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* [PATCH v9 00/11] Inline Encryption Support
@ 2020-03-26  3:06 Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption Satya Tangirala
                   ` (11 more replies)
  0 siblings, 12 replies; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

This patch series adds support for Inline Encryption to the block layer,
UFS, fscrypt, f2fs and ext4.

Note that the patches in this series for the block layer (i.e. patches 1, 2,
3 and 4) can be applied independently of the subsequent patches in this
series.

Inline Encryption hardware allows software to specify an encryption context
(an encryption key, crypto algorithm, data unit num, data unit size, etc.)
along with a data transfer request to a storage device, and the inline
encryption hardware will use that context to en/decrypt the data. The
inline encryption hardware is part of the storage device, and it
conceptually sits on the data path between system memory and the storage
device. Inline Encryption hardware has become increasingly common, and we
want to support it in the kernel.

Inline Encryption hardware implementations often function around the
concept of a limited number of "keyslots", which can hold an encryption
context each. The storage device can be directed to en/decrypt any
particular request with the encryption context stored in any particular
keyslot.

Patch 1 introduces a Keyslot Manager to efficiently manage keyslots.
The keyslot manager also functions as the interface that blk-crypto
(introduced in Patch 2), will use to program keys into inline encryption
hardware. For more information on the Keyslot Manager, refer to
documentation found in block/keyslot-manager.c and linux/keyslot-manager.h.

Patch 2 adds the block layer changes for inline encryption support. It
introduces struct bio_crypt_ctx, and a ptr to one in struct bio, which
allows struct bio to represent an encryption context that can be passed
down the storage stack from the filesystem layer to the storage driver.

Patch 3 precludes inline encryption support in a device whenever it
supports blk-integrity, because there is currently no known hardware that
supports both features, and it is not completely straightfoward to support
both of them properly, and doing it improperly might result in leaks of
information about the plaintext.

Patch 4 introduces blk-crypto-fallback - a kernel crypto API fallback for
blk-crypto to use when inline encryption hardware isn't present. This
allows filesystems to specify encryption contexts for bios without
having to worry about whether the underlying hardware has inline
encryption support, and allows for testing without real hardware inline
encryption support. This fallback is separately configurable from
blk-crypto, and can be disabled if desired while keeping inline
encryption support. It may also be possible to remove file content
en/decryption from fscrypt and simply use blk-crypto-fallback in a future
patch. For more details on blk-crypto and the fallback, refer to
Documentation/block/inline-encryption.rst.

Patches 5-7 add support for inline encryption into the UFS driver according
to the JEDEC UFS HCI v2.1 specification. Inline encryption support for
other drivers (like eMMC) may be added in the same way - the device driver
should set up a Keyslot Manager in the device's request_queue (refer to
the UFS crypto additions in ufshcd-crypto.c and ufshcd.c for an example).

Patch 8 adds the SB_INLINECRYPT mount flag to the fs layer, which filesystems
must set to indicate that they want to use blk-crypto for en/decryption of
file contents.

Patch 9 adds support to fscrypt - to use inline encryption with fscrypt,
the filesystem must be mounted with '-o inlinecrypt' - when this option is
specified, the contents of any AES-256-XTS encrypted file will be
encrypted using blk-crypto.

Patches 10 and 11 add support to f2fs and ext4 respectively, so that we have
a complete stack that can make use of inline encryption.

The patches were tested running kvm-xfstests, by specifying the introduced
"inlinecrypt" mount option, so that en/decryption happens with the
blk-crypto fallback. The patches were also tested on a Pixel 4 with UFS
hardware that has support for inline encryption.

There have been a few patch sets addressing Inline Encryption Support in
the past. Briefly, this patch set differs from those as follows:

1) "crypto: qce: ice: Add support for Inline Crypto Engine"
is specific to certain hardware, while our patch set's Inline
Encryption support for UFS is implemented according to the JEDEC UFS
specification.

2) "scsi: ufs: UFS Host Controller crypto changes" registers inline
encryption support as a kernel crypto algorithm. Our patch views inline
encryption as being fundamentally different from a generic crypto
provider (in that inline encryption is tied to a device), and so does
not use the kernel crypto API to represent inline encryption hardware.

3) "scsi: ufs: add real time/inline crypto support to UFS HCD" requires
the device mapper to work - our patch does not.

Changes v8 => v9:
 - Don't open code bio_has_crypt_ctx into callers of blk-crypto functions.
 - Lots of cleanups

Changes v7 => v8:
 - Pass a struct blk_ksm_keyslot * around instead of slot numbers which
   simplifies some functions and passes around arguments with better types
 - Make bios with no encryption context avoid making calls into blk-crypto
   by checking for the presence of bi_crypt_context before making the call
 - Make blk-integrity preclude inline encryption support at probe time
 - Many many cleanups

Changes v6 => v7:
 - Keyslot management is now done on a per-request basis rather than a
   per-bio basis.
 - Storage drivers can now specify the maximum number of bytes they
   can accept for the data unit number (DUN) for each crypto algorithm,
   and upper layers can specify the minimum number of bytes of DUN they
   want with the blk_crypto_key they send with the bio - a driver is
   only considered to support a blk_crypto_key if the driver supports at
   least as many DUN bytes as the upper layer wants. This is necessary
   because storage drivers may not support as many bytes as the
   algorithm specification dictates (for e.g. UFS only supports 8 byte
   DUNs for AES-256-XTS, even though the algorithm specification
   says DUNs are 16 bytes long).
 - Introduce SB_INLINECRYPT to keep track of whether inline encryption
   is enabled for a filesystem (instead of using an fscrypt_operation).
 - Expose keyslot manager declaration and embed it within ufs_hba to
   clean up code.
 - Make blk-crypto preclude blk-integrity.
 - Some bug fixes
 - Introduce UFSHCD_QUIRK_BROKEN_CRYPTO for UFS drivers that don't
   support inline encryption (yet)

Changes v5 => v6:
 - Blk-crypto's kernel crypto API fallback is no longer restricted to
   8-byte DUNs. It's also now separately configurable from blk-crypto, and
   can be disabled entirely, while still allowing the kernel to use inline
   encryption hardware. Further, struct bio_crypt_ctx takes up less space,
   and no longer contains the information needed by the crypto API
   fallback - the fallback allocates the required memory when necessary.
 - Blk-crypto now supports all file content encryption modes supported by
   fscrypt.
 - Fixed bio merging logic in blk-merge.c
 - Fscrypt now supports inline encryption with the direct key policy, since
   blk-crypto now has support for larger DUNs.
 - Keyslot manager now uses a hashtable to lookup which keyslot contains
   any particular key (thanks Eric!)
 - Fscrypt support for inline encryption now handles filesystems with
   multiple underlying block devices (thanks Eric!)
 - Numerous cleanups

Changes v4 => v5:
 - The fscrypt patch has been separated into 2. The first adds support
   for the IV_INO_LBLK_64 policy (which was called INLINE_CRYPT_OPTIMIZED
   in past versions of this series). This policy is now purely an on disk
   format, and doesn't dictate whether blk-crypto is used for file content
   encryption or not. Instead, this is now decided based on the
   "inlinecrypt" mount option.
 - Inline crypto key eviction is now handled by blk-crypto instead of
   fscrypt.
 - More refactoring.

Changes v3 => v4:
 - Fixed the issue with allocating crypto_skcipher in
   blk_crypto_keyslot_program.
 - bio_crypto_alloc_ctx is now mempool backed.
 - In f2fs, a bio's bi_crypt_context is now set up when the
   bio is allocated, rather than just before the bio is
   submitted - this fixes bugs in certain cases, like when an
   encrypted block is being moved without decryption.
 - Lots of refactoring and cleanup of blk-crypto - thanks Eric!

Changes v2 => v3:
 - Overhauled keyslot manager's get keyslot logic and optimized LRU.
 - Block crypto en/decryption fallback now supports data unit sizes
   that divide the bvec length (instead of requiring each bvec's length
   to be the same as the data unit size).
 - fscrypt master key is now keyed additionally by super_block and
   ci_ctfm != NULL.
 - all references of "hw encryption" are replaced by inline encryption.
 - address various other review comments from Eric.

Changes v1 => v2:
 - Block layer and UFS changes are split into 3 patches each.
 - We now only have a ptr to a struct bio_crypt_ctx in struct bio, instead
   of the struct itself.
 - struct bio_crypt_ctx no longer has flags.
 - blk-crypto now correctly handles the case when it fails to init
   (because of insufficient memory), but kernel continues to boot.
 - ufshcd-crypto now works on big endian cpus.
 - Many cleanups.


Eric Biggers (1):
  ext4: add inline encryption support

Satya Tangirala (10):
  block: Keyslot Manager for Inline Encryption
  block: Inline encryption support for blk-mq
  block: Make blk-integrity preclude hardware inline encryption
  block: blk-crypto-fallback for Inline Encryption
  scsi: ufs: UFS driver v2.1 spec crypto additions
  scsi: ufs: UFS crypto API
  scsi: ufs: Add inline encryption support to UFS
  fs: introduce SB_INLINECRYPT
  fscrypt: add inline encryption support
  f2fs: add inline encryption support

 Documentation/admin-guide/ext4.rst        |   6 +
 Documentation/block/index.rst             |   1 +
 Documentation/block/inline-encryption.rst | 195 +++++++
 Documentation/filesystems/f2fs.txt        |   6 +
 block/Kconfig                             |  17 +
 block/Makefile                            |   2 +
 block/bio-integrity.c                     |   3 +
 block/bio.c                               |   6 +
 block/blk-core.c                          |  20 +-
 block/blk-crypto-fallback.c               | 666 ++++++++++++++++++++++
 block/blk-crypto-internal.h               | 197 +++++++
 block/blk-crypto.c                        | 408 +++++++++++++
 block/blk-integrity.c                     |   7 +
 block/blk-map.c                           |   1 +
 block/blk-merge.c                         |  11 +
 block/blk-mq.c                            |  12 +
 block/blk.h                               |   4 +
 block/bounce.c                            |   2 +
 block/keyslot-manager.c                   | 396 +++++++++++++
 drivers/md/dm.c                           |   3 +
 drivers/scsi/ufs/Kconfig                  |   9 +
 drivers/scsi/ufs/Makefile                 |   1 +
 drivers/scsi/ufs/ufshcd-crypto.c          | 226 ++++++++
 drivers/scsi/ufs/ufshcd-crypto.h          |  62 ++
 drivers/scsi/ufs/ufshcd.c                 |  46 +-
 drivers/scsi/ufs/ufshcd.h                 |  23 +
 drivers/scsi/ufs/ufshci.h                 |  67 ++-
 fs/buffer.c                               |   7 +-
 fs/crypto/Kconfig                         |   6 +
 fs/crypto/Makefile                        |   1 +
 fs/crypto/bio.c                           |  51 ++
 fs/crypto/crypto.c                        |   2 +-
 fs/crypto/fname.c                         |   4 +-
 fs/crypto/fscrypt_private.h               | 120 +++-
 fs/crypto/inline_crypt.c                  | 328 +++++++++++
 fs/crypto/keyring.c                       |   4 +-
 fs/crypto/keysetup.c                      |  92 ++-
 fs/crypto/keysetup_v1.c                   |  16 +-
 fs/ext4/inode.c                           |   4 +-
 fs/ext4/page-io.c                         |   6 +-
 fs/ext4/readpage.c                        |  11 +-
 fs/ext4/super.c                           |   9 +
 fs/f2fs/compress.c                        |   2 +-
 fs/f2fs/data.c                            |  68 ++-
 fs/f2fs/super.c                           |  32 ++
 fs/proc_namespace.c                       |   1 +
 include/linux/blk-crypto.h                | 129 +++++
 include/linux/blk_types.h                 |   6 +
 include/linux/blkdev.h                    |  41 ++
 include/linux/fs.h                        |   1 +
 include/linux/fscrypt.h                   |  57 ++
 include/linux/keyslot-manager.h           | 107 ++++
 52 files changed, 3413 insertions(+), 89 deletions(-)
 create mode 100644 Documentation/block/inline-encryption.rst
 create mode 100644 block/blk-crypto-fallback.c
 create mode 100644 block/blk-crypto-internal.h
 create mode 100644 block/blk-crypto.c
 create mode 100644 block/keyslot-manager.c
 create mode 100644 drivers/scsi/ufs/ufshcd-crypto.c
 create mode 100644 drivers/scsi/ufs/ufshcd-crypto.h
 create mode 100644 fs/crypto/inline_crypt.c
 create mode 100644 include/linux/blk-crypto.h
 create mode 100644 include/linux/keyslot-manager.h

-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  6:22   ` Eric Biggers
  2020-03-26  3:06 ` [PATCH v9 02/11] block: Inline encryption support for blk-mq Satya Tangirala
                   ` (10 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala,
	Eric Biggers

Inline Encryption hardware allows software to specify an encryption context
(an encryption key, crypto algorithm, data unit num, data unit size) along
with a data transfer request to a storage device, and the inline encryption
hardware will use that context to en/decrypt the data. The inline
encryption hardware is part of the storage device, and it conceptually sits
on the data path between system memory and the storage device.

Inline Encryption hardware implementations often function around the
concept of "keyslots". These implementations often have a limited number
of "keyslots", each of which can hold a key (we say that a key can be
"programmed" into a keyslot). Requests made to the storage device may have
a keyslot and a data unit number associated with them, and the inline
encryption hardware will en/decrypt the data in the requests using the key
programmed into that associated keyslot and the data unit number specified
with the request.

As keyslots are limited, and programming keys may be expensive in many
implementations, and multiple requests may use exactly the same encryption
contexts, we introduce a Keyslot Manager to efficiently manage keyslots.

We also introduce a blk_crypto_key, which will represent the key that's
programmed into keyslots managed by keyslot managers. The keyslot manager
also functions as the interface that upper layers will use to program keys
into inline encryption hardware. For more information on the Keyslot
Manager, refer to documentation found in block/keyslot-manager.c and
linux/keyslot-manager.h.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
 block/Kconfig                   |   7 +
 block/Makefile                  |   1 +
 block/keyslot-manager.c         | 377 ++++++++++++++++++++++++++++++++
 include/linux/blk-crypto.h      |  45 ++++
 include/linux/blkdev.h          |   6 +
 include/linux/keyslot-manager.h | 107 +++++++++
 6 files changed, 543 insertions(+)
 create mode 100644 block/keyslot-manager.c
 create mode 100644 include/linux/blk-crypto.h
 create mode 100644 include/linux/keyslot-manager.h

diff --git a/block/Kconfig b/block/Kconfig
index 3bc76bb113a08..c04a1d5008421 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -185,6 +185,13 @@ config BLK_SED_OPAL
 	Enabling this option enables users to setup/unlock/lock
 	Locking ranges for SED devices using the Opal protocol.
 
+config BLK_INLINE_ENCRYPTION
+	bool "Enable inline encryption support in block layer"
+	help
+	  Build the blk-crypto subsystem. Enabling this lets the
+	  block layer handle encryption, so users can take
+	  advantage of inline encryption hardware if present.
+
 menu "Partition Types"
 
 source "block/partitions/Kconfig"
diff --git a/block/Makefile b/block/Makefile
index 1a43750f4b01f..ef3a05dcf1f26 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= keyslot-manager.o
diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
new file mode 100644
index 0000000000000..3a5f2e445809e
--- /dev/null
+++ b/block/keyslot-manager.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+/**
+ * DOC: The Keyslot Manager
+ *
+ * Many devices with inline encryption support have a limited number of "slots"
+ * into which encryption contexts may be programmed, and requests can be tagged
+ * with a slot number to specify the key to use for en/decryption.
+ *
+ * As the number of slots are limited, and programming keys is expensive on
+ * many inline encryption hardware, we don't want to program the same key into
+ * multiple slots - if multiple requests are using the same key, we want to
+ * program just one slot with that key and use that slot for all requests.
+ *
+ * The keyslot manager manages these keyslots appropriately, and also acts as
+ * an abstraction between the inline encryption hardware and the upper layers.
+ *
+ * Lower layer devices will set up a keyslot manager in their request queue
+ * and tell it how to perform device specific operations like programming/
+ * evicting keys from keyslots.
+ *
+ * Upper layers will call blk_ksm_get_slot_for_key() to program a
+ * key into some slot in the inline encryption hardware.
+ */
+#include <crypto/algapi.h>
+#include <linux/keyslot-manager.h>
+#include <linux/atomic.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/wait.h>
+#include <linux/blkdev.h>
+
+struct blk_ksm_keyslot {
+	atomic_t slot_refs;
+	struct list_head idle_slot_node;
+	struct hlist_node hash_node;
+	struct blk_crypto_key key;
+	struct blk_keyslot_manager *ksm;
+};
+
+static inline void blk_ksm_hw_enter(struct blk_keyslot_manager *ksm)
+{
+	/*
+	 * Calling into the driver requires ksm->lock held and the device
+	 * resumed.  But we must resume the device first, since that can acquire
+	 * and release ksm->lock via blk_ksm_reprogram_all_keys().
+	 */
+	if (ksm->dev)
+		pm_runtime_get_sync(ksm->dev);
+	down_write(&ksm->lock);
+}
+
+static inline void blk_ksm_hw_exit(struct blk_keyslot_manager *ksm)
+{
+	up_write(&ksm->lock);
+	if (ksm->dev)
+		pm_runtime_put_sync(ksm->dev);
+}
+
+/**
+ * blk_ksm_init() - Initialize a keyslot manager
+ * @ksm: The keyslot_manager to initialize.
+ * @dev: Device for runtime power management (NULL if none)
+ * @num_slots: The number of key slots to manage.
+ *
+ * Allocate memory for keyslots and initialize a keyslot manager. Called by
+ * e.g. storage drivers to set up a keyslot manager in their request_queue.
+ *
+ * Return: 0 on success, or else a negative error code.
+ */
+int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots)
+{
+	unsigned int slot;
+	unsigned int i;
+
+	memset(ksm, 0, sizeof(*ksm));
+
+	if (num_slots == 0)
+		return -EINVAL;
+
+	ksm->slots = kvcalloc(num_slots, sizeof(ksm->slots[0]), GFP_KERNEL);
+	if (!ksm->slots)
+		return -ENOMEM;
+
+	ksm->num_slots = num_slots;
+
+	init_rwsem(&ksm->lock);
+
+	init_waitqueue_head(&ksm->idle_slots_wait_queue);
+	INIT_LIST_HEAD(&ksm->idle_slots);
+
+	for (slot = 0; slot < num_slots; slot++) {
+		ksm->slots[slot].ksm = ksm;
+		list_add_tail(&ksm->slots[slot].idle_slot_node,
+			      &ksm->idle_slots);
+	}
+
+	spin_lock_init(&ksm->idle_slots_lock);
+
+	ksm->slot_hashtable_size = roundup_pow_of_two(num_slots);
+	ksm->slot_hashtable = kvmalloc_array(ksm->slot_hashtable_size,
+					     sizeof(ksm->slot_hashtable[0]),
+					     GFP_KERNEL);
+	if (!ksm->slot_hashtable)
+		goto err_destroy_ksm;
+	for (i = 0; i < ksm->slot_hashtable_size; i++)
+		INIT_HLIST_HEAD(&ksm->slot_hashtable[i]);
+
+	return 0;
+
+err_destroy_ksm:
+	blk_ksm_destroy(ksm);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(blk_ksm_init);
+
+static inline struct hlist_head *
+blk_ksm_hash_bucket_for_key(struct blk_keyslot_manager *ksm,
+			    const struct blk_crypto_key *key)
+{
+	return &ksm->slot_hashtable[key->hash & (ksm->slot_hashtable_size - 1)];
+}
+
+static void blk_ksm_remove_slot_from_lru_list(struct blk_ksm_keyslot *slot)
+{
+	struct blk_keyslot_manager *ksm = slot->ksm;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ksm->idle_slots_lock, flags);
+	list_del(&slot->idle_slot_node);
+	spin_unlock_irqrestore(&ksm->idle_slots_lock, flags);
+}
+
+static struct blk_ksm_keyslot *blk_ksm_find_keyslot(
+					struct blk_keyslot_manager *ksm,
+					const struct blk_crypto_key *key)
+{
+	const struct hlist_head *head = blk_ksm_hash_bucket_for_key(ksm, key);
+	struct blk_ksm_keyslot *slotp;
+
+	hlist_for_each_entry(slotp, head, hash_node) {
+		if (slotp->key.hash == key->hash &&
+		    slotp->key.crypto_mode == key->crypto_mode &&
+		    slotp->key.data_unit_size == key->data_unit_size &&
+		    !crypto_memneq(slotp->key.raw, key->raw, key->size))
+			return slotp;
+	}
+	return NULL;
+}
+
+static struct blk_ksm_keyslot *blk_ksm_find_and_grab_keyslot(
+					struct blk_keyslot_manager *ksm,
+					const struct blk_crypto_key *key)
+{
+	struct blk_ksm_keyslot *slot;
+
+	slot = blk_ksm_find_keyslot(ksm, key);
+	if (!slot)
+		return NULL;
+	if (atomic_inc_return(&slot->slot_refs) == 1) {
+		/* Took first reference to this slot; remove it from LRU list */
+		blk_ksm_remove_slot_from_lru_list(slot);
+	}
+	return slot;
+}
+
+unsigned int blk_ksm_get_slot_idx(struct blk_ksm_keyslot *slot)
+{
+	return slot - slot->ksm->slots;
+}
+EXPORT_SYMBOL_GPL(blk_ksm_get_slot_idx);
+
+/**
+ * blk_ksm_get_slot_for_key() - Program a key into a keyslot.
+ * @ksm: The keyslot manager to program the key into.
+ * @key: Pointer to the key object to program, including the raw key, crypto
+ *	 mode, and data unit size.
+ * @keyslot: A pointer to return the pointer of the allocated keyslot.
+ *
+ * Get a keyslot that's been programmed with the specified key.  If one already
+ * exists, return it with incremented refcount.  Otherwise, wait for a keyslot
+ * to become idle and program it.
+ *
+ * Context: Process context. Takes and releases ksm->lock.
+ * Return: BLK_STATUS_OK on success (and keyslot is set to the pointer of the
+ *	   allocated keyslot), or some other blk_status_t otherwise (and
+ *	   keyslot is set to NULL).
+ */
+blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm,
+				      const struct blk_crypto_key *key,
+				      struct blk_ksm_keyslot **slot_ptr)
+{
+	struct blk_ksm_keyslot *slot;
+	int slot_idx;
+	int err;
+
+	*slot_ptr = NULL;
+	down_read(&ksm->lock);
+	slot = blk_ksm_find_and_grab_keyslot(ksm, key);
+	up_read(&ksm->lock);
+	if (slot)
+		goto success;
+
+	for (;;) {
+		blk_ksm_hw_enter(ksm);
+		slot = blk_ksm_find_and_grab_keyslot(ksm, key);
+		if (slot) {
+			blk_ksm_hw_exit(ksm);
+			goto success;
+		}
+
+		/*
+		 * If we're here, that means there wasn't a slot that was
+		 * already programmed with the key. So try to program it.
+		 */
+		if (!list_empty(&ksm->idle_slots))
+			break;
+
+		blk_ksm_hw_exit(ksm);
+		wait_event(ksm->idle_slots_wait_queue,
+			   !list_empty(&ksm->idle_slots));
+	}
+
+	slot = list_first_entry(&ksm->idle_slots, struct blk_ksm_keyslot,
+				idle_slot_node);
+	slot_idx = blk_ksm_get_slot_idx(slot);
+
+	err = ksm->ksm_ll_ops.keyslot_program(ksm, key, slot_idx);
+	if (err) {
+		wake_up(&ksm->idle_slots_wait_queue);
+		blk_ksm_hw_exit(ksm);
+		return errno_to_blk_status(err);
+	}
+
+	/* Move this slot to the hash list for the new key. */
+	if (slot->key.crypto_mode != BLK_ENCRYPTION_MODE_INVALID)
+		hlist_del(&slot->hash_node);
+	hlist_add_head(&slot->hash_node, blk_ksm_hash_bucket_for_key(ksm, key));
+
+	atomic_set(&slot->slot_refs, 1);
+	slot->key = *key;
+
+	blk_ksm_remove_slot_from_lru_list(slot);
+
+	blk_ksm_hw_exit(ksm);
+success:
+	*slot_ptr = slot;
+	return BLK_STS_OK;
+}
+
+/**
+ * blk_ksm_put_slot() - Release a reference to a slot
+ * @slot: The keyslot to release the reference of.
+ *
+ * Context: Any context.
+ */
+void blk_ksm_put_slot(struct blk_ksm_keyslot *slot)
+{
+	struct blk_keyslot_manager *ksm;
+	unsigned long flags;
+
+	if (!slot)
+		return;
+
+	ksm = slot->ksm;
+
+	if (atomic_dec_and_lock_irqsave(&slot->slot_refs,
+					&ksm->idle_slots_lock, flags)) {
+		list_add_tail(&slot->idle_slot_node, &ksm->idle_slots);
+		spin_unlock_irqrestore(&ksm->idle_slots_lock, flags);
+		wake_up(&ksm->idle_slots_wait_queue);
+	}
+}
+
+/**
+ * blk_ksm_crypto_key_supported() - Find out if the crypto_mode, dusize, dun
+ *				    bytes of a crypto_key are supported by a
+ *				    ksm.
+ * @ksm: The keyslot manager to check
+ * @key: The key whose crypto_mode, dusize and dun bytes to check for.
+ *
+ * Checks for crypto_mode/data unit size/dun bytes support.
+ *
+ * Return: Whether or not this ksm supports the specified crypto key.
+ */
+bool blk_ksm_crypto_key_supported(struct blk_keyslot_manager *ksm,
+				  const struct blk_crypto_key *key)
+{
+	if (!ksm)
+		return false;
+	return (ksm->crypto_modes_supported[key->crypto_mode] &
+		key->data_unit_size) &&
+	       (ksm->max_dun_bytes_supported >= key->dun_bytes);
+}
+
+/**
+ * blk_ksm_evict_key() - Evict a key from the lower layer device.
+ * @ksm: The keyslot manager to evict from
+ * @key: The key to evict
+ *
+ * Find the keyslot that the specified key was programmed into, and evict that
+ * slot from the lower layer device if that slot is not currently in use.
+ *
+ * Context: Process context. Takes and releases ksm->lock.
+ * Return: 0 on success or if there's no keyslot with the specified key, -EBUSY
+ *	   if the key is still in use, or another -errno value on other error.
+ */
+int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
+		      const struct blk_crypto_key *key)
+{
+	struct blk_ksm_keyslot *slot;
+	int err = 0;
+
+	blk_ksm_hw_enter(ksm);
+	slot = blk_ksm_find_keyslot(ksm, key);
+	if (!slot)
+		goto out_unlock;
+
+	if (atomic_read(&slot->slot_refs) != 0) {
+		err = -EBUSY;
+		goto out_unlock;
+	}
+	err = ksm->ksm_ll_ops.keyslot_evict(ksm, key,
+					    blk_ksm_get_slot_idx(slot));
+	if (err)
+		goto out_unlock;
+
+	hlist_del(&slot->hash_node);
+	memzero_explicit(&slot->key, sizeof(slot->key));
+	err = 0;
+out_unlock:
+	blk_ksm_hw_exit(ksm);
+	return err;
+}
+
+/**
+ * blk_ksm_reprogram_all_keys() - Re-program all keyslots.
+ * @ksm: The keyslot manager
+ *
+ * Re-program all keyslots that are supposed to have a key programmed.  This is
+ * intended only for use by drivers for hardware that loses its keys on reset.
+ *
+ * Context: Process context. Takes and releases ksm->lock.
+ */
+void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm)
+{
+	unsigned int slot;
+
+	/* This is for device initialization, so don't resume the device */
+	down_write(&ksm->lock);
+	for (slot = 0; slot < ksm->num_slots; slot++) {
+		const struct blk_ksm_keyslot *slotp = &ksm->slots[slot];
+		int err;
+
+		if (slotp->key.crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
+			continue;
+
+		err = ksm->ksm_ll_ops.keyslot_program(ksm, &slotp->key, slot);
+		WARN_ON(err);
+	}
+	up_write(&ksm->lock);
+}
+EXPORT_SYMBOL_GPL(blk_ksm_reprogram_all_keys);
+
+void blk_ksm_destroy(struct blk_keyslot_manager *ksm)
+{
+	if (!ksm)
+		return;
+	kvfree(ksm->slot_hashtable);
+	memzero_explicit(ksm->slots, sizeof(ksm->slots[0]) * ksm->num_slots);
+	kvfree(ksm->slots);
+	memzero_explicit(ksm, sizeof(*ksm));
+}
+EXPORT_SYMBOL_GPL(blk_ksm_destroy);
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
new file mode 100644
index 0000000000000..b8d54eca1c0d8
--- /dev/null
+++ b/include/linux/blk-crypto.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef __LINUX_BLK_CRYPTO_H
+#define __LINUX_BLK_CRYPTO_H
+
+enum blk_crypto_mode_num {
+	BLK_ENCRYPTION_MODE_INVALID,
+	BLK_ENCRYPTION_MODE_AES_256_XTS,
+	BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV,
+	BLK_ENCRYPTION_MODE_ADIANTUM,
+	BLK_ENCRYPTION_MODE_MAX,
+};
+
+#define BLK_CRYPTO_MAX_KEY_SIZE		64
+
+/**
+ * struct blk_crypto_key - an inline encryption key
+ * @crypto_mode: encryption algorithm this key is for
+ * @data_unit_size: the data unit size for all encryption/decryptions with this
+ *	key.  This is the size in bytes of each individual plaintext and
+ *	ciphertext.  This is always a power of 2.  It might be e.g. the
+ *	filesystem block size or the disk sector size.
+ * @data_unit_size_bits: log2 of data_unit_size
+ * @dun_bytes: the number of bytes of DUN used when using this key
+ * @size: size of this key in bytes (determined by @crypto_mode)
+ * @hash: hash of this key, for keyslot manager use only
+ * @raw: the raw bytes of this key.  Only the first @size bytes are used.
+ *
+ * A blk_crypto_key is immutable once created, and many bios can reference it at
+ * the same time.  It must not be freed until all bios using it have completed.
+ */
+struct blk_crypto_key {
+	enum blk_crypto_mode_num crypto_mode;
+	unsigned int data_unit_size;
+	unsigned int data_unit_size_bits;
+	unsigned int dun_bytes;
+	unsigned int size;
+	unsigned int hash;
+	u8 raw[BLK_CRYPTO_MAX_KEY_SIZE];
+};
+
+#endif /* __LINUX_BLK_CRYPTO_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f629d40c645cd..27d460d0a8508 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -43,6 +43,7 @@ struct pr_ops;
 struct rq_qos;
 struct blk_queue_stats;
 struct blk_stat_callback;
+struct blk_keyslot_manager;
 
