linux/fs/ext2/super.c
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   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
  41static void ext2_write_super(struct super_block *sb);
  42static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44static int ext2_sync_fs(struct super_block *sb, int wait);
  45static int ext2_freeze(struct super_block *sb);
  46static int ext2_unfreeze(struct super_block *sb);
  47
  48void 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
  83void 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 */
 102void 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
 128static int ext2_quota_off(struct super_block *sb, int type);
 129
 130static 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
 138static inline void ext2_quota_off_umount(struct super_block *sb)
 139{
 140}
 141#endif
 142
 143static 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
 179static struct kmem_cache * ext2_inode_cachep;
 180
 181static 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
 196static 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
 202static void ext2_destroy_inode(struct inode *inode)
 203{
 204        call_rcu(&inode->i_rcu, ext2_i_callback);
 205}
 206
 207static 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
 222static 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
 236static 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
 246static 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
 335static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 336static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 337static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 338                         const struct path *path);
 339static struct dquot **ext2_get_dquots(struct inode *inode)
 340{
 341        return EXT2_I(inode)->i_dquot;
 342}
 343
 344static 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
 356static 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
 375static 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
 401static 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
 408static 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
 415static 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
 421static 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
 441enum {
 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
 450static 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
 485static 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
 654static 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) <= get_seconds()))
 686                ext2_msg(sb, KERN_WARNING,
 687                        "warning: checktime reached, "
 688                        "running e2fsck is recommended");
 689        if (!le16_to_cpu(es->s_max_mnt_count))
 690                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 691        le16_add_cpu(&es->s_mnt_count, 1);
 692        if (test_opt (sb, DEBUG))
 693                ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 694                        "bpg=%lu, ipg=%lu, mo=%04lx]",
 695                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 696                        sbi->s_frag_size,
 697                        sbi->s_groups_count,
 698                        EXT2_BLOCKS_PER_GROUP(sb),
 699                        EXT2_INODES_PER_GROUP(sb),
 700                        sbi->s_mount_opt);
 701        return res;
 702}
 703
 704static int ext2_check_descriptors(struct super_block *sb)
 705{
 706        int i;
 707        struct ext2_sb_info *sbi = EXT2_SB(sb);
 708
 709        ext2_debug ("Checking group descriptors");
 710
 711        for (i = 0; i < sbi->s_groups_count; i++) {
 712                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 713                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 714                ext2_fsblk_t last_block;
 715
 716                if (i == sbi->s_groups_count - 1)
 717                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 718                else
 719                        last_block = first_block +
 720                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 721
 722                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 723                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 724                {
 725                        ext2_error (sb, "ext2_check_descriptors",
 726                                    "Block bitmap for group %d"
 727                                    " not in group (block %lu)!",
 728                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 729                        return 0;
 730                }
 731                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 732                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 733                {
 734                        ext2_error (sb, "ext2_check_descriptors",
 735                                    "Inode bitmap for group %d"
 736                                    " not in group (block %lu)!",
 737                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 738                        return 0;
 739                }
 740                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 741                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 742                    last_block)
 743                {
 744                        ext2_error (sb, "ext2_check_descriptors",
 745                                    "Inode table for group %d"
 746                                    " not in group (block %lu)!",
 747                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 748                        return 0;
 749                }
 750        }
 751        return 1;
 752}
 753
 754/*
 755 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 756 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 757 * We need to be 1 filesystem block less than the 2^32 sector limit.
