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super.c

/*
 * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
 *
 * Copyright (c) 2001-2006 Anton Altaparmakov
 * Copyright (c) 2001,2002 Richard Russon
 *
 * This program/include file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>     /* For bdev_hardsect_size(). */
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <linux/moduleparam.h>
#include <linux/smp_lock.h>

#include "sysctl.h"
#include "logfile.h"
#include "quota.h"
#include "usnjrnl.h"
#include "dir.h"
#include "debug.h"
#include "index.h"
#include "aops.h"
#include "layout.h"
#include "malloc.h"
#include "ntfs.h"

/* Number of mounted filesystems which have compression enabled. */
static unsigned long ntfs_nr_compression_users;

/* A global default upcase table and a corresponding reference count. */
static ntfschar *default_upcase = NULL;
static unsigned long ntfs_nr_upcase_users = 0;

/* Error constants/strings used in inode.c::ntfs_show_options(). */
typedef enum {
      /* One of these must be present, default is ON_ERRORS_CONTINUE. */
      ON_ERRORS_PANIC               = 0x01,
      ON_ERRORS_REMOUNT_RO          = 0x02,
      ON_ERRORS_CONTINUE            = 0x04,
      /* Optional, can be combined with any of the above. */
      ON_ERRORS_RECOVER       = 0x10,
} ON_ERRORS_ACTIONS;

const option_t on_errors_arr[] = {
      { ON_ERRORS_PANIC,      "panic" },
      { ON_ERRORS_REMOUNT_RO, "remount-ro", },
      { ON_ERRORS_CONTINUE,   "continue", },
      { ON_ERRORS_RECOVER,    "recover" },
      { 0,              NULL }
};

/**
 * simple_getbool -
 *
 * Copied from old ntfs driver (which copied from vfat driver).
 */
static int simple_getbool(char *s, BOOL *setval)
{
      if (s) {
            if (!strcmp(s, "1") || !strcmp(s, "yes") || !strcmp(s, "true"))
                  *setval = TRUE;
            else if (!strcmp(s, "0") || !strcmp(s, "no") ||
                                          !strcmp(s, "false"))
                  *setval = FALSE;
            else
                  return 0;
      } else
            *setval = TRUE;
      return 1;
}

/**
 * parse_options - parse the (re)mount options
 * @vol:    ntfs volume
 * @opt:    string containing the (re)mount options
 *
 * Parse the recognized options in @opt for the ntfs volume described by @vol.
 */
static BOOL parse_options(ntfs_volume *vol, char *opt)
{
      char *p, *v, *ov;
      static char *utf8 = "utf8";
      int errors = 0, sloppy = 0;
      uid_t uid = (uid_t)-1;
      gid_t gid = (gid_t)-1;
      mode_t fmask = (mode_t)-1, dmask = (mode_t)-1;
      int mft_zone_multiplier = -1, on_errors = -1;
      int show_sys_files = -1, case_sensitive = -1, disable_sparse = -1;
      struct nls_table *nls_map = NULL, *old_nls;

      /* I am lazy... (-8 */
#define NTFS_GETOPT_WITH_DEFAULT(option, variable, default_value) \
      if (!strcmp(p, option)) {                             \
            if (!v || !*v)                                  \
                  variable = default_value;                 \
            else {                                          \
                  variable = simple_strtoul(ov = v, &v, 0); \
                  if (*v)                                   \
                        goto needs_val;                     \
            }                                         \
      }
#define NTFS_GETOPT(option, variable)                             \
      if (!strcmp(p, option)) {                             \
            if (!v || !*v)                                  \
                  goto needs_arg;                           \
            variable = simple_strtoul(ov = v, &v, 0);       \
            if (*v)                                         \
                  goto needs_val;                           \
      }
#define NTFS_GETOPT_OCTAL(option, variable)                       \
      if (!strcmp(p, option)) {                             \
            if (!v || !*v)                                  \
                  goto needs_arg;                           \
            variable = simple_strtoul(ov = v, &v, 8);       \
            if (*v)                                         \
                  goto needs_val;                           \
      }
#define NTFS_GETOPT_BOOL(option, variable)                        \
      if (!strcmp(p, option)) {                             \
            BOOL val;                                 \
            if (!simple_getbool(v, &val))                   \
                  goto needs_bool;                    \
            variable = val;                                 \
      }
#define NTFS_GETOPT_OPTIONS_ARRAY(option, variable, opt_array)          \
      if (!strcmp(p, option)) {                             \
            int _i;                                         \
            if (!v || !*v)                                  \
                  goto needs_arg;                           \
            ov = v;                                         \
            if (variable == -1)                             \
                  variable = 0;                             \
            for (_i = 0; opt_array[_i].str && *opt_array[_i].str; _i++) \
                  if (!strcmp(opt_array[_i].str, v)) {            \
                        variable |= opt_array[_i].val;            \
                        break;                              \
                  }                                   \
            if (!opt_array[_i].str || !*opt_array[_i].str)        \
                  goto needs_val;                           \
      }
      if (!opt || !*opt)
            goto no_mount_options;
      ntfs_debug("Entering with mount options string: %s", opt);
      while ((p = strsep(&opt, ","))) {
            if ((v = strchr(p, '=')))
                  *v++ = 0;
            NTFS_GETOPT("uid", uid)
            else NTFS_GETOPT("gid", gid)
            else NTFS_GETOPT_OCTAL("umask", fmask = dmask)
            else NTFS_GETOPT_OCTAL("fmask", fmask)
            else NTFS_GETOPT_OCTAL("dmask", dmask)
            else NTFS_GETOPT("mft_zone_multiplier", mft_zone_multiplier)
            else NTFS_GETOPT_WITH_DEFAULT("sloppy", sloppy, TRUE)
            else NTFS_GETOPT_BOOL("show_sys_files", show_sys_files)
            else NTFS_GETOPT_BOOL("case_sensitive", case_sensitive)
            else NTFS_GETOPT_BOOL("disable_sparse", disable_sparse)
            else NTFS_GETOPT_OPTIONS_ARRAY("errors", on_errors,
                        on_errors_arr)
            else if (!strcmp(p, "posix") || !strcmp(p, "show_inodes"))
                  ntfs_warning(vol->sb, "Ignoring obsolete option %s.",
                              p);
            else if (!strcmp(p, "nls") || !strcmp(p, "iocharset")) {
                  if (!strcmp(p, "iocharset"))
                        ntfs_warning(vol->sb, "Option iocharset is "
                                    "deprecated. Please use "
                                    "option nls=<charsetname> in "
                                    "the future.");
                  if (!v || !*v)
                        goto needs_arg;
use_utf8:
                  old_nls = nls_map;
                  nls_map = load_nls(v);
                  if (!nls_map) {
                        if (!old_nls) {
                              ntfs_error(vol->sb, "NLS character set "
                                          "%s not found.", v);
                              return FALSE;
                        }
                        ntfs_error(vol->sb, "NLS character set %s not "
                                    "found. Using previous one %s.",
                                    v, old_nls->charset);
                        nls_map = old_nls;
                  } else /* nls_map */ {
                        if (old_nls)
                              unload_nls(old_nls);
                  }
            } else if (!strcmp(p, "utf8")) {
                  BOOL val = FALSE;
                  ntfs_warning(vol->sb, "Option utf8 is no longer "
                           "supported, using option nls=utf8. Please "
                           "use option nls=utf8 in the future and "
                           "make sure utf8 is compiled either as a "
                           "module or into the kernel.");
                  if (!v || !*v)
                        val = TRUE;
                  else if (!simple_getbool(v, &val))
                        goto needs_bool;
                  if (val) {
                        v = utf8;
                        goto use_utf8;
                  }
            } else {
                  ntfs_error(vol->sb, "Unrecognized mount option %s.", p);
                  if (errors < INT_MAX)
                        errors++;
            }
#undef NTFS_GETOPT_OPTIONS_ARRAY
#undef NTFS_GETOPT_BOOL
#undef NTFS_GETOPT
#undef NTFS_GETOPT_WITH_DEFAULT
      }
no_mount_options:
      if (errors && !sloppy)
            return FALSE;
      if (sloppy)
            ntfs_warning(vol->sb, "Sloppy option given. Ignoring "
                        "unrecognized mount option(s) and continuing.");
      /* Keep this first! */
      if (on_errors != -1) {
            if (!on_errors) {
                  ntfs_error(vol->sb, "Invalid errors option argument "
                              "or bug in options parser.");
                  return FALSE;
            }
      }
      if (nls_map) {
            if (vol->nls_map && vol->nls_map != nls_map) {
                  ntfs_error(vol->sb, "Cannot change NLS character set "
                              "on remount.");
                  return FALSE;
            } /* else (!vol->nls_map) */
            ntfs_debug("Using NLS character set %s.", nls_map->charset);
            vol->nls_map = nls_map;
      } else /* (!nls_map) */ {
            if (!vol->nls_map) {
                  vol->nls_map = load_nls_default();
                  if (!vol->nls_map) {
                        ntfs_error(vol->sb, "Failed to load default "
                                    "NLS character set.");
                        return FALSE;
                  }
                  ntfs_debug("Using default NLS character set (%s).",
                              vol->nls_map->charset);
            }
      }
      if (mft_zone_multiplier != -1) {
            if (vol->mft_zone_multiplier && vol->mft_zone_multiplier !=
                        mft_zone_multiplier) {
                  ntfs_error(vol->sb, "Cannot change mft_zone_multiplier "
                              "on remount.");
                  return FALSE;
            }
            if (mft_zone_multiplier < 1 || mft_zone_multiplier > 4) {
                  ntfs_error(vol->sb, "Invalid mft_zone_multiplier. "
                              "Using default value, i.e. 1.");
                  mft_zone_multiplier = 1;
            }
            vol->mft_zone_multiplier = mft_zone_multiplier;
      }
      if (!vol->mft_zone_multiplier)
            vol->mft_zone_multiplier = 1;
      if (on_errors != -1)
            vol->on_errors = on_errors;
      if (!vol->on_errors || vol->on_errors == ON_ERRORS_RECOVER)
            vol->on_errors |= ON_ERRORS_CONTINUE;
      if (uid != (uid_t)-1)
            vol->uid = uid;
      if (gid != (gid_t)-1)
            vol->gid = gid;
      if (fmask != (mode_t)-1)
            vol->fmask = fmask;
      if (dmask != (mode_t)-1)
            vol->dmask = dmask;
      if (show_sys_files != -1) {
            if (show_sys_files)
                  NVolSetShowSystemFiles(vol);
            else
                  NVolClearShowSystemFiles(vol);
      }
      if (case_sensitive != -1) {
            if (case_sensitive)
                  NVolSetCaseSensitive(vol);
            else
                  NVolClearCaseSensitive(vol);
      }
      if (disable_sparse != -1) {
            if (disable_sparse)
                  NVolClearSparseEnabled(vol);
            else {
                  if (!NVolSparseEnabled(vol) &&
                              vol->major_ver && vol->major_ver < 3)
                        ntfs_warning(vol->sb, "Not enabling sparse "
                                    "support due to NTFS volume "
                                    "version %i.%i (need at least "
                                    "version 3.0).", vol->major_ver,
                                    vol->minor_ver);
                  else
                        NVolSetSparseEnabled(vol);
            }
      }
      return TRUE;
needs_arg:
      ntfs_error(vol->sb, "The %s option requires an argument.", p);
      return FALSE;
needs_bool:
      ntfs_error(vol->sb, "The %s option requires a boolean argument.", p);
      return FALSE;
needs_val:
      ntfs_error(vol->sb, "Invalid %s option argument: %s", p, ov);
      return FALSE;
}

#ifdef NTFS_RW

/**
 * ntfs_write_volume_flags - write new flags to the volume information flags
 * @vol:    ntfs volume on which to modify the flags
 * @flags:  new flags value for the volume information flags
 *
 * Internal function.  You probably want to use ntfs_{set,clear}_volume_flags()
 * instead (see below).
 *
 * Replace the volume information flags on the volume @vol with the value
 * supplied in @flags.  Note, this overwrites the volume information flags, so
 * make sure to combine the flags you want to modify with the old flags and use
 * the result when calling ntfs_write_volume_flags().
 *
 * Return 0 on success and -errno on error.
 */
static int ntfs_write_volume_flags(ntfs_volume *vol, const VOLUME_FLAGS flags)
{
      ntfs_inode *ni = NTFS_I(vol->vol_ino);
      MFT_RECORD *m;
      VOLUME_INFORMATION *vi;
      ntfs_attr_search_ctx *ctx;
      int err;

      ntfs_debug("Entering, old flags = 0x%x, new flags = 0x%x.",
                  le16_to_cpu(vol->vol_flags), le16_to_cpu(flags));
      if (vol->vol_flags == flags)
            goto done;
      BUG_ON(!ni);
      m = map_mft_record(ni);
      if (IS_ERR(m)) {
            err = PTR_ERR(m);
            goto err_out;
      }
      ctx = ntfs_attr_get_search_ctx(ni, m);
      if (!ctx) {
            err = -ENOMEM;
            goto put_unm_err_out;
      }
      err = ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
                  ctx);
      if (err)
            goto put_unm_err_out;
      vi = (VOLUME_INFORMATION*)((u8*)ctx->attr +
                  le16_to_cpu(ctx->attr->data.resident.value_offset));
      vol->vol_flags = vi->flags = flags;
      flush_dcache_mft_record_page(ctx->ntfs_ino);
      mark_mft_record_dirty(ctx->ntfs_ino);
      ntfs_attr_put_search_ctx(ctx);
      unmap_mft_record(ni);
done:
      ntfs_debug("Done.");
      return 0;
put_unm_err_out:
      if (ctx)
            ntfs_attr_put_search_ctx(ctx);
      unmap_mft_record(ni);
err_out:
      ntfs_error(vol->sb, "Failed with error code %i.", -err);
      return err;
}

/**
 * ntfs_set_volume_flags - set bits in the volume information flags
 * @vol:    ntfs volume on which to modify the flags
 * @flags:  flags to set on the volume
 *
 * Set the bits in @flags in the volume information flags on the volume @vol.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_set_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
{
      flags &= VOLUME_FLAGS_MASK;
      return ntfs_write_volume_flags(vol, vol->vol_flags | flags);
}

/**
 * ntfs_clear_volume_flags - clear bits in the volume information flags
 * @vol:    ntfs volume on which to modify the flags
 * @flags:  flags to clear on the volume
 *
 * Clear the bits in @flags in the volume information flags on the volume @vol.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_clear_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
{
      flags &= VOLUME_FLAGS_MASK;
      flags = vol->vol_flags & cpu_to_le16(~le16_to_cpu(flags));
      return ntfs_write_volume_flags(vol, flags);
}

#endif /* NTFS_RW */

/**
 * ntfs_remount - change the mount options of a mounted ntfs filesystem
 * @sb:           superblock of mounted ntfs filesystem
 * @flags:  remount flags
 * @opt:    remount options string
 *
 * Change the mount options of an already mounted ntfs filesystem.
 *
 * NOTE:  The VFS sets the @sb->s_flags remount flags to @flags after
 * ntfs_remount() returns successfully (i.e. returns 0).  Otherwise,
 * @sb->s_flags are not changed.
 */
static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
{
      ntfs_volume *vol = NTFS_SB(sb);

      ntfs_debug("Entering with remount options string: %s", opt);
#ifndef NTFS_RW
      /* For read-only compiled driver, enforce read-only flag. */
      *flags |= MS_RDONLY;
#else /* NTFS_RW */
      /*
       * For the read-write compiled driver, if we are remounting read-write,
       * make sure there are no volume errors and that no unsupported volume
       * flags are set.  Also, empty the logfile journal as it would become
       * stale as soon as something is written to the volume and mark the
       * volume dirty so that chkdsk is run if the volume is not umounted
       * cleanly.  Finally, mark the quotas out of date so Windows rescans
       * the volume on boot and updates them.
       *
       * When remounting read-only, mark the volume clean if no volume errors
       * have occured.
       */
      if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
            static const char *es = ".  Cannot remount read-write.";