 #define BLKDEV_MIN_RQ	4
 #define BLKDEV_MAX_RQ	128	/* Default maximum */
@@ -474,6 +475,11 @@ struct request_queue {
 	unsigned int		dma_pad_mask;
 	unsigned int		dma_alignment;
 
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	/* Inline crypto capabilities */
+	struct blk_keyslot_manager *ksm;
+#endif
+
 	unsigned int		rq_timeout;
 	int			poll_nsec;
 
diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h
new file mode 100644
index 0000000000000..b4dfb48519114
--- /dev/null
+++ b/include/linux/keyslot-manager.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef __LINUX_KEYSLOT_MANAGER_H
+#define __LINUX_KEYSLOT_MANAGER_H
+
+#include <linux/bio.h>
+#include <linux/blk-crypto.h>
+
+struct blk_keyslot_manager;
+
+/**
+ * struct blk_ksm_ll_ops - functions to manage keyslots in hardware
+ * @keyslot_program:	Program the specified key into the specified slot in the
+ *			inline encryption hardware.
+ * @keyslot_evict:	Evict key from the specified keyslot in the hardware.
+ *			The key is provided so that e.g. dm layers can evict
+ *			keys from the devices that they map over.
+ *			Returns 0 on success, -errno otherwise.
+ *
+ * This structure should be provided by storage device drivers when they set up
+ * a keyslot manager - this structure holds the function ptrs that the keyslot
+ * manager will use to manipulate keyslots in the hardware.
+ */
+struct blk_ksm_ll_ops {
+	int (*keyslot_program)(struct blk_keyslot_manager *ksm,
+			       const struct blk_crypto_key *key,
+			       unsigned int slot);
+	int (*keyslot_evict)(struct blk_keyslot_manager *ksm,
+			     const struct blk_crypto_key *key,
+			     unsigned int slot);
+};
+
+struct blk_keyslot_manager {
+	/*
+	 * The struct blk_ksm_ll_ops that this keyslot manager will use
+	 * to perform operations like programming and evicting keys on the
+	 * device
+	 */
+	struct blk_ksm_ll_ops ksm_ll_ops;
+
+	/*
+	 * The maximum number of bytes supported for specifying the data unit
+	 * number.
+	 */
+	unsigned int max_dun_bytes_supported;
+
+	/*
+	 * Array of size BLK_ENCRYPTION_MODE_MAX of bitmasks that represents
+	 * whether a crypto mode and data unit size are supported. The i'th
+	 * bit of crypto_mode_supported[crypto_mode] is set iff a data unit
+	 * size of (1 << i) is supported. We only support data unit sizes
+	 * that are powers of 2.
+	 */
+	unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX];
+
+	/* Device for runtime power management (NULL if none) */
+	struct device *dev;
+
+	/* Here onwards are *private* fields for internal keyslot manager use */
+
+	unsigned int num_slots;
+
+	/* Protects programming and evicting keys from the device */
+	struct rw_semaphore lock;
+
+	/* List of idle slots, with least recently used slot at front */
+	wait_queue_head_t idle_slots_wait_queue;
+	struct list_head idle_slots;
+	spinlock_t idle_slots_lock;
+
+	/*
+	 * Hash table which maps key hashes to keyslots, so that we can find a
+	 * key's keyslot in O(1) time rather than O(num_slots).  Protected by
+	 * 'lock'.  A cryptographic hash function is used so that timing attacks
+	 * can't leak information about the raw keys.
+	 */
+	struct hlist_head *slot_hashtable;
+	unsigned int slot_hashtable_size;
+
+	/* Per-keyslot data */
+	struct blk_ksm_keyslot *slots;
+};
+
+int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots);
+
+blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm,
+				      const struct blk_crypto_key *key,
+				      struct blk_ksm_keyslot **slot_ptr);
+
+unsigned int blk_ksm_get_slot_idx(struct blk_ksm_keyslot *slot);
+
+void blk_ksm_put_slot(struct blk_ksm_keyslot *slot);
+
+bool blk_ksm_crypto_key_supported(struct blk_keyslot_manager *ksm,
+				  const struct blk_crypto_key *key);
+
+int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
+		      const struct blk_crypto_key *key);
+
+void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm);
+
+void blk_ksm_destroy(struct blk_keyslot_manager *ksm);
+
+#endif /* __LINUX_KEYSLOT_MANAGER_H */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 02/11] block: Inline encryption support for blk-mq
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26 20:05   ` Eric Biggers
  2020-03-26  3:06 ` [PATCH v9 03/11] block: Make blk-integrity preclude hardware inline encryption Satya Tangirala
                   ` (9 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

We must have some way of letting a storage device driver know what
encryption context it should use for en/decrypting a request. However,
it's the upper layers (like the filesystem/fscrypt) that know about and
manages encryption contexts. As such, when the upper layer submits a bio
to the block layer, and this bio eventually reaches a device driver with
support for inline encryption, the device driver will need to have been
told the encryption context for that bio.

We want to communicate the encryption context from the upper layer to the
storage device along with the bio, when the bio is submitted to the block
layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can
represent an encryption context (note that we can't use the bi_private
field in struct bio to do this because that field does not function to pass
information across layers in the storage stack). We also introduce various
functions to manipulate the bio_crypt_ctx and make the bio/request merging
logic aware of the bio_crypt_ctx.

We also make changes to blk-mq to make it handle bios with encryption
contexts. blk-mq can merge many bios into the same request. These bios need
to have contiguous data unit numbers (the necessary changes to blk-merge
are also made to ensure this) - as such, it suffices to keep the data unit
number of just the first bio, since that's all a storage driver needs to
infer the data unit number to use for each data block in each bio in a
request. blk-mq keeps track of the encryption context to be used for all
the bios in a request with the request's rq_crypt_ctx. When the first bio
is added to an empty request, blk-mq will program the encryption context
of that bio into the request_queue's keyslot manager, and store the
returned keyslot in the request's rq_crypt_ctx. All the functions to
operate on encryption contexts are in blk-crypto.c.

Upper layers only need to call bio_crypt_set_ctx with the encryption key,
algorithm and data_unit_num; they don't have to worry about getting a
keyslot for each encryption context, as blk-mq/blk-crypto handles that.
Blk-crypto also makes it possible for request-based layered devices like
dm-rq to make use of inline encryption hardware by cloning the
rq_crypt_ctx and programming a keyslot in the new request_queue when
necessary.

Note that any user of the block layer can submit bios with an
encryption context, such as filesystems, device-mapper targets, etc.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 block/Makefile              |   2 +-
 block/bio.c                 |   6 +
 block/blk-core.c            |  20 +-
 block/blk-crypto-internal.h | 172 ++++++++++++++++
 block/blk-crypto.c          | 388 ++++++++++++++++++++++++++++++++++++
 block/blk-map.c             |   1 +
 block/blk-merge.c           |  11 +
 block/blk-mq.c              |  12 ++
 block/blk.h                 |   4 +
 block/bounce.c              |   2 +
 drivers/md/dm.c             |   3 +
 include/linux/blk-crypto.h  |  71 ++++++-
 include/linux/blk_types.h   |   6 +
 include/linux/blkdev.h      |   5 +
 14 files changed, 697 insertions(+), 6 deletions(-)
 create mode 100644 block/blk-crypto-internal.h
 create mode 100644 block/blk-crypto.c

diff --git a/block/Makefile b/block/Makefile
index ef3a05dcf1f26..82f42ca3f7695 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -37,4 +37,4 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
-obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= keyslot-manager.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= keyslot-manager.o blk-crypto.o
diff --git a/block/bio.c b/block/bio.c
index 94d697217887a..d3e3d3e3dca53 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -17,6 +17,7 @@
 #include <linux/cgroup.h>
 #include <linux/blk-cgroup.h>
 #include <linux/highmem.h>
+#include <linux/blk-crypto.h>
 
 #include <trace/events/block.h>
 #include "blk.h"
@@ -236,6 +237,8 @@ void bio_uninit(struct bio *bio)
 
 	if (bio_integrity(bio))
 		bio_integrity_free(bio);
+
+	bio_crypt_free_ctx(bio);
 }
 EXPORT_SYMBOL(bio_uninit);
 
@@ -664,6 +667,8 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
 
 	__bio_clone_fast(b, bio);
 
+	bio_crypt_clone(b, bio, gfp_mask);
+
 	if (bio_integrity(bio)) {
 		int ret;
 
@@ -1046,6 +1051,7 @@ void bio_advance(struct bio *bio, unsigned bytes)
 	if (bio_integrity(bio))
 		bio_integrity_advance(bio, bytes);
 
+	bio_crypt_advance(bio, bytes);
 	bio_advance_iter(bio, &bio->bi_iter, bytes);
 }
 EXPORT_SYMBOL(bio_advance);
diff --git a/block/blk-core.c b/block/blk-core.c
index 60dc9552ef8de..91c537fc9a6f4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -38,6 +38,7 @@
 #include <linux/debugfs.h>
 #include <linux/bpf.h>
 #include <linux/psi.h>
+#include <linux/blk-crypto.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/block.h>
@@ -120,6 +121,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
 	rq->start_time_ns = ktime_get_ns();
 	rq->part = NULL;
 	refcount_set(&rq->ref, 1);
+	blk_crypto_rq_set_defaults(rq);
 }
 EXPORT_SYMBOL(blk_rq_init);
 
@@ -617,6 +619,8 @@ bool bio_attempt_back_merge(struct request *req, struct bio *bio,
 	req->biotail = bio;
 	req->__data_len += bio->bi_iter.bi_size;
 
+	bio_crypt_free_ctx(bio);
+
 	blk_account_io_start(req, false);
 	return true;
 }
@@ -641,6 +645,8 @@ bool bio_attempt_front_merge(struct request *req, struct bio *bio,
 	req->__sector = bio->bi_iter.bi_sector;
 	req->__data_len += bio->bi_iter.bi_size;
 
+	blk_crypto_rq_bio_prep(req, bio);
+
 	blk_account_io_start(req, false);
 	return true;
 }
@@ -1066,7 +1072,8 @@ blk_qc_t generic_make_request(struct bio *bio)
 			/* Create a fresh bio_list for all subordinate requests */
 			bio_list_on_stack[1] = bio_list_on_stack[0];
 			bio_list_init(&bio_list_on_stack[0]);
-			ret = q->make_request_fn(q, bio);
+			if (blk_crypto_bio_prep(&bio))
+				ret = q->make_request_fn(q, bio);
 
 			blk_queue_exit(q);
 
@@ -1114,7 +1121,7 @@ blk_qc_t direct_make_request(struct bio *bio)
 {
 	struct request_queue *q = bio->bi_disk->queue;
 	bool nowait = bio->bi_opf & REQ_NOWAIT;
-	blk_qc_t ret;
+	blk_qc_t ret = BLK_QC_T_NONE;
 
 	if (!generic_make_request_checks(bio))
 		return BLK_QC_T_NONE;
@@ -1127,8 +1134,8 @@ blk_qc_t direct_make_request(struct bio *bio)
 		bio_endio(bio);
 		return BLK_QC_T_NONE;
 	}
-
-	ret = q->make_request_fn(q, bio);
+	if (blk_crypto_bio_prep(&bio))
+		ret = q->make_request_fn(q, bio);
 	blk_queue_exit(q);
 	return ret;
 }
@@ -1258,6 +1265,9 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
 	    should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
 		return BLK_STS_IOERR;
 
+	if (blk_crypto_insert_cloned_request(rq))
+		return BLK_STS_IOERR;
+
 	if (blk_queue_io_stat(q))
 		blk_account_io_start(rq, true);
 
@@ -1646,6 +1656,8 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 
 	__blk_rq_prep_clone(rq, rq_src);
 
+	blk_crypto_rq_prep_clone(rq, rq_src);
+
 	return 0;
 
