inode.c

上一个上传的有问题,这个是好的。visopsys包括系统内核和GUI的全部SOURCE code ,还包括一些基本的docs文档。里面src子目录对应所有SOURCE code.对于想研究操作系统的朋

		return -1;
	}

	if (ni->nr_extents == -1)
		ni = ni->base_ni;

	ntfs_log_trace("Entering for inode 0x%llx.\n", (long long) ni->mft_no);

	/* Inode haven't got attribute list, thus nothing to attach. */
	if (!NInoAttrList(ni))
		return 0;

	if (!ni->attr_list) {
		ntfs_log_trace("Corrupt in-memory struct.\n");
		errno = EINVAL;
		return -1;
	}

	/* Walk through attribute list and attach all extents. */
	errno = 0;
	ale = (ATTR_LIST_ENTRY *)ni->attr_list;
	while ((u8*)ale < ni->attr_list + ni->attr_list_size) {
		if (ni->mft_no != MREF_LE(ale->mft_reference) &&
				prev_attached != MREF_LE(ale->mft_reference)) {
			if (!ntfs_extent_inode_open(ni,
					MREF_LE(ale->mft_reference))) {
				ntfs_log_trace("Couldn't attach extent inode.\n");
				return -1;
			}
			prev_attached = MREF_LE(ale->mft_reference);
		}
		ale = (ATTR_LIST_ENTRY *)((u8*)ale + le16_to_cpu(ale->length));
	}
	return 0;
}

/**
 * ntfs_inode_sync_standard_information - update standard information attribute
 * @ni:		ntfs inode to update standard information
 *
 * Return 0 on success or -1 on error with errno set to the error code.
 */
static int ntfs_inode_sync_standard_information(ntfs_inode *ni)
{
	ntfs_attr_search_ctx *ctx;
	STANDARD_INFORMATION *std_info;
	int err;

	ntfs_log_trace("Entering for inode 0x%llx.\n", (long long) ni->mft_no);

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx)
		return -1;
	if (ntfs_attr_lookup(AT_STANDARD_INFORMATION, AT_UNNAMED,
				0, CASE_SENSITIVE, 0, NULL, 0, ctx)) {
		err = errno;
		ntfs_log_trace("Failed to receive STANDARD_INFORMATION "
				"attribute.\n");
		ntfs_attr_put_search_ctx(ctx);
		errno = err;
		return -1;
	}
	std_info = (STANDARD_INFORMATION *)((u8 *)ctx->attr +
			le16_to_cpu(ctx->attr->value_offset));
	std_info->file_attributes = ni->flags;
	std_info->creation_time = utc2ntfs(ni->creation_time);
	std_info->last_data_change_time = utc2ntfs(ni->last_data_change_time);
	std_info->last_mft_change_time = utc2ntfs(ni->last_mft_change_time);
	std_info->last_access_time = utc2ntfs(ni->last_access_time);
	ntfs_inode_mark_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	return 0;
}

/**
 * ntfs_inode_sync_file_name - update FILE_NAME attributes
 * @ni:		ntfs inode to update FILE_NAME attributes
 *
 * Update all FILE_NAME attributes for inode @ni in the index.
 *
 * Return 0 on success or -1 on error with errno set to the error code.
 */
static int ntfs_inode_sync_file_name(ntfs_inode *ni)
{
	ntfs_attr_search_ctx *ctx = NULL;
	ntfs_index_context *ictx;
	ntfs_inode *index_ni;
	FILE_NAME_ATTR *fn;
	int err = 0;

	ntfs_log_trace("Entering for inode 0x%llx.\n", (long long) ni->mft_no);

