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Commit 9d8d0512 authored by Eric Biggers's avatar Eric Biggers Committed by Paul Lawrence
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FROMLIST: ext4: add inline encryption support 



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.

Bug: 137270441
Test: tested as series; see Ie1b77f7615d6a7a60fdc9105c7ab2200d17636a8
Change-Id: I73dac46ff1eba56a13975c387b20554416ddbad8
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarSatya Tangirala <satyat@google.com>
Link: https://patchwork.kernel.org/patch/11214781/
parent fb710731

fs/buffer.c

+3 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ 
#include <linux/pagevec.h>

#include <linux/sched/mm.h>

#include <trace/events/block.h>

#include <linux/fscrypt.h>



static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);

static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
@@ -3068,6 +3069,8 @@ 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 | __GFP_NOFAIL);



	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;

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -1148,6 +1148,7 @@ struct ext4_inode_info { 
#define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */

#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */

#define EXT4_MOUNT_WARN_ON_ERROR	0x2000000 /* Trigger WARN_ON on error */

#define EXT4_MOUNT_INLINECRYPT		0x4000000 /* Inline encryption support */

#define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */

#define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */

#define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */

fs/ext4/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -1238,7 +1238,7 @@ 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;
@@ -4089,7 +4089,7 @@ 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));

			WARN_ON_ONCE(fscrypt_decrypt_pagecache_blocks(

fs/ext4/page-io.c

+9 −2
Original line number Diff line number Diff line
@@ -362,10 +362,16 @@ static int io_submit_init_bio(struct ext4_io_submit *io, 
			      struct buffer_head *bh)

{

	struct bio *bio;

	int err;



	bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);

	if (!bio)

		return -ENOMEM;

	err = fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);

	if (err) {

		bio_put(bio);

		return err;

	}

	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;
@@ -383,7 +389,8 @@ static int 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);

	}
@@ -474,7 +481,7 @@ 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));

fs/ext4/readpage.c

+12 −3
Original line number Diff line number Diff line
@@ -198,7 +198,7 @@ static struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode, 
	unsigned int post_read_steps = 0;

	struct bio_post_read_ctx *ctx = NULL;



	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))
@@ -259,6 +259,7 @@ int ext4_mpage_readpages(struct address_space *mapping, 
	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;
@@ -291,7 +292,8 @@ int ext4_mpage_readpages(struct address_space *mapping, 
		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;
@@ -391,7 +393,8 @@ int ext4_mpage_readpages(struct address_space *mapping, 
		 * 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:

			ext4_submit_bio_read(bio);

			bio = NULL;
@@ -403,6 +406,12 @@ int ext4_mpage_readpages(struct address_space *mapping, 
				min_t(int, nr_pages, BIO_MAX_PAGES));

			if (!bio)

				goto set_error_page;

			if (fscrypt_set_bio_crypt_ctx(bio, inode, next_block,

						      GFP_KERNEL) != 0) {

				bio_put(bio);

				bio = NULL;

				goto set_error_page;

			}

			ctx = get_bio_post_read_ctx(inode, bio, page->index);

			if (IS_ERR(ctx)) {

				bio_put(bio);