 free_and_out:
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
new file mode 100644
index 0000000000000..1e6d339fe1429
--- /dev/null
+++ b/block/blk-crypto-internal.h
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
+#define __LINUX_BLK_CRYPTO_INTERNAL_H
+
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+
+/* Represents a crypto mode supported by blk-crypto  */
+struct blk_crypto_mode {
+	const char *cipher_str; /* crypto API name (for fallback case) */
+	unsigned int keysize; /* key size in bytes */
+	unsigned int ivsize; /* iv size in bytes */
+};
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+
+static inline const struct blk_crypto_key *bio_crypt_key(struct bio *bio)
+{
+	if (!bio_has_crypt_ctx(bio))
+		return NULL;
+	return bio->bi_crypt_context->bc_key;
+}
+
+void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+			     unsigned int inc);
+
+bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
+
+bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
+			     struct bio_crypt_ctx *bc2);
+
+static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
+						struct bio *bio)
+{
+	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
+				       bio->bi_crypt_context);
+}
+
+static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
+						 struct bio *bio)
+{
+	return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
+				       bio->bi_iter.bi_size, req->crypt_ctx);
+}
+
+static inline bool bio_crypt_ctx_merge_rq(struct request *req,
+					  struct request *next)
+{
+	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
+				       next->crypt_ctx);
+}
+
+static inline void blk_crypto_rq_set_defaults(struct request *rq)
+{
+	rq->crypt_ctx = NULL;
+	rq->crypt_keyslot = NULL;
+}
+
+static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
+{
+	return rq->crypt_ctx;
+}
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+static inline struct blk_crypto_key *bio_crypt_key(struct bio *bio)
+{
+	return NULL;
+}
+
+static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
+					       struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
+						 struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
+						struct bio *bio)
+{
+	return true;
+}
+
+static inline bool bio_crypt_ctx_merge_rq(struct request *req,
+					  struct request *next)
+{
+	return true;
+}
+
+static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
+
+static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
+{
+	return false;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
+static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
+{
+	if (bio_has_crypt_ctx(bio))
+		__bio_crypt_advance(bio, bytes);
+}
+
+void __bio_crypt_free_ctx(struct bio *bio);
+static inline void bio_crypt_free_ctx(struct bio *bio)
+{
+	if (bio_has_crypt_ctx(bio))
+		__bio_crypt_free_ctx(bio);
+}
+
+bool __blk_crypto_bio_prep(struct bio **bio_ptr);
+static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
+{
+	if (bio_has_crypt_ctx(*bio_ptr))
+		return __blk_crypto_bio_prep(bio_ptr);
+	return true;
+}
+
+blk_status_t __blk_crypto_init_request(struct request *rq,
+				       const struct blk_crypto_key *key);
+static inline blk_status_t blk_crypto_init_request(struct request *rq,
+					const struct blk_crypto_key *key)
+{
+	if (key)
+		return __blk_crypto_init_request(rq, key);
+	return BLK_STS_OK;
+}
+
+void __blk_crypto_free_request(struct request *rq);
+static inline void blk_crypto_free_request(struct request *rq)
+{
+	if (blk_crypto_rq_is_encrypted(rq))
+		__blk_crypto_free_request(rq);
+}
+
+void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio);
+static inline void blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio)
+{
+	if (bio_has_crypt_ctx(bio))
+		__blk_crypto_rq_bio_prep(rq, bio);
+}
+
+void __blk_crypto_rq_prep_clone(struct request *dst, struct request *src);
+static inline void blk_crypto_rq_prep_clone(struct request *dst,
+					    struct request *src)
+{
+
+	if (blk_crypto_rq_is_encrypted(src))
+		__blk_crypto_rq_prep_clone(dst, src);
+}
+
+blk_status_t __blk_crypto_insert_cloned_request(struct request *rq);
+static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
+{
+
+	if (blk_crypto_rq_is_encrypted(rq))
+		return __blk_crypto_insert_cloned_request(rq);
+	return BLK_STS_OK;
+}
+
+#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
new file mode 100644
index 0000000000000..a52ec4eb153be
--- /dev/null
+++ b/block/blk-crypto.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#define pr_fmt(fmt) "blk-crypto: " fmt
+
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/keyslot-manager.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/siphash.h>
+#include <linux/slab.h>
+
+#include "blk-crypto-internal.h"
+
+const struct blk_crypto_mode blk_crypto_modes[] = {
+	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
+		.cipher_str = "xts(aes)",
+		.keysize = 64,
+		.ivsize = 16,
+	},
+	[BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV] = {
+		.cipher_str = "essiv(cbc(aes),sha256)",
+		.keysize = 16,
+		.ivsize = 16,
+	},
+	[BLK_ENCRYPTION_MODE_ADIANTUM] = {
+		.cipher_str = "adiantum(xchacha12,aes)",
+		.keysize = 32,
+		.ivsize = 32,
+	},
+};
+
+/*
+ * This number needs to be at least (the number of threads doing IO
+ * concurrently) * (maximum recursive depth of a bio), so that we don't
+ * deadlock on crypt_ctx allocations. The default is chosen to be the same
+ * as the default number of post read contexts in both EXT4 and F2FS.
+ */
+static int num_prealloc_crypt_ctxs = 128;
+
+module_param(num_prealloc_crypt_ctxs, int, 0444);
+MODULE_PARM_DESC(num_prealloc_crypt_ctxs,
+		"Number of bio crypto contexts to preallocate");
+
+static struct kmem_cache *bio_crypt_ctx_cache;
+static mempool_t *bio_crypt_ctx_pool;
+
+static void __init bio_crypt_ctx_init(void)
+{
+	size_t i;
+
+	bio_crypt_ctx_cache = KMEM_CACHE(bio_crypt_ctx, 0);
+	if (!bio_crypt_ctx_cache)
+		goto out_no_mem;
+
+	bio_crypt_ctx_pool = mempool_create_slab_pool(num_prealloc_crypt_ctxs,
+						      bio_crypt_ctx_cache);
+	if (!bio_crypt_ctx_pool)
+		goto out_no_mem;
+
+	/* This is assumed in various places. */
+	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+
+	/* Sanity check that no algorithm exceeds the defined limits. */
+	for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+		BUG_ON(blk_crypto_modes[i].keysize > BLK_CRYPTO_MAX_KEY_SIZE);
+		BUG_ON(blk_crypto_modes[i].ivsize > BLK_CRYPTO_MAX_IV_SIZE);
+	}
+
+	return;
+out_no_mem:
+	panic("Failed to allocate mem for bio crypt ctxs\n");
+}
+subsys_initcall(bio_crypt_ctx_init);
+
+void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
+		       const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], gfp_t gfp_mask)
+{
+	struct bio_crypt_ctx *bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+
+	bc->bc_key = key;
+	memcpy(bc->bc_dun, dun, sizeof(bc->bc_dun));
+
+	bio->bi_crypt_context = bc;
+}
+
+void __bio_crypt_free_ctx(struct bio *bio)
+{
+	mempool_free(bio->bi_crypt_context, bio_crypt_ctx_pool);
+	bio->bi_crypt_context = NULL;
+}
+
+void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask)
+{
+	dst->bi_crypt_context = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+	*dst->bi_crypt_context = *src->bi_crypt_context;
+}
+EXPORT_SYMBOL_GPL(__bio_crypt_clone);
+
+void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+			     unsigned int inc)
+{
+	int i = 0;
+
+	while (inc && i < BLK_CRYPTO_DUN_ARRAY_SIZE) {
+		dun[i] += inc;
+		inc = (dun[i] < inc);
+		i++;
+	}
+}
+
+void __bio_crypt_advance(struct bio *bio, unsigned int bytes)
+{
+	struct bio_crypt_ctx *bc = bio->bi_crypt_context;
+
+	bio_crypt_dun_increment(bc->bc_dun,
+				bytes >> bc->bc_key->data_unit_size_bits);
+}
+
+bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc,
+				 unsigned int bytes,
+				 u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE])
+{
+	int i = 0;
+	unsigned int inc = bytes >> bc->bc_key->data_unit_size_bits;
+
+	while (i < BLK_CRYPTO_DUN_ARRAY_SIZE) {
+		if (bc->bc_dun[i] + inc != next_dun[i])
+			return false;
+		/*
+		 * If addition of inc to the current entry caused an overflow,
+		 * then we have to carry "1" for the next entry - so inc
+		 * needs to be "1" for the next loop iteration). Otherwise,
+		 * we need inc to be 0 for the next loop iteration. Since
+		 * overflow can be determined by (bc->bc_dun[i] + inc)  < inc
+		 * we can do the following.
+		 */
+		inc = ((bc->bc_dun[i] + inc)  < inc);
+		i++;
+	}
+
+	/*
+	 * After going through all the entries in the dun, inc must be 0 for
+	 * the duns to be contiguous.
+	 */
+	return !inc;
+}
+
+/*
+ * Checks that two bio crypt contexts are compatible - i.e. that
+ * they are mergeable except for data_unit_num continuity.
+ */
+static bool bio_crypt_ctx_compatible(struct bio_crypt_ctx *bc1,
+				     struct bio_crypt_ctx *bc2)
+{
+	if (!bc1)
+		return !bc2;
+
+	return bc2 && bc1->bc_key == bc2->bc_key;
+}
+
+bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio)
+{
+	return bio_crypt_ctx_compatible(rq->crypt_ctx, bio->bi_crypt_context);
+}
+
+/*
+ * Checks that two bio crypt contexts are compatible, and also
+ * that their data_unit_nums are continuous (and can hence be merged)
+ * in the order b_1 followed by b_2.
+ */
+bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
+			     struct bio_crypt_ctx *bc2)
+{
+	if (!bio_crypt_ctx_compatible(bc1, bc2))
+		return false;
+
+	return !bc1 || bio_crypt_dun_is_contiguous(bc1, bc1_bytes, bc2->bc_dun);
+}
+
+/*
+ * Check that all I/O segments are data unit aligned, and set bio->bi_status
+ * on error.
+ */
+static bool bio_crypt_check_alignment(struct bio *bio)
+{
+	const unsigned int data_unit_size =
+				bio->bi_crypt_context->bc_key->data_unit_size;
+	struct bvec_iter iter;
+	struct bio_vec bv;
+
+	bio_for_each_segment(bv, bio, iter) {
+		if (!IS_ALIGNED(bv.bv_len | bv.bv_offset, data_unit_size)) {
+			bio->bi_status = BLK_STS_IOERR;
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/**
+ * __blk_crypto_init_request - Initializes the request's crypto fields based on
+ *			       the blk_crypto_key for a bio to be added to the
+ *			       request, and prepares it for hardware inline
+ *			       encryption.
+ *
+ * @rq: The request to init
+ * @key: The blk_crypto_key of bios that will (eventually) be added to @rq.
+ *
+ * Initializes the request's crypto fields to appropriate default values and
+ * tries to get a keyslot for the blk_crypto_key.
+ *
+ * Return: BLK_STATUS_OK on success, and negative error code otherwise.
+ */
+blk_status_t __blk_crypto_init_request(struct request *rq,
+				       const struct blk_crypto_key *key)
+{
+	return blk_ksm_get_slot_for_key(rq->q->ksm, key, &rq->crypt_keyslot);
+}
+
+/**
+ * __blk_crypto_free_request - Uninitialize the crypto fields of a request.
+ *
+ * @rq: The request whose crypto fields to uninitialize.
+ *
+ * Completely uninitializes the crypto fields of a request. If a keyslot has
+ * been programmed into some inline encryption hardware, that keyslot is
+ * released. The rq->crypt_ctx is also freed.
+ */
+void __blk_crypto_free_request(struct request *rq)
+{
+	blk_ksm_put_slot(rq->crypt_keyslot);
+	mempool_free(rq->crypt_ctx, bio_crypt_ctx_pool);
+	blk_crypto_rq_set_defaults(rq);
+}
+
+/**
+ * __blk_crypto_bio_prep - Prepare bio for inline encryption
+ *
+ * @bio_ptr: pointer to original bio pointer
+ *
+ * Succeeds if the bio doesn't have inline encryption enabled or if the bio
+ * crypt context provided for the bio is supported by the underlying device's
+ * inline encryption hardware. Ends the bio with error otherwise.
+ *
+ * Caller must ensure bio has bio_crypt_ctx.
+ *
+ * Return: true on success; false on error (and bio->bi_status will be set
+ *	   appropriately, and bio_endio() will have been called so bio
+ *	   submission should abort).
+ */
+bool __blk_crypto_bio_prep(struct bio **bio_ptr)
+{
+	struct bio *bio = *bio_ptr;
+
+	/* Error if bio has no data. */
+	if (WARN_ON_ONCE(!bio_has_data(bio)))
+		goto fail;
+
+	if (!bio_crypt_check_alignment(bio))
+		goto fail;
+
+	/*
+	 * Success if device supports the encryption context, and blk-integrity
+	 * isn't supported by device/is turned off.
+	 */
+	if (!blk_ksm_crypto_key_supported(bio->bi_disk->queue->ksm,
+					  bio->bi_crypt_context->bc_key)) {
+		bio->bi_status = BLK_STS_NOTSUPP;
+		goto fail;
+	}
+
+	return true;
+fail:
+	bio_endio(*bio_ptr);
+	return false;
+}
+
+/**
+ * __blk_crypto_rq_bio_prep - Prepare a request when its first bio is inserted
+ *
+ * @rq: The request to prepare
+ * @bio: The first bio being inserted into the request
+ *
+ * Frees the bio crypt context in the request's old rq->crypt_ctx, if any, and
+ * moves the bio crypt context of the bio into the request's rq->crypt_ctx.
+ */
+void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio)
+{
+	mempool_free(rq->crypt_ctx, bio_crypt_ctx_pool);
+	rq->crypt_ctx = bio->bi_crypt_context;
+	bio->bi_crypt_context = NULL;
+}
+
+void __blk_crypto_rq_prep_clone(struct request *dst, struct request *src)
+{
+	dst->crypt_ctx = src->crypt_ctx;
+}
+
+/**
+ * __blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
+ *					into a request queue.
+ * @rq: the request being queued
+ *
+ * Return: BLK_STS_OK on success, nonzero on error.
+ */
+blk_status_t __blk_crypto_insert_cloned_request(struct request *rq)
+{
+	return blk_crypto_init_request(rq, rq->crypt_ctx->bc_key);
+}
+
+/**
+ * blk_crypto_init_key() - Prepare a key for use with blk-crypto
+ * @blk_key: Pointer to the blk_crypto_key to initialize.
+ * @raw_key: Pointer to the raw key. Must be the correct length for the chosen
+ *	     @crypto_mode; see blk_crypto_modes[].
+ * @crypto_mode: identifier for the encryption algorithm to use
+ * @dun_bytes: number of bytes that will be used to specify the DUN when this
+ *	       key is used
+ * @data_unit_size: the data unit size to use for en/decryption
+ *
+ * Return: 0 on success, -errno on failure.  The caller is responsible for
+ *	   zeroizing both blk_key and raw_key when done with them.
+ */
+int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
+			enum blk_crypto_mode_num crypto_mode,
+			unsigned int dun_bytes,
+			unsigned int data_unit_size)
+{
+	const struct blk_crypto_mode *mode;
+	static siphash_key_t hash_key;
+
+	memset(blk_key, 0, sizeof(*blk_key));
+
+	if (crypto_mode >= ARRAY_SIZE(blk_crypto_modes))
+		return -EINVAL;
+
+	mode = &blk_crypto_modes[crypto_mode];
+	if (mode->keysize == 0)
+		return -EINVAL;
+
+	if (!is_power_of_2(data_unit_size))
+		return -EINVAL;
+
+	blk_key->crypto_mode = crypto_mode;
+	blk_key->dun_bytes = dun_bytes;
+	blk_key->data_unit_size = data_unit_size;
+	blk_key->data_unit_size_bits = ilog2(data_unit_size);
+	blk_key->size = mode->keysize;
+	memcpy(blk_key->raw, raw_key, mode->keysize);
+
+	/*
+	 * The keyslot manager uses the SipHash of the key to implement O(1) key
+	 * lookups while avoiding leaking information about the keys.  It's
+	 * precomputed here so that it only needs to be computed once per key.
+	 */
+	get_random_once(&hash_key, sizeof(hash_key));
+	blk_key->hash = siphash(raw_key, mode->keysize, &hash_key);
+
+	return 0;
+}
+
+/**
+ * blk_crypto_evict_key() - Evict a key from any inline encryption hardware
+ *			    it may have been programmed into
+ * @q: The request queue who's keyslot manager this key might have been
+ *     programmed into
+ * @key: The key to evict
+ *
+ * Upper layers (filesystems) should call this function to ensure that a key
+ * is evicted from hardware that it might have been programmed into. This
+ * will call blk_ksm_evict_key on the queue's keyslot manager, if one
+ * exists, and supports the crypto algorithm with the specified data unit size.
+ *
+ * Return: 0 on success or if key is not present in the q's ksm, -err on error.
+ */
+int blk_crypto_evict_key(struct request_queue *q,
+			 const struct blk_crypto_key *key)
+{
+	if (q->ksm && blk_ksm_crypto_key_supported(q->ksm, key))
+		return blk_ksm_evict_key(q->ksm, key);
+
+	return 0;
+}
diff --git a/block/blk-map.c b/block/blk-map.c
index b0790268ed9d9..4484e37d316ec 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -41,6 +41,7 @@ int blk_rq_append_bio(struct request *rq, struct bio **bio)
 		rq->biotail->bi_next = *bio;
 		rq->biotail = *bio;
 		rq->__data_len += (*bio)->bi_iter.bi_size;
+		bio_crypt_free_ctx(*bio);
 	}
 
 	return 0;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 1534ed736363f..a0c24b6e0eb3e 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -596,6 +596,8 @@ int ll_back_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs)
 	if (blk_integrity_rq(req) &&
 	    integrity_req_gap_back_merge(req, bio))
 		return 0;
+	if (!bio_crypt_ctx_back_mergeable(req, bio))
+		return 0;
 	if (blk_rq_sectors(req) + bio_sectors(bio) >
 	    blk_rq_get_max_sectors(req, blk_rq_pos(req))) {
 		req_set_nomerge(req->q, req);
@@ -612,6 +614,8 @@ int ll_front_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs
 	if (blk_integrity_rq(req) &&
 	    integrity_req_gap_front_merge(req, bio))
 		return 0;
+	if (!bio_crypt_ctx_front_mergeable(req, bio))
+		return 0;
 	if (blk_rq_sectors(req) + bio_sectors(bio) >
 	    blk_rq_get_max_sectors(req, bio->bi_iter.bi_sector)) {
 		req_set_nomerge(req->q, req);
@@ -661,6 +665,9 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 	if (blk_integrity_merge_rq(q, req, next) == false)
 		return 0;
 
+	if (!bio_crypt_ctx_merge_rq(req, next))
+		return 0;
+
 	/* Merge is OK... */
 	req->nr_phys_segments = total_phys_segments;
 	return 1;
@@ -885,6 +892,10 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
 		return false;
 
+	/* Only merge if the crypt contexts are compatible */
+	if (!bio_crypt_rq_ctx_compatible(rq, bio))
+		return false;
+
 	/* must be using the same buffer */
 	if (req_op(rq) == REQ_OP_WRITE_SAME &&
 	    !blk_write_same_mergeable(rq->bio, bio))
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d92088dec6c35..5d414c8974433 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -26,6 +26,7 @@
 #include <linux/delay.h>
 #include <linux/crash_dump.h>
 #include <linux/prefetch.h>
+#include <linux/blk-crypto.h>
 
 #include <trace/events/block.h>
 
@@ -317,6 +318,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 	rq->nr_integrity_segments = 0;
 #endif
+	blk_crypto_rq_set_defaults(rq);
 	/* tag was already set */
 	rq->extra_len = 0;
 	WRITE_ONCE(rq->deadline, 0);
@@ -474,6 +476,7 @@ static void __blk_mq_free_request(struct request *rq)
 	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
 	const int sched_tag = rq->internal_tag;
 
+	blk_crypto_free_request(rq);
 	blk_pm_mark_last_busy(rq);
 	rq->mq_hctx = NULL;
 	if (rq->tag != -1)
@@ -1971,6 +1974,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	struct request *same_queue_rq = NULL;
 	unsigned int nr_segs;
 	blk_qc_t cookie;
+	blk_status_t ret;
 
 	blk_queue_bounce(q, &bio);
 	__blk_queue_split(q, &bio, &nr_segs);
@@ -2002,6 +2006,14 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
 	cookie = request_to_qc_t(data.hctx, rq);
 
+	ret = blk_crypto_init_request(rq, bio_crypt_key(bio));
+	if (ret != BLK_STS_OK) {
+		bio->bi_status = ret;
+		bio_endio(bio);
+		blk_mq_free_request(rq);
+		return BLK_QC_T_NONE;
+	}
+
 	blk_mq_bio_to_request(rq, bio, nr_segs);
 
 	plug = blk_mq_plug(q, bio);
diff --git a/block/blk.h b/block/blk.h
index 0b8884353f6bf..0ffe7d1a68ba2 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -4,7 +4,9 @@
 
 #include <linux/idr.h>
 #include <linux/blk-mq.h>
+#include <linux/blk-crypto.h>
 #include <xen/xen.h>
+#include "blk-crypto-internal.h"
 #include "blk-mq.h"
 #include "blk-mq-sched.h"
 
@@ -117,6 +119,8 @@ static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
 
 	if (bio->bi_disk)
 		rq->rq_disk = bio->bi_disk;
+
+	blk_crypto_rq_bio_prep(rq, bio);
 }
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY
diff --git a/block/bounce.c b/block/bounce.c
index f8ed677a1bf7e..c3aaed0701246 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -267,6 +267,8 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
 		break;
 	}
 
+	bio_crypt_clone(bio, bio_src, gfp_mask);
+
 	if (bio_integrity(bio_src)) {
 		int ret;
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 0413018c83058..9d5e25833cf00 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -25,6 +25,7 @@
 #include <linux/wait.h>
 #include <linux/pr.h>
 #include <linux/refcount.h>
+#include <linux/blk-crypto.h>
 
 #define DM_MSG_PREFIX "core"
 
@@ -1304,6 +1305,8 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 
 	__bio_clone_fast(clone, bio);
 
+	bio_crypt_clone(clone, bio, GFP_NOIO);
+
 	if (bio_integrity(bio)) {
 		int r;
 
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index b8d54eca1c0d8..4add2e8846fea 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -6,6 +6,8 @@
 #ifndef __LINUX_BLK_CRYPTO_H
 #define __LINUX_BLK_CRYPTO_H
 
+#include <linux/types.h>
+
 enum blk_crypto_mode_num {
 	BLK_ENCRYPTION_MODE_INVALID,
 	BLK_ENCRYPTION_MODE_AES_256_XTS,
@@ -24,7 +26,7 @@ enum blk_crypto_mode_num {
  *	ciphertext.  This is always a power of 2.  It might be e.g. the
  *	filesystem block size or the disk sector size.
  * @data_unit_size_bits: log2 of data_unit_size
- * @dun_bytes: the number of bytes of DUN used when using this key
+ * @dun_bytes: the maximum number of bytes of DUN used when using this key
  * @size: size of this key in bytes (determined by @crypto_mode)
  * @hash: hash of this key, for keyslot manager use only
  * @raw: the raw bytes of this key.  Only the first @size bytes are used.
@@ -42,4 +44,71 @@ struct blk_crypto_key {
 	u8 raw[BLK_CRYPTO_MAX_KEY_SIZE];
 };
 
+#define BLK_CRYPTO_MAX_IV_SIZE		32
+#define BLK_CRYPTO_DUN_ARRAY_SIZE	(BLK_CRYPTO_MAX_IV_SIZE/sizeof(u64))
+
+/**
+ * struct bio_crypt_ctx - an inline encryption context
+ * @bc_key: the key, algorithm, and data unit size to use
+ * @bc_dun: the data unit number (starting IV) to use
+ * @bc_keyslot: the keyslot that has been assigned for this key in @bc_ksm,
+ *		or -1 if no keyslot has been assigned yet.
+ * @bc_ksm: the keyslot manager into which the key has been programmed with
+ *	    @bc_keyslot, or NULL if this key hasn't yet been programmed.
+ *
+ * A bio_crypt_ctx specifies that the contents of the bio will be encrypted (for
+ * write requests) or decrypted (for read requests) inline by the storage device
+ * or controller.
+ */
+struct bio_crypt_ctx {
+	const struct blk_crypto_key	*bc_key;
+	u64				bc_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+};
+
+#include <linux/blk_types.h>
+#include <linux/blkdev.h>
+
+struct request;
+struct request_queue;
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+
+static inline bool bio_has_crypt_ctx(struct bio *bio)
+{
+	return bio->bi_crypt_context;
+}
+
+void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
+		       const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+		       gfp_t gfp_mask);
+
+bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc,
+				 unsigned int bytes,
+				 u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]);
+
+int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
+			enum blk_crypto_mode_num crypto_mode,
+			unsigned int dun_bytes,
+			unsigned int data_unit_size);
+
+int blk_crypto_evict_key(struct request_queue *q,
+			 const struct blk_crypto_key *key);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+static inline bool bio_has_crypt_ctx(struct bio *bio)
+{
+	return false;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask);
+static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
+				   gfp_t gfp_mask)
+{
+	if (bio_has_crypt_ctx(src))
+		__bio_crypt_clone(dst, src, gfp_mask);
+}
+
 #endif /* __LINUX_BLK_CRYPTO_H */
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 70254ae117690..1996689c51d38 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -18,6 +18,7 @@ struct block_device;
 struct io_context;
 struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
+struct bio_crypt_ctx;
 
 /*
  * Block error status values.  See block/blk-core:blk_errors for the details.
@@ -173,6 +174,11 @@ struct bio {
 	u64			bi_iocost_cost;
 #endif
 #endif
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	struct bio_crypt_ctx	*bi_crypt_context;
+#endif
+
 	union {
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 		struct bio_integrity_payload *bi_integrity; /* data integrity */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 27d460d0a8508..167297e153592 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -224,6 +224,11 @@ struct request {
 	unsigned short nr_integrity_segments;
 #endif
 
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	struct bio_crypt_ctx *crypt_ctx;
+	struct blk_ksm_keyslot *crypt_keyslot;
+#endif
+
 	unsigned short write_hint;
 	unsigned short ioprio;
 
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 03/11] block: Make blk-integrity preclude hardware inline encryption
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 02/11] block: Inline encryption support for blk-mq Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption Satya Tangirala
                   ` (8 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Whenever a device supports blk-integrity, the kernel will now always
pretend that the device doesn't support inline encryption (essentially
by setting the keyslot manager in the request queue to NULL).

There's no hardware currently that supports both integrity and inline
encryption. However, it seems possible that there will be such hardware
in the near future (like the NVMe key per I/O support that might support
both inline encryption and PI).