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		err = errno;
		ntfs_log_trace("Failed to get attribute search context.\n");
		goto err_out;
	}
	/* Walk through all FILE_NAME attributes and update them. */
	while (!ntfs_attr_lookup(AT_FILE_NAME, NULL, 0, 0, 0, NULL, 0, ctx)) {
		fn = (FILE_NAME_ATTR *)((u8 *)ctx->attr +
				le16_to_cpu(ctx->attr->value_offset));
		if (MREF_LE(fn->parent_directory) == ni->mft_no) {
			/*
			 * WARNING: We cheater here and obtain 2 attribute
			 * search contexts for one inode (first we obtained
			 * above, second will be obtained inside
			 * ntfs_index_lookup), it's acceptable for library,
			 * but will lock kernel.
			 */
			index_ni = ni;
		} else
			index_ni = ntfs_inode_open(ni->vol,
				le64_to_cpu(fn->parent_directory));
		if (!index_ni) {
			if (!err)
				err = errno;
			ntfs_log_trace("Failed to open inode with index.\n");
			continue;
		}
		ictx = ntfs_index_ctx_get(index_ni, NTFS_INDEX_I30, 4);
		if (!ictx) {
			if (!err)
				err = errno;
			ntfs_log_trace("Failed to get index context.\n");
			ntfs_inode_close(index_ni);
			continue;
		}
		if (ntfs_index_lookup(fn, sizeof(FILE_NAME_ATTR), ictx)) {
			if (!err) {
				if (errno == ENOENT)
					err = EIO;
				else
					err = errno;
			}
			ntfs_log_trace("Index lookup failed.\n");
			ntfs_index_ctx_put(ictx);
			ntfs_inode_close(index_ni);
			continue;
		}
		/* Update flags and file size. */
		fn = (FILE_NAME_ATTR *)ictx->data;
		fn->file_attributes =
				(fn->file_attributes & ~FILE_ATTR_VALID_FLAGS) |
				(ni->flags & FILE_ATTR_VALID_FLAGS);
		fn->allocated_size = cpu_to_sle64(ni->allocated_size);
		fn->data_size = cpu_to_sle64(ni->data_size);
		fn->creation_time = utc2ntfs(ni->creation_time);
		fn->last_data_change_time = utc2ntfs(ni->last_data_change_time);
		fn->last_mft_change_time = utc2ntfs(ni->last_mft_change_time);
		fn->last_access_time = utc2ntfs(ni->last_access_time);
		ntfs_index_entry_mark_dirty(ictx);
		ntfs_index_ctx_put(ictx);
		if (ni != index_ni)
			ntfs_inode_close(index_ni);
	}
	/* Check for real error occurred. */
	if (errno != ENOENT) {
		err = errno;
		ntfs_log_trace("Attribute lookup failed.\n");
		goto err_out;
	}
	ntfs_attr_put_search_ctx(ctx);
	if (err) {
		errno = err;
		return -1;
	}
	return 0;
err_out:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	errno = err;
	return -1;
}

/**
 * ntfs_inode_sync - write the inode (and its dirty extents) to disk
 * @ni:		ntfs inode to write
 *
 * Write the inode @ni to disk as well as its dirty extent inodes if such
 * exist and @ni is a base inode. If @ni is an extent inode, only @ni is
 * written completely disregarding its base inode and any other extent inodes.
 *
 * For a base inode with dirty extent inodes if any writes fail for whatever
 * reason, the failing inode is skipped and the sync process is continued. At
 * the end the error condition that brought about the failure is returned. Thus
 * the smallest amount of data loss possible occurs.
 *
 * Return 0 on success or -1 on error with errno set to the error code.
 * The following error codes are defined:
 *	EINVAL	- Invalid arguments were passed to the function.
 *	EBUSY	- Inode and/or one of its extents is busy, try again later.
 *	EIO	- I/O error while writing the inode (or one of its extents).
 */
int ntfs_inode_sync(ntfs_inode *ni)
{
	int err = 0;

	if (!ni) {
		errno = EINVAL;
		return -1;
	}

	ntfs_log_trace("Entering for inode 0x%llx.\n", (long long) ni->mft_no);

