Commit 05a4d33b authored May 20, 2019 by Eric Biggers Committed by Jaegeuk Kim Aug 30, 2019

fscrypt: decrypt only the needed blocks in __fscrypt_decrypt_bio()



In __fscrypt_decrypt_bio(), only decrypt the blocks that actually
comprise the bio, rather than assuming blocksize == PAGE_SIZE and
decrypting the entirety of every page used in the bio.

This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.

This is based on work by Chandan Rajendra.

Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

parent 8780629b

fs/crypto/bio.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -33,8 +33,8 @@ static void __fscrypt_decrypt_bio(struct bio *bio, bool done)

		bio_for_each_segment_all(bv, bio, i) {
		struct page *page = bv->bv_page;
		int ret = fscrypt_decrypt_pagecache_blocks(page, PAGE_SIZE, 0);

		int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
		bv->bv_offset);
		if (ret)
		SetPageError(page);
		else if (done)