 758 */
 759static loff_t ext2_max_size(int bits)
 760{
 761        loff_t res = EXT2_NDIR_BLOCKS;
 762        int meta_blocks;
 763        loff_t upper_limit;
 764
 765        /* This is calculated to be the largest file size for a
 766         * dense, file such that the total number of
 767         * sectors in the file, including data and all indirect blocks,
 768         * does not exceed 2^32 -1
 769         * __u32 i_blocks representing the total number of
 770         * 512 bytes blocks of the file
 771         */
 772        upper_limit = (1LL << 32) - 1;
 773
 774        /* total blocks in file system block size */
 775        upper_limit >>= (bits - 9);
 776
 777
 778        /* indirect blocks */
 779        meta_blocks = 1;
 780        /* double indirect blocks */
 781        meta_blocks += 1 + (1LL << (bits-2));
 782        /* tripple indirect blocks */
 783        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 784
 785        upper_limit -= meta_blocks;
 786        upper_limit <<= bits;
 787
 788        res += 1LL << (bits-2);
 789        res += 1LL << (2*(bits-2));
 790        res += 1LL << (3*(bits-2));
 791        res <<= bits;
 792        if (res > upper_limit)
 793                res = upper_limit;
 794
 795        if (res > MAX_LFS_FILESIZE)
 796                res = MAX_LFS_FILESIZE;
 797
 798        return res;
 799}
 800
 801static unsigned long descriptor_loc(struct super_block *sb,
 802                                    unsigned long logic_sb_block,
 803                                    int nr)
 804{
 805        struct ext2_sb_info *sbi = EXT2_SB(sb);
 806        unsigned long bg, first_meta_bg;
 807        int has_super = 0;
 808        
 809        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 810
 811        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 812            nr < first_meta_bg)
 813                return (logic_sb_block + nr + 1);
 814        bg = sbi->s_desc_per_block * nr;
 815        if (ext2_bg_has_super(sb, bg))
 816                has_super = 1;
 817
 818        return ext2_group_first_block_no(sb, bg) + has_super;
 819}
 820
 821static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 822{
 823        struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 824        struct buffer_head * bh;
 825        struct ext2_sb_info * sbi;
 826        struct ext2_super_block * es;
 827        struct inode *root;
 828        unsigned long block;
 829        unsigned long sb_block = get_sb_block(&data);
 830        unsigned long logic_sb_block;
 831        unsigned long offset = 0;
 832        unsigned long def_mount_opts;
 833        long ret = -ENOMEM;
 834        int blocksize = BLOCK_SIZE;
 835        int db_count;
 836        int i, j;
 837        __le32 features;
 838        int err;
 839        struct ext2_mount_options opts;
 840
 841        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 842        if (!sbi)
 843                goto failed;
 844
 845        sbi->s_blockgroup_lock =
 846                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 847        if (!sbi->s_blockgroup_lock) {
 848                kfree(sbi);
 849                goto failed;
 850        }
 851        sb->s_fs_info = sbi;
 852        sbi->s_sb_block = sb_block;
 853        sbi->s_daxdev = dax_dev;
 854
 855        spin_lock_init(&sbi->s_lock);
 856        ret = -EINVAL;
 857
 858        /*
 859         * See what the current blocksize for the device is, and
 860         * use that as the blocksize.  Otherwise (or if the blocksize
 861         * is smaller than the default) use the default.
 862         * This is important for devices that have a hardware
 863         * sectorsize that is larger than the default.
 864         */
 865        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 866        if (!blocksize) {
 867                ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 868                goto failed_sbi;
 869        }
 870
 871        /*
 872         * If the superblock doesn't start on a hardware sector boundary,
 873         * calculate the offset.  