But properly integrating both features is not trivial, and without
real hardware that implements both, it is difficult to tell if it will
be done correctly by the majority of hardware that support both.
So it seems best not to support both features together right now, and
to decide what to do at probe time.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 block/bio-integrity.c   |  3 +++
 block/blk-integrity.c   |  7 +++++++
 block/keyslot-manager.c | 19 +++++++++++++++++++
 include/linux/blkdev.h  | 30 ++++++++++++++++++++++++++++++
 4 files changed, 59 insertions(+)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index bf62c25cde8f4..3579ac0f6ec1f 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -42,6 +42,9 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 	struct bio_set *bs = bio->bi_pool;
 	unsigned inline_vecs;
 
+	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
+		return ERR_PTR(-EOPNOTSUPP);
+
 	if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
 		bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
 		inline_vecs = nr_vecs;
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index ff1070edbb400..b45711fc37df4 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -409,6 +409,13 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template
 	bi->tag_size = template->tag_size;
 
 	disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	if (disk->queue->ksm) {
+		pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Unregistering keyslot manager from request queue, to disable hardware inline encryption.\n");
+		blk_ksm_unregister(disk->queue);
+	}
+#endif
 }
 EXPORT_SYMBOL(blk_integrity_register);
 
diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
index 3a5f2e445809e..abcd14320a5ce 100644
--- a/block/keyslot-manager.c
+++ b/block/keyslot-manager.c
@@ -25,6 +25,9 @@
  * Upper layers will call blk_ksm_get_slot_for_key() to program a
  * key into some slot in the inline encryption hardware.
  */
+
+#define pr_fmt(fmt) "blk_crypto: " fmt
+
 #include <crypto/algapi.h>
 #include <linux/keyslot-manager.h>
 #include <linux/atomic.h>
@@ -375,3 +378,19 @@ void blk_ksm_destroy(struct blk_keyslot_manager *ksm)
 	memzero_explicit(ksm, sizeof(*ksm));
 }
 EXPORT_SYMBOL_GPL(blk_ksm_destroy);
+
+bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q)
+{
+	if (blk_integrity_queue_supports_integrity(q)) {
+		pr_warn("Integrity and hardware inline encryption are not supported together. Hardware inline encryption is being disabled.\n");
+		return false;
+	}
+	q->ksm = ksm;
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_ksm_register);
+
+void blk_ksm_unregister(struct request_queue *q)
+{
+	q->ksm = NULL;
+}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 167297e153592..f0b4bff9c78a1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1569,6 +1569,12 @@ struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
 	return blk_get_integrity(bdev->bd_disk);
 }
 
+static inline bool
+blk_integrity_queue_supports_integrity(struct request_queue *q)
+{
+	return q->integrity.profile;
+}
+
 static inline bool blk_integrity_rq(struct request *rq)
 {
 	return rq->cmd_flags & REQ_INTEGRITY;
@@ -1649,6 +1655,11 @@ static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
 {
 	return NULL;
 }
+static inline bool
+blk_integrity_queue_supports_integrity(struct request_queue *q)
+{
+	return false;
+}
 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
 {
 	return 0;
@@ -1700,6 +1711,25 @@ static inline struct bio_vec *rq_integrity_vec(struct request *rq)
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+
+bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q);
+
+void blk_ksm_unregister(struct request_queue *q);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+static inline bool blk_ksm_register(struct blk_keyslot_manager *ksm,
+				    struct request_queue *q)
+{
+	return true;
+}
+
+static inline void blk_ksm_unregister(struct request_queue *q) { }
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+
 struct block_device_operations {
 	int (*open) (struct block_device *, fmode_t);
 	void (*release) (struct gendisk *, fmode_t);
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (2 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 03/11] block: Make blk-integrity preclude hardware inline encryption Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26 20:28   ` Eric Biggers
  2020-03-26  3:06 ` [PATCH v9 05/11] scsi: ufs: UFS driver v2.1 spec crypto additions Satya Tangirala
                   ` (7 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Blk-crypto delegates crypto operations to inline encryption hardware when
available. The separately configurable blk-crypto-fallback contains a
software fallback to the kernel crypto API - when enabled, blk-crypto
will use this fallback for en/decryption when inline encryption hardware is
not available. This lets upper layers not have to worry about whether or
not the underlying device has support for inline encryption before
deciding to specify an encryption context for a bio, and also allows for
testing without actual inline encryption hardware. For more details, refer
to Documentation/block/inline-encryption.rst.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 Documentation/block/index.rst             |   1 +
 Documentation/block/inline-encryption.rst | 195 +++++++
 block/Kconfig                             |  10 +
 block/Makefile                            |   1 +
 block/blk-crypto-fallback.c               | 666 ++++++++++++++++++++++
 block/blk-crypto-internal.h               |  25 +
 block/blk-crypto.c                        |  46 +-
 include/linux/blk-crypto.h                |  17 +-
 8 files changed, 947 insertions(+), 14 deletions(-)
 create mode 100644 Documentation/block/inline-encryption.rst
 create mode 100644 block/blk-crypto-fallback.c

diff --git a/Documentation/block/index.rst b/Documentation/block/index.rst
index 3fa7a52fafa46..026addfc69bc9 100644
--- a/Documentation/block/index.rst
+++ b/Documentation/block/index.rst
@@ -14,6 +14,7 @@ Block
    cmdline-partition
    data-integrity
    deadline-iosched
+   inline-encryption
    ioprio
    kyber-iosched
    null_blk
diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
new file mode 100644
index 0000000000000..3fa475799ecd1
--- /dev/null
+++ b/Documentation/block/inline-encryption.rst
@@ -0,0 +1,195 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Inline Encryption
+=================
+
+Background
+==========
+
+Inline encryption hardware sits logically between memory and the disk, and can
+en/decrypt data as it goes in/out of the disk. Inline encryption hardware has a
+fixed number of "keyslots" - slots into which encryption contexts (i.e. the
+encryption key, encryption algorithm, data unit size) can be programmed by the
+kernel at any time. Each request sent to the disk can be tagged with the index
+of a keyslot (and also a data unit number to act as an encryption tweak), and
+the inline encryption hardware will en/decrypt the data in the request with the
+encryption context programmed into that keyslot. This is very different from
+full disk encryption solutions like self encrypting drives/TCG OPAL/ATA
+Security standards, since with inline encryption, any block on disk could be
+encrypted with any encryption context the kernel chooses.
+
+
+Objective
+=========
+
+We want to support inline encryption (IE) in the kernel.
+To allow for testing, we also want a crypto API fallback when actual
+IE hardware is absent. We also want IE to work with layered devices
+like dm and loopback (i.e. we want to be able to use the IE hardware
+of the underlying devices if present, or else fall back to crypto API
+en/decryption).
+
+
+Constraints and notes
+=====================
+
+- IE hardware has a limited number of "keyslots" that can be programmed
+  with an encryption context (key, algorithm, data unit size, etc.) at any time.
+  One can specify a keyslot in a data request made to the device, and the
+  device will en/decrypt the data using the encryption context programmed into
+  that specified keyslot. When possible, we want to make multiple requests with
+  the same encryption context share the same keyslot.
+
+- We need a way for upper layers like filesystems to specify an encryption
+  context to use for en/decrypting a struct bio, and a device driver (like UFS)
+  needs to be able to use that encryption context when it processes the bio.
+
+- We need a way for device drivers to expose their capabilities in a unified
+  way to the upper layers.
+
+
+Design
+======
+
+We add a :c:type:`struct bio_crypt_ctx` to :c:type:`struct bio` that can
+represent an encryption context, because we need to be able to pass this
+encryption context from the FS layer to the device driver to act upon.
+
+While IE hardware works on the notion of keyslots, the FS layer has no
+knowledge of keyslots - it simply wants to specify an encryption context to
+use while en/decrypting a bio.
+
+We introduce a keyslot manager (KSM) that handles the translation from
+encryption contexts specified by the FS to keyslots on the IE hardware.
+This KSM also serves as the way IE hardware can expose its capabilities to
+upper layers. The generic mode of operation is: each device driver that wants
+to support IE will construct a KSM and set it up in its struct request_queue.
+Upper layers that want to use IE on this device can then use this KSM in
+the device's struct request_queue to translate an encryption context into
+a keyslot. The presence of the KSM in the request queue shall be used to mean
+that the device supports IE.
+
+On the device driver end of the interface, the device driver needs to tell the
+KSM how to actually manipulate the IE hardware in the device to do things like
+programming the crypto key into the IE hardware into a particular keyslot. All
+this is achieved through the :c:type:`struct keyslot_mgmt_ll_ops` that the
+device driver passes to the KSM when creating it.
+
+It uses refcounts to track which keyslots are idle (either they have no
+encryption context programmed, or there are no in-flight struct bios
+referencing that keyslot). When a new encryption context needs a keyslot, it
+tries to find a keyslot that has already been programmed with the same
+encryption context, and if there is no such keyslot, it evicts the least
+recently used idle keyslot and programs the new encryption context into that
+one. If no idle keyslots are available, then the caller will sleep until there
+is at least one.
+
+
+blk-mq changes, other block layer changes and blk-crypto-fallback
+=================================================================
+
+We add a pointer to a ``bi_crypt_context`` and ``keyslot`` to
+:c:type:`struct request`. These will be referred to as the ``crypto fields``
+for the request. This ``keyslot`` is the keyslot into which the
+``bi_crypt_context`` has been programmed into in the keyslot manager of the
+``request_queue`` that this request is being sent to.
+
+We introduce ``block/blk-crypto-fallback.c``, which allows upper layers to remain
+blissfully unaware of whether or not real inline encryption hardware is present
+underneath.
+
+When a bio is submitted with a target ``request_queue`` that doesn't support the
+encryption context specified with the bio, the block layer will en/decrypt the
+bio with the blk-crypto-fallback.
+
+If the bio is a ``WRITE`` bio, a bounce bio is allocated, and the data in the bio
+is encrypted stored in the bounce bio - blk-mq will then proceed to process the
+bounce bio as if it were not encrypted at all (except when blk-integrity is
+concerned). ``blk-crypto-fallback`` sets the bounce bio's ``bi_end_io`` to an
+internal function that cleans up the bounce bio and ends the original bio.
+
+If the bio is a ``READ`` bio, the bio's ``bi_end_io`` (and also ``bi_private``)
+is saved and overwritten by ``blk-crypto-fallback`` to
+``bio_crypto_fallback_decrypt_bio``.  The bio's ``bi_crypt_context`` is also
+overwritten with ``NULL``, so that to the rest of the stack, the bio looks
+as if it was a regular bio that never had an encryption context specified.
+``bio_crypto_fallback_decrypt_bio`` will decrypt the bio, restore the original
+``bi_end_io`` (and also ``bi_private``) and end the bio again.
+
+If we reach a point when a :c:type:`struct request` needs to be allocated for a
+bio that still has an encryption context, that means that the bio was not
+handled by the ``blk-crypto-fallback``, which means that the underlying inline
+encryption hardware claimed to support the encryption context specified with the
+bio. So in this situation, blk-mq tries to program the encryption context into
+the ``request_queue``'s keyslot_manager, and obtain a keyslot, which it stores
+in its newly added ``keyslot`` field. This keyslot is released when the request
+is completed.
+
+When a bio is added to a request, the request takes over ownership of the
+``bi_crypt_context`` of the bio - in particular, the request keeps the
+``bi_crypt_context`` of the first bio in its bio-list, and frees the rest
+(blk-mq needs to be careful to maintain this invariant during bio and request
+merges).
+
+To make it possible for inline encryption to work with request queue based
+layered devices, when a request is cloned, its ``crypto fields`` are cloned as
+well. When the cloned request is submitted, blk-mq programs the
+``bi_crypt_context`` of the request into the clone's request_queue's keyslot
+manager, and stores the returned keyslot in the clone's ``keyslot``.
+
+
+Layered Devices
+===============
+
+Request queue based layered devices like dm-rq that wish to support IE need to
+create their own keyslot manager for their request queue, and expose whatever
+functionality they choose. When a layered device wants to pass a clone of that
+request to another ``request_queue``, blk-crypto will initialize and prepare the
+clone as necessary - see ``blk_crypto_rq_prep_clone`` and
+``blk_crypto_insert_cloned_request`` in ``blk-crypto.c``.
+
+
+Future Optimizations for layered devices
+========================================
+
+Creating a keyslot manager for a layered device uses up memory for each
+keyslot, and in general, a layered device merely passes the request on to a
+"child" device, so the keyslots in the layered device itself are completely
+unused, and don't need any refcounting or keyslot programming. We can instead
+define a new type of KSM; the "passthrough KSM", that layered devices can use
+to advertise an unlimited number of keyslots, and support for any encryption
+algorithms they choose, while not actually using any memory for each keyslot.
+Another use case for the "passthrough KSM" is for IE devices that do not have a
+limited number of keyslots.
+
+
+Interaction between inline encryption and blk integrity
+=======================================================
+
+At the time of this patch, there is no real hardware that supports both these
+features. However, these features do interact with each other, and it's not
+completely trivial to make them both work together properly. In particular,
+when a WRITE bio wants to use inline encryption on a device that supports both
+features, the bio will have an encryption context specified, after which
+its integrity information is calculated (using the plaintext data, since
+the encryption will happen while data is being written), and the data and
+integrity info is sent to the device. Obviously, the integrity info must be
+verified before the data is encrypted. After the data is encrypted, the device
+must not store the integrity info that it received with the plaintext data
+since that might reveal information about the plaintext data. As such, it must
+re-generate the integrity info from the ciphertext data and store that on disk
+instead. Another issue with storing the integrity info of the plaintext data is
+that it changes the on disk format depending on whether hardware inline
+encryption support is present or the kernel crypto API fallback is used (since
+if the fallback is used, the device will receive the integrity info of the
+ciphertext, not that of the plaintext).
+
+Because there isn't any real hardware yet, it seems prudent to assume that
+hardware implementations might not implement both features together correctly,
+and disallow the combination for now. Whenever a device supports integrity, the
+kernel will pretend that the device does not support hardware inline encryption
+(by essentially setting the keyslot manager in the request_queue of the device
+to NULL). When the crypto API fallback is enabled, this means that all bios with
+and encryption context will use the fallback, and IO will complete as usual.
+When the fallback is disabled, a bio with an encryption context will be failed.
diff --git a/block/Kconfig b/block/Kconfig
index c04a1d5008421..0af3876237748 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -192,6 +192,16 @@ config BLK_INLINE_ENCRYPTION
 	  block layer handle encryption, so users can take
 	  advantage of inline encryption hardware if present.
 
+config BLK_INLINE_ENCRYPTION_FALLBACK
+	bool "Enable crypto API fallback for blk-crypto"
+	depends on BLK_INLINE_ENCRYPTION
+	select CRYPTO
+	select CRYPTO_SKCIPHER
+	help
+	  Enabling this lets the block layer handle inline encryption
+	  by falling back to the kernel crypto API when inline
+	  encryption hardware is not present.
+
 menu "Partition Types"
 
 source "block/partitions/Kconfig"
diff --git a/block/Makefile b/block/Makefile
index 82f42ca3f7695..9464fb6ae423a 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= keyslot-manager.o blk-crypto.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
new file mode 100644
index 0000000000000..928118ba2da0d
--- /dev/null
+++ b/block/blk-crypto-fallback.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+/*
+ * Refer to Documentation/block/inline-encryption.rst for detailed explanation.
+ */
+
+#define pr_fmt(fmt) "blk-crypto-fallback: " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/blk-cgroup.h>
+#include <linux/blk-crypto.h>
+#include <linux/blkdev.h>
+#include <linux/crypto.h>
+#include <linux/keyslot-manager.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/random.h>
+
+#include "blk-crypto-internal.h"
+
+static unsigned int num_prealloc_bounce_pg = 32;
+module_param(num_prealloc_bounce_pg, uint, 0);
+MODULE_PARM_DESC(num_prealloc_bounce_pg,
+		 "Number of preallocated bounce pages for the blk-crypto crypto API fallback");
+
+static unsigned int blk_crypto_num_keyslots = 100;
+module_param_named(num_keyslots, blk_crypto_num_keyslots, uint, 0);
+MODULE_PARM_DESC(num_keyslots,
+		 "Number of keyslots for the blk-crypto crypto API fallback");
+
+static unsigned int num_prealloc_fallback_crypt_ctxs = 128;
+module_param(num_prealloc_fallback_crypt_ctxs, uint, 0);
+MODULE_PARM_DESC(num_prealloc_crypt_fallback_ctxs,
+		 "Number of preallocated bio fallback crypto contexts for blk-crypto to use during crypto API fallback");
+
+struct bio_fallback_crypt_ctx {
+	struct bio_crypt_ctx crypt_ctx;
+	/*
+	 * Copy of the bvec_iter when this bio was submitted.
+	 * We only want to en/decrypt the part of the bio as described by the
+	 * bvec_iter upon submission because bio might be split before being
+	 * resubmitted
+	 */
+	struct bvec_iter crypt_iter;
+	u64 fallback_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+	union {
+		struct {
+			struct work_struct work;
+			struct bio *bio;
+		};
+		struct {
+			void *bi_private_orig;
+			bio_end_io_t *bi_end_io_orig;
+		};
+	};
+};
+
+static struct kmem_cache *bio_fallback_crypt_ctx_cache;
+static mempool_t *bio_fallback_crypt_ctx_pool;
+
+/*
+ * Allocating a crypto tfm during I/O can deadlock, so we have to preallocate
+ * all of a mode's tfms when that mode starts being used. Since each mode may
+ * need all the keyslots at some point, each mode needs its own tfm for each
+ * keyslot; thus, a keyslot may contain tfms for multiple modes.  However, to
+ * match the behavior of real inline encryption hardware (which only supports a
+ * single encryption context per keyslot), we only allow one tfm per keyslot to
+ * be used at a time - the rest of the unused tfms have their keys cleared.
+ */
+static DEFINE_MUTEX(tfms_init_lock);
+static bool tfms_inited[BLK_ENCRYPTION_MODE_MAX];
+
+static struct blk_crypto_keyslot {
+	enum blk_crypto_mode_num crypto_mode;
+	struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
+} *blk_crypto_keyslots;
+
+static struct blk_keyslot_manager blk_crypto_ksm;
+static struct workqueue_struct *blk_crypto_wq;
+static mempool_t *blk_crypto_bounce_page_pool;
+
+/*
+ * This is the key we set when evicting a keyslot. This *should* be the all 0's
+ * key, but AES-XTS rejects that key, so we use some random bytes instead.
+ */
+static u8 blank_key[BLK_CRYPTO_MAX_KEY_SIZE];
+
+static void blk_crypto_evict_keyslot(unsigned int slot)
+{
+	struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
+	enum blk_crypto_mode_num crypto_mode = slotp->crypto_mode;
+	int err;
+
+	WARN_ON(slotp->crypto_mode == BLK_ENCRYPTION_MODE_INVALID);
+
+	/* Clear the key in the skcipher */
+	err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], blank_key,
+				     blk_crypto_modes[crypto_mode].keysize);
+	WARN_ON(err);
+	slotp->crypto_mode = BLK_ENCRYPTION_MODE_INVALID;
+}
+
+static int blk_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
+				      const struct blk_crypto_key *key,
+				      unsigned int slot)
+{
+	struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
+	const enum blk_crypto_mode_num crypto_mode = key->crypto_mode;
+	int err;
+
+	if (crypto_mode != slotp->crypto_mode &&
+	    slotp->crypto_mode != BLK_ENCRYPTION_MODE_INVALID)
+		blk_crypto_evict_keyslot(slot);
+
+	slotp->crypto_mode = crypto_mode;
+	err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], key->raw,
+				     key->size);
+	if (err) {
+		blk_crypto_evict_keyslot(slot);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int blk_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
+				    const struct blk_crypto_key *key,
+				    unsigned int slot)
+{
+	blk_crypto_evict_keyslot(slot);
+	return 0;
+}
+
+/*
+ * The crypto API fallback KSM ops - only used for a bio when it specifies a
+ * blk_crypto_key that was not supported by the device's inline encryption
+ * hardware.
+ */
+static const struct blk_ksm_ll_ops blk_crypto_ksm_ll_ops = {
+	.keyslot_program	= blk_crypto_keyslot_program,
+	.keyslot_evict		= blk_crypto_keyslot_evict,
+};
+
+static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)
+{
+	struct bio *src_bio = enc_bio->bi_private;
+	int i;
+
+	for (i = 0; i < enc_bio->bi_vcnt; i++)
+		mempool_free(enc_bio->bi_io_vec[i].bv_page,
+			     blk_crypto_bounce_page_pool);
+
+	src_bio->bi_status = enc_bio->bi_status;
+
+	bio_put(enc_bio);
+	bio_endio(src_bio);
+}
+
+static struct bio *blk_crypto_clone_bio(struct bio *bio_src)
+{
+	struct bvec_iter iter;
+	struct bio_vec bv;
+	struct bio *bio;
+
+	bio = bio_alloc_bioset(GFP_NOIO, bio_segments(bio_src), NULL);
+	if (!bio)
+		return NULL;
+	bio->bi_disk		= bio_src->bi_disk;
+	bio->bi_opf		= bio_src->bi_opf;
+	bio->bi_ioprio		= bio_src->bi_ioprio;
+	bio->bi_write_hint	= bio_src->bi_write_hint;
+	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
+	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
+
+	bio_for_each_segment(bv, bio_src, iter)
+		bio->bi_io_vec[bio->bi_vcnt++] = bv;
+
+	bio_clone_blkg_association(bio, bio_src);
+	blkcg_bio_issue_init(bio);
+
+	return bio;
+}
+
+static bool blk_crypto_alloc_cipher_req(struct bio *src_bio,
+					struct blk_ksm_keyslot *slot,
+					struct skcipher_request **ciph_req_ret,
+					struct crypto_wait *wait)
+{
+	struct skcipher_request *ciph_req;
+	const struct blk_crypto_keyslot *slotp;
+	int keyslot_idx = blk_ksm_get_slot_idx(slot);
+
+	slotp = &blk_crypto_keyslots[keyslot_idx];
+	ciph_req = skcipher_request_alloc(slotp->tfms[slotp->crypto_mode],
+					  GFP_NOIO);
+	if (!ciph_req) {
+		src_bio->bi_status = BLK_STS_RESOURCE;
+		return false;
+	}
+
+	skcipher_request_set_callback(ciph_req,
+				      CRYPTO_TFM_REQ_MAY_BACKLOG |
+				      CRYPTO_TFM_REQ_MAY_SLEEP,
+				      crypto_req_done, wait);
+	*ciph_req_ret = ciph_req;
+
+	return true;
+}
+
+static bool blk_crypto_split_bio_if_needed(struct bio **bio_ptr)
+{
+	struct bio *bio = *bio_ptr;
+	unsigned int i = 0;
+	unsigned int num_sectors = 0;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+
+	bio_for_each_segment(bv, bio, iter) {
+		num_sectors += bv.bv_len >> SECTOR_SHIFT;
+		if (++i == BIO_MAX_PAGES)
+			break;
+	}
+	if (num_sectors < bio_sectors(bio)) {
+		struct bio *split_bio;
+
+		split_bio = bio_split(bio, num_sectors, GFP_NOIO, NULL);
+		if (!split_bio) {
+			bio->bi_status = BLK_STS_RESOURCE;
+			return false;
+		}
+		bio_chain(split_bio, bio);
+		generic_make_request(bio);
+		*bio_ptr = split_bio;
+	}
+
+	return true;
+}
+
+union blk_crypto_iv {
+	__le64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+	u8 bytes[BLK_CRYPTO_MAX_IV_SIZE];
+};
+
+static void blk_crypto_dun_to_iv(const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+				 union blk_crypto_iv *iv)
+{
+	int i;
+
+	for (i = 0; i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++)
+		iv->dun[i] = cpu_to_le64(dun[i]);
+}
+
+/*
+ * The crypto API fallback's encryption routine.
+ * Allocate a bounce bio for encryption, encrypt the input bio using crypto API,
+ * and replace *bio_ptr with the bounce bio. May split input bio if it's too
+ * large. Returns true on success. Returns false and sets bio->bi_status on
+ * error.
+ */
+static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
+{
+	struct bio *src_bio, *enc_bio;
+	struct bio_crypt_ctx *bc;
+	struct blk_ksm_keyslot *slot;
+	int data_unit_size;
+	struct skcipher_request *ciph_req = NULL;
+	DECLARE_CRYPTO_WAIT(wait);
+	u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+	struct scatterlist src, dst;
+	union blk_crypto_iv iv;
+	unsigned int i, j;
+	bool ret = false;
+	blk_status_t blk_st;
+
+	/* Split the bio if it's too big for single page bvec */
+	if (!blk_crypto_split_bio_if_needed(bio_ptr))
+		return false;
+
+	src_bio = *bio_ptr;
+	bc = src_bio->bi_crypt_context;
+	data_unit_size = bc->bc_key->data_unit_size;
+
+	/* Allocate bounce bio for encryption */
+	enc_bio = blk_crypto_clone_bio(src_bio);
+	if (!enc_bio) {
+		src_bio->bi_status = BLK_STS_RESOURCE;
+		return false;
+	}
+
+	/*
+	 * Use the crypto API fallback keyslot manager to get a crypto_skcipher
+	 * for the algorithm and key specified for this bio.
+	 */
+	blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
+	if (blk_st != BLK_STS_OK) {
+		src_bio->bi_status = blk_st;
+		goto out_put_enc_bio;
+	}
+
+	/* and then allocate an skcipher_request for it */
+	if (!blk_crypto_alloc_cipher_req(src_bio, slot, &ciph_req, &wait))
+		goto out_release_keyslot;
+
+	memcpy(curr_dun, bc->bc_dun, sizeof(curr_dun));
+	sg_init_table(&src, 1);
+	sg_init_table(&dst, 1);
+
+	skcipher_request_set_crypt(ciph_req, &src, &dst, data_unit_size,
+				   iv.bytes);
+
+	/* Encrypt each page in the bounce bio */
+	for (i = 0; i < enc_bio->bi_vcnt; i++) {
+		struct bio_vec *enc_bvec = &enc_bio->bi_io_vec[i];
+		struct page *plaintext_page = enc_bvec->bv_page;
+		struct page *ciphertext_page =
+			mempool_alloc(blk_crypto_bounce_page_pool, GFP_NOIO);
+
+		enc_bvec->bv_page = ciphertext_page;
+
+		if (!ciphertext_page) {
+			src_bio->bi_status = BLK_STS_RESOURCE;
+			goto out_free_bounce_pages;
+		}
+
+		sg_set_page(&src, plaintext_page, data_unit_size,
+			    enc_bvec->bv_offset);
+		sg_set_page(&dst, ciphertext_page, data_unit_size,
+			    enc_bvec->bv_offset);
+
+		/* Encrypt each data unit in this page */
+		for (j = 0; j < enc_bvec->bv_len; j += data_unit_size) {
+			blk_crypto_dun_to_iv(curr_dun, &iv);
+			if (crypto_wait_req(crypto_skcipher_encrypt(ciph_req),
+					    &wait)) {
+				i++;
+				src_bio->bi_status = BLK_STS_IOERR;
+				goto out_free_bounce_pages;
+			}
+			bio_crypt_dun_increment(curr_dun, 1);
+			src.offset += data_unit_size;
+			dst.offset += data_unit_size;
+		}
+	}
+
+	enc_bio->bi_private = src_bio;
+	enc_bio->bi_end_io = blk_crypto_fallback_encrypt_endio;
+	*bio_ptr = enc_bio;
+	ret = true;
+
+	enc_bio = NULL;
+	goto out_free_ciph_req;
+
+out_free_bounce_pages:
+	while (i > 0)
+		mempool_free(enc_bio->bi_io_vec[--i].bv_page,
+			     blk_crypto_bounce_page_pool);
+out_free_ciph_req:
+	skcipher_request_free(ciph_req);
+out_release_keyslot:
+	blk_ksm_put_slot(slot);
+out_put_enc_bio:
+	if (enc_bio)
+		bio_put(enc_bio);
+
+	return ret;
+}
+
+/*
+ * The crypto API fallback's main decryption routine.
+ * Decrypts input bio in place, and calls bio_endio on the bio.
+ */
+static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
+{
+	struct bio_fallback_crypt_ctx *f_ctx =
+		container_of(work, struct bio_fallback_crypt_ctx, work);
+	struct bio *bio = f_ctx->bio;
+	struct bio_crypt_ctx *bc = &f_ctx->crypt_ctx;
+	struct blk_ksm_keyslot *slot;
+	struct skcipher_request *ciph_req = NULL;
+	DECLARE_CRYPTO_WAIT(wait);
+	u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+	union blk_crypto_iv iv;
+	struct scatterlist sg;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+	const int data_unit_size = bc->bc_key->data_unit_size;
+	unsigned int i;
+	blk_status_t blk_st;
+
+	/*
+	 * Use the crypto API fallback keyslot manager to get a crypto_skcipher
+	 * for the algorithm and key specified for this bio.
+	 */
+	blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
+	if (blk_st != BLK_STS_OK) {
+		bio->bi_status = blk_st;
+		goto out_no_keyslot;
+	}
+
+	/* and then allocate an skcipher_request for it */
+	if (!blk_crypto_alloc_cipher_req(bio, slot, &ciph_req, &wait))
+		goto out;
+
+	memcpy(curr_dun, f_ctx->fallback_dun, sizeof(curr_dun));
+	sg_init_table(&sg, 1);
+	skcipher_request_set_crypt(ciph_req, &sg, &sg, data_unit_size,
+				   iv.bytes);
+
+	/* Decrypt each segment in the bio */
+	__bio_for_each_segment(bv, bio, iter, f_ctx->crypt_iter) {
+		struct page *page = bv.bv_page;
+
+		sg_set_page(&sg, page, data_unit_size, bv.bv_offset);
+
+		/* Decrypt each data unit in the segment */
+		for (i = 0; i < bv.bv_len; i += data_unit_size) {
+			blk_crypto_dun_to_iv(curr_dun, &iv);
+			if (crypto_wait_req(crypto_skcipher_decrypt(ciph_req),
+					    &wait)) {
+				bio->bi_status = BLK_STS_IOERR;
+				goto out;
+			}
+			bio_crypt_dun_increment(curr_dun, 1);
+			sg.offset += data_unit_size;
+		}
+	}
+
+out:
+	skcipher_request_free(ciph_req);
+	blk_ksm_put_slot(slot);
+out_no_keyslot:
+	mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);
+	bio_endio(bio);
+}
+
+/**
+ * blk_crypto_fallback_decrypt_endio - clean up bio w.r.t fallback decryption
+ *
+ * @bio: the bio to clean up.
+ *
+ * Restore bi_private and bi_end_io, and queue the bio for decryption into a
+ * workqueue, since this function will be called from an atomic context.
+ */
+static void blk_crypto_fallback_decrypt_endio(struct bio *bio)
+{
+	struct bio_fallback_crypt_ctx *f_ctx = bio->bi_private;
+
+	bio->bi_private = f_ctx->bi_private_orig;
+	bio->bi_end_io = f_ctx->bi_end_io_orig;
+
+	/* If there was an IO error, don't queue for decrypt. */
+	if (bio->bi_status) {
+		mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);
+		bio_endio(bio);
+		return;
+	}
+
+	INIT_WORK(&f_ctx->work, blk_crypto_fallback_decrypt_bio);
+	f_ctx->bio = bio;
+	queue_work(blk_crypto_wq, &f_ctx->work);
+}
+
+/**
+ * blk_crypto_fallback_bio_prep - Prepare a bio to use fallback en/decryption
+ *
+ * @bio_ptr: pointer to the bio to prepare
+ *
+ * If bio is doing a WRITE operation, we split the bio into two parts, resubmit
+ * the second part. Allocates a bounce bio for the first part, encrypts it, and
+ * update bio_ptr to point to the bounce bio.
+ *
+ * For a READ operation, we mark the bio for decryption by using bi_private and
+ * bi_end_io.
+ *
+ * In either case, this function will make the bio look like a regular bio (i.e.
+ * as if no encryption context was ever specified) for the purposes of the rest
+ * of the stack except for blk-integrity (blk-integrity and blk-crypto are not
+ * currently supported together).
+ *
+ * Returns true on success. Sets bio->bi_status and returns false on error.
+ */
+bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
+{
+	struct bio *bio = *bio_ptr;
+	struct bio_crypt_ctx *bc = bio->bi_crypt_context;
+	struct bio_fallback_crypt_ctx *f_ctx;
+
+	if (!tfms_inited[bc->bc_key->crypto_mode]) {
+		bio->bi_status = BLK_STS_IOERR;
+		return false;
+	}
+
+	if (!blk_ksm_crypto_key_supported(&blk_crypto_ksm, bc->bc_key)) {
+		bio->bi_status = BLK_STS_NOTSUPP;
+		return false;
+	}
+
+	if (bio_data_dir(bio) == WRITE)
+		return blk_crypto_fallback_encrypt_bio(bio_ptr);
+
+	/*
+	 * bio READ case: Set up a f_ctx in the bio's bi_private and set the
+	 * bi_end_io appropriately to trigger decryption when the bio is ended.
+	 */
+	f_ctx = mempool_alloc(bio_fallback_crypt_ctx_pool, GFP_NOIO);
+	f_ctx->crypt_ctx = *bc;
+	memcpy(f_ctx->fallback_dun, bc->bc_dun, sizeof(f_ctx->fallback_dun));
+	f_ctx->crypt_iter = bio->bi_iter;
+	f_ctx->bi_private_orig = bio->bi_private;
+	f_ctx->bi_end_io_orig = bio->bi_end_io;
+	bio->bi_private = (void *)f_ctx;
+	bio->bi_end_io = blk_crypto_fallback_decrypt_endio;
+	bio_crypt_free_ctx(bio);
+
+	return true;
+}
+
+int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
+{
+	return blk_ksm_evict_key(&blk_crypto_ksm, key);
+}
+
+static bool blk_crypto_fallback_inited;
+static int blk_crypto_fallback_init(void)
+{
+	int i;
+	int err = -ENOMEM;
+
+	if (blk_crypto_fallback_inited)
+		return 0;
+
+	prandom_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE);
+
+	err = blk_ksm_init(&blk_crypto_ksm, blk_crypto_num_keyslots);
+	if (err)
+		goto out;
+	err = -ENOMEM;
+
+	blk_crypto_ksm.ksm_ll_ops = blk_crypto_ksm_ll_ops;
+	blk_crypto_ksm.max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
+
+	/* All blk-crypto modes have a crypto API fallback. */
+	for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++)
+		blk_crypto_ksm.crypto_modes_supported[i] = 0xFFFFFFFF;
+	blk_crypto_ksm.crypto_modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;
+
+	blk_crypto_wq = alloc_workqueue("blk_crypto_wq",
+					WQ_UNBOUND | WQ_HIGHPRI |
+					WQ_MEM_RECLAIM, num_online_cpus());
+	if (!blk_crypto_wq)
+		goto fail_free_ksm;
+
+	blk_crypto_keyslots = kcalloc(blk_crypto_num_keyslots,
+				      sizeof(blk_crypto_keyslots[0]),
+				      GFP_KERNEL);
+	if (!blk_crypto_keyslots)
+		goto fail_free_wq;
+
+	blk_crypto_bounce_page_pool =
+		mempool_create_page_pool(num_prealloc_bounce_pg, 0);
+	if (!blk_crypto_bounce_page_pool)
+		goto fail_free_keyslots;
+
+	bio_fallback_crypt_ctx_cache = KMEM_CACHE(bio_fallback_crypt_ctx, 0);
+	if (!bio_fallback_crypt_ctx_cache)
+		goto fail_free_bounce_page_pool;
+
+	bio_fallback_crypt_ctx_pool =
+		mempool_create_slab_pool(num_prealloc_fallback_crypt_ctxs,
+					 bio_fallback_crypt_ctx_cache);
+	if (!bio_fallback_crypt_ctx_pool)
+		goto fail_free_crypt_ctx_cache;
+
+	blk_crypto_fallback_inited = true;
+
+	return 0;
+fail_free_crypt_ctx_cache:
+	kmem_cache_destroy(bio_fallback_crypt_ctx_cache);
+fail_free_bounce_page_pool:
+	mempool_destroy(blk_crypto_bounce_page_pool);
+fail_free_keyslots:
+	kfree(blk_crypto_keyslots);
+fail_free_wq:
+	destroy_workqueue(blk_crypto_wq);
+fail_free_ksm:
+	blk_ksm_destroy(&blk_crypto_ksm);
+out:
+	return err;
+}
+
+/**
+ * blk_crypto_start_using_key() - Start using a blk_crypto_key on a device
+ * @key: A key to use on the device
+ * @q: the request queue for the device
+ *
+ * Upper layers must call this function to ensure that the crypto API fallback
+ * has transforms for the algorithm/data_unit_size/dun_bytes combo specified by
+ * the key, if it becomes necessary.
+ *
+ * Return: 0 on success and -err on error.
+ */
+int blk_crypto_start_using_key(struct blk_crypto_key *key,
+			       struct request_queue *q)
+{
+	enum blk_crypto_mode_num mode_num = key->crypto_mode;
+	struct blk_crypto_keyslot *slotp;
+	unsigned int i;
+	int err = 0;
+
+	/*
+	 * Fast path
+	 * Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]
+	 * for each i are visible before we try to access them.
+	 */
+	if (likely(smp_load_acquire(&tfms_inited[mode_num])))
+		return 0;
+
+	/*
+	 * If the keyslot manager of the request queue supports this crypto
+	 * mode, then we don't need to allocate this mode.
+	 */
+	if (blk_ksm_crypto_key_supported(q->ksm, key))
+		return 0;
+
+	mutex_lock(&tfms_init_lock);
+	err = blk_crypto_fallback_init();
+	if (err)
+		goto out;
+
+	if (tfms_inited[mode_num])
+		goto out;
+
+	for (i = 0; i < blk_crypto_num_keyslots; i++) {
+		slotp = &blk_crypto_keyslots[i];
+		slotp->tfms[mode_num] = crypto_alloc_skcipher(
+					blk_crypto_modes[mode_num].cipher_str,
+					0, 0);
+		if (IS_ERR(slotp->tfms[mode_num])) {
+			err = PTR_ERR(slotp->tfms[mode_num]);
+			slotp->tfms[mode_num] = NULL;
+			goto out_free_tfms;
+		}
+
+		crypto_skcipher_set_flags(slotp->tfms[mode_num],
+					  CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
+	}
+
+	/*
+	 * Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]
+	 * for each i are visible before we set tfms_inited[mode_num].
+	 */
+	smp_store_release(&tfms_inited[mode_num], true);
+	goto out;
+
+out_free_tfms:
+	for (i = 0; i < blk_crypto_num_keyslots; i++) {
+		slotp = &blk_crypto_keyslots[i];
+		crypto_free_skcipher(slotp->tfms[mode_num]);
+		slotp->tfms[mode_num] = NULL;
+	}
+out:
+	mutex_unlock(&tfms_init_lock);
+	return err;
+}
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
index 1e6d339fe1429..45889df33b25a 100644
--- a/block/blk-crypto-internal.h
+++ b/block/blk-crypto-internal.h
@@ -16,6 +16,8 @@ struct blk_crypto_mode {
 	unsigned int ivsize; /* iv size in bytes */
 };
 
