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super.c
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super.c
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/*
* super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2011 Anton Altaparmakov and Tuxera Inc.
* Copyright (c) 2001,2002 Richard Russon
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h> /* For bdev_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 = NULL;
static unsigned long ntfs_nr_upcase_users = 0;
/* Error constants/strings used in inode.c::ntfs_show_options(). */
typedef enum {
/* One of these must be present, default is ON_ERRORS_CONTINUE. */
ON_ERRORS_PANIC = 0x01,
ON_ERRORS_REMOUNT_RO = 0x02,
ON_ERRORS_CONTINUE = 0x04,
/* Optional, can be combined with any of the above. */
ON_ERRORS_RECOVER = 0x10,
} ON_ERRORS_ACTIONS;
const option_t on_errors_arr[] = {
{ ON_ERRORS_PANIC, "panic" },
{ ON_ERRORS_REMOUNT_RO, "remount-ro", },
{ ON_ERRORS_CONTINUE, "continue", },
{ ON_ERRORS_RECOVER, "recover" },
{ 0, NULL }
};
/**
* simple_getbool -
*
* Copied from old ntfs driver (which copied from vfat driver).
*/
static int simple_getbool(char *s, bool *setval)
{
if (s) {
if (!strcmp(s, "1") || !strcmp(s, "yes") || !strcmp(s, "true"))
*setval = true;
else if (!strcmp(s, "0") || !strcmp(s, "no") ||
!strcmp(s, "false"))
*setval = false;
else
return 0;
} else
*setval = true;
return 1;
}
/**
* parse_options - parse the (re)mount options
* @vol: ntfs volume
* @opt: string containing the (re)mount options
*
* Parse the recognized options in @opt for the ntfs volume described by @vol.
*/
static bool parse_options(ntfs_volume *vol, char *opt)
{
char *p, *v, *ov;
static char *utf8 = "utf8";
int errors = 0, sloppy = 0;
uid_t uid = (uid_t)-1;
gid_t gid = (gid_t)-1;
mode_t fmask = (mode_t)-1, dmask = (mode_t)-1;
int mft_zone_multiplier = -1, on_errors = -1;
int show_sys_files = -1, case_sensitive = -1, disable_sparse = -1;
struct nls_table *nls_map = NULL, *old_nls;
/* I am lazy... (-8 */
#define NTFS_GETOPT_WITH_DEFAULT(option, variable, default_value) \
if (!strcmp(p, option)) { \
if (!v || !*v) \
variable = default_value; \
else { \
variable = simple_strtoul(ov = v, &v, 0); \
if (*v) \
goto needs_val; \
} \
}
#define NTFS_GETOPT(option, variable) \
if (!strcmp(p, option)) { \
if (!v || !*v) \
goto needs_arg; \
variable = simple_strtoul(ov = v, &v, 0); \
if (*v) \
goto needs_val; \
}
#define NTFS_GETOPT_OCTAL(option, variable) \
if (!strcmp(p, option)) { \
if (!v || !*v) \
goto needs_arg; \
variable = simple_strtoul(ov = v, &v, 8); \
if (*v) \
goto needs_val; \
}
#define NTFS_GETOPT_BOOL(option, variable) \
if (!strcmp(p, option)) { \
bool val; \
if (!simple_getbool(v, &val)) \
goto needs_bool; \
variable = val; \
}
#define NTFS_GETOPT_OPTIONS_ARRAY(option, variable, opt_array) \
if (!strcmp(p, option)) { \
int _i; \
if (!v || !*v) \
goto needs_arg; \
ov = v; \
if (variable == -1) \
variable = 0; \
for (_i = 0; opt_array[_i].str && *opt_array[_i].str; _i++) \
if (!strcmp(opt_array[_i].str, v)) { \
variable |= opt_array[_i].val; \
break; \
} \
if (!opt_array[_i].str || !*opt_array[_i].str) \
goto needs_val; \
}
if (!opt || !*opt)
goto no_mount_options;
ntfs_debug("Entering with mount options string: %s", opt);
while ((p = strsep(&opt, ","))) {
if ((v = strchr(p, '=')))
*v++ = 0;
NTFS_GETOPT("uid", uid)
else NTFS_GETOPT("gid", gid)
else NTFS_GETOPT_OCTAL("umask", fmask = dmask)
else NTFS_GETOPT_OCTAL("fmask", fmask)
else NTFS_GETOPT_OCTAL("dmask", dmask)
else NTFS_GETOPT("mft_zone_multiplier", mft_zone_multiplier)
else NTFS_GETOPT_WITH_DEFAULT("sloppy", sloppy, true)
else NTFS_GETOPT_BOOL("show_sys_files", show_sys_files)
else NTFS_GETOPT_BOOL("case_sensitive", case_sensitive)
else NTFS_GETOPT_BOOL("disable_sparse", disable_sparse)
else NTFS_GETOPT_OPTIONS_ARRAY("errors", on_errors,
on_errors_arr)
else if (!strcmp(p, "posix") || !strcmp(p, "show_inodes"))
ntfs_warning(vol->sb, "Ignoring obsolete option %s.",
p);