            /* Remounting read-write. */
            if (NVolErrors(vol)) {
                  ntfs_error(sb, "Volume has errors and is read-only%s",
                              es);
                  return -EROFS;
            }
            if (vol->vol_flags & VOLUME_IS_DIRTY) {
                  ntfs_error(sb, "Volume is dirty and read-only%s", es);
                  return -EROFS;
            }
            if (vol->vol_flags & VOLUME_MODIFIED_BY_CHKDSK) {
                  ntfs_error(sb, "Volume has been modified by chkdsk "
                              "and is read-only%s", es);
                  return -EROFS;
            }
            if (vol->vol_flags & VOLUME_MUST_MOUNT_RO_MASK) {
                  ntfs_error(sb, "Volume has unsupported flags set "
                              "(0x%x) and is read-only%s",
                              (unsigned)le16_to_cpu(vol->vol_flags),
                              es);
                  return -EROFS;
            }
            if (ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY)) {
                  ntfs_error(sb, "Failed to set dirty bit in volume "
                              "information flags%s", es);
                  return -EROFS;
            }
#if 0
            // TODO: Enable this code once we start modifying anything that
            //     is different between NTFS 1.2 and 3.x...
            /* Set NT4 compatibility flag on newer NTFS version volumes. */
            if ((vol->major_ver > 1)) {
                  if (ntfs_set_volume_flags(vol, VOLUME_MOUNTED_ON_NT4)) {
                        ntfs_error(sb, "Failed to set NT4 "
                                    "compatibility flag%s", es);
                        NVolSetErrors(vol);
                        return -EROFS;
                  }
            }
#endif
            if (!ntfs_empty_logfile(vol->logfile_ino)) {
                  ntfs_error(sb, "Failed to empty journal $LogFile%s",
                              es);
                  NVolSetErrors(vol);
                  return -EROFS;
            }
            if (!ntfs_mark_quotas_out_of_date(vol)) {
                  ntfs_error(sb, "Failed to mark quotas out of date%s",
                              es);
                  NVolSetErrors(vol);
                  return -EROFS;
            }
            if (!ntfs_stamp_usnjrnl(vol)) {
                  ntfs_error(sb, "Failed to stamp transation log "
                              "($UsnJrnl)%s", es);
                  NVolSetErrors(vol);
                  return -EROFS;
            }
      } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
            /* Remounting read-only. */
            if (!NVolErrors(vol)) {
                  if (ntfs_clear_volume_flags(vol, VOLUME_IS_DIRTY))
                        ntfs_warning(sb, "Failed to clear dirty bit "
                                    "in volume information "
                                    "flags.  Run chkdsk.");
            }
      }
#endif /* NTFS_RW */

      // TODO: Deal with *flags.

      if (!parse_options(vol, opt))
            return -EINVAL;
      ntfs_debug("Done.");
      return 0;
}

/**
 * is_boot_sector_ntfs - check whether a boot sector is a valid NTFS boot sector
 * @sb:           Super block of the device to which @b belongs.
 * @b:            Boot sector of device @sb to check.
 * @silent: If TRUE, all output will be silenced.
 *
 * is_boot_sector_ntfs() checks whether the boot sector @b is a valid NTFS boot
 * sector. Returns TRUE if it is valid and FALSE if not.
 *
 * @sb is only needed for warning/error output, i.e. it can be NULL when silent
 * is TRUE.
 */
static BOOL is_boot_sector_ntfs(const struct super_block *sb,
            const NTFS_BOOT_SECTOR *b, const BOOL silent)
{
      /*
       * Check that checksum == sum of u32 values from b to the checksum
       * field.  If checksum is zero, no checking is done.  We will work when
       * the checksum test fails, since some utilities update the boot sector
       * ignoring the checksum which leaves the checksum out-of-date.  We
       * report a warning if this is the case.
       */
      if ((void*)b < (void*)&b->checksum && b->checksum && !silent) {
            le32 *u;
            u32 i;

            for (i = 0, u = (le32*)b; u < (le32*)(&b->checksum); ++u)
                  i += le32_to_cpup(u);
            if (le32_to_cpu(b->checksum) != i)
                  ntfs_warning(sb, "Invalid boot sector checksum.");
      }
      /* Check OEMidentifier is "NTFS    " */
      if (b->oem_id != magicNTFS)
            goto not_ntfs;
      /* Check bytes per sector value is between 256 and 4096. */
      if (le16_to_cpu(b->bpb.bytes_per_sector) < 0x100 ||
                  le16_to_cpu(b->bpb.bytes_per_sector) > 0x1000)
            goto not_ntfs;
      /* Check sectors per cluster value is valid. */
      switch (b->bpb.sectors_per_cluster) {
      case 1: case 2: case 4: case 8: case 16: case 32: case 64: case 128:
            break;
      default:
            goto not_ntfs;
      }
      /* Check the cluster size is not above the maximum (64kiB). */
      if ((u32)le16_to_cpu(b->bpb.bytes_per_sector) *
                  b->bpb.sectors_per_cluster > NTFS_MAX_CLUSTER_SIZE)
            goto not_ntfs;
      /* Check reserved/unused fields are really zero. */
      if (le16_to_cpu(b->bpb.reserved_sectors) ||
                  le16_to_cpu(b->bpb.root_entries) ||
                  le16_to_cpu(b->bpb.sectors) ||
                  le16_to_cpu(b->bpb.sectors_per_fat) ||
                  le32_to_cpu(b->bpb.large_sectors) || b->bpb.fats)
            goto not_ntfs;
      /* Check clusters per file mft record value is valid. */
      if ((u8)b->clusters_per_mft_record < 0xe1 ||
                  (u8)b->clusters_per_mft_record > 0xf7)
            switch (b->clusters_per_mft_record) {
            case 1: case 2: case 4: case 8: case 16: case 32: case 64:
                  break;
            default:
                  goto not_ntfs;
            }
      /* Check clusters per index block value is valid. */
      if ((u8)b->clusters_per_index_record < 0xe1 ||
                  (u8)b->clusters_per_index_record > 0xf7)
            switch (b->clusters_per_index_record) {
            case 1: case 2: case 4: case 8: case 16: case 32: case 64:
                  break;
            default:
                  goto not_ntfs;
            }
      /*
       * Check for valid end of sector marker. We will work without it, but
       * many BIOSes will refuse to boot from a bootsector if the magic is
       * incorrect, so we emit a warning.
       */
      if (!silent && b->end_of_sector_marker != const_cpu_to_le16(0xaa55))
            ntfs_warning(sb, "Invalid end of sector marker.");
      return TRUE;
not_ntfs:
      return FALSE;
}

/**
 * read_ntfs_boot_sector - read the NTFS boot sector of a device
 * @sb:           super block of device to read the boot sector from
 * @silent: if true, suppress all output
 *
 * Reads the boot sector from the device and validates it. If that fails, tries
 * to read the backup boot sector, first from the end of the device a-la NT4 and
 * later and then from the middle of the device a-la NT3.51 and before.
 *
 * If a valid boot sector is found but it is not the primary boot sector, we
 * repair the primary boot sector silently (unless the device is read-only or
 * the primary boot sector is not accessible).
 *
 * NOTE: To call this function, @sb must have the fields s_dev, the ntfs super
 * block (u.ntfs_sb), nr_blocks and the device flags (s_flags) initialized
 * to their respective values.
 *
 * Return the unlocked buffer head containing the boot sector or NULL on error.
 */
static struct buffer_head *read_ntfs_boot_sector(struct super_block *sb,
            const int silent)
{
      const char *read_err_str = "Unable to read %s boot sector.";
      struct buffer_head *bh_primary, *bh_backup;
      sector_t nr_blocks = NTFS_SB(sb)->nr_blocks;

      /* Try to read primary boot sector. */
      if ((bh_primary = sb_bread(sb, 0))) {
            if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
                        bh_primary->b_data, silent))
                  return bh_primary;
            if (!silent)
                  ntfs_error(sb, "Primary boot sector is invalid.");
      } else if (!silent)
            ntfs_error(sb, read_err_str, "primary");
      if (!(NTFS_SB(sb)->on_errors & ON_ERRORS_RECOVER)) {
            if (bh_primary)
                  brelse(bh_primary);
            if (!silent)
                  ntfs_error(sb, "Mount option errors=recover not used. "
                              "Aborting without trying to recover.");
            return NULL;
      }
      /* Try to read NT4+ backup boot sector. */
      if ((bh_backup = sb_bread(sb, nr_blocks - 1))) {
            if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
                        bh_backup->b_data, silent))
                  goto hotfix_primary_boot_sector;
            brelse(bh_backup);
      } else if (!silent)
            ntfs_error(sb, read_err_str, "backup");
      /* Try to read NT3.51- backup boot sector. */
      if ((bh_backup = sb_bread(sb, nr_blocks >> 1))) {
            if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
                        bh_backup->b_data, silent))
                  goto hotfix_primary_boot_sector;
            if (!silent)
                  ntfs_error(sb, "Could not find a valid backup boot "
                              "sector.");
            brelse(bh_backup);
      } else if (!silent)
            ntfs_error(sb, read_err_str, "backup");
      /* We failed. Cleanup and return. */
      if (bh_primary)
            brelse(bh_primary);
      return NULL;
hotfix_primary_boot_sector:
      if (bh_primary) {
            /*
             * If we managed to read sector zero and the volume is not
             * read-only, copy the found, valid backup boot sector to the
             * primary boot sector.  Note we only copy the actual boot
             * sector structure, not the actual whole device sector as that
             * may be bigger and would potentially damage the $Boot system
             * file (FIXME: Would be nice to know if the backup boot sector
             * on a large sector device contains the whole boot loader or
             * just the first 512 bytes).
             */
            if (!(sb->s_flags & MS_RDONLY)) {
                  ntfs_warning(sb, "Hot-fix: Recovering invalid primary "
                              "boot sector from backup copy.");
                  memcpy(bh_primary->b_data, bh_backup->b_data,
                              NTFS_BLOCK_SIZE);
                  mark_buffer_dirty(bh_primary);
                  sync_dirty_buffer(bh_primary);
                  if (buffer_uptodate(bh_primary)) {
                        brelse(bh_backup);
                        return bh_primary;
                  }
                  ntfs_error(sb, "Hot-fix: Device write error while "
                              "recovering primary boot sector.");
            } else {
                  ntfs_warning(sb, "Hot-fix: Recovery of primary boot "
                              "sector failed: Read-only mount.");
            }
            brelse(bh_primary);
      }
      ntfs_warning(sb, "Using backup boot sector.");
      return bh_backup;
}

/**
 * parse_ntfs_boot_sector - parse the boot sector and store the data in @vol
 * @vol:    volume structure to initialise with data from boot sector
 * @b:            boot sector to parse
 *
 * Parse the ntfs boot sector @b and store all imporant information therein in
 * the ntfs super block @vol.  Return TRUE on success and FALSE on error.
 */
static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
{
      unsigned int sectors_per_cluster_bits, nr_hidden_sects;
      int clusters_per_mft_record, clusters_per_index_record;
      s64 ll;

      vol->sector_size = le16_to_cpu(b->bpb.bytes_per_sector);
      vol->sector_size_bits = ffs(vol->sector_size) - 1;
      ntfs_debug("vol->sector_size = %i (0x%x)", vol->sector_size,
                  vol->sector_size);
      ntfs_debug("vol->sector_size_bits = %i (0x%x)", vol->sector_size_bits,
                  vol->sector_size_bits);
      if (vol->sector_size < vol->sb->s_blocksize) {
            ntfs_error(vol->sb, "Sector size (%i) is smaller than the "
                        "device block size (%lu).  This is not "
                        "supported.  Sorry.", vol->sector_size,
                        vol->sb->s_blocksize);
            return FALSE;
      }
      ntfs_debug("sectors_per_cluster = 0x%x", b->bpb.sectors_per_cluster);
      sectors_per_cluster_bits = ffs(b->bpb.sectors_per_cluster) - 1;
      ntfs_debug("sectors_per_cluster_bits = 0x%x",
                  sectors_per_cluster_bits);
      nr_hidden_sects = le32_to_cpu(b->bpb.hidden_sectors);
      ntfs_debug("number of hidden sectors = 0x%x", nr_hidden_sects);
      vol->cluster_size = vol->sector_size << sectors_per_cluster_bits;
      vol->cluster_size_mask = vol->cluster_size - 1;
      vol->cluster_size_bits = ffs(vol->cluster_size) - 1;
      ntfs_debug("vol->cluster_size = %i (0x%x)", vol->cluster_size,
                  vol->cluster_size);
      ntfs_debug("vol->cluster_size_mask = 0x%x", vol->cluster_size_mask);
      ntfs_debug("vol->cluster_size_bits = %i", vol->cluster_size_bits);
      if (vol->cluster_size < vol->sector_size) {
            ntfs_error(vol->sb, "Cluster size (%i) is smaller than the "
                        "sector size (%i).  This is not supported.  "
                        "Sorry.", vol->cluster_size, vol->sector_size);
            return FALSE;
      }
      clusters_per_mft_record = b->clusters_per_mft_record;
      ntfs_debug("clusters_per_mft_record = %i (0x%x)",
                  clusters_per_mft_record, clusters_per_mft_record);
      if (clusters_per_mft_record > 0)
            vol->mft_record_size = vol->cluster_size <<
                        (ffs(clusters_per_mft_record) - 1);
      else
            /*
             * When mft_record_size < cluster_size, clusters_per_mft_record
             * = -log2(mft_record_size) bytes. mft_record_size normaly is
             * 1024 bytes, which is encoded as 0xF6 (-10 in decimal).
             */
            vol->mft_record_size = 1 << -clusters_per_mft_record;
      vol->mft_record_size_mask = vol->mft_record_size - 1;
      vol->mft_record_size_bits = ffs(vol->mft_record_size) - 1;
      ntfs_debug("vol->mft_record_size = %i (0x%x)", vol->mft_record_size,
                  vol->mft_record_size);
      ntfs_debug("vol->mft_record_size_mask = 0x%x",
                  vol->mft_record_size_mask);
      ntfs_debug("vol->mft_record_size_bits = %i (0x%x)",
                  vol->mft_record_size_bits, vol->mft_record_size_bits);
      /*
       * We cannot support mft record sizes above the PAGE_CACHE_SIZE since
       * we store $MFT/$DATA, the table of mft records in the page cache.
       */
      if (vol->mft_record_size > PAGE_CACHE_SIZE) {
            ntfs_error(vol->sb, "Mft record size (%i) exceeds the "
                        "PAGE_CACHE_SIZE on your system (%lu).  "
                        "This is not supported.  Sorry.",
                        vol->mft_record_size, PAGE_CACHE_SIZE);
            return FALSE;
      }
      /* We cannot support mft record sizes below the sector size. */
      if (vol->mft_record_size < vol->sector_size) {
            ntfs_error(vol->sb, "Mft record size (%i) is smaller than the "
                        "sector size (%i).  This is not supported.  "
                        "Sorry.", vol->mft_record_size,
                        vol->sector_size);
            return FALSE;
      }
      clusters_per_index_record = b->clusters_per_index_record;
      ntfs_debug("clusters_per_index_record = %i (0x%x)",
                  clusters_per_index_record, clusters_per_index_record);
      if (clusters_per_index_record > 0)
            vol->index_record_size = vol->cluster_size <<
                        (ffs(clusters_per_index_record) - 1);
      else
            /*
             * When index_record_size < cluster_size,
             * clusters_per_index_record = -log2(index_record_size) bytes.
             * index_record_size normaly equals 4096 bytes, which is
             * encoded as 0xF4 (-12 in decimal).
             */
            vol->index_record_size = 1 << -clusters_per_index_record;
      vol->index_record_size_mask = vol->index_record_size - 1;
      vol->index_record_size_bits = ffs(vol->index_record_size) - 1;
      ntfs_debug("vol->index_record_size = %i (0x%x)",
                  vol->index_record_size, vol->index_record_size);
      ntfs_debug("vol->index_record_size_mask = 0x%x",
                  vol->index_record_size_mask);
      ntfs_debug("vol->index_record_size_bits = %i (0x%x)",
                  vol->index_record_size_bits,
                  vol->index_record_size_bits);
      /* We cannot support index record sizes below the sector size. */
      if (vol->index_record_size < vol->sector_size) {
            ntfs_error(vol->sb, "Index record size (%i) is smaller than "
                        "the sector size (%i).  This is not "
                        "supported.  Sorry.", vol->index_record_size,
                        vol->sector_size);
            return FALSE;
      }
      /*
       * Get the size of the volume in clusters and check for 64-bit-ness.
       * Windows currently only uses 32 bits to save the clusters so we do
       * the same as it is much faster on 32-bit CPUs.
       */
      ll = sle64_to_cpu(b->number_of_sectors) >> sectors_per_cluster_bits;
      if ((u64)ll >= 1ULL << 32) {
            ntfs_error(vol->sb, "Cannot handle 64-bit clusters.  Sorry.");
            return FALSE;
      }
      vol->nr_clusters = ll;
      ntfs_debug("vol->nr_clusters = 0x%llx", (long long)vol->nr_clusters);
      /*
       * On an architecture where unsigned long is 32-bits, we restrict the
       * volume size to 2TiB (2^41). On a 64-bit architecture, the compiler
       * will hopefully optimize the whole check away.
       */
      if (sizeof(unsigned long) < 8) {
            if ((ll << vol->cluster_size_bits) >= (1ULL << 41)) {
                  ntfs_error(vol->sb, "Volume size (%lluTiB) is too "
                              "large for this architecture.  "
                              "Maximum supported is 2TiB.  Sorry.",
                              (unsigned long long)ll >> (40 -
                              vol->cluster_size_bits));
                  return FALSE;
            }
      }
      ll = sle64_to_cpu(b->mft_lcn);
      if (ll >= vol->nr_clusters) {
            ntfs_error(vol->sb, "MFT LCN (%lli, 0x%llx) is beyond end of "
                        "volume.  Weird.", (unsigned long long)ll,
                        (unsigned long long)ll);
            return FALSE;
      }
      vol->mft_lcn = ll;
      ntfs_debug("vol->mft_lcn = 0x%llx", (long long)vol->mft_lcn);
      ll = sle64_to_cpu(b->mftmirr_lcn);
      if (ll >= vol->nr_clusters) {
            ntfs_error(vol->sb, "MFTMirr LCN (%lli, 0x%llx) is beyond end "
                        "of volume.  Weird.", (unsigned long long)ll,
                        (unsigned long long)ll);
            return FALSE;
      }
      vol->mftmirr_lcn = ll;
      ntfs_debug("vol->mftmirr_lcn = 0x%llx", (long long)vol->mftmirr_lcn);
#ifdef NTFS_RW
      /*
       * Work out the size of the mft mirror in number of mft records. If the
       * cluster size is less than or equal to the size taken by four mft
       * records, the mft mirror stores the first four mft records. If the
       * cluster size is bigger than the size taken by four mft records, the
       * mft mirror contains as many mft records as will fit into one
       * cluster.
       */
      if (vol->cluster_size <= (4 << vol->mft_record_size_bits))
            vol->mftmirr_size = 4;
      else
            vol->mftmirr_size = vol->cluster_size >>
                        vol->mft_record_size_bits;
      ntfs_debug("vol->mftmirr_size = %i", vol->mftmirr_size);
#endif /* NTFS_RW */
      vol->serial_no = le64_to_cpu(b->volume_serial_number);
      ntfs_debug("vol->serial_no = 0x%llx",
                  (unsigned long long)vol->serial_no);
      return TRUE;
}

