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Message-Id: <20200702015607.1215430-5-satyat@google.com>
Date: Thu, 2 Jul 2020 01:56:07 +0000
From: Satya Tangirala <satyat@...gle.com>
To: linux-fscrypt@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net, linux-ext4@...r.kernel.org
Cc: Eric Biggers <ebiggers@...gle.com>,
Satya Tangirala <satyat@...gle.com>
Subject: [PATCH v4 4/4] ext4: add inline encryption support
From: Eric Biggers <ebiggers@...gle.com>
Wire up ext4 to support inline encryption via the helper functions which
fs/crypto/ now provides. This includes:
- Adding a mount option 'inlinecrypt' which enables inline encryption
on encrypted files where it can be used.
- Setting the bio_crypt_ctx on bios that will be submitted to an
inline-encrypted file.
Note: submit_bh_wbc() in fs/buffer.c also needed to be patched for
this part, since ext4 sometimes uses ll_rw_block() on file data.
- Not adding logically discontiguous data to bios that will be submitted
to an inline-encrypted file.
- Not doing filesystem-layer crypto on inline-encrypted files.
Signed-off-by: Eric Biggers <ebiggers@...gle.com>
Co-developed-by: Satya Tangirala <satyat@...gle.com>
Signed-off-by: Satya Tangirala <satyat@...gle.com>
---
Documentation/admin-guide/ext4.rst | 7 +++++++
fs/buffer.c | 7 ++++---
fs/ext4/inode.c | 4 ++--
fs/ext4/page-io.c | 6 ++++--
fs/ext4/readpage.c | 11 ++++++++---
fs/ext4/super.c | 12 ++++++++++++
6 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst
index 9443fcef1876..2162d7909970 100644
--- a/Documentation/admin-guide/ext4.rst
+++ b/Documentation/admin-guide/ext4.rst
@@ -395,6 +395,13 @@ When mounting an ext4 filesystem, the following option are accepted:
Documentation/filesystems/dax.txt. Note that this option is
incompatible with data=journal.
+ inlinecrypt
+ When possible, encrypt/decrypt the contents of encrypted files using the
+ blk-crypto framework rather than filesystem-layer encryption. This
+ allows the use of inline encryption hardware. The on-disk format is
+ unaffected. For more details, see
+ Documentation/block/inline-encryption.rst.
+
Data Mode
=========
There are 3 different data modes:
diff --git a/fs/buffer.c b/fs/buffer.c
index 64fe82ec65ff..dc5e05b47646 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -320,9 +320,8 @@ static void decrypt_bh(struct work_struct *work)
static void end_buffer_async_read_io(struct buffer_head *bh, int uptodate)
{
/* Decrypt if needed */
- if (uptodate && IS_ENABLED(CONFIG_FS_ENCRYPTION) &&
- IS_ENCRYPTED(bh->b_page->mapping->host) &&
- S_ISREG(bh->b_page->mapping->host->i_mode)) {
+ if (uptodate &&
+ fscrypt_inode_uses_fs_layer_crypto(bh->b_page->mapping->host)) {
struct decrypt_bh_ctx *ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
if (ctx) {
@@ -3046,6 +3045,8 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
*/
bio = bio_alloc(GFP_NOIO, 1);
+ fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);
+
bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
bio_set_dev(bio, bh->b_bdev);
bio->bi_write_hint = write_hint;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 10dd470876b3..44bad4bb8831 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1096,7 +1096,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
}
if (unlikely(err)) {
page_zero_new_buffers(page, from, to);
- } else if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) {
+ } else if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
for (i = 0; i < nr_wait; i++) {
int err2;
@@ -3737,7 +3737,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
/* Uhhuh. Read error. Complain and punt. */
if (!buffer_uptodate(bh))
goto unlock;
- if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode)) {
+ if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
/* We expect the key to be set. */
BUG_ON(!fscrypt_has_encryption_key(inode));
err = fscrypt_decrypt_pagecache_blocks(page, blocksize,
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index de6fe969f773..defd2e10dfd1 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -402,6 +402,7 @@ static void io_submit_init_bio(struct ext4_io_submit *io,
* __GFP_DIRECT_RECLAIM is set, see comments for bio_alloc_bioset().