else if (!strcmp(p, "nls") || !strcmp(p, "iocharset")) {
if (!strcmp(p, "iocharset"))
ntfs_warning(vol->sb, "Option iocharset is "
"deprecated. Please use "
"option nls=<charsetname> in "
"the future.");
if (!v || !*v)
goto needs_arg;
use_utf8:
old_nls = nls_map;
nls_map = load_nls(v);
if (!nls_map) {
if (!old_nls) {
ntfs_error(vol->sb, "NLS character set "
"%s not found.", v);
return false;
}
ntfs_error(vol->sb, "NLS character set %s not "
"found. Using previous one %s.",
v, old_nls->charset);
nls_map = old_nls;
} else /* nls_map */ {
unload_nls(old_nls);
}
} else if (!strcmp(p, "utf8")) {
bool val = false;
ntfs_warning(vol->sb, "Option utf8 is no longer "
"supported, using option nls=utf8. Please "
"use option nls=utf8 in the future and "
"make sure utf8 is compiled either as a "
"module or into the kernel.");
if (!v || !*v)
val = true;
else if (!simple_getbool(v, &val))
goto needs_bool;
if (val) {
v = utf8;
goto use_utf8;
}
} else {
ntfs_error(vol->sb, "Unrecognized mount option %s.", p);
if (errors < INT_MAX)
errors++;
}
#undef NTFS_GETOPT_OPTIONS_ARRAY
#undef NTFS_GETOPT_BOOL
#undef NTFS_GETOPT
#undef NTFS_GETOPT_WITH_DEFAULT
}
no_mount_options:
if (errors && !sloppy)
return false;
if (sloppy)
ntfs_warning(vol->sb, "Sloppy option given. Ignoring "
"unrecognized mount option(s) and continuing.");
/* Keep this first! */
if (on_errors != -1) {
if (!on_errors) {
ntfs_error(vol->sb, "Invalid errors option argument "
"or bug in options parser.");
return false;
}
}
if (nls_map) {
if (vol->nls_map && vol->nls_map != nls_map) {
ntfs_error(vol->sb, "Cannot change NLS character set "
"on remount.");
return false;
} /* else (!vol->nls_map) */
ntfs_debug("Using NLS character set %s.", nls_map->charset);
vol->nls_map = nls_map;
} else /* (!nls_map) */ {
if (!vol->nls_map) {
vol->nls_map = load_nls_default();
if (!vol->nls_map) {
ntfs_error(vol->sb, "Failed to load default "
"NLS character set.");
return false;
}
ntfs_debug("Using default NLS character set (%s).",
vol->nls_map->charset);
}
}
if (mft_zone_multiplier != -1) {
if (vol->mft_zone_multiplier && vol->mft_zone_multiplier !=
mft_zone_multiplier) {
ntfs_error(vol->sb, "Cannot change mft_zone_multiplier "
"on remount.");
return false;
}
if (mft_zone_multiplier < 1 || mft_zone_multiplier > 4) {
ntfs_error(vol->sb, "Invalid mft_zone_multiplier. "
"Using default value, i.e. 1.");
mft_zone_multiplier = 1;
}
vol->mft_zone_multiplier = mft_zone_multiplier;
}
if (!vol->mft_zone_multiplier)
vol->mft_zone_multiplier = 1;
if (on_errors != -1)
vol->on_errors = on_errors;
if (!vol->on_errors || vol->on_errors == ON_ERRORS_RECOVER)
vol->on_errors |= ON_ERRORS_CONTINUE;
if (uid != (uid_t)-1)
vol->uid = uid;
if (gid != (gid_t)-1)
vol->gid = gid;
if (fmask != (mode_t)-1)
vol->fmask = fmask;
if (dmask != (mode_t)-1)
vol->dmask = dmask;
if (show_sys_files != -1) {
if (show_sys_files)
NVolSetShowSystemFiles(vol);
else
NVolClearShowSystemFiles(vol);
}
if (case_sensitive != -1) {
if (case_sensitive)
NVolSetCaseSensitive(vol);
else
NVolClearCaseSensitive(vol);
}
if (disable_sparse != -1) {
if (disable_sparse)
NVolClearSparseEnabled(vol);
else {
if (!NVolSparseEnabled(vol) &&
vol->major_ver && vol->major_ver < 3)
ntfs_warning(vol->sb, "Not enabling sparse "
"support due to NTFS volume "
"version %i.%i (need at least "
"version 3.0).", vol->major_ver,
vol->minor_ver);
else
NVolSetSparseEnabled(vol);
}
}
return true;
needs_arg:
ntfs_error(vol->sb, "The %s option requires an argument.", p);
return false;
needs_bool:
ntfs_error(vol->sb, "The %s option requires a boolean argument.", p);
return false;
needs_val:
ntfs_error(vol->sb, "Invalid %s option argument: %s", p, ov);
return false;
}
#ifdef NTFS_RW
/**
* ntfs_write_volume_flags - write new flags to the volume information flags
* @vol: ntfs volume on which to modify the flags
* @flags: new flags value for the volume information flags
*
* Internal function. You probably want to use ntfs_{set,clear}_volume_flags()
* instead (see below).
