tune2fs.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: */
/*
 * tune2fs.c - Change the file system parameters on an ext2 file system
 *
 * Copyright (C) 1992, 1993, 1994  Remy Card <[e-mail]>
 *                                 Laboratoire MASI, Institut Blaise Pascal
 *                                 Universite Pierre et Marie Curie (Paris VI)
 *
 * Copyright 1995, 1996, 1997, 1998, 1999, 2000 by Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

/*
 * History:
 * 93/06/01	- Creation
 * 93/10/31	- Added the -c option to change the maximal mount counts
 * 93/12/14	- Added -l flag to list contents of superblock
 *                M.J.E. Mol ([e-mail])
 *                F.W. ten Wolde ([e-mail])
 * 93/12/29	- Added the -e option to change errors behavior
 * 94/02/27	- Ported to use the ext2fs library
 * 94/03/06	- Added the checks interval from Uwe Ohse ([e-mail])
 */

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

#include "e2fsbb.h"
#include "ext2fs/ext2_fs.h"
#include "ext2fs/ext2fs.h"
#include "uuid/uuid.h"
#include "e2p/e2p.h"
#include "ext2fs/kernel-jbd.h"
#include "util.h"
#include "blkid/blkid.h"

#include "libbb.h"

static char * device_name = NULL;
static char * new_label, *new_last_mounted, *new_UUID;
static char * io_options;
static int c_flag, C_flag, e_flag, f_flag, g_flag, i_flag, l_flag, L_flag;
static int m_flag, M_flag, r_flag, s_flag = -1, u_flag, U_flag, T_flag;
static time_t last_check_time;
static int print_label;
static int max_mount_count, mount_count, mount_flags;
static unsigned long interval, reserved_blocks;
static unsigned reserved_ratio;
static unsigned long resgid, resuid;
static unsigned short errors;
static int open_flag;
static char *features_cmd;
static char *mntopts_cmd;

static int journal_size, journal_flags;
static char *journal_device = NULL;

static const char *please_fsck = "Please run e2fsck on the filesystem\n";

static __u32 ok_features[3] = {
	EXT3_FEATURE_COMPAT_HAS_JOURNAL | EXT2_FEATURE_COMPAT_DIR_INDEX,
	EXT2_FEATURE_INCOMPAT_FILETYPE,
	EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER
};

/*
 * Remove an external journal from the filesystem
 */
static void remove_journal_device(ext2_filsys fs)
{
	char		*journal_path;
	ext2_filsys	jfs;
	char		buf[1024];
	journal_superblock_t	*jsb;
	int		i, nr_users;
	errcode_t	retval;
	int		commit_remove_journal = 0;
	io_manager	io_ptr;

	if (f_flag)
		commit_remove_journal = 1; /* force removal even if error */

	uuid_unparse(fs->super->s_journal_uuid, buf);
	journal_path = blkid_get_devname(NULL, "UUID", buf);

	if (!journal_path) {
		journal_path =
			ext2fs_find_block_device(fs->super->s_journal_dev);
		if (!journal_path)
			return;
	}

	io_ptr = unix_io_manager;
	retval = ext2fs_open(journal_path, EXT2_FLAG_RW|
			     EXT2_FLAG_JOURNAL_DEV_OK, 0,
			     fs->blocksize, io_ptr, &jfs);
	if (retval) {
		bb_error_msg("Failed to open external journal");
		goto no_valid_journal;
	}
	if (!(jfs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
		bb_error_msg("%s is not a journal device", journal_path);
		goto no_valid_journal;
	}

	/* Get the journal superblock */
	if ((retval = io_channel_read_blk(jfs->io, 1, -1024, buf))) {
		bb_error_msg("Failed to read journal superblock");
		goto no_valid_journal;
	}

	jsb = (journal_superblock_t *) buf;
	if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
	    (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2))) {
		bb_error_msg("Journal superblock not found!");
		goto no_valid_journal;
	}