	/* Update STANDARD_INFORMATION. */
	if ((ni->mrec->flags & MFT_RECORD_IN_USE) && ni->nr_extents != -1 &&
			ntfs_inode_sync_standard_information(ni)) {
		if (!err || errno == EIO) {
			err = errno;
			if (err != EIO)
				err = EBUSY;
		}
		ntfs_log_trace("Failed to sync standard information.\n");
	}

	/* Update FILE_NAME's in the index. */
	if ((ni->mrec->flags & MFT_RECORD_IN_USE) && ni->nr_extents != -1 &&
			NInoFileNameTestAndClearDirty(ni) &&
			ntfs_inode_sync_file_name(ni)) {
		if (!err || errno == EIO) {
			err = errno;
			if (err != EIO)
				err = EBUSY;
		}
		ntfs_log_trace("Failed to sync FILE_NAME attributes.\n");
		NInoFileNameSetDirty(ni);
	}

	/* Write out attribute list from cache to disk. */
	if ((ni->mrec->flags & MFT_RECORD_IN_USE) && ni->nr_extents != -1 &&
			NInoAttrList(ni) && NInoAttrListTestAndClearDirty(ni)) {
		ntfs_attr *na;

		na = ntfs_attr_open(ni, AT_ATTRIBUTE_LIST, AT_UNNAMED, 0);
		if (!na) {
			if (!err || errno == EIO) {
				err = errno;
				if (err != EIO)
					err = EBUSY;
				ntfs_log_trace("Attribute list sync failed (open "
						"failed).\n");
			}
			NInoAttrListSetDirty(ni);
		} else {
			if (na->data_size == ni->attr_list_size) {
				if (ntfs_attr_pwrite(na, 0, ni->attr_list_size,
							ni->attr_list) !=
							ni->attr_list_size) {
					if (!err || errno == EIO) {
						err = errno;
						if (err != EIO)
							err = EBUSY;
						ntfs_log_trace("Attribute list sync "
							"failed (write failed).\n");
					}
					NInoAttrListSetDirty(ni);
				}
			} else {
				err = EIO;
				ntfs_log_trace("Attribute list sync failed (invalid size).\n");
				NInoAttrListSetDirty(ni);
			}
			ntfs_attr_close(na);
		}
	}

	/* Write this inode out to the $MFT (and $MFTMirr if applicable). */
	if (NInoTestAndClearDirty(ni)) {
		if (ntfs_mft_record_write(ni->vol, ni->mft_no, ni->mrec)) {
			if (!err || errno == EIO) {
				err = errno;
				if (err != EIO)
					err = EBUSY;
			}
			NInoSetDirty(ni);
			ntfs_log_trace("Base MFT record sync failed.\n");
		}
	}

	/* If this is a base inode with extents write all dirty extents, too. */
	if (ni->nr_extents > 0) {
		s32 i;

		for (i = 0; i < ni->nr_extents; ++i) {
			ntfs_inode *eni;

			eni = ni->extent_nis[i];
			if (NInoTestAndClearDirty(eni)) {
				if (ntfs_mft_record_write(eni->vol, eni->mft_no,
						eni->mrec)) {
					if (!err || errno == EIO) {
						err = errno;
						if (err != EIO)
							err = EBUSY;
					}
					NInoSetDirty(eni);
					ntfs_log_trace("Extent MFT record sync "
							"failed.\n");
				}
			}
		}
	}

	if (!err)
		return 0;
	errno = err;
	return -1;
}

/**
 * ntfs_inode_add_attrlist - add attribute list to inode and fill it
 * @ni: opened ntfs inode to which add attribute list
 *
 * Return 0 on success or -1 on error with errno set to the error code.
 * The following error codes are defined:
 *	EINVAL	- Invalid arguments were passed to the function.
 *	EEXIST	- Attribute list already exist.
 *	EIO	- Input/Ouput error occurred.
 *	ENOMEM	- Not enough memory to perform add.
 */
int ntfs_inode_add_attrlist(ntfs_inode *ni)
{
	int err;
	ntfs_attr_search_ctx *ctx;
	u8 *al, *aln;
	int al_len, al_allocated;
	ATTR_LIST_ENTRY *ale;
	ntfs_attr *na;

