* Return: An allocated and initialized encryption context on success; error
* value or NULL otherwise.
*/
-struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode, gfp_t gfp_flags)
+struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx = NULL;
struct fscrypt_info *ci = inode->i_crypt_info;
FS_ENCRYPT,
} fscrypt_direction_t;
-static int do_page_crypto(struct inode *inode,
+static int do_page_crypto(const struct inode *inode,
fscrypt_direction_t rw, pgoff_t index,
struct page *src_page, struct page *dest_page,
+ unsigned int src_len, unsigned int src_offset,
gfp_t gfp_flags)
{
- u8 xts_tweak[FS_XTS_TWEAK_SIZE];
+ struct {
+ __le64 index;
+ u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
+ } xts_tweak;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct scatterlist dst, src;
req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
page_crypt_complete, &ecr);
- BUILD_BUG_ON(FS_XTS_TWEAK_SIZE < sizeof(index));
- memcpy(xts_tweak, &index, sizeof(index));
- memset(&xts_tweak[sizeof(index)], 0,
- FS_XTS_TWEAK_SIZE - sizeof(index));
+ BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
+ xts_tweak.index = cpu_to_le64(index);
+ memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
sg_init_table(&dst, 1);
- sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
+ sg_set_page(&dst, dest_page, src_len, src_offset);
sg_init_table(&src, 1);
- sg_set_page(&src, src_page, PAGE_SIZE, 0);
- skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE,
- xts_tweak);
+ sg_set_page(&src, src_page, src_len, src_offset);
+ skcipher_request_set_crypt(req, &src, &dst, src_len, &xts_tweak);
if (rw == FS_DECRYPT)
res = crypto_skcipher_decrypt(req);
else
/**
* fscypt_encrypt_page() - Encrypts a page
- * @inode: The inode for which the encryption should take place
- * @plaintext_page: The page to encrypt. Must be locked.
- * @gfp_flags: The gfp flag for memory allocation
+ * @inode: The inode for which the encryption should take place
+ * @plaintext_page: The page to encrypt. Must be locked.
+ * @plaintext_len: Length of plaintext within page
+ * @plaintext_offset: Offset of plaintext within page
+ * @gfp_flags: The gfp flag for memory allocation
*
- * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx
- * encryption context.
+ * Encrypts plaintext_page using the ctx encryption context. If
+ * the filesystem supports it, encryption is performed in-place, otherwise a
+ * new ciphertext_page is allocated and returned.
*
* Called on the page write path. The caller must call
* fscrypt_restore_control_page() on the returned ciphertext page to
* Return: An allocated page with the encrypted content on success. Else, an
* error value or NULL.
*/
-struct page *fscrypt_encrypt_page(struct inode *inode,
- struct page *plaintext_page, gfp_t gfp_flags)
+struct page *fscrypt_encrypt_page(const struct inode *inode,
+ struct page *plaintext_page,
+ unsigned int plaintext_len,
+ unsigned int plaintext_offset,
+ gfp_t gfp_flags)
+
{
struct fscrypt_ctx *ctx;
- struct page *ciphertext_page = NULL;
+ struct page *ciphertext_page = plaintext_page;
int err;
- BUG_ON(!PageLocked(plaintext_page));
+ BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);
ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;
- /* The encryption operation will require a bounce page. */
- ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
- if (IS_ERR(ciphertext_page))
- goto errout;
+ if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
+ /* The encryption operation will require a bounce page. */
+ ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
+ if (IS_ERR(ciphertext_page))
+ goto errout;
+ }
ctx->w.control_page = plaintext_page;
err = do_page_crypto(inode, FS_ENCRYPT, plaintext_page->index,
plaintext_page, ciphertext_page,
+ plaintext_len, plaintext_offset,
gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
}
- SetPagePrivate(ciphertext_page);
- set_page_private(ciphertext_page, (unsigned long)ctx);
- lock_page(ciphertext_page);
+ if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
+ SetPagePrivate(ciphertext_page);
+ set_page_private(ciphertext_page, (unsigned long)ctx);
+ lock_page(ciphertext_page);
+ }
return ciphertext_page;
errout:
EXPORT_SYMBOL(fscrypt_encrypt_page);
/**
- * f2crypt_decrypt_page() - Decrypts a page in-place
- * @page: The page to decrypt. Must be locked.
+ * fscrypt_decrypt_page() - Decrypts a page in-place
+ * @inode: Encrypted inode to decrypt.
+ * @page: The page to decrypt. Must be locked.
+ * @len: Number of bytes in @page to be decrypted.
+ * @offs: Start of data in @page.
*
* Decrypts page in-place using the ctx encryption context.
*
*
* Return: Zero on success, non-zero otherwise.
*/
-int fscrypt_decrypt_page(struct page *page)
+int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
+ unsigned int len, unsigned int offs)
{
- BUG_ON(!PageLocked(page));
-
- return do_page_crypto(page->mapping->host,
- FS_DECRYPT, page->index, page, page, GFP_NOFS);
+ return do_page_crypto(inode, FS_DECRYPT, page->index, page, page, len, offs,
+ GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
-int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
+int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
struct fscrypt_ctx *ctx;
while (len--) {
err = do_page_crypto(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), ciphertext_page,
- GFP_NOFS);
+ PAGE_SIZE, 0, GFP_NOFS);
if (err)
goto errout;
bio_for_each_segment_all(bv, bio, i) {
struct page *page = bv->bv_page;
- int ret = fscrypt_decrypt_page(page);
+ int ret = fscrypt_decrypt_page(page->mapping->host, page,
+ PAGE_SIZE, 0);
if (ret) {
WARN_ON_ONCE(1);
projects / karo-tx-linux.git / blobdiff