*
* Replace the volume information flags on the volume @vol with the value
* supplied in @flags. Note, this overwrites the volume information flags, so
* make sure to combine the flags you want to modify with the old flags and use
* the result when calling ntfs_write_volume_flags().
*
* Return 0 on success and -errno on error.
*/
static int ntfs_write_volume_flags(ntfs_volume *vol, const VOLUME_FLAGS flags)
{
ntfs_inode *ni = NTFS_I(vol->vol_ino);
MFT_RECORD *m;
VOLUME_INFORMATION *vi;
ntfs_attr_search_ctx *ctx;
int err;
ntfs_debug("Entering, old flags = 0x%x, new flags = 0x%x.",
le16_to_cpu(vol->vol_flags), le16_to_cpu(flags));
if (vol->vol_flags == flags)
goto done;
BUG_ON(!ni);
m = map_mft_record(ni);
if (IS_ERR(m)) {
err = PTR_ERR(m);
goto err_out;
}
ctx = ntfs_attr_get_search_ctx(ni, m);
if (!ctx) {
err = -ENOMEM;
goto put_unm_err_out;
}
err = ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
ctx);
if (err)
goto put_unm_err_out;
vi = (VOLUME_INFORMATION*)((u8*)ctx->attr +
le16_to_cpu(ctx->attr->data.resident.value_offset));
vol->vol_flags = vi->flags = flags;
flush_dcache_mft_record_page(ctx->ntfs_ino);
mark_mft_record_dirty(ctx->ntfs_ino);
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(ni);
done:
ntfs_debug("Done.");
return 0;
put_unm_err_out:
if (ctx)
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(ni);
err_out:
ntfs_error(vol->sb, "Failed with error code %i.", -err);
return err;
}
/**
* ntfs_set_volume_flags - set bits in the volume information flags
* @vol: ntfs volume on which to modify the flags
* @flags: flags to set on the volume
*
* Set the bits in @flags in the volume information flags on the volume @vol.
*
* Return 0 on success and -errno on error.
*/
static inline int ntfs_set_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
{
flags &= VOLUME_FLAGS_MASK;
return ntfs_write_volume_flags(vol, vol->vol_flags | flags);
}
/**
* ntfs_clear_volume_flags - clear bits in the volume information flags
* @vol: ntfs volume on which to modify the flags
* @flags: flags to clear on the volume
*
* Clear the bits in @flags in the volume information flags on the volume @vol.
*
* Return 0 on success and -errno on error.
*/
static inline int ntfs_clear_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
{
flags &= VOLUME_FLAGS_MASK;
flags = vol->vol_flags & cpu_to_le16(~le16_to_cpu(flags));
return ntfs_write_volume_flags(vol, flags);
}
#endif /* NTFS_RW */
/**
* ntfs_remount - change the mount options of a mounted ntfs filesystem
* @sb: superblock of mounted ntfs filesystem
* @flags: remount flags
* @opt: remount options string
*
* Change the mount options of an already mounted ntfs filesystem.
*
* NOTE: The VFS sets the @sb->s_flags remount flags to @flags after
* ntfs_remount() returns successfully (i.e. returns 0). Otherwise,
* @sb->s_flags are not changed.
