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 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
  *
  * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
  * Copyright (c) 2001,2002 Richard Russon
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #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_logical_block_size(). */
 #include <linux/backing-dev.h>
 #include <linux/buffer_head.h>
 #include <linux/vfs.h>
 #include <linux/moduleparam.h>
 #include <linux/bitmap.h>
 
 #include "sysctl.h"
 #include "logfile.h"
 #include "quota.h"
 #include "usnjrnl.h"
 #include "dir.h"
 #include "debug.h"
 #include "index.h"
 #include "inode.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;
 static unsigned long ntfs_nr_upcase_users;
 
 /* 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;
     kuid_t uid = INVALID_UID;
     kgid_t gid = INVALID_GID;
     umode_t fmask = (umode_t)-1, dmask = (umode_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_UID(option, variable)               \
     if (!strcmp(p, option)) {                   \
         uid_t uid_value;                    \
         if (!v || !*v)                      \
             goto needs_arg;                 \
         uid_value = simple_strtoul(ov = v, &v, 0);      \
         if (*v)                         \
             goto needs_val;                 \
         variable = make_kuid(current_user_ns(), uid_value); \
         if (!uid_valid(variable))               \
             goto needs_val;                 \
     }
 #define NTFS_GETOPT_GID(option, variable)               \
     if (!strcmp(p, option)) {                   \
         gid_t gid_value;                    \
         if (!v || !*v)                      \
             goto needs_arg;                 \
         gid_value = simple_strtoul(ov = v, &v, 0);      \
         if (*v)                         \
             goto needs_val;                 \
         variable = make_kgid(current_user_ns(), gid_value); \
         if (!gid_valid(variable))               \
             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", uid)
         else NTFS_GETOPT_GID("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 */ {
                 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_valid(uid))
         vol->uid = uid;
     if (gid_valid(gid))
         vol->gid = gid;
     if (fmask != (umode_t)-1)
         vol->fmask = fmask;
     if (dmask != (umode_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);
 
     sync_filesystem(sb);
 
