superblock on 2nd try");
 975                        goto failed_sbi;
 976                }
 977                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 978                sbi->s_es = es;
 979                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 980                        ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 981                        goto failed_mount;
 982                }
 983        }
 984
 985        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 986        sb->s_max_links = EXT2_LINK_MAX;
 987        sb->s_time_min = S32_MIN;
 988        sb->s_time_max = S32_MAX;
 989
 990        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 991                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 992                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 993        } else {
 994                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 995                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 996                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 997                    !is_power_of_2(sbi->s_inode_size) ||
 998                    (sbi->s_inode_size > blocksize)) {
 999                        ext2_msg(sb, KERN_ERR,
1000                                "error: unsupported inode size: %d",
1001                                sbi->s_inode_size);
1002                        goto failed_mount;
1003                }
1004        }
1005
1006        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1007                                   le32_to_cpu(es->s_log_frag_size);
1008        if (sbi->s_frag_size == 0)
1009                goto cantfind_ext2;
1010        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1011
1012        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1013        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1014        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1015
1016        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1017        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1018                goto cantfind_ext2;
1019        sbi->s_itb_per_group = sbi->s_inodes_per_group /
1020                                        sbi->s_inodes_per_block;
1021        sbi->s_desc_per_block = sb->s_blocksize /
1022                                        sizeof (struct ext2_group_desc);
1023        sbi->s_sbh = bh;
1024        sbi->s_mount_state = le16_to_cpu(es->s_state);
1025        sbi->s_addr_per_block_bits =
1026                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1027        sbi->s_desc_per_block_bits =
1028                ilog2 (EXT2_DESC_PER_BLOCK(sb));
1029
1030        if (sb->s_magic != EXT2_SUPER_MAGIC)
1031                goto cantfind_ext2;
1032
1033        if (sb->s_blocksize != bh->b_size) {
1034                if (!silent)
1035                        ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1036                goto failed_mount;
1037        }
1038
1039        if (sb->s_blocksize != sbi->s_frag_size) {
1040                ext2_msg(sb, KERN_ERR,
1041                        "error: fragsize %lu != blocksize %lu"
1042                        "(not supported yet)",
1043                        sbi->s_frag_size, sb->s_blocksize);
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        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1054                ext2_msg(sb, KERN_ERR,
1055                        "error: #fragments per group too big: %lu",
1056                        sbi->s_frags_per_group);
1057                goto failed_mount;
1058        }
1059        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1060                ext2_msg(sb, KERN_ERR,
1061                        "error: #inodes per group too big: %lu",
1062                        sbi->s_inodes_per_group);
1063                goto failed_mount;
1064        }
1065
1066        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1067                goto cantfind_ext2;
1068        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1069                                le32_to_cpu(es->s_first_data_block) - 1)
1070                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1071        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1072                   EXT2_DESC_PER_BLOCK(sb);
1073        sbi->s_group_desc = kmalloc_array(db_count,
1074                                           sizeof(struct buffer_head *),
1075                                           GFP_KERNEL);
1076        if (sbi->s_group_desc == NULL) {
1077                ret = -ENOMEM;
1078                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1079                goto failed_mount;
1080        }
1081        bgl_lock_init(sbi->s_blockgroup_lock);
1082        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1083        if (!sbi->s_debts) {
1084                ret = -ENOMEM;
1085                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1086                goto failed_mount_group_desc;
1087        }
1088        for (i = 0; i < db_count; i++) {
1089                block = descriptor_loc(sb, logic_sb_block, i);
1090                sbi->s_group_desc[i] = sb_bread(sb, block);
1091                if (!sbi->s_group_desc[i]) {
1092                        for (j = 0; j < i; j++)
1093                                brelse (sbi->s_group_desc[j]);
1094                        ext2_msg(sb, KERN_ERR,
1095                                "error: unable to read group descriptors");
1096                        goto failed_mount_group_desc;
1097                }
1098        }
1099        if (!ext2_check_descriptors (sb)) {
1100                ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1101                goto failed_mount2;
1102        }
1103        sbi->s_gdb_count = db_count;
1104        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1105        spin_lock_init(&sbi->s_next_gen_lock);
1106
1107        /* per fileystem reservation list head & lock */
1108        spin_lock_init(&sbi->s_rsv_window_lock);
1109        sbi->s_rsv_window_root = RB_ROOT;
1110        /*
1111         * Add a single, static dummy reservation to the start of the
1112         * reservation window list --- it gives us a placeholder for
1113         * append-at-start-of-list which makes the allocation logic
1114         * _much_ simpler.