*/
static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
{
ntfs_volume *vol = NTFS_SB(sb);
ntfs_debug("Entering with remount options string: %s", opt);
#ifndef NTFS_RW
/* For read-only compiled driver, enforce read-only flag. */
*flags |= MS_RDONLY;
#else /* NTFS_RW */
/*
* For the read-write compiled driver, if we are remounting read-write,
* make sure there are no volume errors and that no unsupported volume
* flags are set. Also, empty the logfile journal as it would become
* stale as soon as something is written to the volume and mark the
* volume dirty so that chkdsk is run if the volume is not umounted
* cleanly. Finally, mark the quotas out of date so Windows rescans
* the volume on boot and updates them.
*
* When remounting read-only, mark the volume clean if no volume errors
* have occured.
*/
if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
static const char *es = ". Cannot remount read-write.";
/* Remounting read-write. */
if (NVolErrors(vol)) {
ntfs_error(sb, "Volume has errors and is read-only%s",
es);
return -EROFS;
}
if (vol->vol_flags & VOLUME_IS_DIRTY) {
ntfs_error(sb, "Volume is dirty and read-only%s", es);
return -EROFS;
}
if (vol->vol_flags & VOLUME_MODIFIED_BY_CHKDSK) {
ntfs_error(sb, "Volume has been modified by chkdsk "
"and is read-only%s", es);
return -EROFS;
}
if (vol->vol_flags & VOLUME_MUST_MOUNT_RO_MASK) {
ntfs_error(sb, "Volume has unsupported flags set "
"(0x%x) and is read-only%s",
(unsigned)le16_to_cpu(vol->vol_flags),
es);
return -EROFS;
}
if (ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY)) {
ntfs_error(sb, "Failed to set dirty bit in volume "
"information flags%s", es);
return -EROFS;
}
#if 0
// TODO: Enable this code once we start modifying anything that
// is different between NTFS 1.2 and 3.x...
/* Set NT4 compatibility flag on newer NTFS version volumes. */
if ((vol->major_ver > 1)) {
if (ntfs_set_volume_flags(vol, VOLUME_MOUNTED_ON_NT4)) {
ntfs_error(sb, "Failed to set NT4 "
"compatibility flag%s", es);
NVolSetErrors(vol);
return -EROFS;
}
}
#endif
if (!ntfs_empty_logfile(vol->logfile_ino)) {
ntfs_error(sb, "Failed to empty journal $LogFile%s",
es);
NVolSetErrors(vol);
return -EROFS;
}
if (!ntfs_mark_quotas_out_of_date(vol)) {
ntfs_error(sb, "Failed to mark quotas out of date%s",
es);
NVolSetErrors(vol);
return -EROFS;
}
if (!ntfs_stamp_usnjrnl(vol)) {
ntfs_error(sb, "Failed to stamp transation log "
"($UsnJrnl)%s", es);
NVolSetErrors(vol);
return -EROFS;
}
} else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
/* Remounting read-only. */
if (!NVolErrors(vol)) {
if (ntfs_clear_volume_flags(vol, VOLUME_IS_DIRTY))
ntfs_warning(sb, "Failed to clear dirty bit "
"in volume information "
"flags. Run chkdsk.");
}
}
#endif /* NTFS_RW */
// TODO: Deal with *flags.
if (!parse_options(vol, opt))
return -EINVAL;
ntfs_debug("Done.");
return 0;
}
/**
* is_boot_sector_ntfs - check whether a boot sector is a valid NTFS boot sector
* @sb: Super block of the device to which @b belongs.
* @b: Boot sector of device @sb to check.
* @silent: If 'true', all output will be silenced.
*
* is_boot_sector_ntfs() checks whether the boot sector @b is a valid NTFS boot
* sector. Returns 'true' if it is valid and 'false' if not.
*
* @sb is only needed for warning/error output, i.e. it can be NULL when silent
* is 'true'.
*/
static bool is_boot_sector_ntfs(const struct super_block *sb,
const NTFS_BOOT_SECTOR *b, const bool silent)
{
/*
* Check that checksum == sum of u32 values from b to the checksum
* field. If checksum is zero, no checking is done. We will work when
* the checksum test fails, since some utilities update the boot sector
* ignoring the checksum which leaves the checksum out-of-date. We
* report a warning if this is the case.
