@@ -121,8 +121,8 @@ struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags)
/**
* fscrypt_free_bounce_page() - free a ciphertext bounce page
*
- * Free a bounce page that was allocated by fscrypt_encrypt_page(), or by
- * fscrypt_alloc_bounce_page() directly.
+ * Free a bounce page that was allocated by fscrypt_encrypt_pagecache_blocks(),
+ * or by fscrypt_alloc_bounce_page() directly.
*/
void fscrypt_free_bounce_page(struct page *bounce_page)
{
@@ -197,52 +197,63 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
}
/**
- * fscypt_encrypt_page() - Encrypts a page
- * @inode: The inode for which the encryption should take place
- * @page: The page to encrypt. Must be locked.
- * @len: Length of data to encrypt in @page and encrypted
- * data in returned page.
- * @offs: Offset of data within @page and returned
- * page holding encrypted data.
- * @lblk_num: Logical block number. This must be unique for multiple
- * calls with same inode, except when overwriting
- * previously written data.
- * @gfp_flags: The gfp flag for memory allocation
+ * fscrypt_encrypt_pagecache_blocks() - Encrypt filesystem blocks from a pagecache page
+ * @page: The locked pagecache page containing the block(s) to encrypt
+ * @len: Total size of the block(s) to encrypt. Must be a nonzero
+ * multiple of the filesystem's block size.
+ * @offs: Byte offset within @page of the first block to encrypt. Must be
+ * a multiple of the filesystem's block size.
+ * @gfp_flags: Memory allocation flags
+ *
+ * A new bounce page is allocated, and the specified block(s) are encrypted into
+ * it. In the bounce page, the ciphertext block(s) will be located at the same
+ * offsets at which the plaintext block(s) were located in the source page; any
+ * other parts of the bounce page will be left uninitialized. However, normally
+ * blocksize == PAGE_SIZE and the whole page is encrypted at once.
*
- * Encrypts @page. A bounce page is allocated, the data is encrypted into the
- * bounce page, and the bounce page is returned. The caller is responsible for
- * calling fscrypt_free_bounce_page().
+ * This is for use by the filesystem's ->writepages() method.
*
- * Return: A page containing the encrypted data on success; else an ERR_PTR()
+ * Return: the new encrypted bounce page on success; an ERR_PTR() on failure
*/
-struct page *fscrypt_encrypt_page(const struct inode *inode,
- struct page *page,
- unsigned int len,
- unsigned int offs,
- u64 lblk_num, gfp_t gfp_flags)
+struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags)
{
+ const struct inode *inode = page->mapping->host;
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocksize = 1 << blockbits;
struct page *ciphertext_page;
+ u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
+ (offs >> blockbits);
+ unsigned int i;
int err;
if (WARN_ON_ONCE(!PageLocked(page)))
return ERR_PTR(-EINVAL);
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ return ERR_PTR(-EINVAL);
+
ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags);
if (!ciphertext_page)
return ERR_PTR(-ENOMEM);
- err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page,
- ciphertext_page, len, offs, gfp_flags);
- if (err) {
- fscrypt_free_bounce_page(ciphertext_page);
- return ERR_PTR(err);
+ for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
+ err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num,
+ page, ciphertext_page,
+ blocksize, i, gfp_flags);
+ if (err) {
+ fscrypt_free_bounce_page(ciphertext_page);
+ return ERR_PTR(err);
+ }
}
SetPagePrivate(ciphertext_page);
set_page_private(ciphertext_page, (unsigned long)page);
return ciphertext_page;
}
-EXPORT_SYMBOL(fscrypt_encrypt_page);
+EXPORT_SYMBOL(fscrypt_encrypt_pagecache_blocks);
/**
* fscrypt_encrypt_block_inplace() - Encrypt a filesystem block in-place
@@ -472,8 +472,8 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
gfp_t gfp_flags = GFP_NOFS;
retry_encrypt:
- bounce_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0,
- page->index, gfp_flags);
+ bounce_page = fscrypt_encrypt_pagecache_blocks(page, PAGE_SIZE,
+ 0, gfp_flags);
if (IS_ERR(bounce_page)) {
ret = PTR_ERR(bounce_page);
if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
@@ -1692,8 +1692,9 @@ static int encrypt_one_page(struct f2fs_io_info *fio)
f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
retry_encrypt:
- fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
- PAGE_SIZE, 0, fio->page->index, gfp_flags);
+ fio->encrypted_page = fscrypt_encrypt_pagecache_blocks(fio->page,
+ PAGE_SIZE, 0,
+ gfp_flags);
if (IS_ERR(fio->encrypted_page)) {
/* flush pending IOs and wait for a while in the ENOMEM case */
if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
@@ -103,9 +103,11 @@ static inline void fscrypt_handle_d_move(struct dentry *dentry)
extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
extern struct fscrypt_ctx *fscrypt_get_ctx(gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
-extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
- unsigned int, unsigned int,
- u64, gfp_t);
+
+extern struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags);
extern int fscrypt_encrypt_block_inplace(const struct inode *inode,
struct page *page, unsigned int len,
unsigned int offs, u64 lblk_num,
@@ -283,11 +285,10 @@ static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
return;
}
-static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
- struct page *page,
- unsigned int len,
- unsigned int offs,
- u64 lblk_num, gfp_t gfp_flags)
+static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags)
{
return ERR_PTR(-EOPNOTSUPP);
}