[PATCH v2 2/6] fscrypt: Never allocate fscrypt_ctx on in-place encryption

From: David Gstir
Date: Tue Dec 06 2016 - 17:58:05 EST


In case of in-place encryption fscrypt_ctx was allocated but never
released. Since we don't need it for in-place encryption, we skip
allocating it.

Fixes: 1c7dcf69eea3 ("fscrypt: Add in-place encryption mode")

Signed-off-by: David Gstir <david@xxxxxxxxxxxxx>
---
fs/crypto/crypto.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 3c1124beae28..8536ac0b50d3 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -246,16 +246,26 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,

BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);

+ if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) {
+ /* with inplace-encryption we just encrypt the page */
+ err = do_page_crypto(inode, FS_ENCRYPT, index,
+ plaintext_page, ciphertext_page,
+ plaintext_len, plaintext_offset,
+ gfp_flags);
+ if (err)
+ return ERR_PTR(err);
+
+ return ciphertext_page;
+ }
+
ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;

- 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;
- }
+ /* 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, index,
@@ -266,11 +276,9 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
ciphertext_page = ERR_PTR(err);
goto errout;
}
- 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);
- }
+ SetPagePrivate(ciphertext_page);
+ set_page_private(ciphertext_page, (unsigned long)ctx);
+ lock_page(ciphertext_page);
return ciphertext_page;

errout:
--
2.10.1