1115         */
1116        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1117        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1118        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1119        sbi->s_rsv_window_head.rsv_goal_size = 0;
1120        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1121
1122        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1123                                ext2_count_free_blocks(sb), GFP_KERNEL);
1124        if (!err) {
1125                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1126                                ext2_count_free_inodes(sb), GFP_KERNEL);
1127        }
1128        if (!err) {
1129                err = percpu_counter_init(&sbi->s_dirs_counter,
1130                                ext2_count_dirs(sb), GFP_KERNEL);
1131        }
1132        if (err) {
1133                ret = err;
1134                ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1135                goto failed_mount3;
1136        }
1137
1138#ifdef CONFIG_EXT2_FS_XATTR
1139        sbi->s_ea_block_cache = ext2_xattr_create_cache();
1140        if (!sbi->s_ea_block_cache) {
1141                ret = -ENOMEM;
1142                ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1143                goto failed_mount3;
1144        }
1145#endif
1146        /*
1147         * set up enough so that it can read an inode
1148         */
1149        sb->s_op = &ext2_sops;
1150        sb->s_export_op = &ext2_export_ops;
1151        sb->s_xattr = ext2_xattr_handlers;
1152
1153#ifdef CONFIG_QUOTA
1154        sb->dq_op = &dquot_operations;
1155        sb->s_qcop = &ext2_quotactl_ops;
1156        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1157#endif
1158
1159        root = ext2_iget(sb, EXT2_ROOT_INO);
1160        if (IS_ERR(root)) {
1161                ret = PTR_ERR(root);
1162                goto failed_mount3;
1163        }
1164        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1165                iput(root);
1166                ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1167                goto failed_mount3;
1168        }
1169
1170        sb->s_root = d_make_root(root);
1171        if (!sb->s_root) {
1172                ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1173                ret = -ENOMEM;
1174                goto failed_mount3;
1175        }
1176        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1177                ext2_msg(sb, KERN_WARNING,
1178                        "warning: mounting ext3 filesystem as ext2");
1179        if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1180                sb->s_flags |= SB_RDONLY;
1181        ext2_write_super(sb);
1182        return 0;
1183
1184cantfind_ext2:
1185        if (!silent)
1186                ext2_msg(sb, KERN_ERR,
1187                        "error: can't find an ext2 filesystem on dev %s.",
1188                        sb->s_id);
1189        goto failed_mount;
1190failed_mount3:
1191        ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1192        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1193        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1194        percpu_counter_destroy(&sbi->s_dirs_counter);
1195failed_mount2:
1196        for (i = 0; i < db_count; i++)
1197                brelse(sbi->s_group_desc[i]);
1198failed_mount_group_desc:
1199        kfree(sbi->s_group_desc);
1200        kfree(sbi->s_debts);
1201failed_mount:
1202        brelse(bh);
1203failed_sbi:
1204        sb->s_fs_info = NULL;
1205        kfree(sbi->s_blockgroup_lock);
1206        kfree(sbi);
1207failed:
1208        fs_put_dax(dax_dev);
1209        return ret;
1210}
1211
1212static void ext2_clear_super_error(struct super_block *sb)
1213{
1214        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1215
1216        if (buffer_write_io_error(sbh)) {
1217                /*
1218                 * Oh, dear.  A previous attempt to write the
1219                 * superblock failed.  This could happen because the
1220                 * USB device was yanked out.  Or it could happen to
1221                 * be a transient write error and maybe the block will
1222                 * be remapped.  Nothing we can do but to retry the
1223                 * write and hope for the best.
1224                 */
1225                ext2_msg(sb, KERN_ERR,
1226                       "previous I/O error to superblock detected");
1227                clear_buffer_write_io_error(sbh);
1228                set_buffer_uptodate(sbh);
1229        }
1230}
1231
1232void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1233                     int wait)
1234{
1235        ext2_clear_super_error(sb);
1236        spin_lock(&EXT2_SB(sb)->s_lock);
1237        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1238        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1239        es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1240        /* unlock before we do IO */
1241        spin_unlock(&EXT2_SB(sb)->s_lock);
1242        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1243        if (wait)
1244                sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1245}
1246
1247/*
1248 * In the second extended file system, it is not necessary to
1249 * write the super block since we use a mapping of the
1250 * disk super block in a buffer.
