Пример #1
0
static errcode_t e2fsck_journal_load(journal_t *journal)
{
	e2fsck_t ctx = journal->j_dev->k_ctx;
	journal_superblock_t *jsb;
	struct buffer_head *jbh = journal->j_sb_buffer;
	struct problem_context pctx;

	clear_problem_context(&pctx);

	ll_rw_block(READ, 1, &jbh);
	if (jbh->b_err) {
		com_err(ctx->device_name, jbh->b_err,
			_("reading journal superblock\n"));
		return jbh->b_err;
	}

	jsb = journal->j_superblock;
	/* If we don't even have JFS_MAGIC, we probably have a wrong inode */
	if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER))
		return e2fsck_journal_fix_bad_inode(ctx, &pctx);

	switch (ntohl(jsb->s_header.h_blocktype)) {
	case JFS_SUPERBLOCK_V1:
		journal->j_format_version = 1;
		if (jsb->s_feature_compat ||
		    jsb->s_feature_incompat ||
		    jsb->s_feature_ro_compat ||
		    jsb->s_nr_users)
			clear_v2_journal_fields(journal);
		break;
		
	case JFS_SUPERBLOCK_V2:
		journal->j_format_version = 2;
		if (ntohl(jsb->s_nr_users) > 1 &&
		    uuid_is_null(ctx->fs->super->s_journal_uuid))
			clear_v2_journal_fields(journal);
		if (ntohl(jsb->s_nr_users) > 1) {
			fix_problem(ctx, PR_0_JOURNAL_UNSUPP_MULTIFS, &pctx);
			return EXT2_ET_JOURNAL_UNSUPP_VERSION;
		}
		break;

	/*
	 * These should never appear in a journal super block, so if
	 * they do, the journal is badly corrupted.
	 */
	case JFS_DESCRIPTOR_BLOCK:
	case JFS_COMMIT_BLOCK:
	case JFS_REVOKE_BLOCK:
		return EXT2_ET_CORRUPT_SUPERBLOCK;
		
	/* If we don't understand the superblock major type, but there
	 * is a magic number, then it is likely to be a new format we
	 * just don't understand, so leave it alone. */
	default:
		return EXT2_ET_JOURNAL_UNSUPP_VERSION;
	}

	if (JFS_HAS_INCOMPAT_FEATURE(journal, ~JFS_KNOWN_INCOMPAT_FEATURES))
		return EXT2_ET_UNSUPP_FEATURE;
	
	if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
		return EXT2_ET_RO_UNSUPP_FEATURE;

	/* We have now checked whether we know enough about the journal
	 * format to be able to proceed safely, so any other checks that
	 * fail we should attempt to recover from. */
	if (jsb->s_blocksize != htonl(journal->j_blocksize)) {
		com_err(ctx->program_name, EXT2_ET_CORRUPT_SUPERBLOCK,
			_("%s: no valid journal superblock found\n"),
			ctx->device_name);
		return EXT2_ET_CORRUPT_SUPERBLOCK;
	}

	if (ntohl(jsb->s_maxlen) < journal->j_maxlen)
		journal->j_maxlen = ntohl(jsb->s_maxlen);
	else if (ntohl(jsb->s_maxlen) > journal->j_maxlen) {
		com_err(ctx->program_name, EXT2_ET_CORRUPT_SUPERBLOCK,
			_("%s: journal too short\n"),
			ctx->device_name);
		return EXT2_ET_CORRUPT_SUPERBLOCK;
	}

	journal->j_tail_sequence = ntohl(jsb->s_sequence);
	journal->j_transaction_sequence = journal->j_tail_sequence;
	journal->j_tail = ntohl(jsb->s_start);
	journal->j_first = ntohl(jsb->s_first);
	journal->j_last = ntohl(jsb->s_maxlen);

	return 0;
}
Пример #2
0
static errcode_t ext2fs_journal_load(journal_t *journal)
{
	ext2_filsys fs = journal->j_dev->k_fs;
	journal_superblock_t *jsb;
	struct buffer_head *jbh = journal->j_sb_buffer;

	ll_rw_block(READ, 1, &jbh);
	if (jbh->b_err)
		return jbh->b_err;

	jsb = journal->j_superblock;
	/* If we don't even have JFS_MAGIC, we probably have a wrong inode */
	if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER))
		return ext2fs_journal_fix_bad_inode(fs);

	switch (ntohl(jsb->s_header.h_blocktype)) {
	case JFS_SUPERBLOCK_V1:
		journal->j_format_version = 1;
		if (jsb->s_feature_compat ||
		    jsb->s_feature_incompat ||
		    jsb->s_feature_ro_compat ||
		    jsb->s_nr_users)
			clear_v2_journal_fields(journal);
		break;

	case JFS_SUPERBLOCK_V2:
		journal->j_format_version = 2;
		if (ntohl(jsb->s_nr_users) > 1 &&
		    uuid_is_null(fs->super->s_journal_uuid))
			clear_v2_journal_fields(journal);
		if (ntohl(jsb->s_nr_users) > 1)
			return EXT2_ET_JOURNAL_UNSUPP_VERSION;
		break;

	/*
	 * These should never appear in a journal super block, so if
	 * they do, the journal is badly corrupted.
	 */
	case JFS_DESCRIPTOR_BLOCK:
	case JFS_COMMIT_BLOCK:
	case JFS_REVOKE_BLOCK:
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	/* If we don't understand the superblock major type, but there
	 * is a magic number, then it is likely to be a new format we
	 * just don't understand, so leave it alone. */
	default:
		return EXT2_ET_JOURNAL_UNSUPP_VERSION;
	}

	if (JFS_HAS_INCOMPAT_FEATURE(journal, ~JFS_KNOWN_INCOMPAT_FEATURES))
		return EXT2_ET_UNSUPP_FEATURE;

	if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
		return EXT2_ET_RO_UNSUPP_FEATURE;

	/* Checksum v1-3 are mutually exclusive features. */
	if (jfs_has_feature_csum2(journal) && jfs_has_feature_csum3(journal))
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	if (journal_has_csum_v2or3(journal) &&
	    jfs_has_feature_checksum(journal))
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	if (!ext2fs_journal_verify_csum_type(journal, jsb) ||
	    !ext2fs_journal_sb_csum_verify(journal, jsb))
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	if (journal_has_csum_v2or3(journal))
		journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
						   sizeof(jsb->s_uuid));

	/* We have now checked whether we know enough about the journal
	 * format to be able to proceed safely, so any other checks that
	 * fail we should attempt to recover from. */
	if (jsb->s_blocksize != htonl(journal->j_blocksize))
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	if (ntohl(jsb->s_maxlen) < journal->j_maxlen)
		journal->j_maxlen = ntohl(jsb->s_maxlen);
	else if (ntohl(jsb->s_maxlen) > journal->j_maxlen)
		return EXT2_ET_CORRUPT_JOURNAL_SB;

	journal->j_tail_sequence = ntohl(jsb->s_sequence);
	journal->j_transaction_sequence = journal->j_tail_sequence;
	journal->j_tail = ntohl(jsb->s_start);
	journal->j_first = ntohl(jsb->s_first);
	journal->j_last = ntohl(jsb->s_maxlen);

	return 0;
}