 #ifndef NTFS_RW
     /* For read-only compiled driver, enforce read-only flag. */
     *flags |= SB_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 occurred.
      */
     if (sb_rdonly(sb) && !(*flags & SB_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 $LogFile%s",
                     es);
             NVolSetErrors(vol);
             return -EROFS;
         }
         if (!ntfs_mark_quotas_out_of_date(vol)) {
             ntfs_error(sb, "Failed to mark quotas out of date%s",
                     es);
             NVolSetErrors(vol);
             return -EROFS;
         }
         if (!ntfs_stamp_usnjrnl(vol)) {
             ntfs_error(sb, "Failed to stamp transaction log "
                     "($UsnJrnl)%s", es);
             NVolSetErrors(vol);
             return -EROFS;
         }
     } else if (!sb_rdonly(sb) && (*flags & SB_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 != 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_rdonly(sb)) {
             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_SIZE since
      * we store $MFT/$DATA, the table of mft records in the page cache.
      */
     if (vol->mft_record_size > PAGE_SIZE) {
         ntfs_error(vol->sb, "Mft record size (%i) exceeds the "
                 "PAGE_SIZE on your system (%lu).  "
                 "This is not supported.  Sorry.",
                 vol->mft_record_size, PAGE_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 = GLOBAL_ROOT_UID;
     tmp_ino->i_gid = GLOBAL_ROOT_GID;
     /* 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_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;
     struct page *page;
     u32 *kaddr, *kend;
     ntfs_name *name = NULL;
     int ret = 1;
     static const ntfschar hiberfil[13] = { cpu_to_le16('h'),
             cpu_to_le16('i'), cpu_to_le16('b'),
             cpu_to_le16('e'), cpu_to_le16('r'),
             cpu_to_le16('f'), cpu_to_le16('i'),
             cpu_to_le16('l'), cpu_to_le16('.'),
             cpu_to_le16('s'), cpu_to_le16('y'),
             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.
      */
     inode_lock(vol->root_ino);
     mref = ntfs_lookup_inode_by_name(NTFS_I(vol->root_ino), hiberfil, 12,
             &name);
     inode_unlock(vol->root_ino);
     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 occurred. */
         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;
     }
     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 == 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 $Quota is not present, we
  * leave vol->quota_ino as NULL and return success.
  */
 static bool load_and_init_quota(ntfs_volume *vol)
 {
     MFT_REF mref;
     struct inode *tmp_ino;
     ntfs_name *name = NULL;
     static const ntfschar Quota[7] = { cpu_to_le16('$'),
             cpu_to_le16('Q'), cpu_to_le16('u'),
             cpu_to_le16('o'), cpu_to_le16('t'),
             cpu_to_le16('a'), 0 };
     static ntfschar Q[3] = { cpu_to_le16('$'),
             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 $Extend.
      */
     inode_lock(vol->extend_ino);
     mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), Quota, 6,
             &name);
     inode_unlock(vol->extend_ino);
     if (IS_ERR_MREF(mref)) {
         /*
          * If the file does not exist, quotas are disabled and have
          * never been enabled on this volume, just return success.
          */
         if (MREF_ERR(mref) == -ENOENT) {
             ntfs_debug("$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 occurred. */
         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] = { cpu_to_le16('$'),
             cpu_to_le16('U'), cpu_to_le16('s'),
             cpu_to_le16('n'), cpu_to_le16('J'),
             cpu_to_le16('r'), cpu_to_le16('n'),
             cpu_to_le16('l'), 0 };
     static ntfschar Max[5] = { cpu_to_le16('$'),
             cpu_to_le16('M'), cpu_to_le16('a'),
             cpu_to_le16('x'), 0 };
     static ntfschar J[3] = { cpu_to_le16('$'),
             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 $Extend.
      */
     inode_lock(vol->extend_ino);
     mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), UsnJrnl, 8,
             &name);
     inode_unlock(vol->extend_ino);
     if (IS_ERR_MREF(mref)) {
         /*
          * If the file does not exist, transaction logging is disabled,
          * just return success.
          */
         if (MREF_ERR(mref) == -ENOENT) {
             ntfs_debug("$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 occurred. */
         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 (IS_ERR(tmp_ino) || unlikely(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_SHIFT;
     size = PAGE_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_SHIFT),
                 page_address(page), size);
         ntfs_unmap_page(page);
     };
     if (size == PAGE_SIZE) {
         size = i_size & ~PAGE_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_SHIFT;
     size = PAGE_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_SHIFT),
                 page_address(page), size);
         ntfs_unmap_page(page);
     };
     if (size == PAGE_SIZE) {
         size = i_size & ~PAGE_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_rdonly(sb)) {
             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 |= SB_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));
     pr_info("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_rdonly(sb)) {
             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 |= SB_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_rdonly(sb)) {
             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 |= SB_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_rdonly(sb)) {
             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 |= SB_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_rdonly(sb) && 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 |= SB_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 & SB_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 |= SB_RDONLY;
         NVolSetErrors(vol);
     }
 #endif
     /* If (still) a read-write mount, empty the logfile. */
     if (!sb_rdonly(sb) && !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 |= SB_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) ||
         !S_ISDIR(vol->extend_ino->i_mode)) {
         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_rdonly(sb)) {
             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 |= SB_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_rdonly(sb) && !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 |= SB_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_rdonly(sb)) {
             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 |= SB_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_rdonly(sb) && !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 |= SB_RDONLY;
         NVolSetErrors(vol);
     }
 #endif /* NTFS_RW */
     return true;
 #ifdef NTFS_RW
 iput_usnjrnl_err_out:
     iput(vol->usnjrnl_j_ino);
     iput(vol->usnjrnl_max_ino);
     iput(vol->usnjrnl_ino);
 iput_quota_err_out:
     iput(vol->quota_q_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
     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
     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 occurred, mark the
      * volume clean.  Also, re-commit all affected inodes.
      */
     if (!sb_rdonly(sb)) {
         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;
     }
     /*
      * We should have no dirty inodes left, due to
      * mft.c::ntfs_mft_writepage() cleaning all the dirty pages as
      * the underlying mft records are written out and cleaned.
      */
     ntfs_commit_inode(vol->mft_ino);
     write_inode_now(vol->mft_ino, 1);
 #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;
     }
 