+extern const struct blk_crypto_mode blk_crypto_modes[];
+
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
 static inline const struct blk_crypto_key *bio_crypt_key(struct bio *bio)
@@ -169,4 +171,27 @@ static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
 	return BLK_STS_OK;
 }
 
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
+
+bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
+
+int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
+static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
+{
+	pr_warn_once("crypto API fallback disabled; failing request.\n");
+	(*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
+	return false;
+}
+
+static inline int
+blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
+{
+	return 0;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
 #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index a52ec4eb153be..41d5e421624e5 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -3,6 +3,10 @@
  * Copyright 2019 Google LLC
  */
 
+/*
+ * Refer to Documentation/block/inline-encryption.rst for detailed explanation.
+ */
+
 #define pr_fmt(fmt) "blk-crypto: " fmt
 
 #include <linux/bio.h>
@@ -206,7 +210,8 @@ static bool bio_crypt_check_alignment(struct bio *bio)
  * __blk_crypto_init_request - Initializes the request's crypto fields based on
  *			       the blk_crypto_key for a bio to be added to the
  *			       request, and prepares it for hardware inline
- *			       encryption.
+ *			       encryption (as opposed to using the crypto API
+ *			       fallback).
  *
  * @rq: The request to init
  * @key: The blk_crypto_key of bios that will (eventually) be added to @rq.
@@ -219,6 +224,10 @@ static bool bio_crypt_check_alignment(struct bio *bio)
 blk_status_t __blk_crypto_init_request(struct request *rq,
 				       const struct blk_crypto_key *key)
 {
+	/*
+	 * We have a bio crypt context here - that means we didn't fallback
+	 * to crypto API, so try to program a keyslot now.
+	 */
 	return blk_ksm_get_slot_for_key(rq->q->ksm, key, &rq->crypt_keyslot);
 }
 
@@ -243,9 +252,16 @@ void __blk_crypto_free_request(struct request *rq)
  *
  * @bio_ptr: pointer to original bio pointer
  *
- * Succeeds if the bio doesn't have inline encryption enabled or if the bio
- * crypt context provided for the bio is supported by the underlying device's
- * inline encryption hardware. Ends the bio with error otherwise.
+ * If the bio crypt context provided for the bio is supported by the underlying
+ * device's inline encryption hardware, do nothing.
+ *
+ * Otherwise, try to perform en/decryption for this bio by falling back to the
+ * kernel crypto API. When the crypto API fallback is used for encryption,
+ * blk-crypto may choose to split the bio into 2 - the first one that will
+ * continue to be processed and the second one that will be resubmitted via
+ * generic_make_request. A bounce bio will be allocated to encrypt the contents
+ * of the aforementioned "first one", and *bio_ptr will be updated to this
+ * bounce bio.
  *
  * Caller must ensure bio has bio_crypt_ctx.
  *
@@ -265,16 +281,15 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr)
 		goto fail;
 
 	/*
-	 * Success if device supports the encryption context, and blk-integrity
-	 * isn't supported by device/is turned off.
+	 * Success if device supports the encryption context, or we succeeded
+	 * in falling back to the crypto API.
 	 */
-	if (!blk_ksm_crypto_key_supported(bio->bi_disk->queue->ksm,
-					  bio->bi_crypt_context->bc_key)) {
-		bio->bi_status = BLK_STS_NOTSUPP;
-		goto fail;
-	}
+	if (blk_ksm_crypto_key_supported(bio->bi_disk->queue->ksm,
+					 bio->bi_crypt_context->bc_key))
+		return true;
 
-	return true;
+	if (blk_crypto_fallback_bio_prep(bio_ptr))
+		return true;
 fail:
 	bio_endio(*bio_ptr);
 	return false;
@@ -298,6 +313,10 @@ void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio)
 
 void __blk_crypto_rq_prep_clone(struct request *dst, struct request *src)
 {
+	/* Don't clone crypto info if src uses fallback en/decryption */
+	if (!src->crypt_keyslot)
+		return;
+
 	dst->crypt_ctx = src->crypt_ctx;
 }
 
@@ -375,6 +394,7 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
  * is evicted from hardware that it might have been programmed into. This
  * will call blk_ksm_evict_key on the queue's keyslot manager, if one
  * exists, and supports the crypto algorithm with the specified data unit size.
+ * Otherwise, it will evict the key from the blk-crypto-fallback's ksm.
  *
  * Return: 0 on success or if key is not present in the q's ksm, -err on error.
  */
@@ -384,5 +404,5 @@ int blk_crypto_evict_key(struct request_queue *q,
 	if (q->ksm && blk_ksm_crypto_key_supported(q->ksm, key))
 		return blk_ksm_evict_key(q->ksm, key);
 
-	return 0;
+	return blk_crypto_fallback_evict_key(key);
 }
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index 4add2e8846fea..c83fc736b97a4 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -58,7 +58,7 @@ struct blk_crypto_key {
  *
  * A bio_crypt_ctx specifies that the contents of the bio will be encrypted (for
  * write requests) or decrypted (for read requests) inline by the storage device
- * or controller.
+ * or controller, or by the crypto API fallback.
  */
 struct bio_crypt_ctx {
 	const struct blk_crypto_key	*bc_key;
@@ -111,4 +111,19 @@ static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
 		__bio_crypt_clone(dst, src, gfp_mask);
 }
 
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
+
+int blk_crypto_start_using_key(struct blk_crypto_key *key,
+			       struct request_queue *q);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
+static inline int blk_crypto_start_using_key(struct blk_crypto_key *key,
+					     struct request_queue *q)
+{
+	return 0;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
+
 #endif /* __LINUX_BLK_CRYPTO_H */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 05/11] scsi: ufs: UFS driver v2.1 spec crypto additions
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (3 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  3:06 ` [PATCH v9 06/11] scsi: ufs: UFS crypto API Satya Tangirala
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Add the crypto registers and structs defined in v2.1 of the JEDEC UFSHCI
specification in preparation to add support for inline encryption to
UFS.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 drivers/scsi/ufs/ufshcd.c |  2 ++
 drivers/scsi/ufs/ufshcd.h |  5 +++
 drivers/scsi/ufs/ufshci.h | 67 +++++++++++++++++++++++++++++++++++++--
 3 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2d705694636c2..a9c2ae9984ad7 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4766,6 +4766,8 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 	case OCS_MISMATCH_RESP_UPIU_SIZE:
 	case OCS_PEER_COMM_FAILURE:
 	case OCS_FATAL_ERROR:
+	case OCS_INVALID_CRYPTO_CONFIG:
+	case OCS_GENERAL_CRYPTO_ERROR:
 	default:
 		result |= DID_ERROR << 16;
 		dev_err(hba->dev,
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 2ae6c7c8528c7..978781c538c41 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -716,6 +716,11 @@ struct ufs_hba {
 	 * for userspace to control the power management.
 	 */
 #define UFSHCD_CAP_RPM_AUTOSUSPEND (1 << 6)
+	/*
+	 * This capability allows the host controller driver to use the
+	 * inline crypto engine, if it is present
+	 */
+#define UFSHCD_CAP_CRYPTO (1 << 7)
 
 	struct devfreq *devfreq;
 	struct ufs_clk_scaling clk_scaling;
diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h
index c2961d37cc1cf..c0651fe6dbbc6 100644
--- a/drivers/scsi/ufs/ufshci.h
+++ b/drivers/scsi/ufs/ufshci.h
@@ -90,6 +90,7 @@ enum {
 	MASK_64_ADDRESSING_SUPPORT		= 0x01000000,
 	MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT	= 0x02000000,
 	MASK_UIC_DME_TEST_MODE_SUPPORT		= 0x04000000,
+	MASK_CRYPTO_SUPPORT			= 0x10000000,
 };
 
 #define UFS_MASK(mask, offset)		((mask) << (offset))
@@ -143,6 +144,7 @@ enum {
 #define DEVICE_FATAL_ERROR			0x800
 #define CONTROLLER_FATAL_ERROR			0x10000
 #define SYSTEM_BUS_FATAL_ERROR			0x20000
+#define CRYPTO_ENGINE_FATAL_ERROR		0x40000
 
 #define UFSHCD_UIC_HIBERN8_MASK	(UIC_HIBERNATE_ENTER |\
 				UIC_HIBERNATE_EXIT)
@@ -155,11 +157,13 @@ enum {
 #define UFSHCD_ERROR_MASK	(UIC_ERROR |\
 				DEVICE_FATAL_ERROR |\
 				CONTROLLER_FATAL_ERROR |\
-				SYSTEM_BUS_FATAL_ERROR)
+				SYSTEM_BUS_FATAL_ERROR |\
+				CRYPTO_ENGINE_FATAL_ERROR)
 
 #define INT_FATAL_ERRORS	(DEVICE_FATAL_ERROR |\
 				CONTROLLER_FATAL_ERROR |\
-				SYSTEM_BUS_FATAL_ERROR)
+				SYSTEM_BUS_FATAL_ERROR |\
+				CRYPTO_ENGINE_FATAL_ERROR)
 
 /* HCS - Host Controller Status 30h */
 #define DEVICE_PRESENT				0x1
@@ -318,6 +322,61 @@ enum {
 	INTERRUPT_MASK_ALL_VER_21	= 0x71FFF,
 };
 
+/* CCAP - Crypto Capability 100h */
+union ufs_crypto_capabilities {
+	__le32 reg_val;
+	struct {
+		u8 num_crypto_cap;
+		u8 config_count;
+		u8 reserved;
+		u8 config_array_ptr;
+	};
+};
+
+enum ufs_crypto_key_size {
+	UFS_CRYPTO_KEY_SIZE_INVALID	= 0x0,
+	UFS_CRYPTO_KEY_SIZE_128		= 0x1,
+	UFS_CRYPTO_KEY_SIZE_192		= 0x2,
+	UFS_CRYPTO_KEY_SIZE_256		= 0x3,
+	UFS_CRYPTO_KEY_SIZE_512		= 0x4,
+};
+
+enum ufs_crypto_alg {
+	UFS_CRYPTO_ALG_AES_XTS			= 0x0,
+	UFS_CRYPTO_ALG_BITLOCKER_AES_CBC	= 0x1,
+	UFS_CRYPTO_ALG_AES_ECB			= 0x2,
+	UFS_CRYPTO_ALG_ESSIV_AES_CBC		= 0x3,
+};
+
+/* x-CRYPTOCAP - Crypto Capability X */
+union ufs_crypto_cap_entry {
+	__le32 reg_val;
+	struct {
+		u8 algorithm_id;
+		u8 sdus_mask; /* Supported data unit size mask */
+		u8 key_size;
+		u8 reserved;
+	};
+};
+
+#define UFS_CRYPTO_CONFIGURATION_ENABLE (1 << 7)
+#define UFS_CRYPTO_KEY_MAX_SIZE 64
+/* x-CRYPTOCFG - Crypto Configuration X */
+union ufs_crypto_cfg_entry {
+	__le32 reg_val[32];
+	struct {
+		u8 crypto_key[UFS_CRYPTO_KEY_MAX_SIZE];
+		u8 data_unit_size;
+		u8 crypto_cap_idx;
+		u8 reserved_1;
+		u8 config_enable;
+		u8 reserved_multi_host;
+		u8 reserved_2;
+		u8 vsb[2];
+		u8 reserved_3[56];
+	};
+};
+
 /*
  * Request Descriptor Definitions
  */
@@ -339,6 +398,7 @@ enum {
 	UTP_NATIVE_UFS_COMMAND		= 0x10000000,
 	UTP_DEVICE_MANAGEMENT_FUNCTION	= 0x20000000,
 	UTP_REQ_DESC_INT_CMD		= 0x01000000,
+	UTP_REQ_DESC_CRYPTO_ENABLE_CMD	= 0x00800000,
 };
 
 /* UTP Transfer Request Data Direction (DD) */
@@ -358,6 +418,9 @@ enum {
 	OCS_PEER_COMM_FAILURE		= 0x5,
 	OCS_ABORTED			= 0x6,
 	OCS_FATAL_ERROR			= 0x7,
+	OCS_DEVICE_FATAL_ERROR		= 0x8,
+	OCS_INVALID_CRYPTO_CONFIG	= 0x9,
+	OCS_GENERAL_CRYPTO_ERROR	= 0xA,
 	OCS_INVALID_COMMAND_STATUS	= 0x0F,
 	MASK_OCS			= 0x0F,
 };
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 06/11] scsi: ufs: UFS crypto API
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (4 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 05/11] scsi: ufs: UFS driver v2.1 spec crypto additions Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  5:07   ` Eric Biggers
  2020-03-26  3:06 ` [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS Satya Tangirala
                   ` (5 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Introduce functions to manipulate UFS inline encryption hardware
in line with the JEDEC UFSHCI v2.1 specification and to work with the
block keyslot manager.

