mke2fs.c

busybox最新版的源码:学习和应用的好东东,多的不说了,大家看后再说吧

/* vi: set sw=4 ts=4: */
/*
 * mke2fs.c - Make a ext2fs filesystem.
 *
 * Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
 *	2003, 2004, 2005 by Theodore Ts'o.
 *
 * This file may be redistributed under the terms of the GNU Public
 * License.
 */

/* Usage: mke2fs [options] device
 *
 * The device may be a block device or a image of one, but this isn't
 * enforced (but it's not much fun on a character device :-).
 */

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <time.h>
#include <getopt.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <mntent.h>
#include <sys/ioctl.h>
#include <sys/types.h>

#include "e2fsbb.h"
#include "ext2fs/ext2_fs.h"
#include "uuid/uuid.h"
#include "e2p/e2p.h"
#include "ext2fs/ext2fs.h"
#include "util.h"

#define STRIDE_LENGTH 8

#ifndef __sparc__
#define ZAP_BOOTBLOCK
#endif

static const char * device_name;

/* Command line options */
static int	cflag;
static int	quiet;
static int	super_only;
static int	force;
static int	noaction;
static int	journal_size;
static int	journal_flags;
static const char *bad_blocks_filename;
static __u32	fs_stride;

static struct ext2_super_block param;
static char *creator_os;
static char *volume_label;
static char *mount_dir;
static char *journal_device = NULL;
static int   sync_kludge; /* Set using the MKE2FS_SYNC env. option */

static int sys_page_size = 4096;
static int linux_version_code = 0;

static int int_log2(int arg)
{
	int l = 0;

	arg >>= 1;
	while (arg) {
		l++;
		arg >>= 1;
	}
	return l;
}

static int int_log10(unsigned int arg)
{
	int	l;

	for (l = 0; arg; l++)
		arg = arg / 10;
	return l;
}

/*
 * This function sets the default parameters for a filesystem
 *
 * The type is specified by the user.  The size is the maximum size
 * (in megabytes) for which a set of parameters applies, with a size
 * of zero meaning that it is the default parameter for the type.
 * Note that order is important in the table below.
 */
#define DEF_MAX_BLOCKSIZE -1
static const char default_str[] = "default";
struct mke2fs_defaults {
	const char	*type;
	int		size;
	int		blocksize;
	int		inode_ratio;
};

static const struct mke2fs_defaults settings[] = {
	{ default_str,	 0, 4096, 8192 },
	{ default_str, 512, 1024, 4096 },
	{ default_str,	 3, 1024, 8192 },
	{ "journal",	 0, 4096, 8192 },
	{ "news",	 0, 4096, 4096 },
	{ "largefile",	 0, 4096, 1024 * 1024 },
	{ "largefile4",  0, 4096, 4096 * 1024 },
	{ 0,		 0,    0, 0},
};

static void set_fs_defaults(const char *fs_type,
			    struct ext2_super_block *super,
			    int blocksize, int sector_size,
			    int *inode_ratio)
{
	int	megs;
	int	ratio = 0;
	const struct mke2fs_defaults *p;
	int	use_bsize = 1024;

	megs = super->s_blocks_count * (EXT2_BLOCK_SIZE(super) / 1024) / 1024;
	if (inode_ratio)
		ratio = *inode_ratio;
	if (!fs_type)
		fs_type = default_str;
	for (p = settings; p->type; p++) {
		if ((strcmp(p->type, fs_type) != 0) &&
		    (strcmp(p->type, default_str) != 0))
			continue;
		if ((p->size != 0) && (megs > p->size))
			continue;
		if (ratio == 0)
			*inode_ratio = p->inode_ratio < blocksize ?
				blocksize : p->inode_ratio;
		use_bsize = p->blocksize;
	}
	if (blocksize <= 0) {
		if (use_bsize == DEF_MAX_BLOCKSIZE) {
			use_bsize = sys_page_size;
			if ((linux_version_code < (2*65536 + 6*256)) &&
			    (use_bsize > 4096))
				use_bsize = 4096;
		}
		if (sector_size && use_bsize < sector_size)
			use_bsize = sector_size;
		if ((blocksize < 0) && (use_bsize < (-blocksize)))
			use_bsize = -blocksize;
		blocksize = use_bsize;
		super->s_blocks_count /= blocksize / 1024;
	}
	super->s_log_frag_size = super->s_log_block_size =
		int_log2(blocksize >> EXT2_MIN_BLOCK_LOG_SIZE);
}


