mft.c

LINUX下读写NTFS分区的工具。 已经集成了通过LIBCONV库支持中文的代码。

 */
static int ntfs_mft_bitmap_extend_initialized(ntfs_volume *vol)
{
	s64 old_data_size, old_initialized_size, ll;
	ntfs_attr *mftbmp_na;
	ntfs_attr_search_ctx *ctx;
	ATTR_RECORD *a;
	int err;
	int ret = -1;

	ntfs_log_enter("Entering\n");
	
	mftbmp_na = vol->mftbmp_na;
	ctx = ntfs_attr_get_search_ctx(mftbmp_na->ni, NULL);
	if (!ctx)
		goto out;

	if (ntfs_attr_lookup(mftbmp_na->type, mftbmp_na->name,
			mftbmp_na->name_len, 0, 0, NULL, 0, ctx)) {
		ntfs_log_error("Failed to find first attribute extent of "
				"mft bitmap attribute.\n");
		err = errno;
		goto put_err_out;
	}
	a = ctx->attr;
	old_data_size = mftbmp_na->data_size;
	old_initialized_size = mftbmp_na->initialized_size;
	mftbmp_na->initialized_size += 8;
	a->initialized_size = cpu_to_sle64(mftbmp_na->initialized_size);
	if (mftbmp_na->initialized_size > mftbmp_na->data_size) {
		mftbmp_na->data_size = mftbmp_na->initialized_size;
		a->data_size = cpu_to_sle64(mftbmp_na->data_size);
	}
	/* Ensure the changes make it to disk. */
	ntfs_inode_mark_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	/* Initialize the mft bitmap attribute value with zeroes. */
	ll = 0;
	ll = ntfs_attr_pwrite(mftbmp_na, old_initialized_size, 8, &ll);
	if (ll == 8) {
		ntfs_log_debug("Wrote eight initialized bytes to mft bitmap.\n");
		vol->free_mft_records += (8 * 8); 
		ret = 0;
		goto out;
	}
	ntfs_log_error("Failed to write to mft bitmap.\n");
	err = errno;
	if (ll >= 0)
		err = EIO;
	/* Try to recover from the error. */
	ctx = ntfs_attr_get_search_ctx(mftbmp_na->ni, NULL);
	if (!ctx)
		goto err_out;

	if (ntfs_attr_lookup(mftbmp_na->type, mftbmp_na->name,
			mftbmp_na->name_len, 0, 0, NULL, 0, ctx)) {
		ntfs_log_error("Failed to find first attribute extent of "
				"mft bitmap attribute.%s\n", es);
put_err_out:
		ntfs_attr_put_search_ctx(ctx);
		goto err_out;
	}
	a = ctx->attr;
	mftbmp_na->initialized_size = old_initialized_size;
	a->initialized_size = cpu_to_sle64(old_initialized_size);
	if (mftbmp_na->data_size != old_data_size) {
		mftbmp_na->data_size = old_data_size;
		a->data_size = cpu_to_sle64(old_data_size);
	}
	ntfs_inode_mark_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	ntfs_log_debug("Restored status of mftbmp: allocated_size 0x%llx, "
			"data_size 0x%llx, initialized_size 0x%llx.\n",
			(long long)mftbmp_na->allocated_size,
			(long long)mftbmp_na->data_size,
			(long long)mftbmp_na->initialized_size);
err_out:
	errno = err;
out:
	ntfs_log_leave("\n");
	return ret;
}

/**
 * ntfs_mft_data_extend_allocation - extend mft data attribute
 * @vol:	volume on which to extend the mft data attribute
 *
 * Extend the mft data attribute on the ntfs volume @vol by 16 mft records
 * worth of clusters or if not enough space for this by one mft record worth
 * of clusters.
 *
 * Note:  Only changes allocated_size, i.e. does not touch initialized_size or
 * data_size.
 *
 * Return 0 on success and -1 on error with errno set to the error code.
 */
static int ntfs_mft_data_extend_allocation(ntfs_volume *vol)
{
	LCN lcn;
	VCN old_last_vcn;
	s64 min_nr, nr, ll = 0; /* silence compiler warning */
	ntfs_attr *mft_na;
	runlist_element *rl, *rl2;
	ntfs_attr_search_ctx *ctx;
	MFT_RECORD *m = NULL; /* silence compiler warning */
	ATTR_RECORD *a = NULL; /* silence compiler warning */
	int err, mp_size;
	int ret = -1;
	u32 old_alen = 0; /* silence compiler warning */
	BOOL mp_rebuilt = FALSE;