/**
 * ntfs_setup_allocators - initialize the cluster and mft allocators
 * @vol:    volume structure for which to setup the allocators
 *
 * Setup the cluster (lcn) and mft allocators to the starting values.
 */
static void ntfs_setup_allocators(ntfs_volume *vol)
{
#ifdef NTFS_RW
      LCN mft_zone_size, mft_lcn;
#endif /* NTFS_RW */

      ntfs_debug("vol->mft_zone_multiplier = 0x%x",
                  vol->mft_zone_multiplier);
#ifdef NTFS_RW
      /* Determine the size of the MFT zone. */
      mft_zone_size = vol->nr_clusters;
      switch (vol->mft_zone_multiplier) {  /* % of volume size in clusters */
      case 4:
            mft_zone_size >>= 1;                /* 50%   */
            break;
      case 3:
            mft_zone_size = (mft_zone_size +
                        (mft_zone_size >> 1)) >> 2;   /* 37.5% */
            break;
      case 2:
            mft_zone_size >>= 2;                /* 25%   */
            break;
      /* case 1: */
      default:
            mft_zone_size >>= 3;                /* 12.5% */
            break;
      }
      /* Setup the mft zone. */
      vol->mft_zone_start = vol->mft_zone_pos = vol->mft_lcn;
      ntfs_debug("vol->mft_zone_pos = 0x%llx",
                  (unsigned long long)vol->mft_zone_pos);
      /*
       * Calculate the mft_lcn for an unmodified NTFS volume (see mkntfs
       * source) and if the actual mft_lcn is in the expected place or even
       * further to the front of the volume, extend the mft_zone to cover the
       * beginning of the volume as well.  This is in order to protect the
       * area reserved for the mft bitmap as well within the mft_zone itself.
       * On non-standard volumes we do not protect it as the overhead would
       * be higher than the speed increase we would get by doing it.
       */
      mft_lcn = (8192 + 2 * vol->cluster_size - 1) / vol->cluster_size;
      if (mft_lcn * vol->cluster_size < 16 * 1024)
            mft_lcn = (16 * 1024 + vol->cluster_size - 1) /
                        vol->cluster_size;
      if (vol->mft_zone_start <= mft_lcn)
            vol->mft_zone_start = 0;
      ntfs_debug("vol->mft_zone_start = 0x%llx",
                  (unsigned long long)vol->mft_zone_start);
      /*
       * Need to cap the mft zone on non-standard volumes so that it does
       * not point outside the boundaries of the volume.  We do this by
       * halving the zone size until we are inside the volume.
       */
      vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
      while (vol->mft_zone_end >= vol->nr_clusters) {
            mft_zone_size >>= 1;
            vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
      }
      ntfs_debug("vol->mft_zone_end = 0x%llx",
                  (unsigned long long)vol->mft_zone_end);
      /*
       * Set the current position within each data zone to the start of the
       * respective zone.
       */
      vol->data1_zone_pos = vol->mft_zone_end;
      ntfs_debug("vol->data1_zone_pos = 0x%llx",
                  (unsigned long long)vol->data1_zone_pos);
      vol->data2_zone_pos = 0;
      ntfs_debug("vol->data2_zone_pos = 0x%llx",
                  (unsigned long long)vol->data2_zone_pos);

      /* Set the mft data allocation position to mft record 24. */
      vol->mft_data_pos = 24;
      ntfs_debug("vol->mft_data_pos = 0x%llx",
                  (unsigned long long)vol->mft_data_pos);
#endif /* NTFS_RW */
}

#ifdef NTFS_RW

/**
 * load_and_init_mft_mirror - load and setup the mft mirror inode for a volume
 * @vol:    ntfs super block describing device whose mft mirror to load
 *
 * Return TRUE on success or FALSE on error.
 */
static BOOL load_and_init_mft_mirror(ntfs_volume *vol)
{
      struct inode *tmp_ino;
      ntfs_inode *tmp_ni;

      ntfs_debug("Entering.");
      /* Get mft mirror inode. */
      tmp_ino = ntfs_iget(vol->sb, FILE_MFTMirr);
      if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
            if (!IS_ERR(tmp_ino))
                  iput(tmp_ino);
            /* Caller will display error message. */
            return FALSE;
      }
      /*
       * Re-initialize some specifics about $MFTMirr's inode as
       * ntfs_read_inode() will have set up the default ones.
       */
      /* Set uid and gid to root. */
      tmp_ino->i_uid = tmp_ino->i_gid = 0;
      /* Regular file.  No access for anyone. */
      tmp_ino->i_mode = S_IFREG;
      /* No VFS initiated operations allowed for $MFTMirr. */
      tmp_ino->i_op = &ntfs_empty_inode_ops;
      tmp_ino->i_fop = &ntfs_empty_file_ops;
      /* Put in our special address space operations. */
      tmp_ino->i_mapping->a_ops = &ntfs_mst_aops;
      tmp_ni = NTFS_I(tmp_ino);
      /* The $MFTMirr, like the $MFT is multi sector transfer protected. */
      NInoSetMstProtected(tmp_ni);
      NInoSetSparseDisabled(tmp_ni);
      /*
       * Set up our little cheat allowing us to reuse the async read io
       * completion handler for directories.
       */
      tmp_ni->itype.index.block_size = vol->mft_record_size;
      tmp_ni->itype.index.block_size_bits = vol->mft_record_size_bits;
      vol->mftmirr_ino = tmp_ino;
      ntfs_debug("Done.");
      return TRUE;
}

/**
 * check_mft_mirror - compare contents of the mft mirror with the mft
 * @vol:    ntfs super block describing device whose mft mirror to check
 *
 * Return TRUE on success or FALSE on error.
 *
 * Note, this function also results in the mft mirror runlist being completely
 * mapped into memory.  The mft mirror write code requires this and will BUG()
 * should it find an unmapped runlist element.
 */
static BOOL check_mft_mirror(ntfs_volume *vol)
{
      struct super_block *sb = vol->sb;
      ntfs_inode *mirr_ni;
      struct page *mft_page, *mirr_page;
      u8 *kmft, *kmirr;
      runlist_element *rl, rl2[2];
      pgoff_t index;
      int mrecs_per_page, i;

      ntfs_debug("Entering.");
      /* Compare contents of $MFT and $MFTMirr. */
      mrecs_per_page = PAGE_CACHE_SIZE / vol->mft_record_size;
      BUG_ON(!mrecs_per_page);
      BUG_ON(!vol->mftmirr_size);
      mft_page = mirr_page = NULL;
      kmft = kmirr = NULL;
      index = i = 0;
      do {
            u32 bytes;

            /* Switch pages if necessary. */
            if (!(i % mrecs_per_page)) {
                  if (index) {
                        ntfs_unmap_page(mft_page);
                        ntfs_unmap_page(mirr_page);
                  }
                  /* Get the $MFT page. */
                  mft_page = ntfs_map_page(vol->mft_ino->i_mapping,
                              index);
                  if (IS_ERR(mft_page)) {
                        ntfs_error(sb, "Failed to read $MFT.");
                        return FALSE;
                  }
                  kmft = page_address(mft_page);
                  /* Get the $MFTMirr page. */
                  mirr_page = ntfs_map_page(vol->mftmirr_ino->i_mapping,
                              index);
                  if (IS_ERR(mirr_page)) {
                        ntfs_error(sb, "Failed to read $MFTMirr.");
                        goto mft_unmap_out;
                  }
                  kmirr = page_address(mirr_page);
                  ++index;
            }
            /* Do not check the record if it is not in use. */
            if (((MFT_RECORD*)kmft)->flags & MFT_RECORD_IN_USE) {
                  /* Make sure the record is ok. */
                  if (ntfs_is_baad_recordp((le32*)kmft)) {
                        ntfs_error(sb, "Incomplete multi sector "
                                    "transfer detected in mft "
                                    "record %i.", i);
mm_unmap_out:
                        ntfs_unmap_page(mirr_page);
mft_unmap_out:
                        ntfs_unmap_page(mft_page);
                        return FALSE;
                  }
            }
            /* Do not check the mirror record if it is not in use. */
            if (((MFT_RECORD*)kmirr)->flags & MFT_RECORD_IN_USE) {
                  if (ntfs_is_baad_recordp((le32*)kmirr)) {
                        ntfs_error(sb, "Incomplete multi sector "
                                    "transfer detected in mft "
                                    "mirror record %i.", i);
                        goto mm_unmap_out;
                  }
            }
            /* Get the amount of data in the current record. */
            bytes = le32_to_cpu(((MFT_RECORD*)kmft)->bytes_in_use);
            if (bytes < sizeof(MFT_RECORD_OLD) ||
                        bytes > vol->mft_record_size ||
                        ntfs_is_baad_recordp((le32*)kmft)) {
                  bytes = le32_to_cpu(((MFT_RECORD*)kmirr)->bytes_in_use);
                  if (bytes < sizeof(MFT_RECORD_OLD) ||
                              bytes > vol->mft_record_size ||
                              ntfs_is_baad_recordp((le32*)kmirr))
                        bytes = vol->mft_record_size;
            }
            /* Compare the two records. */
            if (memcmp(kmft, kmirr, bytes)) {
                  ntfs_error(sb, "$MFT and $MFTMirr (record %i) do not "
                              "match.  Run ntfsfix or chkdsk.", i);
                  goto mm_unmap_out;
            }
            kmft += vol->mft_record_size;
            kmirr += vol->mft_record_size;
      } while (++i < vol->mftmirr_size);
      /* Release the last pages. */
      ntfs_unmap_page(mft_page);
      ntfs_unmap_page(mirr_page);

      /* Construct the mft mirror runlist by hand. */
      rl2[0].vcn = 0;
      rl2[0].lcn = vol->mftmirr_lcn;
      rl2[0].length = (vol->mftmirr_size * vol->mft_record_size +
                  vol->cluster_size - 1) / vol->cluster_size;
      rl2[1].vcn = rl2[0].length;
      rl2[1].lcn = LCN_ENOENT;
      rl2[1].length = 0;
      /*
       * Because we have just read all of the mft mirror, we know we have
       * mapped the full runlist for it.
       */
      mirr_ni = NTFS_I(vol->mftmirr_ino);
      down_read(&mirr_ni->runlist.lock);
      rl = mirr_ni->runlist.rl;
      /* Compare the two runlists.  They must be identical. */
      i = 0;
      do {
            if (rl2[i].vcn != rl[i].vcn || rl2[i].lcn != rl[i].lcn ||
                        rl2[i].length != rl[i].length) {
                  ntfs_error(sb, "$MFTMirr location mismatch.  "
                              "Run chkdsk.");
                  up_read(&mirr_ni->runlist.lock);
                  return FALSE;
            }
      } while (rl2[i++].length);
      up_read(&mirr_ni->runlist.lock);
      ntfs_debug("Done.");
      return TRUE;
}

/**
 * load_and_check_logfile - load and check the logfile inode for a volume
 * @vol:    ntfs super block describing device whose logfile to load
 *
 * Return TRUE on success or FALSE on error.
 */
static BOOL load_and_check_logfile(ntfs_volume *vol,
            RESTART_PAGE_HEADER **rp)
{
      struct inode *tmp_ino;

      ntfs_debug("Entering.");
      tmp_ino = ntfs_iget(vol->sb, FILE_LogFile);
      if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
            if (!IS_ERR(tmp_ino))
                  iput(tmp_ino);
            /* Caller will display error message. */
            return FALSE;
      }
      if (!ntfs_check_logfile(tmp_ino, rp)) {
            iput(tmp_ino);
            /* ntfs_check_logfile() will have displayed error output. */
            return FALSE;
      }
      NInoSetSparseDisabled(NTFS_I(tmp_ino));
      vol->logfile_ino = tmp_ino;
      ntfs_debug("Done.");
      return TRUE;
}

