linux-kernel - [PATCH v2 2/6] fscrypt: Never allocate fscrypt

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Message-Id: <20161206225358.12126-3-david@sigma-star.at>
Date:   Tue,  6 Dec 2016 23:53:54 +0100
From:   David Gstir <david@...ma-star.at>
To:     linux-mtd@...ts.infradead.org
Cc:     tytso@....edu, dedekind1@...il.com, ebiggers@...gle.com,
        mhalcrow@...gle.com, adrian.hunter@...el.com,
        linux-kernel@...r.kernel.org, hch@...radead.org,
        linux-fsdevel@...r.kernel.org, jaegeuk@...nel.org,
        dengler@...utronix.de, sbabic@...x.de, wd@...x.de, richard@....at,
        David Gstir <david@...ma-star.at>
Subject: [PATCH v2 2/6] fscrypt: Never allocate fscrypt_ctx on in-place encryption

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@...ma-star.at>
---
 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