 874         */
 875        if (blocksize != BLOCK_SIZE) {
 876                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 877                offset = (sb_block*BLOCK_SIZE) % blocksize;
 878        } else {
 879                logic_sb_block = sb_block;
 880        }
 881
 882        if (!(bh = sb_bread(sb, logic_sb_block))) {
 883                ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 884                goto failed_sbi;
 885        }
 886        /*
 887         * Note: s_es must be initialized as soon as possible because
 888         *       some ext2 macro-instructions depend on its value
 889         */
 890        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 891        sbi->s_es = es;
 892        sb->s_magic = le16_to_cpu(es->s_magic);
 893
 894        if (sb->s_magic != EXT2_SUPER_MAGIC)
 895                goto cantfind_ext2;
 896
 897        /* Set defaults before we parse the mount options */
 898        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 899        if (def_mount_opts & EXT2_DEFM_DEBUG)
 900                set_opt(opts.s_mount_opt, DEBUG);
 901        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 902                set_opt(opts.s_mount_opt, GRPID);
 903        if (def_mount_opts & EXT2_DEFM_UID16)
 904                set_opt(opts.s_mount_opt, NO_UID32);
 905#ifdef CONFIG_EXT2_FS_XATTR
 906        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 907                set_opt(opts.s_mount_opt, XATTR_USER);
 908#endif
 909#ifdef CONFIG_EXT2_FS_POSIX_ACL
 910        if (def_mount_opts & EXT2_DEFM_ACL)
 911                set_opt(opts.s_mount_opt, POSIX_ACL);
 912#endif
 913        
 914        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 915                set_opt(opts.s_mount_opt, ERRORS_PANIC);
 916        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 917                set_opt(opts.s_mount_opt, ERRORS_CONT);
 918        else
 919                set_opt(opts.s_mount_opt, ERRORS_RO);
 920
 921        opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 922        opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 923        
 924        set_opt(opts.s_mount_opt, RESERVATION);
 925
 926        if (!parse_options((char *) data, sb, &opts))
 927                goto failed_mount;
 928
 929        sbi->s_mount_opt = opts.s_mount_opt;
 930        sbi->s_resuid = opts.s_resuid;
 931        sbi->s_resgid = opts.s_resgid;
 932
 933        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 934                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 935                 SB_POSIXACL : 0);
 936        sb->s_iflags |= SB_I_CGROUPWB;
 937
 938        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 939            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 940             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 941             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 942                ext2_msg(sb, KERN_WARNING,
 943                        "warning: feature flags set on rev 0 fs, "
 944                        "running e2fsck is recommended");
 945        /*
 946         * Check feature flags regardless of the revision level, since we
 947         * previously didn't change the revision level when setting the flags,
 948         * so there is a chance incompat flags are set on a rev 0 filesystem.
 949         */
 950        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 951        if (features) {
 952                ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 953                       "unsupported optional features (%x)",
 954                        le32_to_cpu(features));
 955                goto failed_mount;
 956        }
 957        if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 958                ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 959                       "unsupported optional features (%x)",
 960                       le32_to_cpu(features));
 961                goto failed_mount;
 962        }
 963
 964        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 965
 966        if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 967                if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
 968                        ext2_msg(sb, KERN_ERR,
 969                                "DAX unsupported by block device. Turning off DAX.");
 970                        sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
 971                }
 972        }
 973
 974        /* If the blocksize doesn't match, re-read the thing.. */
 975        if (sb->s_blocksize != blocksize) {
 976                brelse(bh);
 977
 978                if (!sb_set_blocksize(sb, blocksize)) {
 979                        ext2_msg(sb, KERN_ERR,
 980                                "error: bad blocksize %d", blocksize);
 981                        goto failed_sbi;
 982                }
 983
 984                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 985                offset = (sb_block*BLOCK_SIZE) % blocksize;
 986                bh = sb_bread(sb, logic_sb_block);
 987                if(!bh) {
 988                        ext2_msg(sb, KERN_ERR, "error: couldn't read"
 989                                "superblock on 2nd try");
 990                        goto failed_sbi;
 991                }
 992                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 993                sbi->s_es = es;
 994                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 995                        ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 996                        goto failed_mount;
 997                }
 998        }
 999
1000        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1001        sb->s_max_links = EXT2_LINK_MAX;
1002