#define NTFS_HIBERFIL_HEADER_SIZE   4096

/**
 * check_windows_hibernation_status - check if Windows is suspended on a volume
 * @vol:    ntfs super block of device to check
 *
 * Check if Windows is hibernated on the ntfs volume @vol.  This is done by
 * looking for the file hiberfil.sys in the root directory of the volume.  If
 * the file is not present Windows is definitely not suspended.
 *
 * If hiberfil.sys exists and is less than 4kiB in size it means Windows is
 * definitely suspended (this volume is not the system volume).  Caveat:  on a
 * system with many volumes it is possible that the < 4kiB check is bogus but
 * for now this should do fine.
 *
 * If hiberfil.sys exists and is larger than 4kiB in size, we need to read the
 * hiberfil header (which is the first 4kiB).  If this begins with "hibr",
 * Windows is definitely suspended.  If it is completely full of zeroes,
 * Windows is definitely not hibernated.  Any other case is treated as if
 * Windows is suspended.  This caters for the above mentioned caveat of a
 * system with many volumes where no "hibr" magic would be present and there is
 * no zero header.
 *
 * Return 0 if Windows is not hibernated on the volume, >0 if Windows is
 * hibernated on the volume, and -errno on error.
 */
static int check_windows_hibernation_status(ntfs_volume *vol)
{
      MFT_REF mref;
      struct inode *vi;
      ntfs_inode *ni;
      struct page *page;
      u32 *kaddr, *kend;
      ntfs_name *name = NULL;
      int ret = 1;
      static const ntfschar hiberfil[13] = { const_cpu_to_le16('h'),
                  const_cpu_to_le16('i'), const_cpu_to_le16('b'),
                  const_cpu_to_le16('e'), const_cpu_to_le16('r'),
                  const_cpu_to_le16('f'), const_cpu_to_le16('i'),
                  const_cpu_to_le16('l'), const_cpu_to_le16('.'),
                  const_cpu_to_le16('s'), const_cpu_to_le16('y'),
                  const_cpu_to_le16('s'), 0 };

      ntfs_debug("Entering.");
      /*
       * Find the inode number for the hibernation file by looking up the
       * filename hiberfil.sys in the root directory.
       */
      mutex_lock(&vol->root_ino->i_mutex);
      mref = ntfs_lookup_inode_by_name(NTFS_I(vol->root_ino), hiberfil, 12,
                  &name);
      mutex_unlock(&vol->root_ino->i_mutex);
      if (IS_ERR_MREF(mref)) {
            ret = MREF_ERR(mref);
            /* If the file does not exist, Windows is not hibernated. */
            if (ret == -ENOENT) {
                  ntfs_debug("hiberfil.sys not present.  Windows is not "
                              "hibernated on the volume.");
                  return 0;
            }
            /* A real error occured. */
            ntfs_error(vol->sb, "Failed to find inode number for "
                        "hiberfil.sys.");
            return ret;
      }
      /* We do not care for the type of match that was found. */
      kfree(name);
      /* Get the inode. */
      vi = ntfs_iget(vol->sb, MREF(mref));
      if (IS_ERR(vi) || is_bad_inode(vi)) {
            if (!IS_ERR(vi))
                  iput(vi);
            ntfs_error(vol->sb, "Failed to load hiberfil.sys.");
            return IS_ERR(vi) ? PTR_ERR(vi) : -EIO;
      }
      if (unlikely(i_size_read(vi) < NTFS_HIBERFIL_HEADER_SIZE)) {
            ntfs_debug("hiberfil.sys is smaller than 4kiB (0x%llx).  "
                        "Windows is hibernated on the volume.  This "
                        "is not the system volume.", i_size_read(vi));
            goto iput_out;
      }
      ni = NTFS_I(vi);
      page = ntfs_map_page(vi->i_mapping, 0);
      if (IS_ERR(page)) {
            ntfs_error(vol->sb, "Failed to read from hiberfil.sys.");
            ret = PTR_ERR(page);
            goto iput_out;
      }
      kaddr = (u32*)page_address(page);
      if (*(le32*)kaddr == const_cpu_to_le32(0x72626968)/*'hibr'*/) {
            ntfs_debug("Magic \"hibr\" found in hiberfil.sys.  Windows is "
                        "hibernated on the volume.  This is the "
                        "system volume.");
            goto unm_iput_out;
      }
      kend = kaddr + NTFS_HIBERFIL_HEADER_SIZE/sizeof(*kaddr);
      do {
            if (unlikely(*kaddr)) {
                  ntfs_debug("hiberfil.sys is larger than 4kiB "
                              "(0x%llx), does not contain the "
                              "\"hibr\" magic, and does not have a "
                              "zero header.  Windows is hibernated "
                              "on the volume.  This is not the "
                              "system volume.", i_size_read(vi));
                  goto unm_iput_out;
            }
      } while (++kaddr < kend);
      ntfs_debug("hiberfil.sys contains a zero header.  Windows is not "
                  "hibernated on the volume.  This is the system "
                  "volume.");
      ret = 0;
unm_iput_out:
      ntfs_unmap_page(page);
iput_out:
      iput(vi);
      return ret;
}

/**
 * load_and_init_quota - load and setup the quota file for a volume if present
 * @vol:    ntfs super block describing device whose quota file to load
 *
 * Return TRUE on success or FALSE on error.  If $Quota is not present, we
 * leave vol->quota_ino as NULL and return success.
 */
static BOOL load_and_init_quota(ntfs_volume *vol)
{
      MFT_REF mref;
      struct inode *tmp_ino;
      ntfs_name *name = NULL;
      static const ntfschar Quota[7] = { const_cpu_to_le16('$'),
                  const_cpu_to_le16('Q'), const_cpu_to_le16('u'),
                  const_cpu_to_le16('o'), const_cpu_to_le16('t'),
                  const_cpu_to_le16('a'), 0 };
      static ntfschar Q[3] = { const_cpu_to_le16('$'),
                  const_cpu_to_le16('Q'), 0 };

      ntfs_debug("Entering.");
      /*
       * Find the inode number for the quota file by looking up the filename
       * $Quota in the extended system files directory $Extend.
       */
      mutex_lock(&vol->extend_ino->i_mutex);
      mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), Quota, 6,
                  &name);
      mutex_unlock(&vol->extend_ino->i_mutex);
      if (IS_ERR_MREF(mref)) {
            /*
             * If the file does not exist, quotas are disabled and have
             * never been enabled on this volume, just return success.
             */
            if (MREF_ERR(mref) == -ENOENT) {
                  ntfs_debug("$Quota not present.  Volume does not have "
                              "quotas enabled.");
                  /*
                   * No need to try to set quotas out of date if they are
                   * not enabled.
                   */
                  NVolSetQuotaOutOfDate(vol);
                  return TRUE;
            }
            /* A real error occured. */
            ntfs_error(vol->sb, "Failed to find inode number for $Quota.");
            return FALSE;
      }
      /* We do not care for the type of match that was found. */
      kfree(name);
      /* Get the inode. */
      tmp_ino = ntfs_iget(vol->sb, MREF(mref));
      if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
            if (!IS_ERR(tmp_ino))
                  iput(tmp_ino);
            ntfs_error(vol->sb, "Failed to load $Quota.");
            return FALSE;
      }
      vol->quota_ino = tmp_ino;
      /* Get the $Q index allocation attribute. */
      tmp_ino = ntfs_index_iget(vol->quota_ino, Q, 2);
      if (IS_ERR(tmp_ino)) {
            ntfs_error(vol->sb, "Failed to load $Quota/$Q index.");
            return FALSE;
      }
      vol->quota_q_ino = tmp_ino;
      ntfs_debug("Done.");
      return TRUE;
}

/**
 * load_and_init_usnjrnl - load and setup the transaction log if present
 * @vol:    ntfs super block describing device whose usnjrnl file to load
 *
 * Return TRUE on success or FALSE on error.
 *
 * If $UsnJrnl is not present or in the process of being disabled, we set
 * NVolUsnJrnlStamped() and return success.
 *
 * If the $UsnJrnl $DATA/$J attribute has a size equal to the lowest valid usn,
 * i.e. transaction logging has only just been enabled or the journal has been
 * stamped and nothing has been logged since, we also set NVolUsnJrnlStamped()
 * and return success.
 */
static BOOL load_and_init_usnjrnl(ntfs_volume *vol)
{
      MFT_REF mref;
      struct inode *tmp_ino;
      ntfs_inode *tmp_ni;
      struct page *page;
      ntfs_name *name = NULL;
      USN_HEADER *uh;
      static const ntfschar UsnJrnl[9] = { const_cpu_to_le16('$'),
                  const_cpu_to_le16('U'), const_cpu_to_le16('s'),
                  const_cpu_to_le16('n'), const_cpu_to_le16('J'),
                  const_cpu_to_le16('r'), const_cpu_to_le16('n'),
                  const_cpu_to_le16('l'), 0 };
      static ntfschar Max[5] = { const_cpu_to_le16('$'),
                  const_cpu_to_le16('M'), const_cpu_to_le16('a'),
                  const_cpu_to_le16('x'), 0 };
      static ntfschar J[3] = { const_cpu_to_le16('$'),
                  const_cpu_to_le16('J'), 0 };

      ntfs_debug("Entering.");
      /*
       * Find the inode number for the transaction log file by looking up the
       * filename $UsnJrnl in the extended system files directory $Extend.
       */
      mutex_lock(&vol->extend_ino->i_mutex);
      mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), UsnJrnl, 8,
                  &name);
      mutex_unlock(&vol->extend_ino->i_mutex);
      if (IS_ERR_MREF(mref)) {
            /*
             * If the file does not exist, transaction logging is disabled,
             * just return success.
             */
            if (MREF_ERR(mref) == -ENOENT) {
                  ntfs_debug("$UsnJrnl not present.  Volume does not "
                              "have transaction logging enabled.");
not_enabled:
                  /*
                   * No need to try to stamp the transaction log if
                   * transaction logging is not enabled.
                   */
                  NVolSetUsnJrnlStamped(vol);
                  return TRUE;
            }
            /* A real error occured. */
            ntfs_error(vol->sb, "Failed to find inode number for "
                        "$UsnJrnl.");
            return FALSE;
      }
      /* We do not care for the type of match that was found. */
      kfree(name);
      /* Get the inode. */
      tmp_ino = ntfs_iget(vol->sb, MREF(mref));
      if (unlikely(IS_ERR(tmp_ino) || is_bad_inode(tmp_ino))) {
            if (!IS_ERR(tmp_ino))
                  iput(tmp_ino);
            ntfs_error(vol->sb, "Failed to load $UsnJrnl.");
            return FALSE;
      }
      vol->usnjrnl_ino = tmp_ino;
      /*
       * If the transaction log is in the process of being deleted, we can
       * ignore it.
       */
      if (unlikely(vol->vol_flags & VOLUME_DELETE_USN_UNDERWAY)) {
            ntfs_debug("$UsnJrnl in the process of being disabled.  "
                        "Volume does not have transaction logging "
                        "enabled.");
            goto not_enabled;
      }
      /* Get the $DATA/$Max attribute. */
      tmp_ino = ntfs_attr_iget(vol->usnjrnl_ino, AT_DATA, Max, 4);
      if (IS_ERR(tmp_ino)) {
            ntfs_error(vol->sb, "Failed to load $UsnJrnl/$DATA/$Max "
                        "attribute.");
            return FALSE;
      }
      vol->usnjrnl_max_ino = tmp_ino;
      if (unlikely(i_size_read(tmp_ino) < sizeof(USN_HEADER))) {
            ntfs_error(vol->sb, "Found corrupt $UsnJrnl/$DATA/$Max "
                        "attribute (size is 0x%llx but should be at "
                        "least 0x%zx bytes).", i_size_read(tmp_ino),
                        sizeof(USN_HEADER));
            return FALSE;
      }
      /* Get the $DATA/$J attribute. */
      tmp_ino = ntfs_attr_iget(vol->usnjrnl_ino, AT_DATA, J, 2);
      if (IS_ERR(tmp_ino)) {
            ntfs_error(vol->sb, "Failed to load $UsnJrnl/$DATA/$J "
                        "attribute.");
            return FALSE;
      }
      vol->usnjrnl_j_ino = tmp_ino;
      /* Verify $J is non-resident and sparse. */
      tmp_ni = NTFS_I(vol->usnjrnl_j_ino);
      if (unlikely(!NInoNonResident(tmp_ni) || !NInoSparse(tmp_ni))) {
            ntfs_error(vol->sb, "$UsnJrnl/$DATA/$J attribute is resident "
                        "and/or not sparse.");
            return FALSE;
      }
      /* Read the USN_HEADER from $DATA/$Max. */
      page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
      if (IS_ERR(page)) {
            ntfs_error(vol->sb, "Failed to read from $UsnJrnl/$DATA/$Max "
                        "attribute.");
            return FALSE;
      }
      uh = (USN_HEADER*)page_address(page);
      /* Sanity check the $Max. */
      if (unlikely(sle64_to_cpu(uh->allocation_delta) >
                  sle64_to_cpu(uh->maximum_size))) {
            ntfs_error(vol->sb, "Allocation delta (0x%llx) exceeds "
                        "maximum size (0x%llx).  $UsnJrnl is corrupt.",
                        (long long)sle64_to_cpu(uh->allocation_delta),
                        (long long)sle64_to_cpu(uh->maximum_size));
            ntfs_unmap_page(page);
            return FALSE;
      }
      /*
       * If the transaction log has been stamped and nothing has been written
       * to it since, we do not need to stamp it.
       */
      if (unlikely(sle64_to_cpu(uh->lowest_valid_usn) >=
                  i_size_read(vol->usnjrnl_j_ino))) {
            if (likely(sle64_to_cpu(uh->lowest_valid_usn) ==
                        i_size_read(vol->usnjrnl_j_ino))) {
                  ntfs_unmap_page(page);
                  ntfs_debug("$UsnJrnl is enabled but nothing has been "
                              "logged since it was last stamped.  "
                              "Treating this as if the volume does "
                              "not have transaction logging "
                              "enabled.");
                  goto not_enabled;
            }
            ntfs_error(vol->sb, "$UsnJrnl has lowest valid usn (0x%llx) "
                        "which is out of bounds (0x%llx).  $UsnJrnl "
                        "is corrupt.",
                        (long long)sle64_to_cpu(uh->lowest_valid_usn),
                        i_size_read(vol->usnjrnl_j_ino));
            ntfs_unmap_page(page);
            return FALSE;
      }
      ntfs_unmap_page(page);
      ntfs_debug("Done.");
      return TRUE;
}

/**
 * load_and_init_attrdef - load the attribute definitions table for a volume
 * @vol:    ntfs super block describing device whose attrdef to load
 *
 * Return TRUE on success or FALSE on error.
 */
static BOOL load_and_init_attrdef(ntfs_volume *vol)
{
      loff_t i_size;
      struct super_block *sb = vol->sb;
      struct inode *ino;
      struct page *page;
      pgoff_t index, max_index;
      unsigned int size;

      ntfs_debug("Entering.");
      /* Read attrdef table and setup vol->attrdef and vol->attrdef_size. */
      ino = ntfs_iget(sb, FILE_AttrDef);
      if (IS_ERR(ino) || is_bad_inode(ino)) {
            if (!IS_ERR(ino))
                  iput(ino);
            goto failed;
      }
      NInoSetSparseDisabled(NTFS_I(ino));
      /* The size of FILE_AttrDef must be above 0 and fit inside 31 bits. */
      i_size = i_size_read(ino);
      if (i_size <= 0 || i_size > 0x7fffffff)
            goto iput_failed;
      vol->attrdef = (ATTR_DEF*)ntfs_malloc_nofs(i_size);
      if (!vol->attrdef)
            goto iput_failed;
      index = 0;
      max_index = i_size >> PAGE_CACHE_SHIFT;
      size = PAGE_CACHE_SIZE;
      while (index < max_index) {
            /* Read the attrdef table and copy it into the linear buffer. */
read_partial_attrdef_page:
            page = ntfs_map_page(ino->i_mapping, index);
            if (IS_ERR(page))
                  goto free_iput_failed;
            memcpy((u8*)vol->attrdef + (index++ << PAGE_CACHE_SHIFT),
                        page_address(page), size);
            ntfs_unmap_page(page);
      };
      if (size == PAGE_CACHE_SIZE) {
            size = i_size & ~PAGE_CACHE_MASK;
            if (size)
                  goto read_partial_attrdef_page;
      }
      vol->attrdef_size = i_size;
      ntfs_debug("Read %llu bytes from $AttrDef.", i_size);
      iput(ino);
      return TRUE;
free_iput_failed:
      ntfs_free(vol->attrdef);
      vol->attrdef = NULL;
iput_failed:
      iput(ino);
failed:
      ntfs_error(sb, "Failed to initialize attribute definition table.");
      return FALSE;
}