	ntfs_log_enter("Extending mft data allocation.\n");
	
	mft_na = vol->mft_na;
	/*
	 * Determine the preferred allocation location, i.e. the last lcn of
	 * the mft data attribute.  The allocated size of the mft data
	 * attribute cannot be zero so we are ok to do this.
	 */
	rl = ntfs_attr_find_vcn(mft_na,
			(mft_na->allocated_size - 1) >> vol->cluster_size_bits);
	
	if (!rl || !rl->length || rl->lcn < 0) {
		ntfs_log_error("Failed to determine last allocated "
				"cluster of mft data attribute.\n");
		if (rl)
			errno = EIO;
		goto out;
	}
	
	lcn = rl->lcn + rl->length;
	ntfs_log_debug("Last lcn of mft data attribute is 0x%llx.\n", (long long)lcn);
	/* Minimum allocation is one mft record worth of clusters. */
	min_nr = vol->mft_record_size >> vol->cluster_size_bits;
	if (!min_nr)
		min_nr = 1;
	/* Want to allocate 16 mft records worth of clusters. */
	nr = vol->mft_record_size << 4 >> vol->cluster_size_bits;
	if (!nr)
		nr = min_nr;
	
	old_last_vcn = rl[1].vcn;
	do {
		rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE);
		if (rl2)
			break;
		if (errno != ENOSPC || nr == min_nr) {
			ntfs_log_perror("Failed to allocate (%lld) clusters "
					"for $MFT", (long long)nr);
			goto out;
		}
		/*
		 * There is not enough space to do the allocation, but there
		 * might be enough space to do a minimal allocation so try that
		 * before failing.
		 */
		nr = min_nr;
		ntfs_log_debug("Retrying mft data allocation with minimal cluster "
				"count %lli.\n", (long long)nr);
	} while (1);
	
	ntfs_log_debug("Allocated %lli clusters.\n", nr);
	
	rl = ntfs_runlists_merge(mft_na->rl, rl2);
	if (!rl) {
		err = errno;
		ntfs_log_error("Failed to merge runlists for mft data "
				"attribute.\n");
		if (ntfs_cluster_free_from_rl(vol, rl2))
			ntfs_log_error("Failed to deallocate clusters "
					"from the mft data attribute.%s\n", es);
		free(rl2);
		errno = err;
		goto out;
	}
	mft_na->rl = rl;
	
	/* Find the last run in the new runlist. */
	for (; rl[1].length; rl++)
		;
	/* Update the attribute record as well. */
	ctx = ntfs_attr_get_search_ctx(mft_na->ni, NULL);
	if (!ctx)
		goto undo_alloc;