*/
if ((void*)b < (void*)&b->checksum && b->checksum && !silent) {
le32 *u;
u32 i;
for (i = 0, u = (le32*)b; u < (le32*)(&b->checksum); ++u)
i += le32_to_cpup(u);
if (le32_to_cpu(b->checksum) != i)
ntfs_warning(sb, "Invalid boot sector checksum.");
}
/* Check OEMidentifier is "NTFS " */
if (b->oem_id != magicNTFS)
goto not_ntfs;
/* Check bytes per sector value is between 256 and 4096. */
if (le16_to_cpu(b->bpb.bytes_per_sector) < 0x100 ||
le16_to_cpu(b->bpb.bytes_per_sector) > 0x1000)
goto not_ntfs;
/* Check sectors per cluster value is valid. */
switch (b->bpb.sectors_per_cluster) {
case 1: case 2: case 4: case 8: case 16: case 32: case 64: case 128:
break;
default:
goto not_ntfs;
}
/* Check the cluster size is not above the maximum (64kiB). */
if ((u32)le16_to_cpu(b->bpb.bytes_per_sector) *
b->bpb.sectors_per_cluster > NTFS_MAX_CLUSTER_SIZE)
goto not_ntfs;
/* Check reserved/unused fields are really zero. */
if (le16_to_cpu(b->bpb.reserved_sectors) ||
le16_to_cpu(b->bpb.root_entries) ||
le16_to_cpu(b->bpb.sectors) ||
le16_to_cpu(b->bpb.sectors_per_fat) ||
le32_to_cpu(b->bpb.large_sectors) || b->bpb.fats)
goto not_ntfs;
/* Check clusters per file mft record value is valid. */
if ((u8)b->clusters_per_mft_record < 0xe1 ||
(u8)b->clusters_per_mft_record > 0xf7)
switch (b->clusters_per_mft_record) {
case 1: case 2: case 4: case 8: case 16: case 32: case 64:
break;
default:
goto not_ntfs;
}
/* Check clusters per index block value is valid. */
if ((u8)b->clusters_per_index_record < 0xe1 ||
(u8)b->clusters_per_index_record > 0xf7)
switch (b->clusters_per_index_record) {
case 1: case 2: case 4: case 8: case 16: case 32: case 64:
break;
default:
goto not_ntfs;
}
/*
* Check for valid end of sector marker. We will work without it, but
* many BIOSes will refuse to boot from a bootsector if the magic is
* incorrect, so we emit a warning.
*/
if (!silent && b->end_of_sector_marker != cpu_to_le16(0xaa55))
ntfs_warning(sb, "Invalid end of sector marker.");
return true;
not_ntfs:
return false;
}
/**
* read_ntfs_boot_sector - read the NTFS boot sector of a device
* @sb: super block of device to read the boot sector from
* @silent: if true, suppress all output
*
* Reads the boot sector from the device and validates it. If that fails, tries
* to read the backup boot sector, first from the end of the device a-la NT4 and
* later and then from the middle of the device a-la NT3.51 and before.
*
* If a valid boot sector is found but it is not the primary boot sector, we
* repair the primary boot sector silently (unless the device is read-only or
* the primary boot sector is not accessible).
*
* NOTE: To call this function, @sb must have the fields s_dev, the ntfs super
* block (u.ntfs_sb), nr_blocks and the device flags (s_flags) initialized
* to their respective values.
*
* Return the unlocked buffer head containing the boot sector or NULL on error.
*/
static struct buffer_head *read_ntfs_boot_sector(struct super_block *sb,
const int silent)
{
const char *read_err_str = "Unable to read %s boot sector.";
struct buffer_head *bh_primary, *bh_backup;
sector_t nr_blocks = NTFS_SB(sb)->nr_blocks;
/* Try to read primary boot sector. */
if ((bh_primary = sb_bread(sb, 0))) {
if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
bh_primary->b_data, silent))
return bh_primary;
if (!silent)
ntfs_error(sb, "Primary boot sector is invalid.");
} else if (!silent)
ntfs_error(sb, read_err_str, "primary");
if (!(NTFS_SB(sb)->on_errors & ON_ERRORS_RECOVER)) {
if (bh_primary)
brelse(bh_primary);
if (!silent)
ntfs_error(sb, "Mount option errors=recover not used. "
"Aborting without trying to recover.");
return NULL;
}
/* Try to read NT4+ backup boot sector. */
if ((bh_backup = sb_bread(sb, nr_blocks - 1))) {
if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
bh_backup->b_data, silent))
goto hotfix_primary_boot_sector;
brelse(bh_backup);
} else if (!silent)
ntfs_error(sb, read_err_str, "backup");
/* Try to read NT3.51- backup boot sector. */
if ((bh_backup = sb_bread(sb, nr_blocks >> 1))) {
if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
bh_backup->b_data, silent))
goto hotfix_primary_boot_sector;
if (!silent)
ntfs_error(sb, "Could not find a valid backup boot "
"sector.");
brelse(bh_backup);
} else if (!silent)
ntfs_error(sb, read_err_str, "backup");
/* We failed. Cleanup and return. */
if (bh_primary)
brelse(bh_primary);
return NULL;
hotfix_primary_boot_sector:
if (bh_primary) {
/*
* If we managed to read sector zero and the volume is not
* read-only, copy the found, valid backup boot sector to the
* primary boot sector. Note we only copy the actual boot
* sector structure, not the actual whole device sector as that
* may be bigger and would potentially damage the $Boot system
* file (FIXME: Would be nice to know if the backup boot sector
* on a large sector device contains the whole boot loader or
* just the first 512 bytes).