1003        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1004                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1005                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1006        } else {
1007                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1008                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1009                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1010                    !is_power_of_2(sbi->s_inode_size) ||
1011                    (sbi->s_inode_size > blocksize)) {
1012                        ext2_msg(sb, KERN_ERR,
1013                                "error: unsupported inode size: %d",
1014                                sbi->s_inode_size);
1015                        goto failed_mount;
1016                }
1017        }
1018
1019        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1020                                   le32_to_cpu(es->s_log_frag_size);
1021        if (sbi->s_frag_size == 0)
1022                goto cantfind_ext2;
1023        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1024
1025        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1026        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1027        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1028
1029        if (EXT2_INODE_SIZE(sb) == 0)
1030                goto cantfind_ext2;
1031        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1032        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1033                goto cantfind_ext2;
1034        sbi->s_itb_per_group = sbi->s_inodes_per_group /
1035                                        sbi->s_inodes_per_block;
1036        sbi->s_desc_per_block = sb->s_blocksize /
1037                                        sizeof (struct ext2_group_desc);
1038        sbi->s_sbh = bh;
1039        sbi->s_mount_state = le16_to_cpu(es->s_state);
1040        sbi->s_addr_per_block_bits =
1041                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1042        sbi->s_desc_per_block_bits =
1043                ilog2 (EXT2_DESC_PER_BLOCK(sb));
1044
1045        if (sb->s_magic != EXT2_SUPER_MAGIC)
1046                goto cantfind_ext2;
1047
1048        if (sb->s_blocksize != bh->b_size) {
1049                if (!silent)
1050                        ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1051                goto failed_mount;
1052        }
1053
1054        if (sb->s_blocksize != sbi->s_frag_size) {
1055                ext2_msg(sb, KERN_ERR,
1056                        "error: fragsize %lu != blocksize %lu"
1057                        "(not supported yet)",
1058                        sbi->s_frag_size, sb->s_blocksize);
1059                goto failed_mount;
1060        }
1061
1062        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1063                ext2_msg(sb, KERN_ERR,
1064                        "error: #blocks per group too big: %lu",
1065                        sbi->s_blocks_per_group);
1066                goto failed_mount;
1067        }
1068        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1069                ext2_msg(sb, KERN_ERR,
1070                        "error: #fragments per group too big: %lu",
1071                        sbi->s_frags_per_group);
1072                goto failed_mount;
1073        }
1074        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1075                ext2_msg(sb, KERN_ERR,
1076                        "error: #inodes per group too big: %lu",
1077                        sbi->s_inodes_per_group);
1078                goto failed_mount;
1079        }
1080
1081        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1082                goto cantfind_ext2;
1083        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1084                                le32_to_cpu(es->s_first_data_block) - 1)
1085                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1086        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1087                   EXT2_DESC_PER_BLOCK(sb);
1088        sbi->s_group_desc = kmalloc_array (db_count,
1089                                           sizeof(struct buffer_head *),
1090                                           GFP_KERNEL);
1091        if (sbi->s_group_desc == NULL) {
1092                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1093                goto failed_mount;
1094        }
1095        bgl_lock_init(sbi->s_blockgroup_lock);
1096        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1097        if (!sbi->s_debts) {
1098                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1099                goto failed_mount_group_desc;
1100        }
1101        for (i = 0; i < db_count; i++) {
1102                block = descriptor_loc(sb, logic_sb_block, i);
1103                sbi->s_group_desc[i] = sb_bread(sb, block);
1104                if (!sbi->s_group_desc[i]) {
1105                        for (j = 0; j < i; j++)
1106                                brelse (sbi->s_group_desc[j]);
1107                        ext2_msg(sb, KERN_ERR,
1108                                "error: unable to read group descriptors");
1109                        goto failed_mount_group_desc;
1110                }
1111        }
1112        if (!ext2_check_descriptors (sb)) {
1113                ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1114                goto failed_mount2;
1115        }
1116        sbi->s_gdb_count = db_count;
1117        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1118        spin_lock_init(&sbi->s_next_gen_lock);
1119
1120        /* per fileystem reservation list head & lock */
1121        spin_lock_init(&sbi->s_rsv_window_lock);
1122        sbi->s_rsv_window_root = RB_ROOT;
1123        /*
1124         * Add a single, static dummy reservation to the start of the
1125         * reservation window list --- it gives us a placeholder for
1126         * append-at-start-of-list which makes the allocation logic
1127         * _much_ simpler.
