flush_dcache_page(page_for_ecryptfs);
return rc;
}
-
-#if 0
-/**
- * ecryptfs_read
- * @data: The virtual address into which to write the data read (and
- * possibly decrypted) from the lower file
- * @offset: The offset in the decrypted view of the file from which to
- * read into @data
- * @size: The number of bytes to read into @data
- * @ecryptfs_file: The eCryptfs file from which to read
- *
- * Read an arbitrary amount of data from an arbitrary location in the
- * eCryptfs page cache. This is done on an extent-by-extent basis;
- * individual extents are decrypted and read from the lower page
- * cache (via VFS reads). This function takes care of all the
- * address translation to locations in the lower filesystem.
- *
- * Returns zero on success; non-zero otherwise
- */
-int ecryptfs_read(char *data, loff_t offset, size_t size,
- struct file *ecryptfs_file)
-{
- struct inode *ecryptfs_inode = ecryptfs_file->f_dentry->d_inode;
- struct page *ecryptfs_page;
- char *ecryptfs_page_virt;
- loff_t ecryptfs_file_size = i_size_read(ecryptfs_inode);
- loff_t data_offset = 0;
- loff_t pos;
- int rc = 0;
-
- if ((offset + size) > ecryptfs_file_size) {
- rc = -EINVAL;
- printk(KERN_ERR "%s: Attempt to read data past the end of the "
- "file; offset = [%lld]; size = [%td]; "
- "ecryptfs_file_size = [%lld]\n",
- __func__, offset, size, ecryptfs_file_size);
- goto out;
- }
- pos = offset;
- while (pos < (offset + size)) {
- pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT);
- size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK);
- size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page);
- size_t total_remaining_bytes = ((offset + size) - pos);
-
- if (num_bytes > total_remaining_bytes)
- num_bytes = total_remaining_bytes;
- ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_inode,
- ecryptfs_page_idx);
- if (IS_ERR(ecryptfs_page)) {
- rc = PTR_ERR(ecryptfs_page);
- printk(KERN_ERR "%s: Error getting page at "
- "index [%ld] from eCryptfs inode "
- "mapping; rc = [%d]\n", __func__,
- ecryptfs_page_idx, rc);
- goto out;
- }
- ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);
- memcpy((data + data_offset),
- ((char *)ecryptfs_page_virt + start_offset_in_page),
- num_bytes);
- kunmap_atomic(ecryptfs_page_virt, KM_USER0);
- flush_dcache_page(ecryptfs_page);
- SetPageUptodate(ecryptfs_page);
- unlock_page(ecryptfs_page);
- page_cache_release(ecryptfs_page);
- pos += num_bytes;
- data_offset += num_bytes;
- }
-out:
- return rc;
-}
-#endif /* 0 */