*/
if (!(sb->s_flags & MS_RDONLY)) {
ntfs_warning(sb, "Hot-fix: Recovering invalid primary "
"boot sector from backup copy.");
memcpy(bh_primary->b_data, bh_backup->b_data,
NTFS_BLOCK_SIZE);
mark_buffer_dirty(bh_primary);
sync_dirty_buffer(bh_primary);
if (buffer_uptodate(bh_primary)) {
brelse(bh_backup);
return bh_primary;
}
ntfs_error(sb, "Hot-fix: Device write error while "
"recovering primary boot sector.");
} else {
ntfs_warning(sb, "Hot-fix: Recovery of primary boot "
"sector failed: Read-only mount.");
}
brelse(bh_primary);
}
ntfs_warning(sb, "Using backup boot sector.");
return bh_backup;
}
/**
* parse_ntfs_boot_sector - parse the boot sector and store the data in @vol
* @vol: volume structure to initialise with data from boot sector
* @b: boot sector to parse
*
* Parse the ntfs boot sector @b and store all imporant information therein in
* the ntfs super block @vol. Return 'true' on success and 'false' on error.
*/
static bool parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
{
unsigned int sectors_per_cluster_bits, nr_hidden_sects;
int clusters_per_mft_record, clusters_per_index_record;
s64 ll;
vol->sector_size = le16_to_cpu(b->bpb.bytes_per_sector);
vol->sector_size_bits = ffs(vol->sector_size) - 1;
ntfs_debug("vol->sector_size = %i (0x%x)", vol->sector_size,
vol->sector_size);
ntfs_debug("vol->sector_size_bits = %i (0x%x)", vol->sector_size_bits,
vol->sector_size_bits);
if (vol->sector_size < vol->sb->s_blocksize) {
ntfs_error(vol->sb, "Sector size (%i) is smaller than the "
"device block size (%lu). This is not "
"supported. Sorry.", vol->sector_size,
vol->sb->s_blocksize);
return false;
}
ntfs_debug("sectors_per_cluster = 0x%x", b->bpb.sectors_per_cluster);
sectors_per_cluster_bits = ffs(b->bpb.sectors_per_cluster) - 1;
ntfs_debug("sectors_per_cluster_bits = 0x%x",
sectors_per_cluster_bits);
nr_hidden_sects = le32_to_cpu(b->bpb.hidden_sectors);
ntfs_debug("number of hidden sectors = 0x%x", nr_hidden_sects);
vol->cluster_size = vol->sector_size << sectors_per_cluster_bits;
vol->cluster_size_mask = vol->cluster_size - 1;
vol->cluster_size_bits = ffs(vol->cluster_size) - 1;
ntfs_debug("vol->cluster_size = %i (0x%x)", vol->cluster_size,
vol->cluster_size);
ntfs_debug("vol->cluster_size_mask = 0x%x", vol->cluster_size_mask);
ntfs_debug("vol->cluster_size_bits = %i", vol->cluster_size_bits);
if (vol->cluster_size < vol->sector_size) {
ntfs_error(vol->sb, "Cluster size (%i) is smaller than the "
"sector size (%i). This is not supported. "
"Sorry.", vol->cluster_size, vol->sector_size);
return false;
}
clusters_per_mft_record = b->clusters_per_mft_record;
ntfs_debug("clusters_per_mft_record = %i (0x%x)",
clusters_per_mft_record, clusters_per_mft_record);
if (clusters_per_mft_record > 0)
vol->mft_record_size = vol->cluster_size <<
(ffs(clusters_per_mft_record) - 1);
else
/*
* When mft_record_size < cluster_size, clusters_per_mft_record
* = -log2(mft_record_size) bytes. mft_record_size normaly is
* 1024 bytes, which is encoded as 0xF6 (-10 in decimal).
