diff mbox series

[07/13] fscrypt: handle blocksize < PAGE_SIZE in fscrypt_zeroout_range()

Message ID 20190501224515.43059-8-ebiggers@kernel.org (mailing list archive)
State Superseded
Headers show
Series fscrypt, ext4: prepare for blocksize != PAGE_SIZE | expand

Commit Message

Eric Biggers May 1, 2019, 10:45 p.m. UTC 
From: Eric Biggers <ebiggers@google.com>

Adjust fscrypt_zeroout_range() to encrypt a block at a time rather than
a page at a time, so that it works when blocksize < PAGE_SIZE.

This isn't optimized for performance, but then again this function
already wasn't optimized for performance.  As a future optimization, we
could submit much larger bios here.

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

This is based on work by Chandan Rajendra.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/crypto/bio.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

Comments

Chandan Rajendra May 6, 2019, 8:42 a.m. UTC | #1 
On Thursday, May 2, 2019 4:15:09 AM IST Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Adjust fscrypt_zeroout_range() to encrypt a block at a time rather than
> a page at a time, so that it works when blocksize < PAGE_SIZE.
> 
> This isn't optimized for performance, but then again this function
> already wasn't optimized for performance.  As a future optimization, we
> could submit much larger bios here.
> 
> This is in preparation for allowing encryption on ext4 filesystems with
> blocksize != PAGE_SIZE.
> 
> This is based on work by Chandan Rajendra.


Looks good to me,

Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com>
diff mbox series

Patch

diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index bcab8822217b0..e67e9d4d342b3 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -73,12 +73,12 @@  EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio);
 int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 				sector_t pblk, unsigned int len)
 {
+	const unsigned int blockbits = inode->i_blkbits;
+	const unsigned int blocksize = 1 << blockbits;
 	struct page *ciphertext_page;
 	struct bio *bio;
 	int ret, err = 0;
 
-	BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
-
 	ciphertext_page = fscrypt_alloc_bounce_page(GFP_NOWAIT);
 	if (!ciphertext_page)
 		return -ENOMEM;
@@ -86,7 +86,7 @@  int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 	while (len--) {
 		err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk,
 					  ZERO_PAGE(0), ciphertext_page,
-					  PAGE_SIZE, 0, GFP_NOFS);
+					  blocksize, 0, GFP_NOFS);
 		if (err)
 			goto errout;
 
@@ -96,14 +96,11 @@  int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 			goto errout;
 		}
 		bio_set_dev(bio, inode->i_sb->s_bdev);
-		bio->bi_iter.bi_sector =
-			pblk << (inode->i_sb->s_blocksize_bits - 9);
+		bio->bi_iter.bi_sector = pblk << (blockbits - 9);
 		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-		ret = bio_add_page(bio, ciphertext_page,
-					inode->i_sb->s_blocksize, 0);
-		if (ret != inode->i_sb->s_blocksize) {
+		ret = bio_add_page(bio, ciphertext_page, blocksize, 0);
+		if (WARN_ON(ret != blocksize)) {
 			/* should never happen! */
-			WARN_ON(1);
 			bio_put(bio);
 			err = -EIO;
 			goto errout;