#endif /* NTFS_RW */

/**
 * load_and_init_upcase - load the upcase table for an ntfs volume
 * @vol:    ntfs super block describing device whose upcase to load
 *
 * Return TRUE on success or FALSE on error.
 */
static BOOL load_and_init_upcase(ntfs_volume *vol)
{
      loff_t i_size;
      struct super_block *sb = vol->sb;
      struct inode *ino;
      struct page *page;
      pgoff_t index, max_index;
      unsigned int size;
      int i, max;

      ntfs_debug("Entering.");
      /* Read upcase table and setup vol->upcase and vol->upcase_len. */
      ino = ntfs_iget(sb, FILE_UpCase);
      if (IS_ERR(ino) || is_bad_inode(ino)) {
            if (!IS_ERR(ino))
                  iput(ino);
            goto upcase_failed;
      }
      /*
       * The upcase size must not be above 64k Unicode characters, must not
       * be zero and must be a multiple of sizeof(ntfschar).
       */
      i_size = i_size_read(ino);
      if (!i_size || i_size & (sizeof(ntfschar) - 1) ||
                  i_size > 64ULL * 1024 * sizeof(ntfschar))
            goto iput_upcase_failed;
      vol->upcase = (ntfschar*)ntfs_malloc_nofs(i_size);
      if (!vol->upcase)
            goto iput_upcase_failed;
      index = 0;
      max_index = i_size >> PAGE_CACHE_SHIFT;
      size = PAGE_CACHE_SIZE;
      while (index < max_index) {
            /* Read the upcase table and copy it into the linear buffer. */
read_partial_upcase_page:
            page = ntfs_map_page(ino->i_mapping, index);
            if (IS_ERR(page))
                  goto iput_upcase_failed;
            memcpy((char*)vol->upcase + (index++ << PAGE_CACHE_SHIFT),
                        page_address(page), size);
            ntfs_unmap_page(page);
      };
      if (size == PAGE_CACHE_SIZE) {
            size = i_size & ~PAGE_CACHE_MASK;
            if (size)
                  goto read_partial_upcase_page;
      }
      vol->upcase_len = i_size >> UCHAR_T_SIZE_BITS;
      ntfs_debug("Read %llu bytes from $UpCase (expected %zu bytes).",
                  i_size, 64 * 1024 * sizeof(ntfschar));
      iput(ino);
      mutex_lock(&ntfs_lock);
      if (!default_upcase) {
            ntfs_debug("Using volume specified $UpCase since default is "
                        "not present.");
            mutex_unlock(&ntfs_lock);
            return TRUE;
      }
      max = default_upcase_len;
      if (max > vol->upcase_len)
            max = vol->upcase_len;
      for (i = 0; i < max; i++)
            if (vol->upcase[i] != default_upcase[i])
                  break;
      if (i == max) {
            ntfs_free(vol->upcase);
            vol->upcase = default_upcase;
            vol->upcase_len = max;
            ntfs_nr_upcase_users++;
            mutex_unlock(&ntfs_lock);
            ntfs_debug("Volume specified $UpCase matches default. Using "
                        "default.");
            return TRUE;
      }
      mutex_unlock(&ntfs_lock);
      ntfs_debug("Using volume specified $UpCase since it does not match "
                  "the default.");
      return TRUE;
iput_upcase_failed:
      iput(ino);
      ntfs_free(vol->upcase);
      vol->upcase = NULL;
upcase_failed:
      mutex_lock(&ntfs_lock);
      if (default_upcase) {
            vol->upcase = default_upcase;
            vol->upcase_len = default_upcase_len;
            ntfs_nr_upcase_users++;
            mutex_unlock(&ntfs_lock);
            ntfs_error(sb, "Failed to load $UpCase from the volume. Using "
                        "default.");
            return TRUE;
      }
      mutex_unlock(&ntfs_lock);
      ntfs_error(sb, "Failed to initialize upcase table.");
      return FALSE;
}

/*
 * The lcn and mft bitmap inodes are NTFS-internal inodes with
 * their own special locking rules:
 */
static struct lock_class_key
      lcnbmp_runlist_lock_key, lcnbmp_mrec_lock_key,
      mftbmp_runlist_lock_key, mftbmp_mrec_lock_key;

/**
 * load_system_files - open the system files using normal functions
 * @vol:    ntfs super block describing device whose system files to load
 *
 * Open the system files with normal access functions and complete setting up
 * the ntfs super block @vol.
 *
 * Return TRUE on success or FALSE on error.
 */
static BOOL load_system_files(ntfs_volume *vol)
{
      struct super_block *sb = vol->sb;
      MFT_RECORD *m;
      VOLUME_INFORMATION *vi;
      ntfs_attr_search_ctx *ctx;
#ifdef NTFS_RW
      RESTART_PAGE_HEADER *rp;
      int err;
#endif /* NTFS_RW */

      ntfs_debug("Entering.");
#ifdef NTFS_RW
      /* Get mft mirror inode compare the contents of $MFT and $MFTMirr. */
      if (!load_and_init_mft_mirror(vol) || !check_mft_mirror(vol)) {
            static const char *es1 = "Failed to load $MFTMirr";
            static const char *es2 = "$MFTMirr does not match $MFT";
            static const char *es3 = ".  Run ntfsfix and/or chkdsk.";

            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    !vol->mftmirr_ino ? es1 : es2,
                                    es3);
                        goto iput_mirr_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s",
                              !vol->mftmirr_ino ? es1 : es2, es3);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s",
                              !vol->mftmirr_ino ? es1 : es2, es3);
            /* This will prevent a read-write remount. */
            NVolSetErrors(vol);
      }
#endif /* NTFS_RW */
      /* Get mft bitmap attribute inode. */
      vol->mftbmp_ino = ntfs_attr_iget(vol->mft_ino, AT_BITMAP, NULL, 0);
      if (IS_ERR(vol->mftbmp_ino)) {
            ntfs_error(sb, "Failed to load $MFT/$BITMAP attribute.");
            goto iput_mirr_err_out;
      }
      lockdep_set_class(&NTFS_I(vol->mftbmp_ino)->runlist.lock,
                     &mftbmp_runlist_lock_key);
      lockdep_set_class(&NTFS_I(vol->mftbmp_ino)->mrec_lock,
                     &mftbmp_mrec_lock_key);
      /* Read upcase table and setup @vol->upcase and @vol->upcase_len. */
      if (!load_and_init_upcase(vol))
            goto iput_mftbmp_err_out;
#ifdef NTFS_RW
      /*
       * Read attribute definitions table and setup @vol->attrdef and
       * @vol->attrdef_size.
       */
      if (!load_and_init_attrdef(vol))
            goto iput_upcase_err_out;
#endif /* NTFS_RW */
      /*
       * Get the cluster allocation bitmap inode and verify the size, no
       * need for any locking at this stage as we are already running
       * exclusively as we are mount in progress task.
       */
      vol->lcnbmp_ino = ntfs_iget(sb, FILE_Bitmap);
      if (IS_ERR(vol->lcnbmp_ino) || is_bad_inode(vol->lcnbmp_ino)) {
            if (!IS_ERR(vol->lcnbmp_ino))
                  iput(vol->lcnbmp_ino);
            goto bitmap_failed;
      }
      lockdep_set_class(&NTFS_I(vol->lcnbmp_ino)->runlist.lock,
                     &lcnbmp_runlist_lock_key);
      lockdep_set_class(&NTFS_I(vol->lcnbmp_ino)->mrec_lock,
                     &lcnbmp_mrec_lock_key);

      NInoSetSparseDisabled(NTFS_I(vol->lcnbmp_ino));
      if ((vol->nr_clusters + 7) >> 3 > i_size_read(vol->lcnbmp_ino)) {
            iput(vol->lcnbmp_ino);
bitmap_failed:
            ntfs_error(sb, "Failed to load $Bitmap.");
            goto iput_attrdef_err_out;
      }
      /*
       * Get the volume inode and setup our cache of the volume flags and
       * version.
       */
      vol->vol_ino = ntfs_iget(sb, FILE_Volume);
      if (IS_ERR(vol->vol_ino) || is_bad_inode(vol->vol_ino)) {
            if (!IS_ERR(vol->vol_ino))
                  iput(vol->vol_ino);
volume_failed:
            ntfs_error(sb, "Failed to load $Volume.");
            goto iput_lcnbmp_err_out;
      }
      m = map_mft_record(NTFS_I(vol->vol_ino));
      if (IS_ERR(m)) {
iput_volume_failed:
            iput(vol->vol_ino);
            goto volume_failed;
      }
      if (!(ctx = ntfs_attr_get_search_ctx(NTFS_I(vol->vol_ino), m))) {
            ntfs_error(sb, "Failed to get attribute search context.");
            goto get_ctx_vol_failed;
      }
      if (ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
                  ctx) || ctx->attr->non_resident || ctx->attr->flags) {
err_put_vol:
            ntfs_attr_put_search_ctx(ctx);
get_ctx_vol_failed:
            unmap_mft_record(NTFS_I(vol->vol_ino));
            goto iput_volume_failed;
      }
      vi = (VOLUME_INFORMATION*)((char*)ctx->attr +
                  le16_to_cpu(ctx->attr->data.resident.value_offset));
      /* Some bounds checks. */
      if ((u8*)vi < (u8*)ctx->attr || (u8*)vi +
                  le32_to_cpu(ctx->attr->data.resident.value_length) >
                  (u8*)ctx->attr + le32_to_cpu(ctx->attr->length))
            goto err_put_vol;
      /* Copy the volume flags and version to the ntfs_volume structure. */
      vol->vol_flags = vi->flags;
      vol->major_ver = vi->major_ver;
      vol->minor_ver = vi->minor_ver;
      ntfs_attr_put_search_ctx(ctx);
      unmap_mft_record(NTFS_I(vol->vol_ino));
      printk(KERN_INFO "NTFS volume version %i.%i.\n", vol->major_ver,
                  vol->minor_ver);
      if (vol->major_ver < 3 && NVolSparseEnabled(vol)) {
            ntfs_warning(vol->sb, "Disabling sparse support due to NTFS "
                        "volume version %i.%i (need at least version "
                        "3.0).", vol->major_ver, vol->minor_ver);
            NVolClearSparseEnabled(vol);
      }
#ifdef NTFS_RW
      /* Make sure that no unsupported volume flags are set. */
      if (vol->vol_flags & VOLUME_MUST_MOUNT_RO_MASK) {
            static const char *es1a = "Volume is dirty";
            static const char *es1b = "Volume has been modified by chkdsk";
            static const char *es1c = "Volume has unsupported flags set";
            static const char *es2a = ".  Run chkdsk and mount in Windows.";
            static const char *es2b = ".  Mount in Windows.";
            const char *es1, *es2;

            es2 = es2a;
            if (vol->vol_flags & VOLUME_IS_DIRTY)
                  es1 = es1a;
            else if (vol->vol_flags & VOLUME_MODIFIED_BY_CHKDSK) {
                  es1 = es1b;
                  es2 = es2b;
            } else {
                  es1 = es1c;
                  ntfs_warning(sb, "Unsupported volume flags 0x%x "
                              "encountered.",
                              (unsigned)le16_to_cpu(vol->vol_flags));
            }
            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    es1, es2);
                        goto iput_vol_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s", es1, es2);
            /*
             * Do not set NVolErrors() because ntfs_remount() re-checks the
             * flags which we need to do in case any flags have changed.
             */
      }
      /*
       * Get the inode for the logfile, check it and determine if the volume
       * was shutdown cleanly.
       */
      rp = NULL;
      if (!load_and_check_logfile(vol, &rp) ||
                  !ntfs_is_logfile_clean(vol->logfile_ino, rp)) {
            static const char *es1a = "Failed to load $LogFile";
            static const char *es1b = "$LogFile is not clean";
            static const char *es2 = ".  Mount in Windows.";
            const char *es1;

            es1 = !vol->logfile_ino ? es1a : es1b;
            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    es1, es2);
                        if (vol->logfile_ino) {
                              BUG_ON(!rp);
                              ntfs_free(rp);
                        }
                        goto iput_logfile_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s", es1, es2);
            /* This will prevent a read-write remount. */
            NVolSetErrors(vol);
      }
      ntfs_free(rp);
#endif /* NTFS_RW */
      /* Get the root directory inode so we can do path lookups. */
      vol->root_ino = ntfs_iget(sb, FILE_root);
      if (IS_ERR(vol->root_ino) || is_bad_inode(vol->root_ino)) {
            if (!IS_ERR(vol->root_ino))
                  iput(vol->root_ino);
            ntfs_error(sb, "Failed to load root directory.");
            goto iput_logfile_err_out;
      }
#ifdef NTFS_RW
      /*
       * Check if Windows is suspended to disk on the target volume.  If it
       * is hibernated, we must not write *anything* to the disk so set
       * NVolErrors() without setting the dirty volume flag and mount
       * read-only.  This will prevent read-write remounting and it will also
       * prevent all writes.
       */
      err = check_windows_hibernation_status(vol);
      if (unlikely(err)) {
            static const char *es1a = "Failed to determine if Windows is "
                        "hibernated";
            static const char *es1b = "Windows is hibernated";
            static const char *es2 = ".  Run chkdsk.";
            const char *es1;

            es1 = err < 0 ? es1a : es1b;
            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    es1, es2);
                        goto iput_root_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s", es1, es2);
            /* This will prevent a read-write remount. */
            NVolSetErrors(vol);
      }
      /* If (still) a read-write mount, mark the volume dirty. */
      if (!(sb->s_flags & MS_RDONLY) &&
                  ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY)) {
            static const char *es1 = "Failed to set dirty bit in volume "
                        "information flags";
            static const char *es2 = ".  Run chkdsk.";

            /* Convert to a read-only mount. */
            if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                        ON_ERRORS_CONTINUE))) {
                  ntfs_error(sb, "%s and neither on_errors=continue nor "
                              "on_errors=remount-ro was specified%s",
                              es1, es2);
                  goto iput_root_err_out;
            }
            ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            sb->s_flags |= MS_RDONLY;
            /*
             * Do not set NVolErrors() because ntfs_remount() might manage
             * to set the dirty flag in which case all would be well.
             */
      }
#if 0
      // TODO: Enable this code once we start modifying anything that is
      //     different between NTFS 1.2 and 3.x...
      /*
       * If (still) a read-write mount, set the NT4 compatibility flag on
       * newer NTFS version volumes.
       */
      if (!(sb->s_flags & MS_RDONLY) && (vol->major_ver > 1) &&
                  ntfs_set_volume_flags(vol, VOLUME_MOUNTED_ON_NT4)) {
            static const char *es1 = "Failed to set NT4 compatibility flag";
            static const char *es2 = ".  Run chkdsk.";