     unload_nls(vol->nls_map);
 
     sb->s_fs_info = NULL;
     kfree(vol);
 }
 
 /**
  * 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;
     struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
     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_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_SIZE - 1) >>
             PAGE_SHIFT;
     /* Use multiples of 4 bytes, thus max_size is PAGE_SIZE / 4. */
     ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%lx.",
             max_index, PAGE_SIZE / 4);
     for (index = 0; index < max_index; index++) {
         unsigned long *kaddr;
 
         /*
          * Read the page from page cache, getting it from backing store
          * if necessary, and increment the use count.
          */
         page = read_mapping_page(mapping, index, NULL);
         /* Ignore pages which errored synchronously. */
         if (IS_ERR(page)) {
             ntfs_debug("read_mapping_page() error. Skipping "
                     "page (index 0x%lx).", index);
             nr_free -= PAGE_SIZE * 8;
             continue;
         }
         kaddr = kmap_atomic(page);
         /*
          * 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().
          */
         nr_free -= bitmap_weight(kaddr,
                     PAGE_SIZE * BITS_PER_BYTE);
         kunmap_atomic(kaddr);
         put_page(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 occurred 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)
 {
     struct address_space *mapping = vol->mftbmp_ino->i_mapping;
     struct page *page;
     pgoff_t index;
 
     ntfs_debug("Entering.");
     /* Use multiples of 4 bytes, thus max_size is PAGE_SIZE / 4. */
     ntfs_debug("Reading $MFT/$BITMAP, max_index = 0x%lx, max_size = "
             "0x%lx.", max_index, PAGE_SIZE / 4);
     for (index = 0; index < max_index; index++) {
         unsigned long *kaddr;
 
         /*
          * Read the page from page cache, getting it from backing store
          * if necessary, and increment the use count.
          */
         page = read_mapping_page(mapping, index, NULL);
         /* Ignore pages which errored synchronously. */
         if (IS_ERR(page)) {
             ntfs_debug("read_mapping_page() error. Skipping "
                     "page (index 0x%lx).", index);
             nr_free -= PAGE_SIZE * 8;
             continue;
         }
         kaddr = kmap_atomic(page);
         /*
          * 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().
          */
         nr_free -= bitmap_weight(kaddr,
                     PAGE_SIZE * BITS_PER_BYTE);
         kunmap_atomic(kaddr);
         put_page(page);
     }
     ntfs_debug("Finished reading $MFT/$BITMAP, last index = 0x%lx.",
             index - 1);
     /* If errors occurred 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_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_SHIFT;
     /* Free data blocks in filesystem in units of f_bsize. */
     size          = get_nr_free_clusters(vol) << vol->cluster_size_bits >>
                 PAGE_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_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_SIZE - 1) >> PAGE_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 = u64_to_fsid(vol->serial_no);
     /* Maximum length of filenames. */
     sfs->f_namelen     = NTFS_MAX_NAME_LEN;
     return 0;
 }
 
 #ifdef NTFS_RW
 static int ntfs_write_inode(struct inode *vi, struct writeback_control *wbc)
 {
     return __ntfs_write_inode(vi, wbc->sync_mode == WB_SYNC_ALL);
 }
 #endif
 
 /**
  * The complete super operations.
  */
 static const struct super_operations ntfs_sops = {
     .alloc_inode    = ntfs_alloc_big_inode,   /* VFS: Allocate new inode. */
     .free_inode = ntfs_free_big_inode, /* VFS: Deallocate inode. */
 #ifdef NTFS_RW
     .write_inode    = ntfs_write_inode, /* VFS: Write dirty inode to
                            disk. */
 #endif /* NTFS_RW */
     .put_super  = ntfs_put_super,   /* Syscall: umount. */
     .statfs     = ntfs_statfs,      /* Syscall: statfs */
     .remount_fs = ntfs_remount,     /* Syscall: mount -o remount. */
     .evict_inode    = ntfs_evict_big_inode, /* VFS: Called when an inode is
                            removed from memory. */
     .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 |= SB_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);
 
