1 // SPDX-License-Identifier: GPL-2.0-or-later
5  * decryption of the file data as it passes between the lower
8  * Copyright (C) 1997-2003 Erez Zadok
9  * Copyright (C) 2001-2003 Stony Brook University
10  * Copyright (C) 2004-2007 International Business Machines Corp.
16 #include <linux/page-flags.h>
30  * Returns locked and up-to-date page (if ok), with increased
35 	struct page *page = read_mapping_page(inode->i_mapping, index, NULL);  in ecryptfs_get_locked_page()
45  * Returns zero on success; non-zero otherwise
47  * This is where we encrypt the data and pass the encrypted data to
48  * the lower filesystem.  In OpenPGP-compatible mode, we operate on
58 				"page (upper index [0x%.16lx])\n", page->index);  in ecryptfs_writepage()
71 	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {  in strip_xattr_flag()
74 		crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;  in strip_xattr_flag()
77 		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;  in strip_xattr_flag()
83  *     Octets 0-7:        Unencrypted file size (big-endian)
84  *     Octets 8-15:       eCryptfs special marker
85  *     Octets 16-19:      Flags
87  *      Octets 17-18:     Reserved
90  *                        Bits 3-8: Reserved
91  *     Octets 20-23:      Header extent size (big-endian)
92  *     Octets 24-25:      Number of header extents at front of file
93  *                        (big-endian)
113 				       / crypt_stat->extent_size);  in ecryptfs_copy_up_encrypted_with_header()
117 		loff_t view_extent_num = ((((loff_t)page->index)  in ecryptfs_copy_up_encrypted_with_header()
121 			(crypt_stat->metadata_size / crypt_stat->extent_size);  in ecryptfs_copy_up_encrypted_with_header()
134 					page_virt, page->mapping->host);  in ecryptfs_copy_up_encrypted_with_header()
148 			/* This is an encrypted data extent */  in ecryptfs_copy_up_encrypted_with_header()
150 				((view_extent_num * crypt_stat->extent_size)  in ecryptfs_copy_up_encrypted_with_header()
151 				 - crypt_stat->metadata_size);  in ecryptfs_copy_up_encrypted_with_header()
156 				crypt_stat->extent_size, page->mapping->host);  in ecryptfs_copy_up_encrypted_with_header()
174  * @page: Page from eCryptfs inode mapping into which to stick the read data
178  * Returns zero on success; non-zero on error.
183 		&ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;  in ecryptfs_readpage()
186 	if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {  in ecryptfs_readpage()
187 		rc = ecryptfs_read_lower_page_segment(page, page->index, 0,  in ecryptfs_readpage()
189 						      page->mapping->host);  in ecryptfs_readpage()
190 	} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {  in ecryptfs_readpage()
191 		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {  in ecryptfs_readpage()
205 				page, page->index, 0, PAGE_SIZE,  in ecryptfs_readpage()
206 				page->mapping->host);  in ecryptfs_readpage()
227 			page->index);  in ecryptfs_readpage()
237 	struct inode *inode = page->mapping->host;  in fill_zeros_to_end_of_page()
240 	if ((i_size_read(inode) / PAGE_SIZE) != page->index)  in fill_zeros_to_end_of_page()
253  * @mapping: The eCryptfs object
258  * @fsdata: Pointer to return fs data (unused)
262  * Returns zero on success; non-zero otherwise
265 			struct address_space *mapping,  in ecryptfs_write_begin()  argument
274 	page = grab_cache_page_write_begin(mapping, index, flags);  in ecryptfs_write_begin()
276 		return -ENOMEM;  in ecryptfs_write_begin()
282 			&ecryptfs_inode_to_private(mapping->host)->crypt_stat;  in ecryptfs_write_begin()
284 		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {  in ecryptfs_write_begin()
286 				page, index, 0, PAGE_SIZE, mapping->host);  in ecryptfs_write_begin()
295 		} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {  in ecryptfs_write_begin()
296 			if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {  in ecryptfs_write_begin()
313 					mapping->host);  in ecryptfs_write_begin()
325 			    >= i_size_read(page->mapping->host)) {  in ecryptfs_write_begin()
334 					       __func__, page->index, rc);  in ecryptfs_write_begin()
345 		if (prev_page_end_size > i_size_read(page->mapping->host)) {  in ecryptfs_write_begin()
346 			rc = ecryptfs_truncate(file->f_path.dentry,  in ecryptfs_write_begin()
359 	if ((i_size_read(mapping->host) == prev_page_end_size)  in ecryptfs_write_begin()
376  * Returns zero on success; non-zero on error.
385 		rc = -ENOMEM;  in ecryptfs_write_inode_size_to_header()
408 		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_path.dentry;  in ecryptfs_write_inode_size_to_xattr()
412 	if (!(lower_inode->i_opflags & IOP_XATTR)) {  in ecryptfs_write_inode_size_to_xattr()
415 		rc = -ENOSYS;  in ecryptfs_write_inode_size_to_xattr()
420 		rc = -ENOMEM;  in ecryptfs_write_inode_size_to_xattr()
444 	crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;  in ecryptfs_write_inode_size_to_metadata()
445 	BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));  in ecryptfs_write_inode_size_to_metadata()
446 	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)  in ecryptfs_write_inode_size_to_metadata()
455  * @mapping: The eCryptfs object
457  * @len: The length of the data (unused)
458  * @copied: The amount of data copied
463 			struct address_space *mapping,  in ecryptfs_write_end()  argument
468 	unsigned from = pos & (PAGE_SIZE - 1);  in ecryptfs_write_end()
470 	struct inode *ecryptfs_inode = mapping->host;  in ecryptfs_write_end()
472 		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;  in ecryptfs_write_end()
477 	if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {  in ecryptfs_write_end()
525 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)  in ecryptfs_bmap()  argument
527 	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);  in ecryptfs_bmap()