            /* Convert to a read-only mount. */
            if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                        ON_ERRORS_CONTINUE))) {
                  ntfs_error(sb, "%s and neither on_errors=continue nor "
                              "on_errors=remount-ro was specified%s",
                              es1, es2);
                  goto iput_root_err_out;
            }
            ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            sb->s_flags |= MS_RDONLY;
            NVolSetErrors(vol);
      }
#endif
      /* If (still) a read-write mount, empty the logfile. */
      if (!(sb->s_flags & MS_RDONLY) &&
                  !ntfs_empty_logfile(vol->logfile_ino)) {
            static const char *es1 = "Failed to empty $LogFile";
            static const char *es2 = ".  Mount in Windows.";

            /* Convert to a read-only mount. */
            if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                        ON_ERRORS_CONTINUE))) {
                  ntfs_error(sb, "%s and neither on_errors=continue nor "
                              "on_errors=remount-ro was specified%s",
                              es1, es2);
                  goto iput_root_err_out;
            }
            ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            sb->s_flags |= MS_RDONLY;
            NVolSetErrors(vol);
      }
#endif /* NTFS_RW */
      /* If on NTFS versions before 3.0, we are done. */
      if (unlikely(vol->major_ver < 3))
            return TRUE;
      /* NTFS 3.0+ specific initialization. */
      /* Get the security descriptors inode. */
      vol->secure_ino = ntfs_iget(sb, FILE_Secure);
      if (IS_ERR(vol->secure_ino) || is_bad_inode(vol->secure_ino)) {
            if (!IS_ERR(vol->secure_ino))
                  iput(vol->secure_ino);
            ntfs_error(sb, "Failed to load $Secure.");
            goto iput_root_err_out;
      }
      // TODO: Initialize security.
      /* Get the extended system files' directory inode. */
      vol->extend_ino = ntfs_iget(sb, FILE_Extend);
      if (IS_ERR(vol->extend_ino) || is_bad_inode(vol->extend_ino)) {
            if (!IS_ERR(vol->extend_ino))
                  iput(vol->extend_ino);
            ntfs_error(sb, "Failed to load $Extend.");
            goto iput_sec_err_out;
      }
#ifdef NTFS_RW
      /* Find the quota file, load it if present, and set it up. */
      if (!load_and_init_quota(vol)) {
            static const char *es1 = "Failed to load $Quota";
            static const char *es2 = ".  Run chkdsk.";

            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    es1, es2);
                        goto iput_quota_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s", es1, es2);
            /* This will prevent a read-write remount. */
            NVolSetErrors(vol);
      }
      /* If (still) a read-write mount, mark the quotas out of date. */
      if (!(sb->s_flags & MS_RDONLY) &&
                  !ntfs_mark_quotas_out_of_date(vol)) {
            static const char *es1 = "Failed to mark quotas out of date";
            static const char *es2 = ".  Run chkdsk.";

            /* Convert to a read-only mount. */
            if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                        ON_ERRORS_CONTINUE))) {
                  ntfs_error(sb, "%s and neither on_errors=continue nor "
                              "on_errors=remount-ro was specified%s",
                              es1, es2);
                  goto iput_quota_err_out;
            }
            ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            sb->s_flags |= MS_RDONLY;
            NVolSetErrors(vol);
      }
      /*
       * Find the transaction log file ($UsnJrnl), load it if present, check
       * it, and set it up.
       */
      if (!load_and_init_usnjrnl(vol)) {
            static const char *es1 = "Failed to load $UsnJrnl";
            static const char *es2 = ".  Run chkdsk.";

            /* If a read-write mount, convert it to a read-only mount. */
            if (!(sb->s_flags & MS_RDONLY)) {
                  if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                              ON_ERRORS_CONTINUE))) {
                        ntfs_error(sb, "%s and neither on_errors="
                                    "continue nor on_errors="
                                    "remount-ro was specified%s",
                                    es1, es2);
                        goto iput_usnjrnl_err_out;
                  }
                  sb->s_flags |= MS_RDONLY;
                  ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            } else
                  ntfs_warning(sb, "%s.  Will not be able to remount "
                              "read-write%s", es1, es2);
            /* This will prevent a read-write remount. */
            NVolSetErrors(vol);
      }
      /* If (still) a read-write mount, stamp the transaction log. */
      if (!(sb->s_flags & MS_RDONLY) && !ntfs_stamp_usnjrnl(vol)) {
            static const char *es1 = "Failed to stamp transaction log "
                        "($UsnJrnl)";
            static const char *es2 = ".  Run chkdsk.";

            /* Convert to a read-only mount. */
            if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
                        ON_ERRORS_CONTINUE))) {
                  ntfs_error(sb, "%s and neither on_errors=continue nor "
                              "on_errors=remount-ro was specified%s",
                              es1, es2);
                  goto iput_usnjrnl_err_out;
            }
            ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
            sb->s_flags |= MS_RDONLY;
            NVolSetErrors(vol);
      }
#endif /* NTFS_RW */
      return TRUE;
#ifdef NTFS_RW
iput_usnjrnl_err_out:
      if (vol->usnjrnl_j_ino)
            iput(vol->usnjrnl_j_ino);
      if (vol->usnjrnl_max_ino)
            iput(vol->usnjrnl_max_ino);
      if (vol->usnjrnl_ino)
            iput(vol->usnjrnl_ino);
iput_quota_err_out:
      if (vol->quota_q_ino)
            iput(vol->quota_q_ino);
      if (vol->quota_ino)
            iput(vol->quota_ino);
      iput(vol->extend_ino);
#endif /* NTFS_RW */
iput_sec_err_out:
      iput(vol->secure_ino);
iput_root_err_out:
      iput(vol->root_ino);
iput_logfile_err_out:
#ifdef NTFS_RW
      if (vol->logfile_ino)
            iput(vol->logfile_ino);
iput_vol_err_out:
#endif /* NTFS_RW */
      iput(vol->vol_ino);
iput_lcnbmp_err_out:
      iput(vol->lcnbmp_ino);
iput_attrdef_err_out:
      vol->attrdef_size = 0;
      if (vol->attrdef) {
            ntfs_free(vol->attrdef);
            vol->attrdef = NULL;
      }
#ifdef NTFS_RW
iput_upcase_err_out:
#endif /* NTFS_RW */
      vol->upcase_len = 0;
      mutex_lock(&ntfs_lock);
      if (vol->upcase == default_upcase) {
            ntfs_nr_upcase_users--;
            vol->upcase = NULL;
      }
      mutex_unlock(&ntfs_lock);
      if (vol->upcase) {
            ntfs_free(vol->upcase);
            vol->upcase = NULL;
      }
iput_mftbmp_err_out:
      iput(vol->mftbmp_ino);
iput_mirr_err_out:
#ifdef NTFS_RW
      if (vol->mftmirr_ino)
            iput(vol->mftmirr_ino);
#endif /* NTFS_RW */
      return FALSE;
}

/**
 * ntfs_put_super - called by the vfs to unmount a volume
 * @sb:           vfs superblock of volume to unmount
 *
 * ntfs_put_super() is called by the VFS (from fs/super.c::do_umount()) when
 * the volume is being unmounted (umount system call has been invoked) and it
 * releases all inodes and memory belonging to the NTFS specific part of the
 * super block.
 */
static void ntfs_put_super(struct super_block *sb)
{
      ntfs_volume *vol = NTFS_SB(sb);

      ntfs_debug("Entering.");
#ifdef NTFS_RW
      /*
       * Commit all inodes while they are still open in case some of them
       * cause others to be dirtied.
       */
      ntfs_commit_inode(vol->vol_ino);

      /* NTFS 3.0+ specific. */
      if (vol->major_ver >= 3) {
            if (vol->usnjrnl_j_ino)
                  ntfs_commit_inode(vol->usnjrnl_j_ino);
            if (vol->usnjrnl_max_ino)
                  ntfs_commit_inode(vol->usnjrnl_max_ino);
            if (vol->usnjrnl_ino)
                  ntfs_commit_inode(vol->usnjrnl_ino);
            if (vol->quota_q_ino)
                  ntfs_commit_inode(vol->quota_q_ino);
            if (vol->quota_ino)
                  ntfs_commit_inode(vol->quota_ino);
            if (vol->extend_ino)
                  ntfs_commit_inode(vol->extend_ino);
            if (vol->secure_ino)
                  ntfs_commit_inode(vol->secure_ino);
      }

      ntfs_commit_inode(vol->root_ino);

      down_write(&vol->lcnbmp_lock);
      ntfs_commit_inode(vol->lcnbmp_ino);
      up_write(&vol->lcnbmp_lock);

      down_write(&vol->mftbmp_lock);
      ntfs_commit_inode(vol->mftbmp_ino);
      up_write(&vol->mftbmp_lock);

      if (vol->logfile_ino)
            ntfs_commit_inode(vol->logfile_ino);

      if (vol->mftmirr_ino)
            ntfs_commit_inode(vol->mftmirr_ino);
      ntfs_commit_inode(vol->mft_ino);

      /*
       * If a read-write mount and no volume errors have occured, mark the
       * volume clean.  Also, re-commit all affected inodes.
       */
      if (!(sb->s_flags & MS_RDONLY)) {
            if (!NVolErrors(vol)) {
                  if (ntfs_clear_volume_flags(vol, VOLUME_IS_DIRTY))
                        ntfs_warning(sb, "Failed to clear dirty bit "
                                    "in volume information "
                                    "flags.  Run chkdsk.");
                  ntfs_commit_inode(vol->vol_ino);
                  ntfs_commit_inode(vol->root_ino);
                  if (vol->mftmirr_ino)
                        ntfs_commit_inode(vol->mftmirr_ino);
                  ntfs_commit_inode(vol->mft_ino);
            } else {
                  ntfs_warning(sb, "Volume has errors.  Leaving volume "
                              "marked dirty.  Run chkdsk.");
            }
      }
#endif /* NTFS_RW */

      iput(vol->vol_ino);
      vol->vol_ino = NULL;

      /* NTFS 3.0+ specific clean up. */
      if (vol->major_ver >= 3) {
#ifdef NTFS_RW
            if (vol->usnjrnl_j_ino) {
                  iput(vol->usnjrnl_j_ino);
                  vol->usnjrnl_j_ino = NULL;
            }
            if (vol->usnjrnl_max_ino) {
                  iput(vol->usnjrnl_max_ino);
                  vol->usnjrnl_max_ino = NULL;
            }
            if (vol->usnjrnl_ino) {
                  iput(vol->usnjrnl_ino);
                  vol->usnjrnl_ino = NULL;
            }
            if (vol->quota_q_ino) {
                  iput(vol->quota_q_ino);
                  vol->quota_q_ino = NULL;
            }
            if (vol->quota_ino) {
                  iput(vol->quota_ino);
                  vol->quota_ino = NULL;
            }
#endif /* NTFS_RW */
            if (vol->extend_ino) {
                  iput(vol->extend_ino);
                  vol->extend_ino = NULL;
            }
            if (vol->secure_ino) {
                  iput(vol->secure_ino);
                  vol->secure_ino = NULL;
            }
      }

      iput(vol->root_ino);
      vol->root_ino = NULL;

      down_write(&vol->lcnbmp_lock);
      iput(vol->lcnbmp_ino);
      vol->lcnbmp_ino = NULL;
      up_write(&vol->lcnbmp_lock);

      down_write(&vol->mftbmp_lock);
      iput(vol->mftbmp_ino);
      vol->mftbmp_ino = NULL;
      up_write(&vol->mftbmp_lock);

#ifdef NTFS_RW
      if (vol->logfile_ino) {
            iput(vol->logfile_ino);
            vol->logfile_ino = NULL;
      }
      if (vol->mftmirr_ino) {
            /* Re-commit the mft mirror and mft just in case. */
            ntfs_commit_inode(vol->mftmirr_ino);
            ntfs_commit_inode(vol->mft_ino);
            iput(vol->mftmirr_ino);
            vol->mftmirr_ino = NULL;
      }
      /*
       * If any dirty inodes are left, throw away all mft data page cache
       * pages to allow a clean umount.  This should never happen any more
       * due to mft.c::ntfs_mft_writepage() cleaning all the dirty pages as
       * the underlying mft records are written out and cleaned.  If it does,
       * happen anyway, we want to know...
       */
      ntfs_commit_inode(vol->mft_ino);
      write_inode_now(vol->mft_ino, 1);
      if (!list_empty(&sb->s_dirty)) {
            const char *s1, *s2;

            mutex_lock(&vol->mft_ino->i_mutex);
            truncate_inode_pages(vol->mft_ino->i_mapping, 0);
            mutex_unlock(&vol->mft_ino->i_mutex);
            write_inode_now(vol->mft_ino, 1);
            if (!list_empty(&sb->s_dirty)) {
                  static const char *_s1 = "inodes";
                  static const char *_s2 = "";
                  s1 = _s1;
                  s2 = _s2;
            } else {
                  static const char *_s1 = "mft pages";
                  static const char *_s2 = "They have been thrown "
                              "away.  ";
                  s1 = _s1;
                  s2 = _s2;
            }
            ntfs_error(sb, "Dirty %s found at umount time.  %sYou should "
                        "run chkdsk.  Please email "
                        "linux-ntfs-dev@lists.sourceforge.net and say "
                        "that you saw this message.  Thank you.", s1,
                        s2);
      }
#endif /* NTFS_RW */

      iput(vol->mft_ino);
      vol->mft_ino = NULL;

      /* Throw away the table of attribute definitions. */
      vol->attrdef_size = 0;
      if (vol->attrdef) {
            ntfs_free(vol->attrdef);
            vol->attrdef = NULL;
      }
      vol->upcase_len = 0;
      /*
       * Destroy the global default upcase table if necessary.  Also decrease
       * the number of upcase users if we are a user.
       */
      mutex_lock(&ntfs_lock);
      if (vol->upcase == default_upcase) {
            ntfs_nr_upcase_users--;
            vol->upcase = NULL;
      }
      if (!ntfs_nr_upcase_users && default_upcase) {
            ntfs_free(default_upcase);
            default_upcase = NULL;
      }
      if (vol->cluster_size <= 4096 && !--ntfs_nr_compression_users)
            free_compression_buffers();
      mutex_unlock(&ntfs_lock);
      if (vol->upcase) {
            ntfs_free(vol->upcase);
            vol->upcase = NULL;
      }
      if (vol->nls_map) {
            unload_nls(vol->nls_map);
            vol->nls_map = NULL;
      }
      sb->s_fs_info = NULL;
      kfree(vol);
      return;
}

