-static void
-ecryptfs_extent_to_lwr_pg_idx_and_offset(unsigned long *lower_page_idx,
- int *byte_offset,
- struct ecryptfs_crypt_stat *crypt_stat,
- unsigned long extent_num)
-{
- unsigned long lower_extent_num;
- int extents_occupied_by_headers_at_front;
- int bytes_occupied_by_headers_at_front;
- int extent_offset;
- int extents_per_page;
-
- bytes_occupied_by_headers_at_front =
- (crypt_stat->extent_size
- * crypt_stat->num_header_extents_at_front);
- extents_occupied_by_headers_at_front =
- ( bytes_occupied_by_headers_at_front
- / crypt_stat->extent_size );
- lower_extent_num = extents_occupied_by_headers_at_front + extent_num;
- extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size;
- (*lower_page_idx) = lower_extent_num / extents_per_page;
- extent_offset = lower_extent_num % extents_per_page;
- (*byte_offset) = extent_offset * crypt_stat->extent_size;
- ecryptfs_printk(KERN_DEBUG, " * crypt_stat->extent_size = "
- "[%d]\n", crypt_stat->extent_size);
- ecryptfs_printk(KERN_DEBUG, " * crypt_stat->"
- "num_header_extents_at_front = [%d]\n",
- crypt_stat->num_header_extents_at_front);
- ecryptfs_printk(KERN_DEBUG, " * extents_occupied_by_headers_at_"
- "front = [%d]\n", extents_occupied_by_headers_at_front);
- ecryptfs_printk(KERN_DEBUG, " * lower_extent_num = [0x%.16x]\n",
- lower_extent_num);
- ecryptfs_printk(KERN_DEBUG, " * extents_per_page = [%d]\n",
- extents_per_page);
- ecryptfs_printk(KERN_DEBUG, " * (*lower_page_idx) = [0x%.16x]\n",
- (*lower_page_idx));
- ecryptfs_printk(KERN_DEBUG, " * extent_offset = [%d]\n",
- extent_offset);
- ecryptfs_printk(KERN_DEBUG, " * (*byte_offset) = [%d]\n",
- (*byte_offset));
-}
-
-static int ecryptfs_write_out_page(struct ecryptfs_page_crypt_context *ctx,
- struct page *lower_page,
- struct inode *lower_inode,
- int byte_offset_in_page, int bytes_to_write)
-{
- int rc = 0;
-
- if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) {
- rc = ecryptfs_commit_lower_page(lower_page, lower_inode,
- ctx->param.lower_file,
- byte_offset_in_page,
- bytes_to_write);
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error calling lower "
- "commit; rc = [%d]\n", rc);
- goto out;
- }
- } else {
- rc = ecryptfs_writepage_and_release_lower_page(lower_page,
- lower_inode,
- ctx->param.wbc);
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error calling lower "
- "writepage(); rc = [%d]\n", rc);
- goto out;
- }
- }
-out:
- return rc;
-}
-
-static int ecryptfs_read_in_page(struct ecryptfs_page_crypt_context *ctx,
- struct page **lower_page,
- struct inode *lower_inode,
- unsigned long lower_page_idx,
- int byte_offset_in_page)
-{
- int rc = 0;
-
- if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) {
- /* TODO: Limit this to only the data extents that are
- * needed */
- rc = ecryptfs_get_lower_page(lower_page, lower_inode,
- ctx->param.lower_file,
- lower_page_idx,
- byte_offset_in_page,
- (PAGE_CACHE_SIZE
- - byte_offset_in_page));
- if (rc) {
- ecryptfs_printk(
- KERN_ERR, "Error attempting to grab, map, "
- "and prepare_write lower page with index "
- "[0x%.16x]; rc = [%d]\n", lower_page_idx, rc);
- goto out;
- }
- } else {
- *lower_page = grab_cache_page(lower_inode->i_mapping,
- lower_page_idx);
- if (!(*lower_page)) {
- rc = -EINVAL;
- ecryptfs_printk(
- KERN_ERR, "Error attempting to grab and map "
- "lower page with index [0x%.16x]; rc = [%d]\n",
- lower_page_idx, rc);
- goto out;
- }
- }
-out:
- return rc;
-}
-