The UFS crypto API will assume by default that a vendor driver doesn't
support UFS crypto, even if the hardware advertises the capability, because
a lot of hardware requires some special handling that's not specified in
the aforementioned JEDEC spec. Each vendor driver must explicity set
hba->caps |= UFSHCD_CAP_CRYPTO before ufshcd_hba_init_crypto is called to
opt-in to UFS crypto support.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 drivers/scsi/ufs/Kconfig         |   9 ++
 drivers/scsi/ufs/Makefile        |   1 +
 drivers/scsi/ufs/ufshcd-crypto.c | 226 +++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd-crypto.h |  44 ++++++
 drivers/scsi/ufs/ufshcd.h        |  12 ++
 5 files changed, 292 insertions(+)
 create mode 100644 drivers/scsi/ufs/ufshcd-crypto.c
 create mode 100644 drivers/scsi/ufs/ufshcd-crypto.h

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index d14c2243e02a3..c69f1b49167b0 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -160,3 +160,12 @@ config SCSI_UFS_BSG
 
 	  Select this if you need a bsg device node for your UFS controller.
 	  If unsure, say N.
+
+config SCSI_UFS_CRYPTO
+	bool "UFS Crypto Engine Support"
+	depends on SCSI_UFSHCD && BLK_INLINE_ENCRYPTION
+	help
+	  Enable Crypto Engine Support in UFS.
+	  Enabling this makes it possible for the kernel to use the crypto
+	  capabilities of the UFS device (if present) to perform crypto
+	  operations on data being transferred to/from the device.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 94c6c5d7334b6..197e178f44bce 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
 ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
+ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO) += ufshcd-crypto.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
 obj-$(CONFIG_SCSI_UFS_HISI) += ufs-hisi.o
diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
new file mode 100644
index 0000000000000..4c2da3909d13c
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include "ufshcd.h"
+#include "ufshcd-crypto.h"
+
+/* Blk-crypto modes supported by UFS crypto */
+static const struct ufs_crypto_alg_entry {
+	enum ufs_crypto_alg ufs_alg;
+	enum ufs_crypto_key_size ufs_key_size;
+} ufs_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = {
+	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
+		.ufs_alg = UFS_CRYPTO_ALG_AES_XTS,
+		.ufs_key_size = UFS_CRYPTO_KEY_SIZE_256,
+	},
+};
+
+static void ufshcd_program_key(struct ufs_hba *hba,
+			       const union ufs_crypto_cfg_entry *cfg,
+			       int slot)
+{
+	int i;
+	u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
+
+	ufshcd_hold(hba, false);
+	/* Ensure that CFGE is cleared before programming the key */
+	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
+	for (i = 0; i < 16; i++) {
+		ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[i]),
+			      slot_offset + i * sizeof(cfg->reg_val[0]));
+	}
+	/* Write dword 17 */
+	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[17]),
+		      slot_offset + 17 * sizeof(cfg->reg_val[0]));
+	/* Dword 16 must be written last */
+	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),
+		      slot_offset + 16 * sizeof(cfg->reg_val[0]));
+	ufshcd_release(hba);
+}
+
+static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
+					 const struct blk_crypto_key *key,
+					 unsigned int slot)
+{
+	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
+	const struct ufs_crypto_alg_entry *alg =
+			&ufs_crypto_algs[key->crypto_mode];
+	u8 data_unit_mask = key->data_unit_size / 512;
+	int i;
+	int cap_idx = -1;
+	union ufs_crypto_cfg_entry cfg = { 0 };
+
+	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
+	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
+		if (ccap_array[i].algorithm_id == alg->ufs_alg &&
+		    ccap_array[i].key_size == alg->ufs_key_size &&
+		    (ccap_array[i].sdus_mask & data_unit_mask)) {
+			cap_idx = i;
+			break;
+		}
+	}
+
+	if (WARN_ON(cap_idx < 0))
+		return -EOPNOTSUPP;
+
+	cfg.data_unit_size = data_unit_mask;
+	cfg.crypto_cap_idx = cap_idx;
+	cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
+
+	if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
+		/* In XTS mode, the blk_crypto_key's size is already doubled */
+		memcpy(cfg.crypto_key, key->raw, key->size/2);
+		memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
+		       key->raw + key->size/2, key->size/2);
+	} else {
+		memcpy(cfg.crypto_key, key->raw, key->size);
+	}
+
+	ufshcd_program_key(hba, &cfg, slot);
+
+	memzero_explicit(&cfg, sizeof(cfg));
+	return 0;
+}
+
+static void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
+{
+	/*
+	 * Clear the crypto cfg on the device. Clearing CFGE
+	 * might not be sufficient, so just clear the entire cfg.
+	 */
+	union ufs_crypto_cfg_entry cfg = { 0 };
+
+	ufshcd_program_key(hba, &cfg, slot);
+}
+
+static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
+				       const struct blk_crypto_key *key,
+				       unsigned int slot)
+{
+	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+
+	ufshcd_clear_keyslot(hba, slot);
+
+	return 0;
+}
+
+bool ufshcd_crypto_enable(struct ufs_hba *hba)
+{
+	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
+		return false;
+
+	/* Reset might clear all keys, so reprogram all the keys. */
+	blk_ksm_reprogram_all_keys(&hba->ksm);
+	return true;
+}
+
+static const struct blk_ksm_ll_ops ufshcd_ksm_ops = {
+	.keyslot_program	= ufshcd_crypto_keyslot_program,
+	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
+};
+
+static enum blk_crypto_mode_num
+ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
+		BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
+		if (ufs_crypto_algs[i].ufs_alg == cap.algorithm_id &&
+		    ufs_crypto_algs[i].ufs_key_size == cap.key_size) {
+			return i;
+		}
+	}
+	return BLK_ENCRYPTION_MODE_INVALID;
+}
+
+/**
+ * ufshcd_hba_init_crypto - Read crypto capabilities, init crypto fields in hba
+ * @hba: Per adapter instance
+ *
+ * Return: 0 if crypto was initialized or is not supported, else a -errno value.
+ */
+int ufshcd_hba_init_crypto(struct ufs_hba *hba)
+{
+	int cap_idx = 0;
+	int err = 0;
+	enum blk_crypto_mode_num blk_mode_num;
+	int slot = 0;
+	int num_keyslots;
+
+	/*
+	 * Don't use crypto if either the hardware doesn't advertise the
+	 * standard crypto capability bit *or* if the vendor specific driver
+	 * hasn't advertised that crypto is supported.
+	 */
+	if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
+	    !(hba->caps & UFSHCD_CAP_CRYPTO))
+		goto out;
+
+	hba->crypto_capabilities.reg_val =
+			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
+	hba->crypto_cfg_register =
+		(u32)hba->crypto_capabilities.config_array_ptr * 0x100;
+	hba->crypto_cap_array =
+		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
+			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
+	if (!hba->crypto_cap_array) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* The actual number of configurations supported is (CFGC+1) */
+	num_keyslots = hba->crypto_capabilities.config_count + 1;
+	err = blk_ksm_init(&hba->ksm, num_keyslots);
+	if (err)
+		goto out_free_caps;
+
+	hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
+	/* UFS only supports 8 bytes for any DUN */
+	hba->ksm.max_dun_bytes_supported = 8;
+	hba->ksm.dev = hba->dev;
+
+	/*
+	 * Cache all the UFS crypto capabilities and advertise the supported
+	 * crypto modes and data unit sizes to the block layer.
+	 */
+	for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
+	     cap_idx++) {
+		hba->crypto_cap_array[cap_idx].reg_val =
+			cpu_to_le32(ufshcd_readl(hba,
+						 REG_UFS_CRYPTOCAP +
+						 cap_idx * sizeof(__le32)));
+		blk_mode_num = ufshcd_find_blk_crypto_mode(
+						hba->crypto_cap_array[cap_idx]);
+		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
+			hba->ksm.crypto_modes_supported[blk_mode_num] |=
+				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
+	}
+
+	for (slot = 0; slot < num_keyslots; slot++)
+		ufshcd_clear_keyslot(hba, slot);
+
+	return 0;
+
+out_free_caps:
+	devm_kfree(hba->dev, hba->crypto_cap_array);
+out:
+	/* Indicate that init failed by clearing UFSHCD_CAP_CRYPTO */
+	hba->caps &= ~UFSHCD_CAP_CRYPTO;
+	return err;
+}
+
+void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
+					    struct request_queue *q)
+{
+	if ((hba->caps & UFSHCD_CAP_CRYPTO))
+		blk_ksm_register(&hba->ksm, q);
+}
+
+void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
+{
+	blk_ksm_destroy(&hba->ksm);
+}
diff --git a/drivers/scsi/ufs/ufshcd-crypto.h b/drivers/scsi/ufs/ufshcd-crypto.h
new file mode 100644
index 0000000000000..1e98f1fc99965
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd-crypto.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef _UFSHCD_CRYPTO_H
+#define _UFSHCD_CRYPTO_H
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+#include "ufshcd.h"
+#include "ufshci.h"
+
+bool ufshcd_crypto_enable(struct ufs_hba *hba);
+
+void ufshcd_crypto_disable(struct ufs_hba *hba);
+
+int ufshcd_hba_init_crypto(struct ufs_hba *hba);
+
+void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
+					    struct request_queue *q);
+
+void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba);
+
+#else /* CONFIG_SCSI_UFS_CRYPTO */
+
+static inline bool ufshcd_crypto_enable(struct ufs_hba *hba)
+{
+	return false;
+}
+
+static inline int ufshcd_hba_init_crypto(struct ufs_hba *hba)
+{
+	return 0;
+}
+
+static inline void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
+						struct request_queue *q) { }
+
+static inline void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
+{ }
+
+#endif /* CONFIG_SCSI_UFS_CRYPTO */
+
+#endif /* _UFSHCD_CRYPTO_H */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 978781c538c41..eaeb21b9cda24 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -55,6 +55,7 @@
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/regulator/consumer.h>
+#include <linux/keyslot-manager.h>
 #include "unipro.h"
 
 #include <asm/irq.h>
@@ -521,6 +522,10 @@ struct ufs_stats {
  * @is_urgent_bkops_lvl_checked: keeps track if the urgent bkops level for
  *  device is known or not.
  * @scsi_block_reqs_cnt: reference counting for scsi block requests
+ * @crypto_capabilities: Content of crypto capabilities register (0x100)
+ * @crypto_cap_array: Array of crypto capabilities
+ * @crypto_cfg_register: Start of the crypto cfg array
+ * @ksm: the keyslot manager tied to this hba
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -735,6 +740,13 @@ struct ufs_hba {
 
 	struct device		bsg_dev;
 	struct request_queue	*bsg_queue;
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+	union ufs_crypto_capabilities crypto_capabilities;
+	union ufs_crypto_cap_entry *crypto_cap_array;
+	u32 crypto_cfg_register;
+	struct blk_keyslot_manager ksm;
+#endif
 };
 
 /* Returns true if clocks can be gated. Otherwise false */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (5 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 06/11] scsi: ufs: UFS crypto API Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  5:09   ` Eric Biggers
  2020-03-26  3:06 ` [PATCH v9 08/11] fs: introduce SB_INLINECRYPT Satya Tangirala
                   ` (4 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Wire up ufshcd.c with the UFS Crypto API, the block layer inline
encryption additions and the keyslot manager.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 drivers/scsi/ufs/ufshcd-crypto.h | 18 +++++++++++++
 drivers/scsi/ufs/ufshcd.c        | 44 ++++++++++++++++++++++++++++----
 drivers/scsi/ufs/ufshcd.h        |  6 +++++
 3 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-crypto.h b/drivers/scsi/ufs/ufshcd-crypto.h
index 1e98f1fc99965..707e7b77e16fc 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.h
+++ b/drivers/scsi/ufs/ufshcd-crypto.h
@@ -10,6 +10,20 @@
 #include "ufshcd.h"
 #include "ufshci.h"
 
+static inline void ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
+					      struct scsi_cmnd *cmd,
+					      struct ufshcd_lrb *lrbp)
+{
+	struct request *rq = cmd->request;
+
+	if (rq->crypt_keyslot) {
+		lrbp->crypto_key_slot = blk_ksm_get_slot_idx(rq->crypt_keyslot);
+		lrbp->data_unit_num = rq->crypt_ctx->bc_dun[0];
+	} else {
+		lrbp->crypto_key_slot = -1;
+	}
+}
+
 bool ufshcd_crypto_enable(struct ufs_hba *hba);
 
 void ufshcd_crypto_disable(struct ufs_hba *hba);
@@ -23,6 +37,10 @@ void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba);
 
 #else /* CONFIG_SCSI_UFS_CRYPTO */
 
+static inline void ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
+					      struct scsi_cmnd *cmd,
+					      struct ufshcd_lrb *lrbp) { }
+
 static inline bool ufshcd_crypto_enable(struct ufs_hba *hba)
 {
 	return false;
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a9c2ae9984ad7..71b3d1fb4e47c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -47,6 +47,7 @@
 #include "unipro.h"
 #include "ufs-sysfs.h"
 #include "ufs_bsg.h"
+#include "ufshcd-crypto.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/ufs.h>
@@ -816,7 +817,12 @@ static void ufshcd_enable_run_stop_reg(struct ufs_hba *hba)
  */
 static inline void ufshcd_hba_start(struct ufs_hba *hba)
 {
-	ufshcd_writel(hba, CONTROLLER_ENABLE, REG_CONTROLLER_ENABLE);
+	u32 val = CONTROLLER_ENABLE;
+
+	if (ufshcd_crypto_enable(hba))
+		val |= CRYPTO_GENERAL_ENABLE;
+
+	ufshcd_writel(hba, val, REG_CONTROLLER_ENABLE);
 }
 
 /**
@@ -2174,6 +2180,8 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
 	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
 	u32 data_direction;
 	u32 dword_0;
+	u32 dword_1 = 0;
+	u32 dword_3 = 0;
 
 	if (cmd_dir == DMA_FROM_DEVICE) {
 		data_direction = UTP_DEVICE_TO_HOST;
@@ -2192,9 +2200,17 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
 		dword_0 |= UTP_REQ_DESC_INT_CMD;
 
 	/* Transfer request descriptor header fields */
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+	if (lrbp->crypto_key_slot >= 0) {
+		dword_0 |= UTP_REQ_DESC_CRYPTO_ENABLE_CMD;
+		dword_0 |= lrbp->crypto_key_slot;
+		dword_1 = lower_32_bits(lrbp->data_unit_num);
+		dword_3 = upper_32_bits(lrbp->data_unit_num);
+	}
+#endif /* CONFIG_SCSI_UFS_CRYPTO */
+
 	req_desc->header.dword_0 = cpu_to_le32(dword_0);
-	/* dword_1 is reserved, hence it is set to 0 */
-	req_desc->header.dword_1 = 0;
+	req_desc->header.dword_1 = cpu_to_le32(dword_1);
 	/*
 	 * assigning invalid value for command status. Controller
 	 * updates OCS on command completion, with the command
@@ -2202,8 +2218,7 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
 	 */
 	req_desc->header.dword_2 =
 		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
-	/* dword_3 is reserved, hence it is set to 0 */
-	req_desc->header.dword_3 = 0;
+	req_desc->header.dword_3 = cpu_to_le32(dword_3);
 
 	req_desc->prd_table_length = 0;
 }
@@ -2437,6 +2452,9 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 	lrbp->task_tag = tag;
 	lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
 	lrbp->intr_cmd = !ufshcd_is_intr_aggr_allowed(hba) ? true : false;
+
+	ufshcd_prepare_lrbp_crypto(hba, cmd, lrbp);
+
 	lrbp->req_abort_skip = false;
 
 	ufshcd_comp_scsi_upiu(hba, lrbp);
@@ -2470,6 +2488,9 @@ static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
 	lrbp->task_tag = tag;
 	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
 	lrbp->intr_cmd = true; /* No interrupt aggregation */
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+	lrbp->crypto_key_slot = -1; /* No crypto operations */
+#endif
 	hba->dev_cmd.type = cmd_type;
 
 	return ufshcd_comp_devman_upiu(hba, lrbp);
@@ -4631,6 +4652,8 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	if (ufshcd_is_rpm_autosuspend_allowed(hba))
 		sdev->rpm_autosuspend = 1;
 
+	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
+
 	return 0;
 }
 
@@ -5897,6 +5920,9 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
 	lrbp->task_tag = tag;
 	lrbp->lun = 0;
 	lrbp->intr_cmd = true;
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+	lrbp->crypto_key_slot = -1; /* No crypto operations */
+#endif
 	hba->dev_cmd.type = cmd_type;
 
 	switch (hba->ufs_version) {
@@ -8311,6 +8337,7 @@ EXPORT_SYMBOL_GPL(ufshcd_remove);
  */
 void ufshcd_dealloc_host(struct ufs_hba *hba)
 {
+	ufshcd_crypto_destroy_keyslot_manager(hba);
 	scsi_host_put(hba->host);
 }
 EXPORT_SYMBOL_GPL(ufshcd_dealloc_host);
@@ -8520,6 +8547,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	/* Reset the attached device */
 	ufshcd_vops_device_reset(hba);
 
+	/* Init crypto */
+	err = ufshcd_hba_init_crypto(hba);
+	if (err) {
+		dev_err(hba->dev, "crypto setup failed\n");
+		goto out_remove_scsi_host;
+	}
+
 	/* Host controller enable */
 	err = ufshcd_hba_enable(hba);
 	if (err) {
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index eaeb21b9cda24..3af15880e1e36 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -168,6 +168,8 @@ struct ufs_pm_lvl_states {
  * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
  * @issue_time_stamp: time stamp for debug purposes
  * @compl_time_stamp: time stamp for statistics
+ * @crypto_key_slot: the key slot to use for inline crypto
+ * @data_unit_num: the data unit number for the first block for inline crypto
  * @req_abort_skip: skip request abort task flag
  */
 struct ufshcd_lrb {
@@ -192,6 +194,10 @@ struct ufshcd_lrb {
 	bool intr_cmd;
 	ktime_t issue_time_stamp;
 	ktime_t compl_time_stamp;
+#if IS_ENABLED(CONFIG_SCSI_UFS_CRYPTO)
+	int crypto_key_slot;
+	u64 data_unit_num;
+#endif
 
 	bool req_abort_skip;
 };
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 08/11] fs: introduce SB_INLINECRYPT
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (6 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS Satya Tangirala
@ 2020-03-26  3:06 ` Satya Tangirala
  2020-03-26  5:56   ` Eric Biggers
  2020-03-26  3:07 ` [PATCH v9 09/11] fscrypt: add inline encryption support Satya Tangirala
                   ` (3 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:06 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala

Introduce SB_INLINECRYPT, which is set by filesystems that wish to use
blk-crypto for file content en/decryption.

Signed-off-by: Satya Tangirala <satyat@google.com>
---
 fs/proc_namespace.c | 1 +
 include/linux/fs.h  | 1 +
 2 files changed, 2 insertions(+)

diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 273ee82d8aa97..8bf195d3bda69 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -49,6 +49,7 @@ static int show_sb_opts(struct seq_file *m, struct super_block *sb)
 		{ SB_DIRSYNC, ",dirsync" },
 		{ SB_MANDLOCK, ",mand" },
 		{ SB_LAZYTIME, ",lazytime" },
+		{ SB_INLINECRYPT, ",inlinecrypt" },
 		{ 0, NULL }
 	};
 	const struct proc_fs_info *fs_infop;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index abedbffe2c9e4..5c758a765923d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1371,6 +1371,7 @@ extern int send_sigurg(struct fown_struct *fown);
 #define SB_NODIRATIME	2048	/* Do not update directory access times */
 #define SB_SILENT	32768
 #define SB_POSIXACL	(1<<16)	/* VFS does not apply the umask */
+#define SB_INLINECRYPT	(1<<17)	/* Use blk-crypto for encrypted files */
 #define SB_KERNMOUNT	(1<<22) /* this is a kern_mount call */
 #define SB_I_VERSION	(1<<23) /* Update inode I_version field */
 #define SB_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 09/11] fscrypt: add inline encryption support
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (7 preceding siblings ...)
  2020-03-26  3:06 ` [PATCH v9 08/11] fs: introduce SB_INLINECRYPT Satya Tangirala
@ 2020-03-26  3:07 ` Satya Tangirala
  2020-03-26  5:45   ` Eric Biggers
  2020-03-26  3:07 ` [PATCH v9 10/11] f2fs: " Satya Tangirala
                   ` (2 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:07 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala,
	Eric Biggers

Add support for inline encryption to fs/crypto/.  With "inline
encryption", the block layer handles the decryption/encryption as part
of the bio, instead of the filesystem doing the crypto itself via
Linux's crypto API.  This model is needed in order to take advantage of
the inline encryption hardware present on most modern mobile SoCs.

To use inline encryption, the filesystem needs to be mounted with
'-o inlinecrypt'.  The contents of any encrypted files will then be
encrypted using blk-crypto, instead of using the traditional
filesystem-layer crypto. Fscrypt still provides the key and IV to use,
and the actual ciphertext on-disk is still the same; therefore it's
testable using the existing fscrypt ciphertext verification tests.

Note that since blk-crypto has a fallack to Linux's crypto API, and
also supports all the encryption modes currently supported by fscrypt,
this feature is usable and testable even without actual inline
encryption hardware.