     /* 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_SIZE. */
     if (bdev_logical_block_size(sb->s_bdev) > PAGE_SIZE) {
         if (!silent)
             ntfs_error(sb, "Device has unsupported sector size "
                     "(%i).  The maximum supported sector "
                     "size on this architecture is %lu "
                     "bytes.",
                     bdev_logical_block_size(sb->s_bdev),
                     PAGE_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. */
     vol->nr_blocks = sb_bdev_nr_blocks(sb);
     if (!vol->nr_blocks) {
         if (!silent)
             ntfs_error(sb, "Unable to determine device size.");
         goto err_out_now;
     }
     /* 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 = sb_bdev_nr_blocks(sb);
         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;
     }
 
     /* We grab a reference, simulating an ntfs_iget(). */
     ihold(vol->root_ino);
     if ((sb->s_root = d_make_root(vol->root_ino))) {
         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;
         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;
     /* Errors at this stage are irrelevant. */
 err_out_now:
     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)
 {
     ntfs_inode *ni = (ntfs_inode *)foo;
 
     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 struct dentry *ntfs_mount(struct file_system_type *fs_type,
     int flags, const char *dev_name, void *data)
 {
     return mount_bdev(fs_type, flags, dev_name, data, ntfs_fill_super);
 }
 
 static struct file_system_type ntfs_fs_type = {
     .owner      = THIS_MODULE,
     .name       = "ntfs",
     .mount      = ntfs_mount,
     .kill_sb    = kill_block_super,
     .fs_flags   = FS_REQUIRES_DEV,
 };
 MODULE_ALIAS_FS("ntfs");
 
 /* 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 */
     pr_info("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 */);
     if (!ntfs_index_ctx_cache) {
         pr_crit("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 */);
     if (!ntfs_attr_ctx_cache) {
         pr_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);
     if (!ntfs_name_cache) {
         pr_crit("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);
     if (!ntfs_inode_cache) {
         pr_crit("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|
             SLAB_ACCOUNT, ntfs_big_inode_init_once);
     if (!ntfs_big_inode_cache) {
         pr_crit("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) {
         pr_crit("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! */
     }
     pr_crit("Failed to register NTFS filesystem driver!\n");
 
     /* Unregister the ntfs sysctls. */
     ntfs_sysctl(0);
 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) {
         pr_crit("Aborting NTFS filesystem driver registration...\n");
         err = -ENOMEM;
     }
     return err;
 }
 
 static void __exit exit_ntfs_fs(void)
 {
     ntfs_debug("Unregistering NTFS driver.");
 
     unregister_filesystem(&ntfs_fs_type);
 
     /*
      * Make sure all delayed rcu free inodes are flushed before we
      * destroy cache.
      */
     rcu_barrier();
     kmem_cache_destroy(ntfs_big_inode_cache);
     kmem_cache_destroy(ntfs_inode_cache);
     kmem_cache_destroy(ntfs_name_cache);
     kmem_cache_destroy(ntfs_attr_ctx_cache);
     kmem_cache_destroy(ntfs_index_ctx_cache);
     /* Unregister the ntfs sysctls. */
     ntfs_sysctl(0);
 }
 
 MODULE_AUTHOR("Anton Altaparmakov <anton@tuxera.com>");
 MODULE_DESCRIPTION("NTFS 1.2/3.x driver - Copyright (c) 2001-2014 Anton Altaparmakov and Tuxera Inc.");
 MODULE_VERSION(NTFS_VERSION);
 MODULE_LICENSE("GPL");
 #ifdef DEBUG
 module_param(debug_msgs, bint, 0);
 MODULE_PARM_DESC(debug_msgs, "Enable debug messages.");
 #endif
 
 module_init(init_ntfs_fs)
 module_exit(exit_ntfs_fs)