1251 *
1252 * However, this function is still used to set the fs valid
1253 * flags to 0.  We need to set this flag to 0 since the fs
1254 * may have been checked while mounted and e2fsck may have
1255 * set s_state to EXT2_VALID_FS after some corrections.
1256 */
1257static int ext2_sync_fs(struct super_block *sb, int wait)
1258{
1259        struct ext2_sb_info *sbi = EXT2_SB(sb);
1260        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1261
1262        /*
1263         * Write quota structures to quota file, sync_blockdev() will write
1264         * them to disk later
1265         */
1266        dquot_writeback_dquots(sb, -1);
1267
1268        spin_lock(&sbi->s_lock);
1269        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1270                ext2_debug("setting valid to 0\n");
1271                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1272        }
1273        spin_unlock(&sbi->s_lock);
1274        ext2_sync_super(sb, es, wait);
1275        return 0;
1276}
1277
1278static int ext2_freeze(struct super_block *sb)
1279{
1280        struct ext2_sb_info *sbi = EXT2_SB(sb);
1281
1282        /*
1283         * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1284         * because we have unattached inodes and thus filesystem is not fully
1285         * consistent.
1286         */
1287        if (atomic_long_read(&sb->s_remove_count)) {
1288                ext2_sync_fs(sb, 1);
1289                return 0;
1290        }
1291        /* Set EXT2_FS_VALID flag */
1292        spin_lock(&sbi->s_lock);
1293        sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1294        spin_unlock(&sbi->s_lock);
1295        ext2_sync_super(sb, sbi->s_es, 1);
1296
1297        return 0;
1298}
1299
1300static int ext2_unfreeze(struct super_block *sb)
1301{
1302        /* Just write sb to clear EXT2_VALID_FS flag */
1303        ext2_write_super(sb);
1304
1305        return 0;
1306}
1307
1308static void ext2_write_super(struct super_block *sb)
1309{
1310        if (!sb_rdonly(sb))
1311                ext2_sync_fs(sb, 1);
1312}
1313
1314static int ext2_remount (struct super_block * sb, int * flags, char * data)
1315{
1316        struct ext2_sb_info * sbi = EXT2_SB(sb);
1317        struct ext2_super_block * es;
1318        struct ext2_mount_options new_opts;
1319        int err;
1320
1321        sync_filesystem(sb);
1322
1323        spin_lock(&sbi->s_lock);
1324        new_opts.s_mount_opt = sbi->s_mount_opt;
1325        new_opts.s_resuid = sbi->s_resuid;
1326        new_opts.s_resgid = sbi->s_resgid;
1327        spin_unlock(&sbi->s_lock);
1328
1329        if (!parse_options(data, sb, &new_opts))
1330                return -EINVAL;
1331
1332        spin_lock(&sbi->s_lock);
1333        es = sbi->s_es;
1334        if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1335                ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1336                         "dax flag with busy inodes while remounting");
1337                new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1338        }
1339        if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1340                goto out_set;
1341        if (*flags & SB_RDONLY) {
1342                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1343                    !(sbi->s_mount_state & EXT2_VALID_FS))
1344                        goto out_set;
1345
1346                /*
1347                 * OK, we are remounting a valid rw partition rdonly, so set
1348                 * the rdonly flag and then mark the partition as valid again.
1349                 */
1350                es->s_state = cpu_to_le16(sbi->s_mount_state);
1351                es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1352                spin_unlock(&sbi->s_lock);
1353
1354                err = dquot_suspend(sb, -1);
1355                if (err < 0)
1356                        return err;
1357
1358                ext2_sync_super(sb, es, 1);
1359        } else {
1360                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1361                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1362                if (ret) {
1363                        spin_unlock(&sbi->s_lock);
1364                        ext2_msg(sb, KERN_WARNING,
1365                                "warning: couldn't remount RDWR because of "
1366                                "unsupported optional features (%x).",
1367                                le32_to_cpu(ret));
1368                        return -EROFS;
1369                }
1370                /*
1371                 * Mounting a RDONLY partition read-write, so reread and
1372                 * store the current valid flag.  (It may have been changed
1373                 * by e2fsck since we originally mounted the partition.)