1128         */
1129        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1130        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1131        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1132        sbi->s_rsv_window_head.rsv_goal_size = 0;
1133        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1134
1135        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1136                                ext2_count_free_blocks(sb), GFP_KERNEL);
1137        if (!err) {
1138                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1139                                ext2_count_free_inodes(sb), GFP_KERNEL);
1140        }
1141        if (!err) {
1142                err = percpu_counter_init(&sbi->s_dirs_counter,
1143                                ext2_count_dirs(sb), GFP_KERNEL);
1144        }
1145        if (err) {
1146                ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1147                goto failed_mount3;
1148        }
1149
1150#ifdef CONFIG_EXT2_FS_XATTR
1151        sbi->s_ea_block_cache = ext2_xattr_create_cache();
1152        if (!sbi->s_ea_block_cache) {
1153                ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1154                goto failed_mount3;
1155        }
1156#endif
1157        /*
1158         * set up enough so that it can read an inode
1159         */
1160        sb->s_op = &ext2_sops;
1161        sb->s_export_op = &ext2_export_ops;
1162        sb->s_xattr = ext2_xattr_handlers;
1163
1164#ifdef CONFIG_QUOTA
1165        sb->dq_op = &dquot_operations;
1166        sb->s_qcop = &ext2_quotactl_ops;
1167        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1168#endif
1169
1170        root = ext2_iget(sb, EXT2_ROOT_INO);
1171        if (IS_ERR(root)) {
1172                ret = PTR_ERR(root);
1173                goto failed_mount3;
1174        }
1175        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1176                iput(root);
1177                ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1178                goto failed_mount3;
1179        }
1180
1181        sb->s_root = d_make_root(root);
1182        if (!sb->s_root) {
1183                ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1184                ret = -ENOMEM;
1185                goto failed_mount3;
1186        }
1187        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1188                ext2_msg(sb, KERN_WARNING,
1189                        "warning: mounting ext3 filesystem as ext2");
1190        if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1191                sb->s_flags |= SB_RDONLY;
1192        ext2_write_super(sb);
1193        return 0;
1194
1195cantfind_ext2:
1196        if (!silent)
1197                ext2_msg(sb, KERN_ERR,
1198                        "error: can't find an ext2 filesystem on dev %s.",
1199                        sb->s_id);
1200        goto failed_mount;
1201failed_mount3:
1202        if (sbi->s_ea_block_cache)
1203                ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1204        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1205        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1206        percpu_counter_destroy(&sbi->s_dirs_counter);
1207failed_mount2:
1208        for (i = 0; i < db_count; i++)
1209                brelse(sbi->s_group_desc[i]);
1210failed_mount_group_desc:
1211        kfree(sbi->s_group_desc);
1212        kfree(sbi->s_debts);
1213failed_mount:
1214        brelse(bh);
1215failed_sbi:
1216        sb->s_fs_info = NULL;
1217        kfree(sbi->s_blockgroup_lock);
1218        kfree(sbi);
1219failed:
1220        fs_put_dax(dax_dev);
1221        return ret;
1222}
1223
1224static void ext2_clear_super_error(struct super_block *sb)
1225{
1226        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1227
1228        if (buffer_write_io_error(sbh)) {
1229                /*
1230                 * Oh, dear.  A previous attempt to write the
1231                 * superblock failed.  This could happen because the
1232                 * USB device was yanked out.  Or it could happen to
1233                 * be a transient write error and maybe the block will
1234                 * be remapped.  Nothing we can do but to retry the
1235                 * write and hope for the best.
1236                 */
1237                ext2_msg(sb, KERN_ERR,
1238                       "previous I/O error to superblock detected");
1239                clear_buffer_write_io_error(sbh);
1240                set_buffer_uptodate(sbh);
1241        }
1242}
1243
1244void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1245                     int wait)
1246{
1247        ext2_clear_super_error(sb);
1248        spin_lock(&EXT2_SB(sb)->s_lock);
1249        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1250        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1251        es->s_wtime = cpu_to_le32(get_seconds());
1252        /* unlock before we do IO */
1253        spin_unlock(&EXT2_SB(sb)->s_lock);
1254        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1255        if (wait)
1256                sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1257}
1258
1259/*
1260 * In the second extended file system, it is not necessary to
1261 * write the super block since we use a mapping of the
1262 * disk super block in a buffer.
1263 *
1264 * However, this function is still used to set the fs valid
1265 * flags to 0.  We need to set this flag to 0 since the fs
1266 * may have been checked while mounted and e2fsck may have
1267 * set s_state to EXT2_VALID_FS after some corrections.