/*
 * Helper function for read_bb_file and test_disk
 */
static void invalid_block(ext2_filsys fs EXT2FS_ATTR((unused)), blk_t blk)
{
	bb_error_msg("Bad block %u out of range; ignored", blk);
}

/*
 * Busybox stuff
 */
static void mke2fs_error_msg_and_die(int retval, const char *fmt, ...) __attribute__ ((format (printf, 2, 3)));
static void mke2fs_error_msg_and_die(int retval, const char *fmt, ...)
{
	va_list ap;

	if (retval) {
		va_start(ap, fmt);
		fprintf(stderr,"\nCould not ");
		vfprintf(stderr, fmt, ap);
		fprintf(stderr, "\n");
		va_end(ap);
		exit(EXIT_FAILURE);
	}
}

static void mke2fs_verbose(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
static void mke2fs_verbose(const char *fmt, ...)
{
	va_list ap;

	if (!quiet) {
		va_start(ap, fmt);
		vfprintf(stdout, fmt, ap);
		fflush(stdout);
		va_end(ap);
	}
}

static void mke2fs_verbose_done(void)
{
	mke2fs_verbose("done\n");
}

static void mke2fs_warning_msg(int retval, char *fmt, ... ) __attribute__ ((format (printf, 2, 3)));
static void mke2fs_warning_msg(int retval, char *fmt, ... )
{
	va_list ap;

	if (retval) {
		va_start(ap, fmt);
		fprintf(stderr,"\nWarning: ");
		vfprintf(stderr, fmt, ap);
		fprintf(stderr, "\n");
		va_end(ap);
	}
}

/*
 * Reads the bad blocks list from a file
 */
static void read_bb_file(ext2_filsys fs, badblocks_list *bb_list,
			 const char *bad_blocks_file)
{
	FILE		*f;
	errcode_t	retval;

	f = xfopen(bad_blocks_file, "r");
	retval = ext2fs_read_bb_FILE(fs, f, bb_list, invalid_block);
	fclose (f);
	mke2fs_error_msg_and_die(retval, "read bad blocks from list");
}

/*
 * Runs the badblocks program to test the disk
 */
static void test_disk(ext2_filsys fs, badblocks_list *bb_list)
{
	FILE		*f;
	errcode_t	retval;
	char		buf[1024];

	sprintf(buf, "badblocks -b %d %s%s%s %d", fs->blocksize,
		quiet ? "" : "-s ", (cflag > 1) ? "-w " : "",
		fs->device_name, fs->super->s_blocks_count);
	mke2fs_verbose("Running command: %s\n", buf);
	f = popen(buf, "r");
	if (!f) {
		bb_perror_msg_and_die("cannot run '%s'", buf);
	}
	retval = ext2fs_read_bb_FILE(fs, f, bb_list, invalid_block);
	pclose(f);
	mke2fs_error_msg_and_die(retval, "read bad blocks from program");
}

static void handle_bad_blocks(ext2_filsys fs, badblocks_list bb_list)
{
	dgrp_t			i;
	blk_t			j;
	unsigned		must_be_good;
	blk_t			blk;
	badblocks_iterate	bb_iter;
	errcode_t		retval;
	blk_t			group_block;
	int			group;
	int			group_bad;

	if (!bb_list)
		return;

	/*
	 * The primary superblock and group descriptors *must* be
	 * good; if not, abort.
	 */
	must_be_good = fs->super->s_first_data_block + 1 + fs->desc_blocks;
	for (i = fs->super->s_first_data_block; i <= must_be_good; i++) {
		if (ext2fs_badblocks_list_test(bb_list, i)) {
			bb_error_msg_and_die(
				"Block %d in primary superblock/group descriptor area bad\n"
				"Blocks %d through %d must be good in order to build a filesystem\n"
				"Aborting ...", i, fs->super->s_first_data_block, must_be_good);
		}
	}

	/*
	 * See if any of the bad blocks are showing up in the backup
	 * superblocks and/or group descriptors.  If so, issue a
	 * warning and adjust the block counts appropriately.
	 */
	group_block = fs->super->s_first_data_block +
		fs->super->s_blocks_per_group;

	for (i = 1; i < fs->group_desc_count; i++) {
		group_bad = 0;
		for (j=0; j < fs->desc_blocks+1; j++) {
			if (ext2fs_badblocks_list_test(bb_list,
						       group_block + j)) {
				mke2fs_warning_msg(!group_bad,
					"the backup superblock/group descriptors at block %d contain\n"
					"bad blocks\n", group_block);
				group_bad++;
				group = ext2fs_group_of_blk(fs, group_block+j);
				fs->group_desc[group].bg_free_blocks_count++;
				fs->super->s_free_blocks_count++;
			}
		}
		group_block += fs->super->s_blocks_per_group;
	}