1374                 */
1375                sbi->s_mount_state = le16_to_cpu(es->s_state);
1376                if (!ext2_setup_super (sb, es, 0))
1377                        sb->s_flags &= ~SB_RDONLY;
1378                spin_unlock(&sbi->s_lock);
1379
1380                ext2_write_super(sb);
1381
1382                dquot_resume(sb, -1);
1383        }
1384
1385        spin_lock(&sbi->s_lock);
1386out_set:
1387        sbi->s_mount_opt = new_opts.s_mount_opt;
1388        sbi->s_resuid = new_opts.s_resuid;
1389        sbi->s_resgid = new_opts.s_resgid;
1390        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1391                (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
1392        spin_unlock(&sbi->s_lock);
1393
1394        return 0;
1395}
1396
1397static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1398{
1399        struct super_block *sb = dentry->d_sb;
1400        struct ext2_sb_info *sbi = EXT2_SB(sb);
1401        struct ext2_super_block *es = sbi->s_es;
1402        u64 fsid;
1403
1404        spin_lock(&sbi->s_lock);
1405
1406        if (test_opt (sb, MINIX_DF))
1407                sbi->s_overhead_last = 0;
1408        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1409                unsigned long i, overhead = 0;
1410                smp_rmb();
1411
1412                /*
1413                 * Compute the overhead (FS structures). This is constant
1414                 * for a given filesystem unless the number of block groups
1415                 * changes so we cache the previous value until it does.
1416                 */
1417
1418                /*
1419                 * All of the blocks before first_data_block are
1420                 * overhead
1421                 */
1422                overhead = le32_to_cpu(es->s_first_data_block);
1423
1424                /*
1425                 * Add the overhead attributed to the superblock and
1426                 * block group descriptors.  If the sparse superblocks
1427                 * feature is turned on, then not all groups have this.
1428                 */
1429                for (i = 0; i < sbi->s_groups_count; i++)
1430                        overhead += ext2_bg_has_super(sb, i) +
1431                                ext2_bg_num_gdb(sb, i);
1432
1433                /*
1434                 * Every block group has an inode bitmap, a block
1435                 * bitmap, and an inode table.
1436                 */
1437                overhead += (sbi->s_groups_count *
1438                             (2 + sbi->s_itb_per_group));
1439                sbi->s_overhead_last = overhead;
1440                smp_wmb();
1441                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1442        }
1443
1444        buf->f_type = EXT2_SUPER_MAGIC;
1445        buf->f_bsize = sb->s_blocksize;
1446        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1447        buf->f_bfree = ext2_count_free_blocks(sb);
1448        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1449        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1450        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1451                buf->f_bavail = 0;
1452        buf->f_files = le32_to_cpu(es->s_inodes_count);
1453        buf->f_ffree = ext2_count_free_inodes(sb);
1454        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1455        buf->f_namelen = EXT2_NAME_LEN;
1456        fsid = le64_to_cpup((void *)es->s_uuid) ^
1457               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1458        buf->f_fsid = u64_to_fsid(fsid);
1459        spin_unlock(&sbi->s_lock);
1460        return 0;
1461}
1462
1463static struct dentry *ext2_mount(struct file_system_type *fs_type,
1464        int flags, const char *dev_name, void *data)
1465{
1466        return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1467}
1468
1469#ifdef CONFIG_QUOTA
1470
1471/* Read data from quotafile - avoid pagecache and such because we cannot afford
1472 * acquiring the locks... As quota files are never truncated and quota code
1473 * itself serializes the operations (and no one else should touch the files)
1474 * we don't have to be afraid of races */
1475static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1476                               size_t len, loff_t off)
1477{
1478        struct inode *inode = sb_dqopt(sb)->files[type];
1479        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1480        int err = 0;
1481        int offset = off & (sb->s_blocksize - 1);
1482        int tocopy;
1483        size_t toread;
1484        struct buffer_head tmp_bh;
1485        struct buffer_head *bh;
1486        loff_t i_size = i_size_read(inode);
1487
1488        if (off > i_size)
1489                return 0;
1490        if (off+len > i_size)
1491                len = i_size-off;
1492        toread = len;
1493        while (toread > 0) {
1494                tocopy = sb->s_blocksize - offset < toread ?