1268 */
1269static int ext2_sync_fs(struct super_block *sb, int wait)
1270{
1271        struct ext2_sb_info *sbi = EXT2_SB(sb);
1272        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1273
1274        /*
1275         * Write quota structures to quota file, sync_blockdev() will write
1276         * them to disk later
1277         */
1278        dquot_writeback_dquots(sb, -1);
1279
1280        spin_lock(&sbi->s_lock);
1281        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1282                ext2_debug("setting valid to 0\n");
1283                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1284        }
1285        spin_unlock(&sbi->s_lock);
1286        ext2_sync_super(sb, es, wait);
1287        return 0;
1288}
1289
1290static int ext2_freeze(struct super_block *sb)
1291{
1292        struct ext2_sb_info *sbi = EXT2_SB(sb);
1293
1294        /*
1295         * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1296         * because we have unattached inodes and thus filesystem is not fully
1297         * consistent.
1298         */
1299        if (atomic_long_read(&sb->s_remove_count)) {
1300                ext2_sync_fs(sb, 1);
1301                return 0;
1302        }
1303        /* Set EXT2_FS_VALID flag */
1304        spin_lock(&sbi->s_lock);
1305        sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1306        spin_unlock(&sbi->s_lock);
1307        ext2_sync_super(sb, sbi->s_es, 1);
1308
1309        return 0;
1310}
1311
1312static int ext2_unfreeze(struct super_block *sb)
1313{
1314        /* Just write sb to clear EXT2_VALID_FS flag */
1315        ext2_write_super(sb);
1316
1317        return 0;
1318}
1319
1320static void ext2_write_super(struct super_block *sb)
1321{
1322        if (!sb_rdonly(sb))
1323                ext2_sync_fs(sb, 1);
1324}
1325
1326static int ext2_remount (struct super_block * sb, int * flags, char * data)
1327{
1328        struct ext2_sb_info * sbi = EXT2_SB(sb);
1329        struct ext2_super_block * es;
1330        struct ext2_mount_options new_opts;
1331        int err;
1332
1333        sync_filesystem(sb);
1334
1335        spin_lock(&sbi->s_lock);
1336        new_opts.s_mount_opt = sbi->s_mount_opt;
1337        new_opts.s_resuid = sbi->s_resuid;
1338        new_opts.s_resgid = sbi->s_resgid;
1339        spin_unlock(&sbi->s_lock);
1340
1341        if (!parse_options(data, sb, &new_opts))
1342                return -EINVAL;
1343
1344        spin_lock(&sbi->s_lock);
1345        es = sbi->s_es;
1346        if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1347                ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1348                         "dax flag with busy inodes while remounting");
1349                new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1350        }
1351        if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1352                goto out_set;
1353        if (*flags & SB_RDONLY) {
1354                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1355                    !(sbi->s_mount_state & EXT2_VALID_FS))
1356                        goto out_set;
1357
1358                /*
1359                 * OK, we are remounting a valid rw partition rdonly, so set
1360                 * the rdonly flag and then mark the partition as valid again.
1361                 */
1362                es->s_state = cpu_to_le16(sbi->s_mount_state);
1363                es->s_mtime = cpu_to_le32(get_seconds());
1364                spin_unlock(&sbi->s_lock);
1365
1366                err = dquot_suspend(sb, -1);
1367                if (err < 0)
1368                        return err;
1369
1370                ext2_sync_super(sb, es, 1);
1371        } else {
1372                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1373                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1374                if (ret) {
1375                        spin_unlock(&sbi->s_lock);
1376                        ext2_msg(sb, KERN_WARNING,
1377                                "warning: couldn't remount RDWR because of "
1378                                "unsupported optional features (%x).",
1379                                le32_to_cpu(ret));
1380                        return -EROFS;
1381                }
1382                /*
1383                 * Mounting a RDONLY partition read-write, so reread and
1384                 * store the current valid flag.  (It may have been changed
1385                 * by e2fsck since we originally mounted the partition.)