Per-filesystem changes will be needed to set encryption contexts when
submitting bios and to implement the 'inlinecrypt' mount option.  This
patch just adds the common code.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
 fs/crypto/Kconfig           |   6 +
 fs/crypto/Makefile          |   1 +
 fs/crypto/bio.c             |  51 ++++++
 fs/crypto/crypto.c          |   2 +-
 fs/crypto/fname.c           |   4 +-
 fs/crypto/fscrypt_private.h | 120 +++++++++++--
 fs/crypto/inline_crypt.c    | 328 ++++++++++++++++++++++++++++++++++++
 fs/crypto/keyring.c         |   4 +-
 fs/crypto/keysetup.c        |  92 ++++++----
 fs/crypto/keysetup_v1.c     |  16 +-
 include/linux/fscrypt.h     |  57 +++++++
 11 files changed, 624 insertions(+), 57 deletions(-)
 create mode 100644 fs/crypto/inline_crypt.c

diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
index 8046d7c7a3e9c..f1f11a6228ebf 100644
--- a/fs/crypto/Kconfig
+++ b/fs/crypto/Kconfig
@@ -24,3 +24,9 @@ config FS_ENCRYPTION_ALGS
 	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.
diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile
index 232e2bb5a337b..652c7180ec6de 100644
--- a/fs/crypto/Makefile
+++ b/fs/crypto/Makefile
@@ -11,3 +11,4 @@ fscrypto-y := crypto.o \
 	      policy.o
 
 fscrypto-$(CONFIG_BLOCK) += bio.o
+fscrypto-$(CONFIG_FS_ENCRYPTION_INLINE_CRYPT) += inline_crypt.o
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 4fa18fff9c4ef..cec06edd8352c 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/namei.h>
+#include <linux/blkdev.h>
 #include "fscrypt_private.h"
 
 void fscrypt_decrypt_bio(struct bio *bio)
@@ -41,6 +42,52 @@ void fscrypt_decrypt_bio(struct bio *bio)
 }
 EXPORT_SYMBOL(fscrypt_decrypt_bio);
 
+static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
+					      pgoff_t lblk, sector_t pblk,
+					      unsigned int len)
+{
+	const unsigned int blockbits = inode->i_blkbits;
+	const unsigned int blocks_per_page = 1 << (PAGE_SHIFT - blockbits);
+	struct bio *bio;
+	int ret, err = 0;
+	int num_pages = 0;
+
+	/* This always succeeds since __GFP_DIRECT_RECLAIM is set. */
+	bio = bio_alloc(GFP_NOFS, BIO_MAX_PAGES);
+
+	while (len) {
+		unsigned int blocks_this_page = min(len, blocks_per_page);
+		unsigned int bytes_this_page = blocks_this_page << blockbits;
+
+		if (num_pages == 0) {
+			fscrypt_set_bio_crypt_ctx(bio, inode, lblk, GFP_NOFS);
+			bio_set_dev(bio, inode->i_sb->s_bdev);
+			bio->bi_iter.bi_sector =
+					pblk << (blockbits - SECTOR_SHIFT);
+			bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+		}
+		ret = bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0);
+		if (WARN_ON(ret != bytes_this_page)) {
+			err = -EIO;
+			goto out;
+		}
+		num_pages++;
+		len -= blocks_this_page;
+		lblk += blocks_this_page;
+		pblk += blocks_this_page;
+		if (num_pages == BIO_MAX_PAGES || !len) {
+			err = submit_bio_wait(bio);
+			if (err)
+				goto out;
+			bio_reset(bio);
+			num_pages = 0;
+		}
+	}
+out:
+	bio_put(bio);
+	return err;
+}
+
 /**
  * fscrypt_zeroout_range() - zero out a range of blocks in an encrypted file
  * @inode: the file's inode
@@ -75,6 +122,10 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 	if (len == 0)
 		return 0;
 
+	if (fscrypt_inode_uses_inline_crypto(inode))
+		return fscrypt_zeroout_range_inline_crypt(inode, lblk, pblk,
+							  len);
+
 	BUILD_BUG_ON(ARRAY_SIZE(pages) > BIO_MAX_PAGES);
 	nr_pages = min_t(unsigned int, ARRAY_SIZE(pages),
 			 (len + blocks_per_page - 1) >> blocks_per_page_bits);
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 1ecaac7ee3cb8..263bc676c73dd 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -95,7 +95,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
 	DECLARE_CRYPTO_WAIT(wait);
 	struct scatterlist dst, src;
 	struct fscrypt_info *ci = inode->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
+	struct crypto_skcipher *tfm = ci->ci_key.tfm;
 	int res = 0;
 
 	if (WARN_ON_ONCE(len <= 0))
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 4c212442a8f7f..0fca2d7a56453 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -117,7 +117,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
 	struct skcipher_request *req = NULL;
 	DECLARE_CRYPTO_WAIT(wait);
 	const struct fscrypt_info *ci = inode->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
+	struct crypto_skcipher *tfm = ci->ci_key.tfm;
 	union fscrypt_iv iv;
 	struct scatterlist sg;
 	int res;
@@ -170,7 +170,7 @@ static int fname_decrypt(const struct inode *inode,
 	DECLARE_CRYPTO_WAIT(wait);
 	struct scatterlist src_sg, dst_sg;
 	const struct fscrypt_info *ci = inode->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
+	struct crypto_skcipher *tfm = ci->ci_key.tfm;
 	union fscrypt_iv iv;
 	int res;
 
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 9aae851409e55..2032c81a06752 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -14,6 +14,7 @@
 #include <linux/fscrypt.h>
 #include <linux/siphash.h>
 #include <crypto/hash.h>
+#include <linux/blk-crypto.h>
 
 #define CONST_STRLEN(str)	(sizeof(str) - 1)
 
@@ -146,6 +147,20 @@ struct fscrypt_symlink_data {
 	char encrypted_path[1];
 } __packed;
 
+/**
+ * struct fscrypt_prepared_key - a key prepared for actual encryption/decryption
+ * @tfm: crypto API transform object
+ * @blk_key: key for blk-crypto
+ *
+ * Normally only one of the fields will be non-NULL.
+ */
+struct fscrypt_prepared_key {
+	struct crypto_skcipher *tfm;
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+	struct fscrypt_blk_crypto_key *blk_key;
+#endif
+};
+
 /*
  * fscrypt_info - the "encryption key" for an inode
  *
@@ -155,12 +170,20 @@ struct fscrypt_symlink_data {
  */
 struct fscrypt_info {
 
-	/* The actual crypto transform used for encryption and decryption */
-	struct crypto_skcipher *ci_ctfm;
+	/* The key in a form prepared for actual encryption/decryption */
+	struct fscrypt_prepared_key	ci_key;
 
 	/* True if the key should be freed when this fscrypt_info is freed */
 	bool ci_owns_key;
 
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+	/*
+	 * True if this inode will use inline encryption (blk-crypto) instead of
+	 * the traditional filesystem-layer encryption.
+	 */
+	bool ci_inlinecrypt;
+#endif
+
 	/*
 	 * Encryption mode used for this inode.  It corresponds to either the
 	 * contents or filenames encryption mode, depending on the inode type.
@@ -185,7 +208,7 @@ struct fscrypt_info {
 
 	/*
 	 * If non-NULL, then encryption is done using the master key directly
-	 * and ci_ctfm will equal ci_direct_key->dk_ctfm.
+	 * and ci_key will equal ci_direct_key->dk_key.
 	 */
 	struct fscrypt_direct_key *ci_direct_key;
 
@@ -238,6 +261,7 @@ union fscrypt_iv {
 		u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
 	};
 	u8 raw[FSCRYPT_MAX_IV_SIZE];
+	__le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)];
 };
 
 void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
@@ -280,6 +304,76 @@ extern int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context,
 
 extern void fscrypt_destroy_hkdf(struct fscrypt_hkdf *hkdf);
 
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+extern void fscrypt_select_encryption_impl(struct fscrypt_info *ci);
+
+static inline bool
+fscrypt_using_inline_encryption(const struct fscrypt_info *ci)
+{
+	return ci->ci_inlinecrypt;
+}
+
+extern int fscrypt_prepare_inline_crypt_key(
+					struct fscrypt_prepared_key *prep_key,
+					const u8 *raw_key,
+					const struct fscrypt_info *ci);
+
+extern void fscrypt_destroy_inline_crypt_key(
+					struct fscrypt_prepared_key *prep_key);
+
+/*
+ * Check whether the crypto transform or blk-crypto key has been allocated in
+ * @prep_key, depending on which encryption implementation the file will use.
+ */
+static inline bool
+fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key,
+			const struct fscrypt_info *ci)
+{
+	/*
+	 * The READ_ONCE() here pairs with the smp_store_release() in
+	 * fscrypt_prepare_key().  (This only matters for the per-mode keys,
+	 * which are shared by multiple inodes.)
+	 */
+	if (fscrypt_using_inline_encryption(ci))
+		return READ_ONCE(prep_key->blk_key) != NULL;
+	return READ_ONCE(prep_key->tfm) != NULL;
+}
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
+static inline void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+}
+
+static inline bool fscrypt_using_inline_encryption(
+					const struct fscrypt_info *ci)
+{
+	return false;
+}
+
+static inline int
+fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+				 const u8 *raw_key,
+				 const struct fscrypt_info *ci)
+{
+	WARN_ON(1);
+	return -EOPNOTSUPP;
+}
+
+static inline void
+fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
+{
+}
+
+static inline bool
+fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key,
+			const struct fscrypt_info *ci)
+{
+	return READ_ONCE(prep_key->tfm) != NULL;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
 /* keyring.c */
 
 /*
@@ -369,14 +463,11 @@ struct fscrypt_master_key {
 	struct list_head	mk_decrypted_inodes;
 	spinlock_t		mk_decrypted_inodes_lock;
 
-	/* Crypto API transforms for DIRECT_KEY policies, allocated on-demand */
-	struct crypto_skcipher	*mk_direct_tfms[__FSCRYPT_MODE_MAX + 1];
+	/* Per-mode keys for DIRECT_KEY policies, allocated on-demand */
+	struct fscrypt_prepared_key mk_direct_keys[__FSCRYPT_MODE_MAX + 1];
 
-	/*
-	 * Crypto API transforms for filesystem-layer implementation of
-	 * IV_INO_LBLK_64 policies, allocated on-demand.
-	 */
-	struct crypto_skcipher	*mk_iv_ino_lblk_64_tfms[__FSCRYPT_MODE_MAX + 1];
+	/* Per-mode keys for IV_INO_LBLK_64 policies, allocated on-demand */
+	struct fscrypt_prepared_key mk_iv_ino_lblk_64_keys[__FSCRYPT_MODE_MAX + 1];
 
 } __randomize_layout;
 
@@ -433,13 +524,16 @@ struct fscrypt_mode {
 	int keysize;
 	int ivsize;
 	int logged_impl_name;
+	enum blk_crypto_mode_num blk_crypto_mode;
 };
 
 extern struct fscrypt_mode fscrypt_modes[];
 
-extern struct crypto_skcipher *
-fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
-			  const struct inode *inode);
+extern int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
+			       const u8 *raw_key,
+			       const struct fscrypt_info *ci);
+
+extern void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key);
 
 extern int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci,
 					const u8 *raw_key);
diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c
new file mode 100644
index 0000000000000..866398f27f062
--- /dev/null
+++ b/fs/crypto/inline_crypt.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Inline encryption support for fscrypt
+ *
+ * Copyright 2019 Google LLC
+ */
+
+/*
+ * With "inline encryption", the block layer handles the decryption/encryption
+ * as part of the bio, instead of the filesystem doing the crypto itself via
+ * crypto API.  See Documentation/block/inline-encryption.rst.  fscrypt still
+ * provides the key and IV to use.
+ */
+
+#include <linux/blk-crypto.h>
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/sched/mm.h>
+
+#include "fscrypt_private.h"
+
+struct fscrypt_blk_crypto_key {
+	struct blk_crypto_key base;
+	int num_devs;
+	struct request_queue *devs[];
+};
+
+/* Enable inline encryption for this file if supported. */
+void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+	const struct inode *inode = ci->ci_inode;
+	struct super_block *sb = inode->i_sb;
+
+	/* The file must need contents encryption, not filenames encryption */
+	if (!fscrypt_needs_contents_encryption(inode))
+		return;
+
+	/* blk-crypto must implement the needed encryption algorithm */
+	if (ci->ci_mode->blk_crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
+		return;
+
+	/* The filesystem must be mounted with -o inlinecrypt */
+	if (!(sb->s_flags & SB_INLINECRYPT))
+		return;
+
+	ci->ci_inlinecrypt = true;
+}
+
+int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+				     const u8 *raw_key,
+				     const struct fscrypt_info *ci)
+{
+	const struct inode *inode = ci->ci_inode;
+	struct super_block *sb = inode->i_sb;
+	enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode;
+	unsigned int dun_bytes;
+	int num_devs = 1;
+	int queue_refs = 0;
+	struct fscrypt_blk_crypto_key *blk_key;
+	int err;
+	int i;
+	unsigned int flags;
+
+	if (sb->s_cop->get_num_devices)
+		num_devs = sb->s_cop->get_num_devices(sb);
+	if (WARN_ON(num_devs < 1))
+		return -EINVAL;
+
+	blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_NOFS);
+	if (!blk_key)
+		return -ENOMEM;
+
+	blk_key->num_devs = num_devs;
+	if (num_devs == 1)
+		blk_key->devs[0] = bdev_get_queue(sb->s_bdev);
+	else
+		sb->s_cop->get_devices(sb, blk_key->devs);
+
+	dun_bytes = 8;
+	if (fscrypt_policy_flags(&ci->ci_policy) &
+						FSCRYPT_POLICY_FLAG_DIRECT_KEY)
+		dun_bytes += FS_KEY_DERIVATION_NONCE_SIZE;
+
+	err = blk_crypto_init_key(&blk_key->base, raw_key, crypto_mode,
+				  dun_bytes, sb->s_blocksize);
+	if (err) {
+		fscrypt_err(inode, "error %d initializing blk-crypto key", err);
+		goto fail;
+	}
+
+	/*
+	 * We have to start using blk-crypto on all the filesystem's devices.
+	 * We also have to save all the request_queue's for later so that the
+	 * key can be evicted from them.  This is needed because some keys
+	 * aren't destroyed until after the filesystem was already unmounted
+	 * (namely, the per-mode keys in struct fscrypt_master_key).
+	 */
+	for (i = 0; i < num_devs; i++) {
+		if (!blk_get_queue(blk_key->devs[i])) {
+			fscrypt_err(inode, "couldn't get request_queue");
+			err = -EAGAIN;
+			goto fail;
+		}
+		queue_refs++;
+
+		flags = memalloc_nofs_save();
+		err = blk_crypto_start_using_key(&blk_key->base,
+						 blk_key->devs[i]);
+		memalloc_nofs_restore(flags);
+		if (err) {
+			fscrypt_err(inode,
+				    "error %d starting to use blk-crypto", err);
+			goto fail;
+		}
+	}
+	/*
+	 * Pairs with READ_ONCE() in fscrypt_is_key_prepared().  (Only matters
+	 * for the per-mode keys, which are shared by multiple inodes.)
+	 */
+	smp_store_release(&prep_key->blk_key, blk_key);
+	return 0;
+
+fail:
+	for (i = 0; i < queue_refs; i++)
+		blk_put_queue(blk_key->devs[i]);
+	kzfree(blk_key);
+	return err;
+}
+
+void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
+{
+	struct fscrypt_blk_crypto_key *blk_key = prep_key->blk_key;
+	int i;
+
+	if (blk_key) {
+		for (i = 0; i < blk_key->num_devs; i++) {
+			blk_crypto_evict_key(blk_key->devs[i], &blk_key->base);
+			blk_put_queue(blk_key->devs[i]);
+		}
+		kzfree(blk_key);
+	}
+}
+
+/**
+ * fscrypt_inode_uses_inline_crypto - test whether an inode uses inline
+ *				      encryption
+ * @inode: an inode
+ *
+ * Return: true if the inode requires file contents encryption and if the
+ *	   encryption should be done in the block layer via blk-crypto rather
+ *	   than in the filesystem layer.
+ */
+bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+	return fscrypt_needs_contents_encryption(inode) &&
+	       inode->i_crypt_info->ci_inlinecrypt;
+}
+EXPORT_SYMBOL_GPL(fscrypt_inode_uses_inline_crypto);
+
+/**
+ * fscrypt_inode_uses_fs_layer_crypto - test whether an inode uses fs-layer
+ *					encryption
+ * @inode: an inode
+ *
+ * Return: true if the inode requires file contents encryption and if the
+ *	   encryption should be done in the filesystem layer rather than in the
+ *	   block layer via blk-crypto.
+ */
+bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
+{
+	return fscrypt_needs_contents_encryption(inode) &&
+	       !inode->i_crypt_info->ci_inlinecrypt;
+}
+EXPORT_SYMBOL_GPL(fscrypt_inode_uses_fs_layer_crypto);
+
+static void fscrypt_generate_dun(const struct fscrypt_info *ci, u64 lblk_num,
+				 u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE])
+{
+	union fscrypt_iv iv;
+	int i;
+
+	fscrypt_generate_iv(&iv, lblk_num, ci);
+
+	BUILD_BUG_ON(FSCRYPT_MAX_IV_SIZE > BLK_CRYPTO_MAX_IV_SIZE);
+	memset(dun, 0, BLK_CRYPTO_MAX_IV_SIZE);
+	for (i = 0; i < ci->ci_mode->ivsize/sizeof(dun[0]); i++)
+		dun[i] = le64_to_cpu(iv.dun[i]);
+}
+
+/**
+ * fscrypt_set_bio_crypt_ctx - prepare a file contents bio for inline encryption
+ * @bio: a bio which will eventually be submitted to the file
+ * @inode: the file's inode
+ * @first_lblk: the first file logical block number in the I/O
+ * @gfp_mask: memory allocation flags - these must be a waiting mask so that
+ *					bio_crypt_set_ctx can't fail.
+ *
+ * If the contents of the file should be encrypted (or decrypted) with inline
+ * encryption, then assign the appropriate encryption context to the bio.
+ *
+ * Normally the bio should be newly allocated (i.e. no pages added yet), as
+ * otherwise fscrypt_mergeable_bio() won't work as intended.
+ *
+ * The encryption context will be freed automatically when the bio is freed.
+ */
+void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
+			       u64 first_lblk, gfp_t gfp_mask)
+{
+	const struct fscrypt_info *ci = inode->i_crypt_info;
+	u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+
+	if (!fscrypt_inode_uses_inline_crypto(inode))
+		return;
+
+	fscrypt_generate_dun(ci, first_lblk, dun);
+	bio_crypt_set_ctx(bio, &ci->ci_key.blk_key->base, dun, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx);
+
+/* Extract the inode and logical block number from a buffer_head. */
+static bool bh_get_inode_and_lblk_num(const struct buffer_head *bh,
+				      const struct inode **inode_ret,
+				      u64 *lblk_num_ret)
+{
+	struct page *page = bh->b_page;
+	const struct address_space *mapping;
+	const struct inode *inode;
+
+	/*
+	 * The ext4 journal (jbd2) can submit a buffer_head it directly created
+	 * for a non-pagecache page.  fscrypt doesn't care about these.
+	 */
+	mapping = page_mapping(page);
+	if (!mapping)
+		return false;
+	inode = mapping->host;
+
+	*inode_ret = inode;
+	*lblk_num_ret = ((u64)page->index << (PAGE_SHIFT - inode->i_blkbits)) +
+			(bh_offset(bh) >> inode->i_blkbits);
+	return true;
+}
+
+/**
+ * fscrypt_set_bio_crypt_ctx_bh - prepare a file contents bio for inline
+ *				  encryption
+ * @bio: a bio which will eventually be submitted to the file
+ * @first_bh: the first buffer_head for which I/O will be submitted
+ * @gfp_mask: memory allocation flags
+ *
+ * Same as fscrypt_set_bio_crypt_ctx(), except this takes a buffer_head instead
+ * of an inode and block number directly.
+ */
+void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+				  const struct buffer_head *first_bh,
+				  gfp_t gfp_mask)
+{
+	const struct inode *inode;
+	u64 first_lblk;
+
+	if (bh_get_inode_and_lblk_num(first_bh, &inode, &first_lblk))
+		fscrypt_set_bio_crypt_ctx(bio, inode, first_lblk, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh);
+
+/**
+ * fscrypt_mergeable_bio - test whether data can be added to a bio
+ * @bio: the bio being built up
+ * @inode: the inode for the next part of the I/O
+ * @next_lblk: the next file logical block number in the I/O
+ *
+ * When building a bio which may contain data which should undergo inline
+ * encryption (or decryption) via fscrypt, filesystems should call this function
+ * to ensure that the resulting bio contains only logically contiguous data.
+ * This will return false if the next part of the I/O cannot be merged with the
+ * bio because either the encryption key would be different or the encryption
+ * data unit numbers would be discontiguous.
+ *
+ * fscrypt_set_bio_crypt_ctx() must have already been called on the bio.
+ *
+ * Return: true iff the I/O is mergeable
+ */
+bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+			   u64 next_lblk)
+{
+	const struct bio_crypt_ctx *bc = bio->bi_crypt_context;
+	u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+
+	if (!!bc != fscrypt_inode_uses_inline_crypto(inode))
+		return false;
+	if (!bc)
+		return true;
+
+	/*
+	 * Comparing the key pointers is good enough, as all I/O for each key
+	 * uses the same pointer.  I.e., there's currently no need to support
+	 * merging requests where the keys are the same but the pointers differ.
+	 */
+	if (bc->bc_key != &inode->i_crypt_info->ci_key.blk_key->base)
+		return false;
+
+	fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun);
+	return bio_crypt_dun_is_contiguous(bc, bio->bi_iter.bi_size, next_dun);
+}
+EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio);
+
+/**
+ * fscrypt_mergeable_bio_bh - test whether data can be added to a bio
+ * @bio: the bio being built up
+ * @next_bh: the next buffer_head for which I/O will be submitted
+ *
+ * Same as fscrypt_mergeable_bio(), except this takes a buffer_head instead of
+ * an inode and block number directly.
+ *
+ * Return: true iff the I/O is mergeable
+ */
+bool fscrypt_mergeable_bio_bh(struct bio *bio,
+			      const struct buffer_head *next_bh)
+{
+	const struct inode *inode;
+	u64 next_lblk;
+
+	if (!bh_get_inode_and_lblk_num(next_bh, &inode, &next_lblk))
+		return !bio->bi_crypt_context;
+
+	return fscrypt_mergeable_bio(bio, inode, next_lblk);
+}
+EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh);
diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c
index ab41b25d4fa1b..d8ab33f631ba2 100644
--- a/fs/crypto/keyring.c
+++ b/fs/crypto/keyring.c
@@ -44,8 +44,8 @@ static void free_master_key(struct fscrypt_master_key *mk)
 	wipe_master_key_secret(&mk->mk_secret);
 
 	for (i = 0; i <= __FSCRYPT_MODE_MAX; i++) {
-		crypto_free_skcipher(mk->mk_direct_tfms[i]);
-		crypto_free_skcipher(mk->mk_iv_ino_lblk_64_tfms[i]);
+		fscrypt_destroy_prepared_key(&mk->mk_direct_keys[i]);
+		fscrypt_destroy_prepared_key(&mk->mk_iv_ino_lblk_64_keys[i]);
 	}
 
 	key_put(mk->mk_users);
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 08c9f216a54dd..fc5a18adb0d6b 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -19,6 +19,7 @@ struct fscrypt_mode fscrypt_modes[] = {
 		.cipher_str = "xts(aes)",
 		.keysize = 64,
 		.ivsize = 16,
+		.blk_crypto_mode = BLK_ENCRYPTION_MODE_AES_256_XTS,
 	},
 	[FSCRYPT_MODE_AES_256_CTS] = {
 		.friendly_name = "AES-256-CTS-CBC",
@@ -31,6 +32,7 @@ struct fscrypt_mode fscrypt_modes[] = {
 		.cipher_str = "essiv(cbc(aes),sha256)",
 		.keysize = 16,
 		.ivsize = 16,
+		.blk_crypto_mode = BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV,
 	},
 	[FSCRYPT_MODE_AES_128_CTS] = {
 		.friendly_name = "AES-128-CTS-CBC",
@@ -43,6 +45,7 @@ struct fscrypt_mode fscrypt_modes[] = {
 		.cipher_str = "adiantum(xchacha12,aes)",
 		.keysize = 32,
 		.ivsize = 32,
+		.blk_crypto_mode = BLK_ENCRYPTION_MODE_ADIANTUM,
 	},
 };
 
@@ -62,9 +65,9 @@ select_encryption_mode(const union fscrypt_policy *policy,
 }
 
 /* Create a symmetric cipher object for the given encryption mode and key */
-struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode,
-						  const u8 *raw_key,
-						  const struct inode *inode)
+static struct crypto_skcipher *
+fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
+			  const struct inode *inode)
 {
 	struct crypto_skcipher *tfm;
 	int err;
@@ -107,30 +110,55 @@ struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode,
 	return ERR_PTR(err);
 }
 
-/* Given a per-file encryption key, set up the file's crypto transform object */
-int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key)
+/*
+ * Prepare the crypto transform object or blk-crypto key in @prep_key, given the
+ * raw key, encryption mode, and flag indicating which encryption implementation
+ * (fs-layer or blk-crypto) will be used.
+ */
+int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
+			const u8 *raw_key, const struct fscrypt_info *ci)
 {
 	struct crypto_skcipher *tfm;
 
+	if (fscrypt_using_inline_encryption(ci))
+		return fscrypt_prepare_inline_crypt_key(prep_key, raw_key, ci);
+
 	tfm = fscrypt_allocate_skcipher(ci->ci_mode, raw_key, ci->ci_inode);
 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);
+	/*
+	 * Pairs with READ_ONCE() in fscrypt_is_key_prepared().  (Only matters
+	 * for the per-mode keys, which are shared by multiple inodes.)
+	 */
+	smp_store_release(&prep_key->tfm, tfm);
+	return 0;
+}
+
+/* Destroy a crypto transform object and/or blk-crypto key. */
+void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key)
+{
+	crypto_free_skcipher(prep_key->tfm);
+	fscrypt_destroy_inline_crypt_key(prep_key);
+}
 
-	ci->ci_ctfm = tfm;
+/* Given a per-file encryption key, set up the file's crypto transform object */
+int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key)
+{
 	ci->ci_owns_key = true;
-	return 0;
+	return fscrypt_prepare_key(&ci->ci_key, raw_key, ci);
 }
 
 static int setup_per_mode_enc_key(struct fscrypt_info *ci,
 				  struct fscrypt_master_key *mk,
-				  struct crypto_skcipher **tfms,
+				  struct fscrypt_prepared_key *keys,
 				  u8 hkdf_context, bool include_fs_uuid)
 {
+	static DEFINE_MUTEX(mode_key_setup_mutex);
 	const struct inode *inode = ci->ci_inode;
 	const struct super_block *sb = inode->i_sb;
 	struct fscrypt_mode *mode = ci->ci_mode;
 	const u8 mode_num = mode - fscrypt_modes;
-	struct crypto_skcipher *tfm, *prev_tfm;
+	struct fscrypt_prepared_key *prep_key;
 	u8 mode_key[FSCRYPT_MAX_KEY_SIZE];
 	u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)];
 	unsigned int hkdf_infolen = 0;
@@ -139,10 +167,16 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci,
 	if (WARN_ON(mode_num > __FSCRYPT_MODE_MAX))
 		return -EINVAL;
 