1495                                sb->s_blocksize - offset : toread;
1496
1497                tmp_bh.b_state = 0;
1498                tmp_bh.b_size = sb->s_blocksize;
1499                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1500                if (err < 0)
1501                        return err;
1502                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1503                        memset(data, 0, tocopy);
1504                else {
1505                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1506                        if (!bh)
1507                                return -EIO;
1508                        memcpy(data, bh->b_data+offset, tocopy);
1509                        brelse(bh);
1510                }
1511                offset = 0;
1512                toread -= tocopy;
1513                data += tocopy;
1514                blk++;
1515        }
1516        return len;
1517}
1518
1519/* Write to quotafile */
1520static ssize_t ext2_quota_write(struct super_block *sb, int type,
1521                                const char *data, size_t len, loff_t off)
1522{
1523        struct inode *inode = sb_dqopt(sb)->files[type];
1524        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1525        int err = 0;
1526        int offset = off & (sb->s_blocksize - 1);
1527        int tocopy;
1528        size_t towrite = len;
1529        struct buffer_head tmp_bh;
1530        struct buffer_head *bh;
1531
1532        while (towrite > 0) {
1533                tocopy = sb->s_blocksize - offset < towrite ?
1534                                sb->s_blocksize - offset : towrite;
1535
1536                tmp_bh.b_state = 0;
1537                tmp_bh.b_size = sb->s_blocksize;
1538                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1539                if (err < 0)
1540                        goto out;
1541                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1542                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1543                else
1544                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1545                if (unlikely(!bh)) {
1546                        err = -EIO;
1547                        goto out;
1548                }
1549                lock_buffer(bh);
1550                memcpy(bh->b_data+offset, data, tocopy);
1551                flush_dcache_page(bh->b_page);
1552                set_buffer_uptodate(bh);
1553                mark_buffer_dirty(bh);
1554                unlock_buffer(bh);
1555                brelse(bh);
1556                offset = 0;
1557                towrite -= tocopy;
1558                data += tocopy;
1559                blk++;
1560        }
1561out:
1562        if (len == towrite)
1563                return err;
1564        if (inode->i_size < off+len-towrite)
1565                i_size_write(inode, off+len-towrite);
1566        inode_inc_iversion(inode);
1567        inode->i_mtime = inode->i_ctime = current_time(inode);
1568        mark_inode_dirty(inode);
1569        return len - towrite;
1570}
1571
1572static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1573                         const struct path *path)
1574{
1575        int err;
1576        struct inode *inode;
1577
1578        err = dquot_quota_on(sb, type, format_id, path);
1579        if (err)
1580                return err;
1581
1582        inode = d_inode(path->dentry);
1583        inode_lock(inode);
1584        EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1585        inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1586                        S_NOATIME | S_IMMUTABLE);
1587        inode_unlock(inode);
1588        mark_inode_dirty(inode);
1589
1590        return 0;
1591}
1592
1593static int ext2_quota_off(struct super_block *sb, int type)
1594{
1595        struct inode *inode = sb_dqopt(sb)->files[type];
1596        int err;
1597
1598        if (!inode || !igrab(inode))
1599                goto out;
1600
1601        err = dquot_quota_off(sb, type);
1602        if (err)
1603                goto out_put;
1604
1605        inode_lock(inode);
1606        EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1607        inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1608        inode_unlock(inode);
1609        mark_inode_dirty(inode);
1610out_put:
1611        iput(inode);
1612        return err;
1613out:
1614        return dquot_quota_off(sb, type);
1615}
1616
1617#endif
1618
1619static struct file_system_type ext2_fs_type = {
1620        .owner          = THIS_MODULE,
1621        .name           = "ext2",
1622        .mount          = ext2_mount,
1623        .kill_sb        = kill_block_super,
1624        .fs_flags       = FS_REQUIRES_DEV,
1625};
1626MODULE_ALIAS_FS("ext2");
1627
1628static int __init init_ext2_fs(void)
1629{
1630        int err;
1631
1632        err = init_inodecache();
1633        if (err)
1634                return err;
1635        err = register_filesystem(&ext2_fs_type);
1636        if (err)
1637                goto out;
1638        return 0;
1639out:
1640        destroy_inodecache();
1641        return err;
1642}
1643
1644static void __exit exit_ext2_fs(void)
1645{
1646        unregister_filesystem(&ext2_fs_type);
1647        destroy_inodecache();
1648}
1649
1650MODULE_AUTHOR("Remy Card and others");
1651MODULE_DESCRIPTION("Second Extended Filesystem");
1652MODULE_LICENSE("GPL");
1653module_init(init_ext2_fs)
1654module_exit(exit_ext2_fs)
1655