1386                 */
1387                sbi->s_mount_state = le16_to_cpu(es->s_state);
1388                if (!ext2_setup_super (sb, es, 0))
1389                        sb->s_flags &= ~SB_RDONLY;
1390                spin_unlock(&sbi->s_lock);
1391
1392                ext2_write_super(sb);
1393
1394                dquot_resume(sb, -1);
1395        }
1396
1397        spin_lock(&sbi->s_lock);
1398out_set:
1399        sbi->s_mount_opt = new_opts.s_mount_opt;
1400        sbi->s_resuid = new_opts.s_resuid;
1401        sbi->s_resgid = new_opts.s_resgid;
1402        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1403                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1404        spin_unlock(&sbi->s_lock);
1405
1406        return 0;
1407}
1408
1409static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1410{
1411        struct super_block *sb = dentry->d_sb;
1412        struct ext2_sb_info *sbi = EXT2_SB(sb);
1413        struct ext2_super_block *es = sbi->s_es;
1414        u64 fsid;
1415
1416        spin_lock(&sbi->s_lock);
1417
1418        if (test_opt (sb, MINIX_DF))
1419                sbi->s_overhead_last = 0;
1420        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1421                unsigned long i, overhead = 0;
1422                smp_rmb();
1423
1424                /*
1425                 * Compute the overhead (FS structures). This is constant
1426                 * for a given filesystem unless the number of block groups
1427                 * changes so we cache the previous value until it does.
1428                 */
1429
1430                /*
1431                 * All of the blocks before first_data_block are
1432                 * overhead
1433                 */
1434                overhead = le32_to_cpu(es->s_first_data_block);
1435
1436                /*
1437                 * Add the overhead attributed to the superblock and
1438                 * block group descriptors.  If the sparse superblocks
1439                 * feature is turned on, then not all groups have this.
1440                 */
1441                for (i = 0; i < sbi->s_groups_count; i++)
1442                        overhead += ext2_bg_has_super(sb, i) +
1443                                ext2_bg_num_gdb(sb, i);
1444
1445                /*
1446                 * Every block group has an inode bitmap, a block
1447                 * bitmap, and an inode table.
1448                 */
1449                overhead += (sbi->s_groups_count *
1450                             (2 + sbi->s_itb_per_group));
1451                sbi->s_overhead_last = overhead;
1452                smp_wmb();
1453                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1454        }
1455
1456        buf->f_type = EXT2_SUPER_MAGIC;
1457        buf->f_bsize = sb->s_blocksize;
1458        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1459        buf->f_bfree = ext2_count_free_blocks(sb);
1460        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1461        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1462        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1463                buf->f_bavail = 0;
1464        buf->f_files = le32_to_cpu(es->s_inodes_count);
1465        buf->f_ffree = ext2_count_free_inodes(sb);
1466        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1467        buf->f_namelen = EXT2_NAME_LEN;
1468        fsid = le64_to_cpup((void *)es->s_uuid) ^
1469               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1470        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1471        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1472        spin_unlock(&sbi->s_lock);
1473        return 0;
1474}
1475
1476static struct dentry *ext2_mount(struct file_system_type *fs_type,
1477        int flags, const char *dev_name, void *data)
1478{
1479        return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1480}
1481
1482#ifdef CONFIG_QUOTA
1483
1484/* Read data from quotafile - avoid pagecache and such because we cannot afford
1485 * acquiring the locks... As quota files are never truncated and quota code
1486 * itself serializes the operations (and no one else should touch the files)
1487 * we don't have to be afraid of races */
1488static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1489                               size_t len, loff_t off)
1490{
1491        struct inode *inode = sb_dqopt(sb)->files[type];
1492        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1493        int err = 0;
1494        int offset = off & (sb->s_blocksize - 1);
1495        int tocopy;
1496        size_t toread;
1497        struct buffer_head tmp_bh;
1498        struct buffer_head *bh;
1499        loff_t i_size = i_size_read(inode);
1500
1501        if (off > i_size)
1502                return 0;
1503        if (off+len > i_size)
1504                len = i_size-off;
1505        toread = len;
1506        while (toread > 0) {
1507                tocopy = sb->s_blocksize - offset < toread ?