	/* Find the filesystem UUID */
	nr_users = ntohl(jsb->s_nr_users);
	for (i=0; i < nr_users; i++) {
		if (memcmp(fs->super->s_uuid,
			   &jsb->s_users[i*16], 16) == 0)
			break;
	}
	if (i >= nr_users) {
		bb_error_msg("Filesystem's UUID not found on journal device");
		commit_remove_journal = 1;
		goto no_valid_journal;
	}
	nr_users--;
	for (i=0; i < nr_users; i++)
		memcpy(&jsb->s_users[i*16], &jsb->s_users[(i+1)*16], 16);
	jsb->s_nr_users = htonl(nr_users);

	/* Write back the journal superblock */
	if ((retval = io_channel_write_blk(jfs->io, 1, -1024, buf))) {
		bb_error_msg("Failed to write journal superblock");
		goto no_valid_journal;
	}

	commit_remove_journal = 1;

no_valid_journal:
	if (commit_remove_journal == 0)
		bb_error_msg_and_die("Journal NOT removed");
	fs->super->s_journal_dev = 0;
	uuid_clear(fs->super->s_journal_uuid);
	ext2fs_mark_super_dirty(fs);
	puts("Journal removed");
	free(journal_path);
}

/* Helper function for remove_journal_inode */
static int release_blocks_proc(ext2_filsys fs, blk_t *blocknr,
			       int blockcnt EXT2FS_ATTR((unused)),
			       void *private EXT2FS_ATTR((unused)))
{
	blk_t	block;
	int	group;

	block = *blocknr;
	ext2fs_unmark_block_bitmap(fs->block_map,block);
	group = ext2fs_group_of_blk(fs, block);
	fs->group_desc[group].bg_free_blocks_count++;
	fs->super->s_free_blocks_count++;
	return 0;
}

/*
 * Remove the journal inode from the filesystem
 */
static void remove_journal_inode(ext2_filsys fs)
{
	struct ext2_inode	inode;
	errcode_t		retval;
	ino_t			ino = fs->super->s_journal_inum;
	char *msg = "to read";
	char *s = "journal inode";

	retval = ext2fs_read_inode(fs, ino,  &inode);
	if (retval)
		goto REMOVE_JOURNAL_INODE_ERROR;
	if (ino == EXT2_JOURNAL_INO) {
		retval = ext2fs_read_bitmaps(fs);
		if (retval) {
			msg = "to read bitmaps";
			s = "";
			goto REMOVE_JOURNAL_INODE_ERROR;
		}
		retval = ext2fs_block_iterate(fs, ino, 0, NULL,
					      release_blocks_proc, NULL);
		if (retval) {
			msg = "clearing";
			goto REMOVE_JOURNAL_INODE_ERROR;
		}
		memset(&inode, 0, sizeof(inode));
		ext2fs_mark_bb_dirty(fs);
		fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
	} else
		inode.i_flags &= ~EXT2_IMMUTABLE_FL;
	retval = ext2fs_write_inode(fs, ino, &inode);
	if (retval) {
		msg = "writing";
REMOVE_JOURNAL_INODE_ERROR:
		bb_error_msg_and_die("Failed %s %s", msg, s);
	}
	fs->super->s_journal_inum = 0;
	ext2fs_mark_super_dirty(fs);
}

/*
 * Update the default mount options
 */
static void update_mntopts(ext2_filsys fs, char *mntopts)
{
	struct ext2_super_block *sb= fs->super;

	if (e2p_edit_mntopts(mntopts, &sb->s_default_mount_opts, ~0))
		bb_error_msg_and_die("Invalid mount option set: %s", mntopts);
	ext2fs_mark_super_dirty(fs);
}

/*
 * Update the feature set as provided by the user.
 */
static void update_feature_set(ext2_filsys fs, char *features)
{
	int sparse, old_sparse, filetype, old_filetype;
	int journal, old_journal, dxdir, old_dxdir;
	struct ext2_super_block *sb= fs->super;
	__u32	old_compat, old_incompat, old_ro_compat;

	old_compat = sb->s_feature_compat;
	old_ro_compat = sb->s_feature_ro_compat;
	old_incompat = sb->s_feature_incompat;