	if (ntfs_attr_lookup(mft_na->type, mft_na->name, mft_na->name_len, 0,
			rl[1].vcn, NULL, 0, ctx)) {
		ntfs_log_error("Failed to find last attribute extent of "
				"mft data attribute.\n");
		goto undo_alloc;
	}
	m = ctx->mrec;
	a = ctx->attr;
	ll = sle64_to_cpu(a->lowest_vcn);
	rl2 = ntfs_attr_find_vcn(mft_na, ll);
	if (!rl2 || !rl2->length) {
		ntfs_log_error("Failed to determine previous last "
				"allocated cluster of mft data attribute.\n");
		if (rl2)
			errno = EIO;
		goto undo_alloc;
	}
	/* Get the size for the new mapping pairs array for this extent. */
	mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll);
	if (mp_size <= 0) {
		ntfs_log_error("Get size for mapping pairs failed for "
				"mft data attribute extent.\n");
		goto undo_alloc;
	}
	/* Expand the attribute record if necessary. */
	old_alen = le32_to_cpu(a->length);
	if (ntfs_attr_record_resize(m, a,
			mp_size + le16_to_cpu(a->mapping_pairs_offset))) {
		// TODO: Deal with this by moving this extent to a new mft
		// record or by starting a new extent in a new mft record.
		// Note: Use the special reserved mft records and ensure that
		// this extent is not required to find the mft record in
		// question.
		errno = EOPNOTSUPP;
		ntfs_log_perror("Not enough space to extended mft data");
		goto undo_alloc;
	}
	mp_rebuilt = TRUE;
	/*
	 * Generate the mapping pairs array directly into the attribute record.
	 */
	if (ntfs_mapping_pairs_build(vol,
			(u8*)a + le16_to_cpu(a->mapping_pairs_offset), mp_size,
			rl2, ll, NULL)) {
		ntfs_log_error("Failed to build mapping pairs array of "
				"mft data attribute.\n");
		errno = EIO;
		goto undo_alloc;
	}
	/* Update the highest_vcn. */
	a->highest_vcn = cpu_to_sle64(rl[1].vcn - 1);
	/*
	 * We now have extended the mft data allocated_size by nr clusters.
	 * Reflect this in the ntfs_attr structure and the attribute record.
	 * @rl is the last (non-terminator) runlist element of mft data
	 * attribute.
	 */
	if (a->lowest_vcn) {
		/*
		 * We are not in the first attribute extent, switch to it, but
		 * first ensure the changes will make it to disk later.
		 */
		ntfs_inode_mark_dirty(ctx->ntfs_ino);
		ntfs_attr_reinit_search_ctx(ctx);
		if (ntfs_attr_lookup(mft_na->type, mft_na->name,
				mft_na->name_len, 0, 0, NULL, 0, ctx)) {
			ntfs_log_error("Failed to find first attribute "
					"extent of mft data attribute.\n");
			goto restore_undo_alloc;
		}
		a = ctx->attr;
	}
	mft_na->allocated_size += nr << vol->cluster_size_bits;
	a->allocated_size = cpu_to_sle64(mft_na->allocated_size);
	/* Ensure the changes make it to disk. */
	ntfs_inode_mark_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	ret = 0;
out:
	ntfs_log_leave("\n");
	return ret;

restore_undo_alloc:
	err = errno;
	ntfs_attr_reinit_search_ctx(ctx);
	if (ntfs_attr_lookup(mft_na->type, mft_na->name, mft_na->name_len, 0,
			rl[1].vcn, NULL, 0, ctx)) {
		ntfs_log_error("Failed to find last attribute extent of "
				"mft data attribute.%s\n", es);
		ntfs_attr_put_search_ctx(ctx);
		mft_na->allocated_size += nr << vol->cluster_size_bits;
		/*
		 * The only thing that is now wrong is ->allocated_size of the
		 * base attribute extent which chkdsk should be able to fix.
		 */
		errno = err;
		goto out;
	}
	m = ctx->mrec;
	a = ctx->attr;
	a->highest_vcn = cpu_to_sle64(old_last_vcn - 1);
	errno = err;
undo_alloc:
	err = errno;
	if (ntfs_cluster_free(vol, mft_na, old_last_vcn, -1) < 0)
		ntfs_log_error("Failed to free clusters from mft data "
				"attribute.%s\n", es);
	if (ntfs_rl_truncate(&mft_na->rl, old_last_vcn))
		ntfs_log_error("Failed to truncate mft data attribute "
				"runlist.%s\n", es);
	if (mp_rebuilt) {
		if (ntfs_mapping_pairs_build(vol, (u8*)a +
				le16_to_cpu(a->mapping_pairs_offset),
				old_alen - le16_to_cpu(a->mapping_pairs_offset),
				rl2, ll, NULL))
			ntfs_log_error("Failed to restore mapping pairs "
					"array.%s\n", es);
		if (ntfs_attr_record_resize(m, a, old_alen))
			ntfs_log_error("Failed to restore attribute "
					"record.%s\n", es);
		ntfs_inode_mark_dirty(ctx->ntfs_ino);
	}
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	errno = err;
	goto out;
}


static int ntfs_mft_record_init(ntfs_volume *vol, s64 size)
{
	int ret = -1;
	ntfs_attr *mft_na, *mftbmp_na;
	s64 old_data_initialized, old_data_size;
	ntfs_attr_search_ctx *ctx;
	
	ntfs_log_enter("Entering\n");
	