	if (!ni) {
		ntfs_log_trace("Invalid arguments.\n");
		errno = EINVAL;
		return -1;
	}

	ntfs_log_trace("Entering for inode 0x%llx.\n", (long long) ni->mft_no);

	if (NInoAttrList(ni) || ni->nr_extents) {
		ntfs_log_trace("Inode already has got attribute list.\n");
		errno = EEXIST;
		return -1;
	}

	al_allocated = 0x40;
	al_len = 0;
	al = malloc(al_allocated);
	ale = (ATTR_LIST_ENTRY *) al;
	if (!al) {
		ntfs_log_trace("Not enough memory.\n");
		errno = ENOMEM;
		return -1;
	}

	/* Form attribute list. */
	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		err = errno;
		ntfs_log_trace("Couldn't get search context.\n");
		goto err_out;
	}
	/* Walk through all attributes. */
	while (!ntfs_attr_lookup(AT_UNUSED, NULL, 0, 0, 0, NULL, 0, ctx)) {
		if (ctx->attr->type == AT_ATTRIBUTE_LIST) {
			err = EIO;
			ntfs_log_trace("Eeek! Attribute list already present.\n");
			goto put_err_out;
		}
		/* Calculate new length of attribute list. */
		al_len += (sizeof(ATTR_LIST_ENTRY) + sizeof(ntfschar) *
					ctx->attr->name_length + 7) & ~7;
		/* Allocate more memory if needed. */
		while (al_len > al_allocated) {
			al_allocated += 0x40;
			aln = realloc(al, al_allocated);
			if (!aln) {
				ntfs_log_trace("Not enough memory.\n");
				err = ENOMEM;
				goto put_err_out;
			}
			ale = (ATTR_LIST_ENTRY *)(aln + ((u8 *)ale - al));
			al = aln;
		}
		/* Add attribute to attribute list. */
		ale->type = ctx->attr->type;
		ale->length = cpu_to_le16((sizeof(ATTR_LIST_ENTRY) +
			sizeof(ntfschar) * ctx->attr->name_length + 7) & ~7);
		ale->name_length = ctx->attr->name_length;
		ale->name_offset = (u8 *)ale->name - (u8 *)ale;
		if (ctx->attr->non_resident)
			ale->lowest_vcn = ctx->attr->lowest_vcn;
		else
			ale->lowest_vcn = 0;
		ale->mft_reference = MK_LE_MREF(ni->mft_no,
			le16_to_cpu(ni->mrec->sequence_number));
		ale->instance = ctx->attr->instance;
		memcpy(ale->name, (u8 *)ctx->attr +
				le16_to_cpu(ctx->attr->name_offset),
				ctx->attr->name_length * sizeof(ntfschar));
		ale = (ATTR_LIST_ENTRY *)(al + al_len);
	}
	/* Check for real error occurred. */
	if (errno != ENOENT) {
		err = errno;
		ntfs_log_trace("Attribute lookup failed.\n");
		goto put_err_out;
	}
	/* Deallocate trailing memory. */
	aln = realloc(al, al_len);
	if (!aln) {
		err = errno;
		ntfs_log_trace("realloc() failed.\n");
		goto put_err_out;
	}
	al = aln;

	/* Set in-memory attribute list. */
	ni->attr_list = al;
	ni->attr_list_size = al_len;
	NInoSetAttrList(ni);
	NInoAttrListSetDirty(ni);

	/* Free space if there is not enough it for $ATTRIBUTE_LIST. */
	if (le32_to_cpu(ni->mrec->bytes_allocated) -
			le32_to_cpu(ni->mrec->bytes_in_use) <
			offsetof(ATTR_RECORD, resident_end)) {
		if (ntfs_inode_free_space(ni,
				offsetof(ATTR_RECORD, resident_end))) {
			/* Failed to free space. */
			err = errno;
			ntfs_log_trace("Failed to free space for "
					"$ATTRIBUTE_LIST.\n");