From: Chandan Rajendra <chandan@linux.vnet.ibm.com>
To: linux-fscrypt@vger.kernel.org
Cc: Chandan Rajendra <chandan@linux.vnet.ibm.com>,
ebiggers3@gmail.com, tytso@mit.edu, linux-ext4@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: [RFC PATCH V3 08/12] fscrypt_zeroout_range: Encrypt all zeroed out blocks of a page
Date: Tue, 22 May 2018 21:31:06 +0530 [thread overview]
Message-ID: <20180522160110.1161-9-chandan@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180522160110.1161-1-chandan@linux.vnet.ibm.com>
For block size < page size, a page can have more than one block mapped
and the range of blocks to be zeroed out by fscrypt_zeroout_range() can
span more than one block. Hence this commit adds code to encrypt all
zeroed out blocks of a page.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
fs/crypto/bio.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index aba22f7..d8904c0 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -193,10 +193,11 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
{
struct fscrypt_ctx *ctx;
struct page *ciphertext_page = NULL;
+ unsigned int page_nr_blks;
+ unsigned int offset;
struct bio *bio;
int ret, err = 0;
-
- BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
+ int i;
ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
@@ -208,12 +209,22 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
goto errout;
}
- while (len--) {
- err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk,
- ZERO_PAGE(0), ciphertext_page,
- PAGE_SIZE, 0, GFP_NOFS);
- if (err)
- goto errout;
+ page_nr_blks = 1 << (PAGE_SHIFT - inode->i_blkbits);
+
+ while (len) {
+ page_nr_blks = min_t(unsigned int, page_nr_blks, len);
+ offset = 0;
+
+ for (i = 0; i < page_nr_blks; i++) {
+ err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk,
+ ZERO_PAGE(0), ciphertext_page,
+ inode->i_sb->s_blocksize,
+ offset, GFP_NOFS);
+ if (err)
+ goto errout;
+ lblk++;
+ offset += inode->i_sb->s_blocksize;
+ }
bio = bio_alloc(GFP_NOWAIT, 1);
if (!bio) {
@@ -224,9 +235,8 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
bio->bi_iter.bi_sector =
pblk << (inode->i_sb->s_blocksize_bits - 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, offset, 0);
+ if (ret != offset) {
/* should never happen! */
WARN_ON(1);
bio_put(bio);
@@ -239,8 +249,8 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
bio_put(bio);
if (err)
goto errout;
- lblk++;
- pblk++;
+ pblk += page_nr_blks;
+ len -= page_nr_blks;
}
err = 0;
errout:
--
2.9.5
next prev parent reply other threads:[~2018-05-22 16:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-22 16:00 [RFC PATCH V3 00/12] Ext4 encryption support for blocksize < pagesize Chandan Rajendra
2018-05-22 16:00 ` [RFC PATCH V3 01/12] ext4: Clear BH_Uptodate flag on decryption error Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 02/12] Rename fscrypt_do_page_crypto to fscrypt_do_block_crypto Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 03/12] fscrypt_decrypt_page: Decrypt all blocks in a page Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 04/12] __fscrypt_decrypt_bio: Fix page offset and len args to fscrypt_decrypt_page Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 05/12] ext4: Decrypt all boundary blocks when doing buffered write Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 06/12] ext4: Decrypt the block that needs to be partially zeroed Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 07/12] mpage_readpage[s]: Introduce post process callback parameters Chandan Rajendra
2018-05-25 20:01 ` Theodore Y. Ts'o
2018-05-28 5:35 ` Chandan Rajendra
2018-05-28 19:34 ` Theodore Y. Ts'o
2018-05-29 3:04 ` Chandan Rajendra
2018-05-29 17:53 ` Eric Biggers
2018-05-30 3:09 ` Chandan Rajendra
2018-05-30 5:06 ` Theodore Y. Ts'o
2018-05-30 11:33 ` Chandan Rajendra
2018-05-30 16:02 ` Theodore Y. Ts'o
2018-06-04 10:09 ` Chandan Rajendra
2018-05-22 16:01 ` Chandan Rajendra [this message]
2018-05-22 16:01 ` [RFC PATCH V3 09/12] fscrypt_encrypt_page: Encrypt all blocks mapped by a page Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 10/12] ext4: Fix block number passed to fscrypt_encrypt_page Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 11/12] ext4: Move encryption code into its own function Chandan Rajendra
2018-05-22 16:01 ` [RFC PATCH V3 12/12] ext4: Enable encryption for blocksize less than page size Chandan Rajendra
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