	/*
	 * Mark all the bad blocks as used...
	 */
	retval = ext2fs_badblocks_list_iterate_begin(bb_list, &bb_iter);
	mke2fs_error_msg_and_die(retval, "mark bad blocks as used");

	while (ext2fs_badblocks_list_iterate(bb_iter, &blk))
		ext2fs_mark_block_bitmap(fs->block_map, blk);
	ext2fs_badblocks_list_iterate_end(bb_iter);
}

/*
 * These functions implement a generalized progress meter.
 */
struct progress_struct {
	char		format[20];
	char		backup[80];
	__u32		max;
	int		skip_progress;
};

static void progress_init(struct progress_struct *progress,
			  const char *label,__u32 max)
{
	int	i;

	memset(progress, 0, sizeof(struct progress_struct));
	if (quiet)
		return;

	/*
	 * Figure out how many digits we need
	 */
	i = int_log10(max);
	sprintf(progress->format, "%%%dd/%%%dld", i, i);
	memset(progress->backup, '\b', sizeof(progress->backup)-1);
	progress->backup[sizeof(progress->backup)-1] = 0;
	if ((2*i)+1 < (int) sizeof(progress->backup))
		progress->backup[(2*i)+1] = 0;
	progress->max = max;

	progress->skip_progress = 0;
	if (getenv("MKE2FS_SKIP_PROGRESS"))
		progress->skip_progress++;

	fputs(label, stdout);
	fflush(stdout);
}

static void progress_update(struct progress_struct *progress, __u32 val)
{
	if ((progress->format[0] == 0) || progress->skip_progress)
		return;
	printf(progress->format, val, progress->max);
	fputs(progress->backup, stdout);
}

static void progress_close(struct progress_struct *progress)
{
	if (progress->format[0] == 0)
		return;
	printf("%-28s\n", "done");
}


/*
 * Helper function which zeros out _num_ blocks starting at _blk_.  In
 * case of an error, the details of the error is returned via _ret_blk_
 * and _ret_count_ if they are non-NULL pointers.  Returns 0 on
 * success, and an error code on an error.
 *
 * As a special case, if the first argument is NULL, then it will
 * attempt to free the static zeroizing buffer.  (This is to keep
 * programs that check for memory leaks happy.)
 */
static errcode_t zero_blocks(ext2_filsys fs, blk_t blk, int num,
			     struct progress_struct *progress,
			     blk_t *ret_blk, int *ret_count)
{
	int		j, count, next_update, next_update_incr;
	static char	*buf;
	errcode_t	retval;

	/* If fs is null, clean up the static buffer and return */
	if (!fs) {
		if (buf) {
			free(buf);
			buf = 0;
		}
		return 0;
	}
	/* Allocate the zeroizing buffer if necessary */
	if (!buf) {
		buf = xzalloc(fs->blocksize * STRIDE_LENGTH);
	}
	/* OK, do the write loop */
	next_update = 0;
	next_update_incr = num / 100;
	if (next_update_incr < 1)
		next_update_incr = 1;
	for (j=0; j < num; j += STRIDE_LENGTH, blk += STRIDE_LENGTH) {
		count = num - j;
		if (count > STRIDE_LENGTH)
			count = STRIDE_LENGTH;
		retval = io_channel_write_blk(fs->io, blk, count, buf);
		if (retval) {
			if (ret_count)
				*ret_count = count;
			if (ret_blk)
				*ret_blk = blk;
			return retval;
		}
		if (progress && j > next_update) {
			next_update += num / 100;
			progress_update(progress, blk);
		}
	}
	return 0;
}

static void write_inode_tables(ext2_filsys fs)
{
	errcode_t	retval;
	blk_t		blk;
	dgrp_t		i;
	int		num;
	struct progress_struct progress;

	if (quiet)
		memset(&progress, 0, sizeof(progress));
	else
		progress_init(&progress, "Writing inode tables: ",
			      fs->group_desc_count);

	for (i = 0; i < fs->group_desc_count; i++) {
		progress_update(&progress, i);