*/
bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
+ fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);
bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
bio_set_dev(bio, bh->b_bdev);
bio->bi_end_io = ext4_end_bio;
@@ -418,7 +419,8 @@ static void io_submit_add_bh(struct ext4_io_submit *io,
{
int ret;
- if (io->io_bio && bh->b_blocknr != io->io_next_block) {
+ if (io->io_bio && (bh->b_blocknr != io->io_next_block ||
+ !fscrypt_mergeable_bio_bh(io->io_bio, bh))) {
submit_and_retry:
ext4_io_submit(io);
}
@@ -506,7 +508,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
* (e.g. holes) to be unnecessarily encrypted, but this is rare and
* can't happen in the common case of blocksize == PAGE_SIZE.
*/
- if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode) && nr_to_submit) {
+ if (fscrypt_inode_uses_fs_layer_crypto(inode) && nr_to_submit) {
gfp_t gfp_flags = GFP_NOFS;
unsigned int enc_bytes = round_up(len, i_blocksize(inode));
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 5761e9961682..f2df2db0786c 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -195,7 +195,7 @@ static void ext4_set_bio_post_read_ctx(struct bio *bio,
{
unsigned int post_read_steps = 0;
- if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
+ if (fscrypt_inode_uses_fs_layer_crypto(inode))
post_read_steps |= 1 << STEP_DECRYPT;
if (ext4_need_verity(inode, first_idx))
@@ -230,6 +230,7 @@ int ext4_mpage_readpages(struct inode *inode,
const unsigned blkbits = inode->i_blkbits;
const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
const unsigned blocksize = 1 << blkbits;
+ sector_t next_block;
sector_t block_in_file;
sector_t last_block;
sector_t last_block_in_file;
@@ -258,7 +259,8 @@ int ext4_mpage_readpages(struct inode *inode,
if (page_has_buffers(page))
goto confused;
- block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits);
+ block_in_file = next_block =
+ (sector_t)page->index << (PAGE_SHIFT - blkbits);
last_block = block_in_file + nr_pages * blocks_per_page;
last_block_in_file = (ext4_readpage_limit(inode) +
blocksize - 1) >> blkbits;
@@ -358,7 +360,8 @@ int ext4_mpage_readpages(struct inode *inode,
* This page will go to BIO. Do we need to send this
* BIO off first?
*/
- if (bio && (last_block_in_bio != blocks[0] - 1)) {
+ if (bio && (last_block_in_bio != blocks[0] - 1 ||
+ !fscrypt_mergeable_bio(bio, inode, next_block))) {
submit_and_realloc:
submit_bio(bio);
bio = NULL;
@@ -370,6 +373,8 @@ int ext4_mpage_readpages(struct inode *inode,
*/
bio = bio_alloc(GFP_KERNEL,
min_t(int, nr_pages, BIO_MAX_PAGES));
+ fscrypt_set_bio_crypt_ctx(bio, inode, next_block,
+ GFP_KERNEL);
ext4_set_bio_post_read_ctx(bio, inode, page->index);
bio_set_dev(bio, bdev);
bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 330957ed1f05..0907f907c47d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1508,6 +1508,7 @@ enum {
Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
+ Opt_inlinecrypt,
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
@@ -1610,6 +1611,7 @@ static const match_table_t tokens = {
{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
{Opt_test_dummy_encryption, "test_dummy_encryption"},
+ {Opt_inlinecrypt, "inlinecrypt"},
{Opt_nombcache, "nombcache"},
{Opt_nombcache, "no_mbcache"}, /* for backward compatibility */
{Opt_removed, "check=none"}, /* mount option from ext2/3 */
@@ -1946,6 +1948,13 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
case Opt_nolazytime:
sb->s_flags &= ~SB_LAZYTIME;
return 1;
+ case Opt_inlinecrypt:
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+ sb->s_flags |= SB_INLINECRYPT;
+#else
+ ext4_msg(sb, KERN_ERR, "inline encryption not supported");
+#endif
+ return 1;
}
for (m = ext4_mount_opts; m->token != Opt_err; m++)
@@ -2404,6 +2413,9 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
fscrypt_show_test_dummy_encryption(seq, sep, sb);
+ if (sb->s_flags & SB_INLINECRYPT)
+ SEQ_OPTS_PUTS("inlinecrypt");
+
if (test_opt(sb, DAX_ALWAYS)) {
if (IS_EXT2_SB(sb))
SEQ_OPTS_PUTS("dax");
--
2.27.0.212.ge8ba1cc988-goog
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