/**
 * get_nr_free_clusters - return the number of free clusters on a volume
 * @vol:    ntfs volume for which to obtain free cluster count
 *
 * Calculate the number of free clusters on the mounted NTFS volume @vol. We
 * actually calculate the number of clusters in use instead because this
 * allows us to not care about partial pages as these will be just zero filled
 * and hence not be counted as allocated clusters.
 *
 * The only particularity is that clusters beyond the end of the logical ntfs
 * volume will be marked as allocated to prevent errors which means we have to
 * discount those at the end. This is important as the cluster bitmap always
 * has a size in multiples of 8 bytes, i.e. up to 63 clusters could be outside
 * the logical volume and marked in use when they are not as they do not exist.
 *
 * If any pages cannot be read we assume all clusters in the erroring pages are
 * in use. This means we return an underestimate on errors which is better than
 * an overestimate.
 */
static s64 get_nr_free_clusters(ntfs_volume *vol)
{
      s64 nr_free = vol->nr_clusters;
      u32 *kaddr;
      struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
      filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
      struct page *page;
      pgoff_t index, max_index;

      ntfs_debug("Entering.");
      /* Serialize accesses to the cluster bitmap. */
      down_read(&vol->lcnbmp_lock);
      /*
       * Convert the number of bits into bytes rounded up, then convert into
       * multiples of PAGE_CACHE_SIZE, rounding up so that if we have one
       * full and one partial page max_index = 2.
       */
      max_index = (((vol->nr_clusters + 7) >> 3) + PAGE_CACHE_SIZE - 1) >>
                  PAGE_CACHE_SHIFT;
      /* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */
      ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%lx.",
                  max_index, PAGE_CACHE_SIZE / 4);
      for (index = 0; index < max_index; index++) {
            unsigned int i;
            /*
             * Read the page from page cache, getting it from backing store
             * if necessary, and increment the use count.
             */
            page = read_cache_page(mapping, index, (filler_t*)readpage,
                        NULL);
            /* Ignore pages which errored synchronously. */
            if (IS_ERR(page)) {
                  ntfs_debug("Sync read_cache_page() error. Skipping "
                              "page (index 0x%lx).", index);
                  nr_free -= PAGE_CACHE_SIZE * 8;
                  continue;
            }
            wait_on_page_locked(page);
            /* Ignore pages which errored asynchronously. */
            if (!PageUptodate(page)) {
                  ntfs_debug("Async read_cache_page() error. Skipping "
                              "page (index 0x%lx).", index);
                  page_cache_release(page);
                  nr_free -= PAGE_CACHE_SIZE * 8;
                  continue;
            }
            kaddr = (u32*)kmap_atomic(page, KM_USER0);
            /*
             * For each 4 bytes, subtract the number of set bits. If this
             * is the last page and it is partial we don't really care as
             * it just means we do a little extra work but it won't affect
             * the result as all out of range bytes are set to zero by
             * ntfs_readpage().
             */
            for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)
                  nr_free -= (s64)hweight32(kaddr[i]);
            kunmap_atomic(kaddr, KM_USER0);
            page_cache_release(page);
      }
      ntfs_debug("Finished reading $Bitmap, last index = 0x%lx.", index - 1);
      /*
       * Fixup for eventual bits outside logical ntfs volume (see function
       * description above).
       */
      if (vol->nr_clusters & 63)
            nr_free += 64 - (vol->nr_clusters & 63);
      up_read(&vol->lcnbmp_lock);
      /* If errors occured we may well have gone below zero, fix this. */
      if (nr_free < 0)
            nr_free = 0;
      ntfs_debug("Exiting.");
      return nr_free;
}

/**
 * __get_nr_free_mft_records - return the number of free inodes on a volume
 * @vol:    ntfs volume for which to obtain free inode count
 * @nr_free:      number of mft records in filesystem
 * @max_index:    maximum number of pages containing set bits
 *
 * Calculate the number of free mft records (inodes) on the mounted NTFS
 * volume @vol. We actually calculate the number of mft records in use instead
 * because this allows us to not care about partial pages as these will be just
 * zero filled and hence not be counted as allocated mft record.
 *
 * If any pages cannot be read we assume all mft records in the erroring pages
 * are in use. This means we return an underestimate on errors which is better
 * than an overestimate.
 *
 * NOTE: Caller must hold mftbmp_lock rw_semaphore for reading or writing.
 */
static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
            s64 nr_free, const pgoff_t max_index)
{
      u32 *kaddr;
      struct address_space *mapping = vol->mftbmp_ino->i_mapping;
      filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
      struct page *page;
      pgoff_t index;

      ntfs_debug("Entering.");
      /* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */
      ntfs_debug("Reading $MFT/$BITMAP, max_index = 0x%lx, max_size = "
                  "0x%lx.", max_index, PAGE_CACHE_SIZE / 4);
      for (index = 0; index < max_index; index++) {
            unsigned int i;
            /*
             * Read the page from page cache, getting it from backing store
             * if necessary, and increment the use count.
             */
            page = read_cache_page(mapping, index, (filler_t*)readpage,
                        NULL);
            /* Ignore pages which errored synchronously. */
            if (IS_ERR(page)) {
                  ntfs_debug("Sync read_cache_page() error. Skipping "
                              "page (index 0x%lx).", index);
                  nr_free -= PAGE_CACHE_SIZE * 8;
                  continue;
            }
            wait_on_page_locked(page);
            /* Ignore pages which errored asynchronously. */
            if (!PageUptodate(page)) {
                  ntfs_debug("Async read_cache_page() error. Skipping "
                              "page (index 0x%lx).", index);
                  page_cache_release(page);
                  nr_free -= PAGE_CACHE_SIZE * 8;
                  continue;
            }
            kaddr = (u32*)kmap_atomic(page, KM_USER0);
            /*
             * For each 4 bytes, subtract the number of set bits. If this
             * is the last page and it is partial we don't really care as
             * it just means we do a little extra work but it won't affect
             * the result as all out of range bytes are set to zero by
             * ntfs_readpage().
             */
            for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)
                  nr_free -= (s64)hweight32(kaddr[i]);
            kunmap_atomic(kaddr, KM_USER0);
            page_cache_release(page);
      }
      ntfs_debug("Finished reading $MFT/$BITMAP, last index = 0x%lx.",
                  index - 1);
      /* If errors occured we may well have gone below zero, fix this. */
      if (nr_free < 0)
            nr_free = 0;
      ntfs_debug("Exiting.");
      return nr_free;
}

/**
 * ntfs_statfs - return information about mounted NTFS volume
 * @dentry: dentry from mounted volume
 * @sfs:    statfs structure in which to return the information
 *
 * Return information about the mounted NTFS volume @dentry in the statfs structure
 * pointed to by @sfs (this is initialized with zeros before ntfs_statfs is
 * called). We interpret the values to be correct of the moment in time at
 * which we are called. Most values are variable otherwise and this isn't just
 * the free values but the totals as well. For example we can increase the
 * total number of file nodes if we run out and we can keep doing this until
 * there is no more space on the volume left at all.
 *
 * Called from vfs_statfs which is used to handle the statfs, fstatfs, and
 * ustat system calls.
 *
 * Return 0 on success or -errno on error.
 */
static int ntfs_statfs(struct dentry *dentry, struct kstatfs *sfs)
{
      struct super_block *sb = dentry->d_sb;
      s64 size;
      ntfs_volume *vol = NTFS_SB(sb);
      ntfs_inode *mft_ni = NTFS_I(vol->mft_ino);
      pgoff_t max_index;
      unsigned long flags;

      ntfs_debug("Entering.");
      /* Type of filesystem. */
      sfs->f_type   = NTFS_SB_MAGIC;
      /* Optimal transfer block size. */
      sfs->f_bsize  = PAGE_CACHE_SIZE;
      /*
       * Total data blocks in filesystem in units of f_bsize and since
       * inodes are also stored in data blocs ($MFT is a file) this is just
       * the total clusters.
       */
      sfs->f_blocks = vol->nr_clusters << vol->cluster_size_bits >>
                        PAGE_CACHE_SHIFT;
      /* Free data blocks in filesystem in units of f_bsize. */
      size        = get_nr_free_clusters(vol) << vol->cluster_size_bits >>
                        PAGE_CACHE_SHIFT;
      if (size < 0LL)
            size = 0LL;
      /* Free blocks avail to non-superuser, same as above on NTFS. */
      sfs->f_bavail = sfs->f_bfree = size;
      /* Serialize accesses to the inode bitmap. */
      down_read(&vol->mftbmp_lock);
      read_lock_irqsave(&mft_ni->size_lock, flags);
      size = i_size_read(vol->mft_ino) >> vol->mft_record_size_bits;
      /*
       * Convert the maximum number of set bits into bytes rounded up, then
       * convert into multiples of PAGE_CACHE_SIZE, rounding up so that if we
       * have one full and one partial page max_index = 2.
       */
      max_index = ((((mft_ni->initialized_size >> vol->mft_record_size_bits)
                  + 7) >> 3) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
      read_unlock_irqrestore(&mft_ni->size_lock, flags);
      /* Number of inodes in filesystem (at this point in time). */
      sfs->f_files = size;
      /* Free inodes in fs (based on current total count). */
      sfs->f_ffree = __get_nr_free_mft_records(vol, size, max_index);
      up_read(&vol->mftbmp_lock);
      /*
       * File system id. This is extremely *nix flavour dependent and even
       * within Linux itself all fs do their own thing. I interpret this to
       * mean a unique id associated with the mounted fs and not the id
       * associated with the filesystem driver, the latter is already given
       * by the filesystem type in sfs->f_type. Thus we use the 64-bit
       * volume serial number splitting it into two 32-bit parts. We enter
       * the least significant 32-bits in f_fsid[0] and the most significant
       * 32-bits in f_fsid[1].
       */
      sfs->f_fsid.val[0] = vol->serial_no & 0xffffffff;
      sfs->f_fsid.val[1] = (vol->serial_no >> 32) & 0xffffffff;
      /* Maximum length of filenames. */
      sfs->f_namelen       = NTFS_MAX_NAME_LEN;
      return 0;
}

/**
 * The complete super operations.
 */
static struct super_operations ntfs_sops = {
      .alloc_inode      = ntfs_alloc_big_inode,   /* VFS: Allocate new inode. */
      .destroy_inode    = ntfs_destroy_big_inode, /* VFS: Deallocate inode. */
      .put_inode  = ntfs_put_inode,   /* VFS: Called just before
                                         the inode reference count
                                         is decreased. */
#ifdef NTFS_RW
      //.dirty_inode    = NULL,                 /* VFS: Called from
      //                               __mark_inode_dirty(). */
      .write_inode      = ntfs_write_inode,     /* VFS: Write dirty inode to
                                       disk. */
      //.drop_inode     = NULL,                 /* VFS: Called just after the
      //                               inode reference count has
      //                               been decreased to zero.
      //                               NOTE: The inode lock is
      //                               held. See fs/inode.c::
      //                               generic_drop_inode(). */
      //.delete_inode   = NULL,                 /* VFS: Delete inode from disk.
      //                               Called when i_count becomes
      //                               0 and i_nlink is also 0. */
      //.write_super    = NULL,                 /* Flush dirty super block to
      //                               disk. */
      //.sync_fs  = NULL,                 /* ? */
      //.write_super_lockfs   = NULL,           /* ? */
      //.unlockfs = NULL,                 /* ? */
#endif /* NTFS_RW */
      .put_super  = ntfs_put_super, /* Syscall: umount. */
      .statfs           = ntfs_statfs,          /* Syscall: statfs */
      .remount_fs = ntfs_remount,         /* Syscall: mount -o remount. */
      .clear_inode      = ntfs_clear_big_inode, /* VFS: Called when an inode is
                                       removed from memory. */
      //.umount_begin   = NULL,                 /* Forced umount. */
      .show_options     = ntfs_show_options,    /* Show mount options in
                                       proc. */
};

/**
 * ntfs_fill_super - mount an ntfs filesystem
 * @sb:           super block of ntfs filesystem to mount
 * @opt:    string containing the mount options
 * @silent: silence error output
 *
 * ntfs_fill_super() is called by the VFS to mount the device described by @sb
 * with the mount otions in @data with the NTFS filesystem.
 *
 * If @silent is true, remain silent even if errors are detected. This is used
 * during bootup, when the kernel tries to mount the root filesystem with all
 * registered filesystems one after the other until one succeeds. This implies
 * that all filesystems except the correct one will quite correctly and
 * expectedly return an error, but nobody wants to see error messages when in
 * fact this is what is supposed to happen.
 *
 * NOTE: @sb->s_flags contains the mount options flags.
 */
static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
{
      ntfs_volume *vol;
      struct buffer_head *bh;
      struct inode *tmp_ino;
      int blocksize, result;

      /*
       * We do a pretty difficult piece of bootstrap by reading the
       * MFT (and other metadata) from disk into memory. We'll only
       * release this metadata during umount, so the locking patterns
       * observed during bootstrap do not count. So turn off the
       * observation of locking patterns (strictly for this context
       * only) while mounting NTFS. [The validator is still active
       * otherwise, even for this context: it will for example record
       * lock class registrations.]
       */
      lockdep_off();
      ntfs_debug("Entering.");
#ifndef NTFS_RW
      sb->s_flags |= MS_RDONLY;
#endif /* ! NTFS_RW */
      /* Allocate a new ntfs_volume and place it in sb->s_fs_info. */
      sb->s_fs_info = kmalloc(sizeof(ntfs_volume), GFP_NOFS);
      vol = NTFS_SB(sb);
      if (!vol) {
            if (!silent)
                  ntfs_error(sb, "Allocation of NTFS volume structure "
                              "failed. Aborting mount...");
            lockdep_on();
            return -ENOMEM;
      }
      /* Initialize ntfs_volume structure. */
      *vol = (ntfs_volume) {
            .sb = sb,
            /*
             * Default is group and other don't have any access to files or
             * directories while owner has full access. Further, files by
             * default are not executable but directories are of course
             * browseable.
             */
            .fmask = 0177,
            .dmask = 0077,
      };
      init_rwsem(&vol->mftbmp_lock);
      init_rwsem(&vol->lcnbmp_lock);

      unlock_kernel();

      /* By default, enable sparse support. */
      NVolSetSparseEnabled(vol);

      /* Important to get the mount options dealt with now. */
      if (!parse_options(vol, (char*)opt))
            goto err_out_now;