*/
vol->mft_record_size = 1 << -clusters_per_mft_record;
vol->mft_record_size_mask = vol->mft_record_size - 1;
vol->mft_record_size_bits = ffs(vol->mft_record_size) - 1;
ntfs_debug("vol->mft_record_size = %i (0x%x)", vol->mft_record_size,
vol->mft_record_size);
ntfs_debug("vol->mft_record_size_mask = 0x%x",
vol->mft_record_size_mask);
ntfs_debug("vol->mft_record_size_bits = %i (0x%x)",
vol->mft_record_size_bits, vol->mft_record_size_bits);
/*
* We cannot support mft record sizes above the PAGE_CACHE_SIZE since
* we store $MFT/$DATA, the table of mft records in the page cache.
*/
if (vol->mft_record_size > PAGE_CACHE_SIZE) {
ntfs_error(vol->sb, "Mft record size (%i) exceeds the "
"PAGE_CACHE_SIZE on your system (%lu). "
"This is not supported. Sorry.",
vol->mft_record_size, PAGE_CACHE_SIZE);
return false;
}
/* We cannot support mft record sizes below the sector size. */
if (vol->mft_record_size < vol->sector_size) {
ntfs_error(vol->sb, "Mft record size (%i) is smaller than the "
"sector size (%i). This is not supported. "
"Sorry.", vol->mft_record_size,
vol->sector_size);
return false;
}
clusters_per_index_record = b->clusters_per_index_record;
ntfs_debug("clusters_per_index_record = %i (0x%x)",
clusters_per_index_record, clusters_per_index_record);
if (clusters_per_index_record > 0)
vol->index_record_size = vol->cluster_size <<
(ffs(clusters_per_index_record) - 1);
else
/*
* When index_record_size < cluster_size,
* clusters_per_index_record = -log2(index_record_size) bytes.
* index_record_size normaly equals 4096 bytes, which is
* encoded as 0xF4 (-12 in decimal).
*/
vol->index_record_size = 1 << -clusters_per_index_record;
vol->index_record_size_mask = vol->index_record_size - 1;
vol->index_record_size_bits = ffs(vol->index_record_size) - 1;
ntfs_debug("vol->index_record_size = %i (0x%x)",
vol->index_record_size, vol->index_record_size);
ntfs_debug("vol->index_record_size_mask = 0x%x",
vol->index_record_size_mask);
ntfs_debug("vol->index_record_size_bits = %i (0x%x)",
vol->index_record_size_bits,
vol->index_record_size_bits);
/* We cannot support index record sizes below the sector size. */
if (vol->index_record_size < vol->sector_size) {
ntfs_error(vol->sb, "Index record size (%i) is smaller than "
"the sector size (%i). This is not "
"supported. Sorry.", vol->index_record_size,
vol->sector_size);
return false;
}
/*
* Get the size of the volume in clusters and check for 64-bit-ness.
* Windows currently only uses 32 bits to save the clusters so we do
* the same as it is much faster on 32-bit CPUs.
*/
ll = sle64_to_cpu(b->number_of_sectors) >> sectors_per_cluster_bits;
if ((u64)ll >= 1ULL << 32) {
ntfs_error(vol->sb, "Cannot handle 64-bit clusters. Sorry.");
return false;
}
vol->nr_clusters = ll;
ntfs_debug("vol->nr_clusters = 0x%llx", (long long)vol->nr_clusters);
/*
* On an architecture where unsigned long is 32-bits, we restrict the
* volume size to 2TiB (2^41). On a 64-bit architecture, the compiler
* will hopefully optimize the whole check away.
*/
if (sizeof(unsigned long) < 8) {
if ((ll << vol->cluster_size_bits) >= (1ULL << 41)) {
ntfs_error(vol->sb, "Volume size (%lluTiB) is too "
"large for this architecture. "
"Maximum supported is 2TiB. Sorry.",
(unsigned long long)ll >> (40 -
vol->cluster_size_bits));
return false;
}
}
ll = sle64_to_cpu(b->mft_lcn);
if (ll >= vol->nr_clusters) {
ntfs_error(vol->sb, "MFT LCN (%lli, 0x%llx) is beyond end of "
"volume. Weird.", (unsigned long long)ll,
(unsigned long long)ll);
return false;
}
vol->mft_lcn = ll;
ntfs_debug("vol->mft_lcn = 0x%llx", (long long)vol->mft_lcn);
ll = sle64_to_cpu(b->mftmirr_lcn);
if (ll >= vol->nr_clusters) {
ntfs_error(vol->sb, "MFTMirr LCN (%lli, 0x%llx) is beyond end "
"of volume. Weird.", (unsigned long long)ll,
(unsigned long long)ll);
return false;
}
vol->mftmirr_lcn = ll;
ntfs_debug("vol->mftmirr_lcn = 0x%llx", (long long)vol->mftmirr_lcn);
#ifdef NTFS_RW
/*
* Work out the size of the mft mirror in number of mft records. If the
* cluster size is less than or equal to the size taken by four mft
* records, the mft mirror stores the first four mft records. If the
* cluster size is bigger than the size taken by four mft records, the
* mft mirror contains as many mft records as will fit into one
* cluster.
