super.c

linux 内核源代码

/*
 * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
 *
 * Copyright (c) 2001-2007 Anton Altaparmakov
 * Copyright (c) 2001,2002 Richard Russon
 *
 * This program/include file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

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

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

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

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

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

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

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

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

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

#ifdef NTFS_RW

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

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

/**
 * ntfs_set_volume_flags - set bits in the volume information flags
 * @vol:	ntfs volume on which to modify the flags
 * @flags:	flags to set on the volume
 *
 * Set the bits in @flags in the volume information flags on the volume @vol.
 *
 * Return 0 on success and -errno on error.
 */