Commit 690b2567 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt 

Pull fscrypt updates from Eric Biggers:
 "This release, we add support for inline encryption via the blk-crypto
  framework which was added in 5.8.

  Now when an ext4 or f2fs filesystem is mounted with '-o inlinecrypt',
  the contents of encrypted files will be encrypted/decrypted via
  blk-crypto, instead of directly using the crypto API. This model
  allows taking advantage of the inline encryption hardware that is
  integrated into the UFS or eMMC host controllers on most mobile SoCs.

  Note that this is just an alternate implementation; the ciphertext
  written to disk stays the same.

  (This pull request does *not* include support for direct I/O on
  encrypted files, which blk-crypto makes possible, since that part is
  still being discussed.)

  Besides the above feature update, there are also a few fixes and
  cleanups, e.g. strengthening some memory barriers that may be too
  weak.

  All these patches have been in linux-next with no reported issues.
  I've also tested them with the fscrypt xfstests, as usual. It's also
  been tested that the inline encryption support works with the support
  for Qualcomm and Mediatek inline encryption hardware that will be in
  the scsi pull request for 5.9. Also, several SoC vendors are already
  using a previous, functionally equivalent version of these patches"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: don't load ->i_crypt_info before it's known to be valid
  fscrypt: document inline encryption support
  fscrypt: use smp_load_acquire() for ->i_crypt_info
  fscrypt: use smp_load_acquire() for ->s_master_keys
  fscrypt: use smp_load_acquire() for fscrypt_prepared_key
  fscrypt: switch fscrypt_do_sha256() to use the SHA-256 library
  fscrypt: restrict IV_INO_LBLK_* to AES-256-XTS
  fscrypt: rename FS_KEY_DERIVATION_NONCE_SIZE
  fscrypt: add comments that describe the HKDF info strings
  ext4: add inline encryption support
  f2fs: add inline encryption support
  fscrypt: add inline encryption support
  fs: introduce SB_INLINECRYPT
parents 6dec9f40 55e32c54

Documentation/admin-guide/ext4.rst

+7 −0
Original line number Diff line number Diff line
@@ -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:

Documentation/filesystems/f2fs.rst

+7 −0
Original line number Diff line number Diff line
@@ -258,6 +258,13 @@ compress_extension=%s Support adding specified extension, so that f2fs can enab 
                       on compression extension list and enable compression on

                       these file by default rather than to enable it via ioctl.

                       For other files, we can still enable compression via ioctl.

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.

====================== ============================================================



Debugfs Entries

Documentation/filesystems/fscrypt.rst

+21 −4
Original line number Diff line number Diff line
@@ -1158,7 +1158,7 @@ setxattr() because of the special semantics of the encryption xattr. 
were to be added to or removed from anything other than an empty

directory.)  These structs are defined as follows::



    #define FS_KEY_DERIVATION_NONCE_SIZE 16

    #define FSCRYPT_FILE_NONCE_SIZE 16



    #define FSCRYPT_KEY_DESCRIPTOR_SIZE  8

    struct fscrypt_context_v1 {
@@ -1167,7 +1167,7 @@ directory.) These structs are defined as follows:: 
            u8 filenames_encryption_mode;

            u8 flags;

            u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];

            u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];

            u8 nonce[FSCRYPT_FILE_NONCE_SIZE];

    };



    #define FSCRYPT_KEY_IDENTIFIER_SIZE  16
@@ -1178,7 +1178,7 @@ directory.) These structs are defined as follows:: 
            u8 flags;

            u8 __reserved[4];

            u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];

            u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];

            u8 nonce[FSCRYPT_FILE_NONCE_SIZE];

    };



The context structs contain the same information as the corresponding
@@ -1204,6 +1204,18 @@ buffer. Some filesystems, such as UBIFS, already use temporary 
buffers regardless of encryption.  Other filesystems, such as ext4 and

F2FS, have to allocate bounce pages specially for encryption.



Fscrypt is also able to use inline encryption hardware instead of the

kernel crypto API for en/decryption of file contents.  When possible,

and if directed to do so (by specifying the 'inlinecrypt' mount option

for an ext4/F2FS filesystem), it adds encryption contexts to bios and

uses blk-crypto to perform the en/decryption instead of making use of

the above read/write path changes.  Of course, even if directed to

make use of inline encryption, fscrypt will only be able to do so if

either hardware inline encryption support is available for the

selected encryption algorithm or CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK

is selected.  If neither is the case, fscrypt will fall back to using

the above mentioned read/write path changes for en/decryption.



Filename hashing and encoding

-----------------------------
@@ -1250,11 +1262,14 @@ Tests 


To test fscrypt, use xfstests, which is Linux's de facto standard

filesystem test suite.  First, run all the tests in the "encrypt"

group on the relevant filesystem(s).  For example, to test ext4 and

group on the relevant filesystem(s).  One can also run the tests

with the 'inlinecrypt' mount option to test the implementation for

inline encryption support.  For example, to test ext4 and

f2fs encryption using `kvm-xfstests

<https://github.com/tytso/xfstests-bld/blob/master/Documentation/kvm-quickstart.md>`_::



    kvm-xfstests -c ext4,f2fs -g encrypt

    kvm-xfstests -c ext4,f2fs -g encrypt -m inlinecrypt



UBIFS encryption can also be tested this way, but it should be done in

a separate command, and it takes some time for kvm-xfstests to set up
@@ -1276,6 +1291,7 @@ This tests the encrypted I/O paths more thoroughly. To do this with 
kvm-xfstests, use the "encrypt" filesystem configuration::



    kvm-xfstests -c ext4/encrypt,f2fs/encrypt -g auto

    kvm-xfstests -c ext4/encrypt,f2fs/encrypt -g auto -m inlinecrypt



Because this runs many more tests than "-g encrypt" does, it takes

much longer to run; so also consider using `gce-xfstests
@@ -1283,3 +1299,4 @@ much longer to run; so also consider using `gce-xfstests 
instead of kvm-xfstests::



    gce-xfstests -c ext4/encrypt,f2fs/encrypt -g auto

    gce-xfstests -c ext4/encrypt,f2fs/encrypt -g auto -m inlinecrypt

fs/buffer.c

+4 −3
Original line number Diff line number Diff line
@@ -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;

fs/crypto/Kconfig

+7 −1
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ config FS_ENCRYPTION 
	select CRYPTO

	select CRYPTO_HASH

	select CRYPTO_SKCIPHER

	select CRYPTO_LIB_SHA256

	select KEYS

	help

	  Enable encryption of files and directories.  This
@@ -21,6 +22,11 @@ config FS_ENCRYPTION_ALGS 
	select CRYPTO_CTS

	select CRYPTO_ECB

	select CRYPTO_HMAC

	select CRYPTO_SHA256

	select CRYPTO_SHA512

	select CRYPTO_XTS



config FS_ENCRYPTION_INLINE_CRYPT

	bool "Enable fscrypt to use inline crypto"

	depends on FS_ENCRYPTION && BLK_INLINE_ENCRYPTION

	help

	  Enable fscrypt to use inline encryption hardware if available.

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