	/* NOTE: Caller must sanity check vol, vol->mft_na and vol->mftbmp_na */
	
	mft_na = vol->mft_na;
	mftbmp_na = vol->mftbmp_na;
	
	/*
	 * The mft record is outside the initialized data. Extend the mft data
	 * attribute until it covers the allocated record. The loop is only
	 * actually traversed more than once when a freshly formatted volume
	 * is first written to so it optimizes away nicely in the common case.
	 */
	ntfs_log_debug("Status of mft data before extension: "
			"allocated_size 0x%llx, data_size 0x%llx, "
			"initialized_size 0x%llx.\n",
			(long long)mft_na->allocated_size,
			(long long)mft_na->data_size,
			(long long)mft_na->initialized_size);
	while (size > mft_na->allocated_size) {
		if (ntfs_mft_data_extend_allocation(vol))
			goto out;
		ntfs_log_debug("Status of mft data after allocation extension: "
				"allocated_size 0x%llx, data_size 0x%llx, "
				"initialized_size 0x%llx.\n",
				(long long)mft_na->allocated_size,
				(long long)mft_na->data_size,
				(long long)mft_na->initialized_size);
	}
	
	old_data_initialized = mft_na->initialized_size;
	old_data_size = mft_na->data_size;
	
	/*
	 * Extend mft data initialized size (and data size of course) to reach
	 * the allocated mft record, formatting the mft records along the way.
	 * Note: We only modify the ntfs_attr structure as that is all that is
	 * needed by ntfs_mft_record_format().  We will update the attribute
	 * record itself in one fell swoop later on.
	 */
	while (size > mft_na->initialized_size) {
		s64 ll2 = mft_na->initialized_size >> vol->mft_record_size_bits;
		mft_na->initialized_size += vol->mft_record_size;
		if (mft_na->initialized_size > mft_na->data_size)
			mft_na->data_size = mft_na->initialized_size;
		ntfs_log_debug("Initializing mft record 0x%llx.\n", (long long)ll2);
		if (ntfs_mft_record_format(vol, ll2) < 0) {
			ntfs_log_perror("Failed to format mft record");
			goto undo_data_init;
		}
	}
	
	/* Update the mft data attribute record to reflect the new sizes. */
	ctx = ntfs_attr_get_search_ctx(mft_na->ni, NULL);
	if (!ctx)
		goto undo_data_init;

	if (ntfs_attr_lookup(mft_na->type, mft_na->name, mft_na->name_len, 0,
			0, NULL, 0, ctx)) {
		ntfs_log_error("Failed to find first attribute extent of "
				"mft data attribute.\n");
		ntfs_attr_put_search_ctx(ctx);
		goto undo_data_init;
	}
	ctx->attr->initialized_size = cpu_to_sle64(mft_na->initialized_size);
	ctx->attr->data_size = cpu_to_sle64(mft_na->data_size);
	
	/* Ensure the changes make it to disk. */
	ntfs_inode_mark_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	ntfs_log_debug("Status of mft data after mft record initialization: "
			"allocated_size 0x%llx, data_size 0x%llx, "
			"initialized_size 0x%llx.\n",
			(long long)mft_na->allocated_size,
			(long long)mft_na->data_size,
			(long long)mft_na->initialized_size);
	
	/* Sanity checks. */
	if (mft_na->data_size > mft_na->allocated_size ||
	    mft_na->initialized_size > mft_na->data_size)
		NTFS_BUG("mft_na sanity checks failed");
	// BUG_ON(mft_na->initialized_size > mft_na->data_size);
	// BUG_ON(mft_na->data_size > mft_na->allocated_size);