1508                                sb->s_blocksize - offset : toread;
1509
1510                tmp_bh.b_state = 0;
1511                tmp_bh.b_size = sb->s_blocksize;
1512                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1513                if (err < 0)
1514                        return err;
1515                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1516                        memset(data, 0, tocopy);
1517                else {
1518                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1519                        if (!bh)
1520                                return -EIO;
1521                        memcpy(data, bh->b_data+offset, tocopy);
1522                        brelse(bh);
1523                }
1524                offset = 0;
1525                toread -= tocopy;
1526                data += tocopy;
1527                blk++;
1528        }
1529        return len;
1530}
1531
1532/* Write to quotafile */
1533static ssize_t ext2_quota_write(struct super_block *sb, int type,
1534                                const char *data, size_t len, loff_t off)
1535{
1536        struct inode *inode = sb_dqopt(sb)->files[type];
1537        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1538        int err = 0;
1539        int offset = off & (sb->s_blocksize - 1);
1540        int tocopy;
1541        size_t towrite = len;
1542        struct buffer_head tmp_bh;
1543        struct buffer_head *bh;
1544
1545        while (towrite > 0) {
1546                tocopy = sb->s_blocksize - offset < towrite ?
1547                                sb->s_blocksize - offset : towrite;
1548
1549                tmp_bh.b_state = 0;
1550                tmp_bh.b_size = sb->s_blocksize;
1551                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1552                if (err < 0)
1553                        goto out;
1554                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1555                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1556                else
1557                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1558                if (unlikely(!bh)) {
1559                        err = -EIO;
1560                        goto out;
1561                }
1562                lock_buffer(bh);
1563                memcpy(bh->b_data+offset, data, tocopy);
1564                flush_dcache_page(bh->b_page);
1565                set_buffer_uptodate(bh);
1566                mark_buffer_dirty(bh);
1567                unlock_buffer(bh);
1568                brelse(bh);
1569                offset = 0;
1570                towrite -= tocopy;
1571                data += tocopy;
1572                blk++;
1573        }
1574out:
1575        if (len == towrite)
1576                return err;
1577        if (inode->i_size < off+len-towrite)
1578                i_size_write(inode, off+len-towrite);
1579        inode_inc_iversion(inode);
1580        inode->i_mtime = inode->i_ctime = current_time(inode);
1581        mark_inode_dirty(inode);
1582        return len - towrite;
1583}
1584
1585static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1586                         const struct path *path)
1587{
1588        int err;
1589        struct inode *inode;
1590
1591        err = dquot_quota_on(sb, type, format_id, path);
1592        if (err)
1593                return err;
1594
1595        inode = d_inode(path->dentry);
1596        inode_lock(inode);
1597        EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1598        inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1599                        S_NOATIME | S_IMMUTABLE);
1600        inode_unlock(inode);
1601        mark_inode_dirty(inode);
1602
1603        return 0;
1604}
1605
1606static int ext2_quota_off(struct super_block *sb, int type)
1607{
1608        struct inode *inode = sb_dqopt(sb)->files[type];
1609        int err;
1610
1611        if (!inode || !igrab(inode))
1612                goto out;
1613
1614        err = dquot_quota_off(sb, type);
1615        if (err)
1616                goto out_put;
1617
1618        inode_lock(inode);
1619        EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1620        inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1621        inode_unlock(inode);
1622        mark_inode_dirty(inode);
1623out_put:
1624        iput(inode);
1625        return err;
1626out:
1627        return dquot_quota_off(sb, type);
1628}
1629
1630#endif
1631
1632static struct file_system_type ext2_fs_type = {
1633        .owner          = THIS_MODULE,
1634        .name           = "ext2",
1635        .mount          = ext2_mount,
1636        .kill_sb        = kill_block_super,
1637        .fs_flags       = FS_REQUIRES_DEV,
1638};
1639MODULE_ALIAS_FS("ext2");
1640
1641static int __init init_ext2_fs(void)
1642{
1643        int err;
1644
1645        err = init_inodecache();
1646        if (err)
1647                return err;
1648        err = register_filesystem(&ext2_fs_type);
1649        if (err)
1650                goto out;
1651        return 0;
1652out:
1653        destroy_inodecache();
1654        return err;
1655}
1656
1657static void __exit exit_ext2_fs(void)
1658{
1659        unregister_filesystem(&ext2_fs_type);
1660        destroy_inodecache();
1661}
1662
1663MODULE_AUTHOR("Remy Card and others");
1664MODULE_DESCRIPTION("Second Extended Filesystem");
1665MODULE_LICENSE("GPL");
1666module_init(init_ext2_fs)
1667module_exit(exit_ext2_fs)
1668