fs/ecryptfs/mmap.c

16 #include <linux/page-flags.h>
28  * Get one page from cache or lower f/s, return error otherwise.
30  * Returns locked and up-to-date page (if ok), with increased
33 struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index)
35 	struct page *page = read_mapping_page(inode->i_mapping, index, NULL);
36 	if (!IS_ERR(page))
37 		lock_page(page);
38 	return page;
43  * @page: Page that is locked before this call is made
52 static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
56 	rc = ecryptfs_encrypt_page(page);
59 				"page (upper index [0x%.16lx])\n", page->index);
60 		ClearPageUptodate(page);
63 	SetPageUptodate(page);
65 	unlock_page(page);
100  * @page: Sort of a ``virtual'' representation of the encrypted lower
109 ecryptfs_copy_up_encrypted_with_header(struct page *page,
118 		loff_t view_extent_num = ((((loff_t)page->index)
128 			page_virt = kmap_local_page(page);
135 					page_virt, page->mapping->host);
142 			flush_dcache_page(page);
155 				page, (lower_offset >> PAGE_SHIFT),
157 				crypt_stat->extent_size, page->mapping->host);
183 	struct page *page = &folio->page;
185 		&ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
189 		rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
191 						      page->mapping->host);
194 			rc = ecryptfs_copy_up_encrypted_with_header(page,
207 				page, page->index, 0, PAGE_SIZE,
208 				page->mapping->host);
210 				printk(KERN_ERR "Error reading page; rc = "
216 		rc = ecryptfs_decrypt_page(page);
218 			ecryptfs_printk(KERN_ERR, "Error decrypting page; "
225 		ClearPageUptodate(page);
227 		SetPageUptodate(page);
228 	ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
229 			page->index);
230 	unlock_page(page);
237 static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
239 	struct inode *inode = page->mapping->host;
242 	if ((i_size_read(inode) / PAGE_SIZE) != page->index)
247 	zero_user_segment(page, end_byte_in_page, PAGE_SIZE);
258  * @pagep: Pointer to return the page
268 			struct page **pagep, void **fsdata)
271 	struct page *page;
275 	page = grab_cache_page_write_begin(mapping, index);
276 	if (!page)
278 	*pagep = page;
281 	if (!PageUptodate(page)) {
287 				page, index, 0, PAGE_SIZE, mapping->host);
290 				       "lower page segment; rc = [%d]\n",
292 				ClearPageUptodate(page);
295 				SetPageUptodate(page);
299 					page, crypt_stat);
307 					ClearPageUptodate(page);
310 				SetPageUptodate(page);
313 					page, index, 0, PAGE_SIZE,
317 					       "page; rc = [%d]\n",
319 					ClearPageUptodate(page);
322 				SetPageUptodate(page);
326 			    >= i_size_read(page->mapping->host)) {
327 				zero_user(page, 0, PAGE_SIZE);
328 				SetPageUptodate(page);
330 				rc = ecryptfs_decrypt_page(page);
333 					       "page at index [%ld]; "
335 					       __func__, page->index, rc);
336 					ClearPageUptodate(page);
339 				SetPageUptodate(page);
343 	/* If creating a page or more of holes, zero them out via truncate.
346 		if (prev_page_end_size > i_size_read(page->mapping->host)) {
358 	/* Writing to a new page, and creating a small hole from start
359 	 * of page?  Zero it out. */
362 		zero_user(page, 0, PAGE_SIZE);
365 		unlock_page(page);
366 		put_page(page);
460  * @page: The eCryptfs page
466 			struct page *page, void *fsdata)
477 			"(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
479 		rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0,
488 	if (!PageUptodate(page)) {
493 		SetPageUptodate(page);
496 	rc = fill_zeros_to_end_of_page(page, to);
499 			"zeros in page with index = [0x%.16lx]\n", index);
502 	rc = ecryptfs_encrypt_page(page);
504 		ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
521 	unlock_page(page);
522 	put_page(page);