	old_sparse = sb->s_feature_ro_compat &
		EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
	old_filetype = sb->s_feature_incompat &
		EXT2_FEATURE_INCOMPAT_FILETYPE;
	old_journal = sb->s_feature_compat &
		EXT3_FEATURE_COMPAT_HAS_JOURNAL;
	old_dxdir = sb->s_feature_compat &
		EXT2_FEATURE_COMPAT_DIR_INDEX;
	if (e2p_edit_feature(features, &sb->s_feature_compat, ok_features))
		bb_error_msg_and_die("Invalid filesystem option set: %s", features);
	sparse = sb->s_feature_ro_compat &
		EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
	filetype = sb->s_feature_incompat &
		EXT2_FEATURE_INCOMPAT_FILETYPE;
	journal = sb->s_feature_compat &
		EXT3_FEATURE_COMPAT_HAS_JOURNAL;
	dxdir = sb->s_feature_compat &
		EXT2_FEATURE_COMPAT_DIR_INDEX;
	if (old_journal && !journal) {
		if ((mount_flags & EXT2_MF_MOUNTED) &&
		    !(mount_flags & EXT2_MF_READONLY)) {
			bb_error_msg_and_die(
				"The has_journal flag may only be "
				"cleared when the filesystem is\n"
				"unmounted or mounted "
				"read-only");
		}
		if (sb->s_feature_incompat &
		    EXT3_FEATURE_INCOMPAT_RECOVER) {
			bb_error_msg_and_die(
				"The needs_recovery flag is set.  "
				"%s before clearing the has_journal flag.",
				please_fsck);
		}
		if (sb->s_journal_inum) {
			remove_journal_inode(fs);
		}
		if (sb->s_journal_dev) {
			remove_journal_device(fs);
		}
	}
	if (journal && !old_journal) {
		/*
		 * If adding a journal flag, let the create journal
		 * code below handle creating setting the flag and
		 * creating the journal.  We supply a default size if
		 * necessary.
		 */
		if (!journal_size)
			journal_size = -1;
		sb->s_feature_compat &= ~EXT3_FEATURE_COMPAT_HAS_JOURNAL;
	}
	if (dxdir && !old_dxdir) {
		if (!sb->s_def_hash_version)
			sb->s_def_hash_version = EXT2_HASH_TEA;
		if (uuid_is_null((unsigned char *) sb->s_hash_seed))
			uuid_generate((unsigned char *) sb->s_hash_seed);
	}

	if (sb->s_rev_level == EXT2_GOOD_OLD_REV &&
	    (sb->s_feature_compat || sb->s_feature_ro_compat ||
	     sb->s_feature_incompat))
		ext2fs_update_dynamic_rev(fs);
	if ((sparse != old_sparse) ||
	    (filetype != old_filetype)) {
		sb->s_state &= ~EXT2_VALID_FS;
		printf("\n%s\n", please_fsck);
	}
	if ((old_compat != sb->s_feature_compat) ||
	    (old_ro_compat != sb->s_feature_ro_compat) ||
	    (old_incompat != sb->s_feature_incompat))
		ext2fs_mark_super_dirty(fs);
}

/*
 * Add a journal to the filesystem.
 */
static void add_journal(ext2_filsys fs)
{
	if (fs->super->s_feature_compat &
	    EXT3_FEATURE_COMPAT_HAS_JOURNAL) {
		bb_error_msg_and_die("The filesystem already has a journal");
	}
	if (journal_device) {
		make_journal_device(journal_device, fs, 0, 0);
	} else if (journal_size) {
		make_journal_blocks(fs, journal_size, journal_flags, 0);
		/*
		 * If the filesystem wasn't mounted, we need to force
		 * the block group descriptors out.
		 */
		if ((mount_flags & EXT2_MF_MOUNTED) == 0)
			fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
	}
	print_check_message(fs);
}

/*
 * Busybox stuff
 */
static char * x_blkid_get_devname(const char *token)
{
	char * dev_name;

	if (!(dev_name = blkid_get_devname(NULL, token, NULL)))
		bb_error_msg_and_die("Unable to resolve '%s'", token);
	return dev_name;
}

#ifdef CONFIG_E2LABEL
static void parse_e2label_options(int argc, char ** argv)
{
	if ((argc < 2) || (argc > 3))
		bb_show_usage();
	io_options = strchr(argv[1], '?');
	if (io_options)
		*io_options++ = 0;
	device_name = x_blkid_get_devname(argv[1]);