* @plaintext_page: The page to encrypt. Must be locked.
* @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
struct page *plaintext_page, 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));
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,
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:
#define fname_len(p) ((p)->disk_name.len)
/*
+ * fscrypt superblock flags
+ */
+#define FS_CFLG_INPLACE_ENCRYPTION (1U << 1)
+
+/*
* crypto opertions for filesystems
*/
struct fscrypt_operations {
+ unsigned int flags;
int (*get_context)(struct inode *, void *, size_t);
int (*key_prefix)(struct inode *, u8 **);
int (*prepare_context)(struct inode *);