      /* We support sector sizes up to the PAGE_CACHE_SIZE. */
      if (bdev_hardsect_size(sb->s_bdev) > PAGE_CACHE_SIZE) {
            if (!silent)
                  ntfs_error(sb, "Device has unsupported sector size "
                              "(%i).  The maximum supported sector "
                              "size on this architecture is %lu "
                              "bytes.",
                              bdev_hardsect_size(sb->s_bdev),
                              PAGE_CACHE_SIZE);
            goto err_out_now;
      }
      /*
       * Setup the device access block size to NTFS_BLOCK_SIZE or the hard
       * sector size, whichever is bigger.
       */
      blocksize = sb_min_blocksize(sb, NTFS_BLOCK_SIZE);
      if (blocksize < NTFS_BLOCK_SIZE) {
            if (!silent)
                  ntfs_error(sb, "Unable to set device block size.");
            goto err_out_now;
      }
      BUG_ON(blocksize != sb->s_blocksize);
      ntfs_debug("Set device block size to %i bytes (block size bits %i).",
                  blocksize, sb->s_blocksize_bits);
      /* Determine the size of the device in units of block_size bytes. */
      if (!i_size_read(sb->s_bdev->bd_inode)) {
            if (!silent)
                  ntfs_error(sb, "Unable to determine device size.");
            goto err_out_now;
      }
      vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
                  sb->s_blocksize_bits;
      /* Read the boot sector and return unlocked buffer head to it. */
      if (!(bh = read_ntfs_boot_sector(sb, silent))) {
            if (!silent)
                  ntfs_error(sb, "Not an NTFS volume.");
            goto err_out_now;
      }
      /*
       * Extract the data from the boot sector and setup the ntfs volume
       * using it.
       */
      result = parse_ntfs_boot_sector(vol, (NTFS_BOOT_SECTOR*)bh->b_data);
      brelse(bh);
      if (!result) {
            if (!silent)
                  ntfs_error(sb, "Unsupported NTFS filesystem.");
            goto err_out_now;
      }
      /*
       * If the boot sector indicates a sector size bigger than the current
       * device block size, switch the device block size to the sector size.
       * TODO: It may be possible to support this case even when the set
       * below fails, we would just be breaking up the i/o for each sector
       * into multiple blocks for i/o purposes but otherwise it should just
       * work.  However it is safer to leave disabled until someone hits this
       * error message and then we can get them to try it without the setting
       * so we know for sure that it works.
       */
      if (vol->sector_size > blocksize) {
            blocksize = sb_set_blocksize(sb, vol->sector_size);
            if (blocksize != vol->sector_size) {
                  if (!silent)
                        ntfs_error(sb, "Unable to set device block "
                                    "size to sector size (%i).",
                                    vol->sector_size);
                  goto err_out_now;
            }
            BUG_ON(blocksize != sb->s_blocksize);
            vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
                        sb->s_blocksize_bits;
            ntfs_debug("Changed device block size to %i bytes (block size "
                        "bits %i) to match volume sector size.",
                        blocksize, sb->s_blocksize_bits);
      }
      /* Initialize the cluster and mft allocators. */
      ntfs_setup_allocators(vol);
      /* Setup remaining fields in the super block. */
      sb->s_magic = NTFS_SB_MAGIC;
      /*
       * Ntfs allows 63 bits for the file size, i.e. correct would be:
       *    sb->s_maxbytes = ~0ULL >> 1;
       * But the kernel uses a long as the page cache page index which on
       * 32-bit architectures is only 32-bits. MAX_LFS_FILESIZE is kernel
       * defined to the maximum the page cache page index can cope with
       * without overflowing the index or to 2^63 - 1, whichever is smaller.
       */
      sb->s_maxbytes = MAX_LFS_FILESIZE;
      /* Ntfs measures time in 100ns intervals. */
      sb->s_time_gran = 100;
      /*
       * Now load the metadata required for the page cache and our address
       * space operations to function. We do this by setting up a specialised
       * read_inode method and then just calling the normal iget() to obtain
       * the inode for $MFT which is sufficient to allow our normal inode
       * operations and associated address space operations to function.
       */
      sb->s_op = &ntfs_sops;
      tmp_ino = new_inode(sb);
      if (!tmp_ino) {
            if (!silent)
                  ntfs_error(sb, "Failed to load essential metadata.");
            goto err_out_now;
      }
      tmp_ino->i_ino = FILE_MFT;
      insert_inode_hash(tmp_ino);
      if (ntfs_read_inode_mount(tmp_ino) < 0) {
            if (!silent)
                  ntfs_error(sb, "Failed to load essential metadata.");
            goto iput_tmp_ino_err_out_now;
      }
      mutex_lock(&ntfs_lock);
      /*
       * The current mount is a compression user if the cluster size is
       * less than or equal 4kiB.
       */
      if (vol->cluster_size <= 4096 && !ntfs_nr_compression_users++) {
            result = allocate_compression_buffers();
            if (result) {
                  ntfs_error(NULL, "Failed to allocate buffers "
                              "for compression engine.");
                  ntfs_nr_compression_users--;
                  mutex_unlock(&ntfs_lock);
                  goto iput_tmp_ino_err_out_now;
            }
      }
      /*
       * Generate the global default upcase table if necessary.  Also
       * temporarily increment the number of upcase users to avoid race
       * conditions with concurrent (u)mounts.
       */
      if (!default_upcase)
            default_upcase = generate_default_upcase();
      ntfs_nr_upcase_users++;
      mutex_unlock(&ntfs_lock);
      /*
       * From now on, ignore @silent parameter. If we fail below this line,
       * it will be due to a corrupt fs or a system error, so we report it.
       */
      /*
       * Open the system files with normal access functions and complete
       * setting up the ntfs super block.
       */
      if (!load_system_files(vol)) {
            ntfs_error(sb, "Failed to load system files.");
            goto unl_upcase_iput_tmp_ino_err_out_now;
      }
      if ((sb->s_root = d_alloc_root(vol->root_ino))) {
            /* We increment i_count simulating an ntfs_iget(). */
            atomic_inc(&vol->root_ino->i_count);
            ntfs_debug("Exiting, status successful.");
            /* Release the default upcase if it has no users. */
            mutex_lock(&ntfs_lock);
            if (!--ntfs_nr_upcase_users && default_upcase) {
                  ntfs_free(default_upcase);
                  default_upcase = NULL;
            }
            mutex_unlock(&ntfs_lock);
            sb->s_export_op = &ntfs_export_ops;
            lock_kernel();
            lockdep_on();
            return 0;
      }
      ntfs_error(sb, "Failed to allocate root directory.");
      /* Clean up after the successful load_system_files() call from above. */
      // TODO: Use ntfs_put_super() instead of repeating all this code...
      // FIXME: Should mark the volume clean as the error is most likely
      //      -ENOMEM.
      iput(vol->vol_ino);
      vol->vol_ino = NULL;
      /* NTFS 3.0+ specific clean up. */
      if (vol->major_ver >= 3) {
#ifdef NTFS_RW
            if (vol->usnjrnl_j_ino) {
                  iput(vol->usnjrnl_j_ino);
                  vol->usnjrnl_j_ino = NULL;
            }
            if (vol->usnjrnl_max_ino) {
                  iput(vol->usnjrnl_max_ino);
                  vol->usnjrnl_max_ino = NULL;
            }
            if (vol->usnjrnl_ino) {
                  iput(vol->usnjrnl_ino);
                  vol->usnjrnl_ino = NULL;
            }
            if (vol->quota_q_ino) {
                  iput(vol->quota_q_ino);
                  vol->quota_q_ino = NULL;
            }
            if (vol->quota_ino) {
                  iput(vol->quota_ino);
                  vol->quota_ino = NULL;
            }
#endif /* NTFS_RW */
            if (vol->extend_ino) {
                  iput(vol->extend_ino);
                  vol->extend_ino = NULL;
            }
            if (vol->secure_ino) {
                  iput(vol->secure_ino);
                  vol->secure_ino = NULL;
            }
      }
      iput(vol->root_ino);
      vol->root_ino = NULL;
      iput(vol->lcnbmp_ino);
      vol->lcnbmp_ino = NULL;
      iput(vol->mftbmp_ino);
      vol->mftbmp_ino = NULL;
#ifdef NTFS_RW
      if (vol->logfile_ino) {
            iput(vol->logfile_ino);
            vol->logfile_ino = NULL;
      }
      if (vol->mftmirr_ino) {
            iput(vol->mftmirr_ino);
            vol->mftmirr_ino = NULL;
      }
#endif /* NTFS_RW */
      /* Throw away the table of attribute definitions. */
      vol->attrdef_size = 0;
      if (vol->attrdef) {
            ntfs_free(vol->attrdef);
            vol->attrdef = NULL;
      }
      vol->upcase_len = 0;
      mutex_lock(&ntfs_lock);
      if (vol->upcase == default_upcase) {
            ntfs_nr_upcase_users--;
            vol->upcase = NULL;
      }
      mutex_unlock(&ntfs_lock);
      if (vol->upcase) {
            ntfs_free(vol->upcase);
            vol->upcase = NULL;
      }
      if (vol->nls_map) {
            unload_nls(vol->nls_map);
            vol->nls_map = NULL;
      }
      /* Error exit code path. */
unl_upcase_iput_tmp_ino_err_out_now:
      /*
       * Decrease the number of upcase users and destroy the global default
       * upcase table if necessary.
       */
      mutex_lock(&ntfs_lock);
      if (!--ntfs_nr_upcase_users && default_upcase) {
            ntfs_free(default_upcase);
            default_upcase = NULL;
      }
      if (vol->cluster_size <= 4096 && !--ntfs_nr_compression_users)
            free_compression_buffers();
      mutex_unlock(&ntfs_lock);
iput_tmp_ino_err_out_now:
      iput(tmp_ino);
      if (vol->mft_ino && vol->mft_ino != tmp_ino)
            iput(vol->mft_ino);
      vol->mft_ino = NULL;
      /*
       * This is needed to get ntfs_clear_extent_inode() called for each
       * inode we have ever called ntfs_iget()/iput() on, otherwise we A)
       * leak resources and B) a subsequent mount fails automatically due to
       * ntfs_iget() never calling down into our ntfs_read_locked_inode()
       * method again... FIXME: Do we need to do this twice now because of
       * attribute inodes? I think not, so leave as is for now... (AIA)
       */
      if (invalidate_inodes(sb)) {
            ntfs_error(sb, "Busy inodes left. This is most likely a NTFS "
                        "driver bug.");
            /* Copied from fs/super.c. I just love this message. (-; */
            printk("NTFS: Busy inodes after umount. Self-destruct in 5 "
                        "seconds.  Have a nice day...\n");
      }
      /* Errors at this stage are irrelevant. */
err_out_now:
      lock_kernel();
      sb->s_fs_info = NULL;
      kfree(vol);
      ntfs_debug("Failed, returning -EINVAL.");
      lockdep_on();
      return -EINVAL;
}

/*
 * This is a slab cache to optimize allocations and deallocations of Unicode
 * strings of the maximum length allowed by NTFS, which is NTFS_MAX_NAME_LEN
 * (255) Unicode characters + a terminating NULL Unicode character.
 */
struct kmem_cache *ntfs_name_cache;

/* Slab caches for efficient allocation/deallocation of inodes. */
struct kmem_cache *ntfs_inode_cache;
struct kmem_cache *ntfs_big_inode_cache;

/* Init once constructor for the inode slab cache. */
static void ntfs_big_inode_init_once(void *foo, struct kmem_cache *cachep,
            unsigned long flags)
{
      ntfs_inode *ni = (ntfs_inode *)foo;

      if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
                  SLAB_CTOR_CONSTRUCTOR)
            inode_init_once(VFS_I(ni));
}

/*
 * Slab caches to optimize allocations and deallocations of attribute search
 * contexts and index contexts, respectively.
 */
struct kmem_cache *ntfs_attr_ctx_cache;
struct kmem_cache *ntfs_index_ctx_cache;

/* Driver wide mutex. */
DEFINE_MUTEX(ntfs_lock);

static int ntfs_get_sb(struct file_system_type *fs_type,
      int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
      return get_sb_bdev(fs_type, flags, dev_name, data, ntfs_fill_super,
                     mnt);
}

static struct file_system_type ntfs_fs_type = {
      .owner            = THIS_MODULE,
      .name       = "ntfs",
      .get_sb           = ntfs_get_sb,
      .kill_sb    = kill_block_super,
      .fs_flags   = FS_REQUIRES_DEV,
};

/* Stable names for the slab caches. */
static const char ntfs_index_ctx_cache_name[] = "ntfs_index_ctx_cache";
static const char ntfs_attr_ctx_cache_name[] = "ntfs_attr_ctx_cache";
static const char ntfs_name_cache_name[] = "ntfs_name_cache";
static const char ntfs_inode_cache_name[] = "ntfs_inode_cache";
static const char ntfs_big_inode_cache_name[] = "ntfs_big_inode_cache";

static int __init init_ntfs_fs(void)
{
      int err = 0;

      /* This may be ugly but it results in pretty output so who cares. (-8 */
      printk(KERN_INFO "NTFS driver " NTFS_VERSION " [Flags: R/"
#ifdef NTFS_RW
                  "W"
#else
                  "O"
#endif
#ifdef DEBUG
                  " DEBUG"
#endif
#ifdef MODULE
                  " MODULE"
#endif
                  "].\n");

      ntfs_debug("Debug messages are enabled.");

      ntfs_index_ctx_cache = kmem_cache_create(ntfs_index_ctx_cache_name,
                  sizeof(ntfs_index_context), 0 /* offset */,
                  SLAB_HWCACHE_ALIGN, NULL /* ctor */, NULL /* dtor */);
      if (!ntfs_index_ctx_cache) {
            printk(KERN_CRIT "NTFS: Failed to create %s!\n",
                        ntfs_index_ctx_cache_name);
            goto ictx_err_out;
      }
      ntfs_attr_ctx_cache = kmem_cache_create(ntfs_attr_ctx_cache_name,
                  sizeof(ntfs_attr_search_ctx), 0 /* offset */,
                  SLAB_HWCACHE_ALIGN, NULL /* ctor */, NULL /* dtor */);
      if (!ntfs_attr_ctx_cache) {
            printk(KERN_CRIT "NTFS: Failed to create %s!\n",
                        ntfs_attr_ctx_cache_name);
            goto actx_err_out;
      }

      ntfs_name_cache = kmem_cache_create(ntfs_name_cache_name,
                  (NTFS_MAX_NAME_LEN+1) * sizeof(ntfschar), 0,
                  SLAB_HWCACHE_ALIGN, NULL, NULL);
      if (!ntfs_name_cache) {
            printk(KERN_CRIT "NTFS: Failed to create %s!\n",
                        ntfs_name_cache_name);
            goto name_err_out;
      }

      ntfs_inode_cache = kmem_cache_create(ntfs_inode_cache_name,
                  sizeof(ntfs_inode), 0,
                  SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL, NULL);
      if (!ntfs_inode_cache) {
            printk(KERN_CRIT "NTFS: Failed to create %s!\n",
                        ntfs_inode_cache_name);
            goto inode_err_out;
      }

      ntfs_big_inode_cache = kmem_cache_create(ntfs_big_inode_cache_name,
                  sizeof(big_ntfs_inode), 0,
                  SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
                  ntfs_big_inode_init_once, NULL);
      if (!ntfs_big_inode_cache) {
            printk(KERN_CRIT "NTFS: Failed to create %s!\n",
                        ntfs_big_inode_cache_name);
            goto big_inode_err_out;
      }

      /* Register the ntfs sysctls. */
      err = ntfs_sysctl(1);
      if (err) {
            printk(KERN_CRIT "NTFS: Failed to register NTFS sysctls!\n");
            goto sysctl_err_out;
      }

      err = register_filesystem(&ntfs_fs_type);
      if (!err) {
            ntfs_debug("NTFS driver registered successfully.");
            return 0; /* Success! */
      }
      printk(KERN_CRIT "NTFS: Failed to register NTFS filesystem driver!\n");

sysctl_err_out:
      kmem_cache_destroy(ntfs_big_inode_cache);
big_inode_err_out:
      kmem_cache_destroy(ntfs_inode_cache);
inode_err_out:
      kmem_cache_destroy(ntfs_name_cache);
name_err_out:
      kmem_cache_destroy(ntfs_attr_ctx_cache);
actx_err_out:
      kmem_cache_destroy(ntfs_index_ctx_cache);
ictx_err_out:
      if (!err) {
            printk(KERN_CRIT "NTFS: Aborting NTFS filesystem driver "
                        "registration...\n");
            err = -ENOMEM;
      }
      return err;
}

static void __exit exit_ntfs_fs(void)
{
      int err = 0;

      ntfs_debug("Unregistering NTFS driver.");

      unregister_filesystem(&ntfs_fs_type);

      if (kmem_cache_destroy(ntfs_big_inode_cache) && (err = 1))
            printk(KERN_CRIT "NTFS: Failed to destory %s.\n",
                        ntfs_big_inode_cache_name);
      if (kmem_cache_destroy(ntfs_inode_cache) && (err = 1))
            printk(KERN_CRIT "NTFS: Failed to destory %s.\n",
                        ntfs_inode_cache_name);
      if (kmem_cache_destroy(ntfs_name_cache) && (err = 1))
            printk(KERN_CRIT "NTFS: Failed to destory %s.\n",
                        ntfs_name_cache_name);
      if (kmem_cache_destroy(ntfs_attr_ctx_cache) && (err = 1))
            printk(KERN_CRIT "NTFS: Failed to destory %s.\n",
                        ntfs_attr_ctx_cache_name);
      if (kmem_cache_destroy(ntfs_index_ctx_cache) && (err = 1))
            printk(KERN_CRIT "NTFS: Failed to destory %s.\n",
                        ntfs_index_ctx_cache_name);
      if (err)
            printk(KERN_CRIT "NTFS: This causes memory to leak! There is "
                        "probably a BUG in the driver! Please report "
                        "you saw this message to "
                        "linux-ntfs-dev@lists.sourceforge.net\n");
      /* Unregister the ntfs sysctls. */
      ntfs_sysctl(0);
}

MODULE_AUTHOR("Anton Altaparmakov <aia21@cantab.net>");
MODULE_DESCRIPTION("NTFS 1.2/3.x driver - Copyright (c) 2001-2006 Anton Altaparmakov");
MODULE_VERSION(NTFS_VERSION);
MODULE_LICENSE("GPL");
#ifdef DEBUG
module_param(debug_msgs, bool, 0);
MODULE_PARM_DESC(debug_msgs, "Enable debug messages.");
#endif

module_init(init_ntfs_fs)
module_exit(exit_ntfs_fs)

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