*/
if (vol->cluster_size <= (4 << vol->mft_record_size_bits))
vol->mftmirr_size = 4;
else
vol->mftmirr_size = vol->cluster_size >>
vol->mft_record_size_bits;
ntfs_debug("vol->mftmirr_size = %i", vol->mftmirr_size);
#endif /* NTFS_RW */
vol->serial_no = le64_to_cpu(b->volume_serial_number);
ntfs_debug("vol->serial_no = 0x%llx",
(unsigned long long)vol->serial_no);
return true;
}
/**
* ntfs_setup_allocators - initialize the cluster and mft allocators
* @vol: volume structure for which to setup the allocators
*
* Setup the cluster (lcn) and mft allocators to the starting values.
*/
static void ntfs_setup_allocators(ntfs_volume *vol)
{
#ifdef NTFS_RW
LCN mft_zone_size, mft_lcn;
#endif /* NTFS_RW */
ntfs_debug("vol->mft_zone_multiplier = 0x%x",
vol->mft_zone_multiplier);
#ifdef NTFS_RW
/* Determine the size of the MFT zone. */
mft_zone_size = vol->nr_clusters;
switch (vol->mft_zone_multiplier) { /* % of volume size in clusters */
case 4:
mft_zone_size >>= 1; /* 50% */
break;
case 3:
mft_zone_size = (mft_zone_size +
(mft_zone_size >> 1)) >> 2; /* 37.5% */
break;
case 2:
mft_zone_size >>= 2; /* 25% */
break;
/* case 1: */
default:
mft_zone_size >>= 3; /* 12.5% */
break;
}
/* Setup the mft zone. */
vol->mft_zone_start = vol->mft_zone_pos = vol->mft_lcn;
ntfs_debug("vol->mft_zone_pos = 0x%llx",
(unsigned long long)vol->mft_zone_pos);
/*
* Calculate the mft_lcn for an unmodified NTFS volume (see mkntfs
* source) and if the actual mft_lcn is in the expected place or even
* further to the front of the volume, extend the mft_zone to cover the
* beginning of the volume as well. This is in order to protect the
* area reserved for the mft bitmap as well within the mft_zone itself.
* On non-standard volumes we do not protect it as the overhead would
* be higher than the speed increase we would get by doing it.
*/
mft_lcn = (8192 + 2 * vol->cluster_size - 1) / vol->cluster_size;
if (mft_lcn * vol->cluster_size < 16 * 1024)
mft_lcn = (16 * 1024 + vol->cluster_size - 1) /
vol->cluster_size;
if (vol->mft_zone_start <= mft_lcn)
vol->mft_zone_start = 0;
ntfs_debug("vol->mft_zone_start = 0x%llx",
(unsigned long long)vol->mft_zone_start);
/*
* Need to cap the mft zone on non-standard volumes so that it does
* not point outside the boundaries of the volume. We do this by
* halving the zone size until we are inside the volume.
*/
vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
while (vol->mft_zone_end >= vol->nr_clusters) {
mft_zone_size >>= 1;
vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
}
ntfs_debug("vol->mft_zone_end = 0x%llx",
(unsigned long long)vol->mft_zone_end);
/*
* Set the current position within each data zone to the start of the
* respective zone.
*/
vol->data1_zone_pos = vol->mft_zone_end;
ntfs_debug("vol->data1_zone_pos = 0x%llx",
(unsigned long long)vol->data1_zone_pos);
vol->data2_zone_pos = 0;
ntfs_debug("vol->data2_zone_pos = 0x%llx",
(unsigned long long)vol->data2_zone_pos);
/* Set the mft data allocation position to mft record 24. */
vol->mft_data_pos = 24;
ntfs_debug("vol->mft_data_pos = 0x%llx",
(unsigned long long)vol->mft_data_pos);
#endif /* NTFS_RW */
}
#ifdef NTFS_RW