-	/* pairs with cmpxchg() below */
-	tfm = READ_ONCE(tfms[mode_num]);
-	if (likely(tfm != NULL))
-		goto done;
+	prep_key = &keys[mode_num];
+	if (fscrypt_is_key_prepared(prep_key, ci)) {
+		ci->ci_key = *prep_key;
+		return 0;
+	}
+
+	mutex_lock(&mode_key_setup_mutex);
+
+	if (fscrypt_is_key_prepared(prep_key, ci))
+		goto done_unlock;
 
 	BUILD_BUG_ON(sizeof(mode_num) != 1);
 	BUILD_BUG_ON(sizeof(sb->s_uuid) != 16);
@@ -157,21 +191,17 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci,
 				  hkdf_context, hkdf_info, hkdf_infolen,
 				  mode_key, mode->keysize);
 	if (err)
-		return err;
-	tfm = fscrypt_allocate_skcipher(mode, mode_key, inode);
+		goto out_unlock;
+	err = fscrypt_prepare_key(prep_key, mode_key, ci);
 	memzero_explicit(mode_key, mode->keysize);
-	if (IS_ERR(tfm))
-		return PTR_ERR(tfm);
-
-	/* pairs with READ_ONCE() above */
-	prev_tfm = cmpxchg(&tfms[mode_num], NULL, tfm);
-	if (prev_tfm != NULL) {
-		crypto_free_skcipher(tfm);
-		tfm = prev_tfm;
-	}
-done:
-	ci->ci_ctfm = tfm;
-	return 0;
+	if (err)
+		goto out_unlock;
+done_unlock:
+	ci->ci_key = *prep_key;
+	err = 0;
+out_unlock:
+	mutex_unlock(&mode_key_setup_mutex);
+	return err;
 }
 
 int fscrypt_derive_dirhash_key(struct fscrypt_info *ci,
@@ -203,7 +233,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
 		 * encryption key.  This ensures that the master key is
 		 * consistently used only for HKDF, avoiding key reuse issues.
 		 */
-		err = setup_per_mode_enc_key(ci, mk, mk->mk_direct_tfms,
+		err = setup_per_mode_enc_key(ci, mk, mk->mk_direct_keys,
 					     HKDF_CONTEXT_DIRECT_KEY, false);
 	} else if (ci->ci_policy.v2.flags &
 		   FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) {
@@ -213,7 +243,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
 		 * the IVs.  This format is optimized for use with inline
 		 * encryption hardware compliant with the UFS or eMMC standards.
 		 */
-		err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_64_tfms,
+		err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_64_keys,
 					     HKDF_CONTEXT_IV_INO_LBLK_64_KEY,
 					     true);
 	} else {
@@ -261,6 +291,8 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
 	struct fscrypt_key_specifier mk_spec;
 	int err;
 
+	fscrypt_select_encryption_impl(ci);
+
 	switch (ci->ci_policy.version) {
 	case FSCRYPT_POLICY_V1:
 		mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
@@ -353,7 +385,7 @@ static void put_crypt_info(struct fscrypt_info *ci)
 	if (ci->ci_direct_key)
 		fscrypt_put_direct_key(ci->ci_direct_key);
 	else if (ci->ci_owns_key)
-		crypto_free_skcipher(ci->ci_ctfm);
+		fscrypt_destroy_prepared_key(&ci->ci_key);
 
 	key = ci->ci_master_key;
 	if (key) {
diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c
index 801b48c0cd7f3..59c520b200cb0 100644
--- a/fs/crypto/keysetup_v1.c
+++ b/fs/crypto/keysetup_v1.c
@@ -146,7 +146,7 @@ struct fscrypt_direct_key {
 	struct hlist_node		dk_node;
 	refcount_t			dk_refcount;
 	const struct fscrypt_mode	*dk_mode;
-	struct crypto_skcipher		*dk_ctfm;
+	struct fscrypt_prepared_key	dk_key;
 	u8				dk_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
 	u8				dk_raw[FSCRYPT_MAX_KEY_SIZE];
 };
@@ -154,7 +154,7 @@ struct fscrypt_direct_key {
 static void free_direct_key(struct fscrypt_direct_key *dk)
 {
 	if (dk) {
-		crypto_free_skcipher(dk->dk_ctfm);
+		fscrypt_destroy_prepared_key(&dk->dk_key);
 		kzfree(dk);
 	}
 }
@@ -199,6 +199,8 @@ find_or_insert_direct_key(struct fscrypt_direct_key *to_insert,
 			continue;
 		if (ci->ci_mode != dk->dk_mode)
 			continue;
+		if (!fscrypt_is_key_prepared(&dk->dk_key, ci))
+			continue;
 		if (crypto_memneq(raw_key, dk->dk_raw, ci->ci_mode->keysize))
 			continue;
 		/* using existing tfm with same (descriptor, mode, raw_key) */
@@ -231,13 +233,9 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key)
 		return ERR_PTR(-ENOMEM);
 	refcount_set(&dk->dk_refcount, 1);
 	dk->dk_mode = ci->ci_mode;
-	dk->dk_ctfm = fscrypt_allocate_skcipher(ci->ci_mode, raw_key,
-						ci->ci_inode);
-	if (IS_ERR(dk->dk_ctfm)) {
-		err = PTR_ERR(dk->dk_ctfm);
-		dk->dk_ctfm = NULL;
+	err = fscrypt_prepare_key(&dk->dk_key, raw_key, ci);
+	if (err)
 		goto err_free_dk;
-	}
 	memcpy(dk->dk_descriptor, ci->ci_policy.v1.master_key_descriptor,
 	       FSCRYPT_KEY_DESCRIPTOR_SIZE);
 	memcpy(dk->dk_raw, raw_key, ci->ci_mode->keysize);
@@ -259,7 +257,7 @@ static int setup_v1_file_key_direct(struct fscrypt_info *ci,
 	if (IS_ERR(dk))
 		return PTR_ERR(dk);
 	ci->ci_direct_key = dk;
-	ci->ci_ctfm = dk->dk_ctfm;
+	ci->ci_key = dk->dk_key;
 	return 0;
 }
 
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 556f4adf5dc58..1d9810eb88b11 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -64,6 +64,9 @@ struct fscrypt_operations {
 	bool (*has_stable_inodes)(struct super_block *sb);
 	void (*get_ino_and_lblk_bits)(struct super_block *sb,
 				      int *ino_bits_ret, int *lblk_bits_ret);
+	int (*get_num_devices)(struct super_block *sb);
+	void (*get_devices)(struct super_block *sb,
+			    struct request_queue **devs);
 };
 
 static inline bool fscrypt_has_encryption_key(const struct inode *inode)
@@ -497,6 +500,60 @@ static inline void fscrypt_set_ops(struct super_block *sb,
 
 #endif	/* !CONFIG_FS_ENCRYPTION */
 
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+extern bool fscrypt_inode_uses_inline_crypto(const struct inode *inode);
+
+extern bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode);
+
+extern void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+				      const struct inode *inode,
+				      u64 first_lblk, gfp_t gfp_mask);
+
+extern void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+					 const struct buffer_head *first_bh,
+					 gfp_t gfp_mask);
+
+extern bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+				  u64 next_lblk);
+
+extern bool fscrypt_mergeable_bio_bh(struct bio *bio,
+				     const struct buffer_head *next_bh);
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+static inline bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+	return false;
+}
+
+static inline bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
+{
+	return fscrypt_needs_contents_encryption(inode);
+}
+
+static inline void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+					     const struct inode *inode,
+					     u64 first_lblk, gfp_t gfp_mask) { }
+
+static inline void fscrypt_set_bio_crypt_ctx_bh(
+					 struct bio *bio,
+					 const struct buffer_head *first_bh,
+					 gfp_t gfp_mask) { }
+
+static inline bool fscrypt_mergeable_bio(struct bio *bio,
+					 const struct inode *inode,
+					 u64 next_lblk)
+{
+	return true;
+}
+
+static inline bool fscrypt_mergeable_bio_bh(struct bio *bio,
+					    const struct buffer_head *next_bh)
+{
+	return true;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
 /**
  * fscrypt_require_key - require an inode's encryption key
  * @inode: the inode we need the key for
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 10/11] f2fs: add inline encryption support
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (8 preceding siblings ...)
  2020-03-26  3:07 ` [PATCH v9 09/11] fscrypt: add inline encryption support Satya Tangirala
@ 2020-03-26  3:07 ` " Satya Tangirala
  2020-03-26  3:07 ` [PATCH v9 11/11] ext4: " Satya Tangirala
  2020-03-26  3:32 ` [PATCH v9 00/11] Inline Encryption Support Eric Biggers
  11 siblings, 0 replies; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:07 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Satya Tangirala,
	Eric Biggers

Wire up f2fs 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.

- 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.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
 Documentation/filesystems/f2fs.txt |  6 +++
 fs/f2fs/compress.c                 |  2 +-
 fs/f2fs/data.c                     | 68 +++++++++++++++++++++++++-----
 fs/f2fs/super.c                    | 32 ++++++++++++++
 4 files changed, 97 insertions(+), 11 deletions(-)

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 4eb3e2ddd00ec..300d5843cbe4a 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -246,6 +246,12 @@ 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
+                       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
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index d8a64be90a501..6ae313ea54323 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -775,7 +775,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 		.need_lock = LOCK_RETRY,
 		.io_type = io_type,
 		.io_wbc = wbc,
-		.encrypted = f2fs_encrypted_file(cc->inode),
+		.encrypted = fscrypt_inode_uses_fs_layer_crypto(cc->inode),
 	};
 	struct dnode_of_data dn;
 	struct node_info ni;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b27b721079116..75dda67354881 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -14,6 +14,7 @@
 #include <linux/pagevec.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
+#include <linux/blk-crypto.h>
 #include <linux/swap.h>
 #include <linux/prefetch.h>
 #include <linux/uio.h>
@@ -436,6 +437,33 @@ static struct bio *__bio_alloc(struct f2fs_io_info *fio, int npages)
 	return bio;
 }
 
+static void f2fs_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
+				  pgoff_t first_idx,
+				  const struct f2fs_io_info *fio,
+				  gfp_t gfp_mask)
+{
+	/*
+	 * The f2fs garbage collector sets ->encrypted_page when it wants to
+	 * read/write raw data without encryption.
+	 */
+	if (!fio || !fio->encrypted_page)
+		fscrypt_set_bio_crypt_ctx(bio, inode, first_idx, gfp_mask);
+}
+
+static bool f2fs_crypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+				     pgoff_t next_idx,
+				     const struct f2fs_io_info *fio)
+{
+	/*
+	 * The f2fs garbage collector sets ->encrypted_page when it wants to
+	 * read/write raw data without encryption.
+	 */
+	if (fio && fio->encrypted_page)
+		return !bio_has_crypt_ctx(bio);
+
+	return fscrypt_mergeable_bio(bio, inode, next_idx);
+}
+
 static inline void __submit_bio(struct f2fs_sb_info *sbi,
 				struct bio *bio, enum page_type type)
 {
@@ -632,6 +660,9 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 	/* Allocate a new bio */
 	bio = __bio_alloc(fio, 1);
 
+	f2fs_set_bio_crypt_ctx(bio, fio->page->mapping->host,
+			       fio->page->index, fio, GFP_NOIO);
+
 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 		bio_put(bio);
 		return -EFAULT;
@@ -820,12 +851,16 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
 	trace_f2fs_submit_page_bio(page, fio);
 	f2fs_trace_ios(fio, 0);
 
-	if (bio && !page_is_mergeable(fio->sbi, bio, *fio->last_block,
-						fio->new_blkaddr))
+	if (bio && (!page_is_mergeable(fio->sbi, bio, *fio->last_block,
+				       fio->new_blkaddr) ||
+		    !f2fs_crypt_mergeable_bio(bio, fio->page->mapping->host,
+					      fio->page->index, fio)))
 		f2fs_submit_merged_ipu_write(fio->sbi, &bio, NULL);
 alloc_new:
 	if (!bio) {
 		bio = __bio_alloc(fio, BIO_MAX_PAGES);
+		f2fs_set_bio_crypt_ctx(bio, fio->page->mapping->host,
+				       fio->page->index, fio, GFP_NOIO);
 		bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
 		add_bio_entry(fio->sbi, bio, page, fio->temp);
@@ -882,8 +917,11 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 
 	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
 
-	if (io->bio && !io_is_mergeable(sbi, io->bio, io, fio,
-			io->last_block_in_bio, fio->new_blkaddr))
+	if (io->bio &&
+	    (!io_is_mergeable(sbi, io->bio, io, fio, io->last_block_in_bio,
+			      fio->new_blkaddr) ||
+	     !f2fs_crypt_mergeable_bio(io->bio, fio->page->mapping->host,
+				       fio->page->index, fio)))
 		__submit_merged_bio(io);
 alloc_new:
 	if (io->bio == NULL) {
@@ -895,6 +933,8 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 			goto skip;
 		}
 		io->bio = __bio_alloc(fio, BIO_MAX_PAGES);
+		f2fs_set_bio_crypt_ctx(io->bio, fio->page->mapping->host,
+				       fio->page->index, fio, GFP_NOIO);
 		io->fio = *fio;
 	}
 
@@ -938,11 +978,14 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
 	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
 	if (!bio)
 		return ERR_PTR(-ENOMEM);
+
+	f2fs_set_bio_crypt_ctx(bio, inode, first_idx, NULL, GFP_NOFS);
+
 	f2fs_target_device(sbi, blkaddr, bio);
 	bio->bi_end_io = f2fs_read_end_io;
 	bio_set_op_attrs(bio, REQ_OP_READ, op_flag);
 
-	if (f2fs_encrypted_file(inode))
+	if (fscrypt_inode_uses_fs_layer_crypto(inode))
 		post_read_steps |= 1 << STEP_DECRYPT;
 	if (f2fs_compressed_file(inode))
 		post_read_steps |= 1 << STEP_DECOMPRESS;
@@ -1972,8 +2015,9 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
 	 * This page will go to BIO.  Do we need to send this
 	 * BIO off first?
 	 */
-	if (bio && !page_is_mergeable(F2FS_I_SB(inode), bio,
-				*last_block_in_bio, block_nr)) {
+	if (bio && (!page_is_mergeable(F2FS_I_SB(inode), bio,
+				       *last_block_in_bio, block_nr) ||
+		    !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
 submit_and_realloc:
 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
 		bio = NULL;
@@ -2099,8 +2143,9 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 		blkaddr = datablock_addr(dn.inode, dn.node_page,
 						dn.ofs_in_node + i + 1);
 
-		if (bio && !page_is_mergeable(sbi, bio,
-					*last_block_in_bio, blkaddr)) {
+		if (bio && (!page_is_mergeable(sbi, bio,
+					*last_block_in_bio, blkaddr) ||
+		    !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
 submit_and_realloc:
 			__submit_bio(sbi, bio, DATA);
 			bio = NULL;
@@ -2319,6 +2364,9 @@ int f2fs_encrypt_one_page(struct f2fs_io_info *fio)
 	/* wait for GCed page writeback via META_MAPPING */
 	f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
 
+	if (fscrypt_inode_uses_inline_crypto(inode))
+		return 0;
+
 retry_encrypt:
 	fio->encrypted_page = fscrypt_encrypt_pagecache_blocks(page,
 					PAGE_SIZE, 0, gfp_flags);
@@ -2492,7 +2540,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
 			f2fs_unlock_op(fio->sbi);
 		err = f2fs_inplace_write_data(fio);
 		if (err) {
-			if (f2fs_encrypted_file(inode))
+			if (fscrypt_inode_uses_fs_layer_crypto(inode))
 				fscrypt_finalize_bounce_page(&fio->encrypted_page);
 			if (PageWriteback(page))
 				end_page_writeback(page);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a432dfee2..8c55a017d826b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -137,6 +137,7 @@ enum {
 	Opt_alloc,
 	Opt_fsync,
 	Opt_test_dummy_encryption,
+	Opt_inlinecrypt,
 	Opt_checkpoint_disable,
 	Opt_checkpoint_disable_cap,
 	Opt_checkpoint_disable_cap_perc,
@@ -202,6 +203,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_alloc, "alloc_mode=%s"},
 	{Opt_fsync, "fsync_mode=%s"},
 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
+	{Opt_inlinecrypt, "inlinecrypt"},
 	{Opt_checkpoint_disable, "checkpoint=disable"},
 	{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
 	{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
@@ -790,6 +792,13 @@ static int parse_options(struct super_block *sb, char *options)
 			f2fs_info(sbi, "Test dummy encryption mode enabled");
 #else
 			f2fs_info(sbi, "Test dummy encryption mount option ignored");
+#endif
+			break;
+		case Opt_inlinecrypt:
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+			sb->s_flags |= SB_INLINECRYPT;
+#else
+			f2fs_info(sbi, "inline encryption not supported");
 #endif
 			break;
 		case Opt_checkpoint_disable_cap_perc:
@@ -1574,6 +1583,8 @@ static void default_options(struct f2fs_sb_info *sbi)
 	F2FS_OPTION(sbi).compress_log_size = MIN_COMPRESS_LOG_SIZE;
 	F2FS_OPTION(sbi).compress_ext_cnt = 0;
 
+	sbi->sb->s_flags &= ~SB_INLINECRYPT;
+
 	set_opt(sbi, BG_GC);
 	set_opt(sbi, INLINE_XATTR);
 	set_opt(sbi, INLINE_DATA);
@@ -2415,6 +2426,25 @@ static void f2fs_get_ino_and_lblk_bits(struct super_block *sb,
 	*lblk_bits_ret = 8 * sizeof(block_t);
 }
 
+static int f2fs_get_num_devices(struct super_block *sb)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (f2fs_is_multi_device(sbi))
+		return sbi->s_ndevs;
+	return 1;
+}
+
+static void f2fs_get_devices(struct super_block *sb,
+			     struct request_queue **devs)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	int i;
+
+	for (i = 0; i < sbi->s_ndevs; i++)
+		devs[i] = bdev_get_queue(FDEV(i).bdev);
+}
+
 static const struct fscrypt_operations f2fs_cryptops = {
 	.key_prefix		= "f2fs:",
 	.get_context		= f2fs_get_context,
@@ -2424,6 +2454,8 @@ static const struct fscrypt_operations f2fs_cryptops = {
 	.max_namelen		= F2FS_NAME_LEN,
 	.has_stable_inodes	= f2fs_has_stable_inodes,
 	.get_ino_and_lblk_bits	= f2fs_get_ino_and_lblk_bits,
+	.get_num_devices	= f2fs_get_num_devices,
+	.get_devices		= f2fs_get_devices,
 };
 #endif
 
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v9 11/11] ext4: add inline encryption support
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (9 preceding siblings ...)
  2020-03-26  3:07 ` [PATCH v9 10/11] f2fs: " Satya Tangirala
@ 2020-03-26  3:07 ` " Satya Tangirala
  2020-03-26  3:32 ` [PATCH v9 00/11] Inline Encryption Support Eric Biggers
  11 siblings, 0 replies; 22+ messages in thread
From: Satya Tangirala @ 2020-03-26  3:07 UTC (permalink / raw)
  To: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4
  Cc: Barani Muthukumaran, Kuohong Wang, Kim Boojin, Eric Biggers,
	Satya Tangirala

From: Eric Biggers <ebiggers@google.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@google.com>
Co-developed-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
 Documentation/admin-guide/ext4.rst |  6 ++++++
 fs/buffer.c                        |  7 ++++---
 fs/ext4/inode.c                    |  4 ++--
 fs/ext4/page-io.c                  |  6 ++++--
 fs/ext4/readpage.c                 | 11 ++++++++---
 fs/ext4/super.c                    |  9 +++++++++
 6 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst
index 9443fcef18760..ed997e3766781 100644
--- a/Documentation/admin-guide/ext4.rst
+++ b/Documentation/admin-guide/ext4.rst
@@ -395,6 +395,12 @@ When mounting an ext4 filesystem, the following option are accepted:
         Documentation/filesystems/dax.txt.  Note that this option is
         incompatible with data=journal.
 
+  inlinecrypt
+        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 b8d28370cfd7f..226f1784eda74 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -331,9 +331,8 @@ 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) {
@@ -3085,6 +3084,8 @@ 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 fa0ff78dc033f..5714ff6395a1c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1089,7 +1089,7 @@ 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;
 
@@ -3720,7 +3720,7 @@ 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 68b39e75446a1..0757145a31b26 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -404,6 +404,7 @@ 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;
@@ -420,7 +421,8 @@ 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);
 	}
@@ -508,7 +510,7 @@ 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 c1769afbf7995..68eac0aeffad3 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))
@@ -232,6 +232,7 @@ 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;
@@ -264,7 +265,8 @@ 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;
@@ -364,7 +366,8 @@ 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:
 			submit_bio(bio);
 			bio = NULL;
@@ -376,6 +379,8 @@ int ext4_mpage_readpages(struct address_space *mapping,
 			 */
 			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 0c7c4adb664ec..2054da2ddde42 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1514,6 +1514,7 @@ 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,
@@ -1611,6 +1612,7 @@ static const match_table_t tokens = {
 	{Opt_noinit_itable, "noinit_itable"},
 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
 	{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 */
@@ -1898,6 +1900,13 @@ 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++)
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 00/11] Inline Encryption Support
  2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
                   ` (10 preceding siblings ...)
  2020-03-26  3:07 ` [PATCH v9 11/11] ext4: " Satya Tangirala
@ 2020-03-26  3:32 ` Eric Biggers
  11 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  3:32 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:51PM -0700, Satya Tangirala wrote:
> This patch series adds support for Inline Encryption to the block layer,
> UFS, fscrypt, f2fs and ext4.
> 

This patch series can also be retrieved from

        Repo: https://git.kernel.org/pub/scm/fs/fscrypt/fscrypt.git
        Tag: inline-encryption-v9

I based it on v5.6-rc2 (same base commit as v7 and v8) since it still applies
cleanly to it.  You can see what changed from v8 by:

        git diff inline-encryption-v8..inline-encryption-v9

or from v7 by:

        git diff inline-encryption-v7..inline-encryption-v9

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 06/11] scsi: ufs: UFS crypto API
  2020-03-26  3:06 ` [PATCH v9 06/11] scsi: ufs: UFS crypto API Satya Tangirala
@ 2020-03-26  5:07   ` Eric Biggers
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  5:07 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:57PM -0700, Satya Tangirala wrote:
> Introduce functions to manipulate UFS inline encryption hardware
> in line with the JEDEC UFSHCI v2.1 specification and to work with the
> block keyslot manager.
> 
> The UFS crypto API will assume by default that a vendor driver doesn't
> support UFS crypto, even if the hardware advertises the capability, because
> a lot of hardware requires some special handling that's not specified in
> the aforementioned JEDEC spec. Each vendor driver must explicity set
> hba->caps |= UFSHCD_CAP_CRYPTO before ufshcd_hba_init_crypto is called to
> opt-in to UFS crypto support.
> 

Thanks, this looks much better now!

A couple minor nits I noticed while reading this latest version:

> +void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
> +					    struct request_queue *q)
> +{
> +	if ((hba->caps & UFSHCD_CAP_CRYPTO))
> +		blk_ksm_register(&hba->ksm, q);
> +}

There's an extra pair of parentheses in the 'if'.

> diff --git a/drivers/scsi/ufs/ufshcd-crypto.h b/drivers/scsi/ufs/ufshcd-crypto.h
> new file mode 100644
> index 0000000000000..1e98f1fc99965
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufshcd-crypto.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2019 Google LLC
> + */
> +
> +#ifndef _UFSHCD_CRYPTO_H
> +#define _UFSHCD_CRYPTO_H
> +
> +#ifdef CONFIG_SCSI_UFS_CRYPTO
> +#include "ufshcd.h"
> +#include "ufshci.h"
> +
> +bool ufshcd_crypto_enable(struct ufs_hba *hba);
> +
> +void ufshcd_crypto_disable(struct ufs_hba *hba);

ufshcd_crypto_disable() has been removed, so its declaration should be removed
too.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS
  2020-03-26  3:06 ` [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS Satya Tangirala
@ 2020-03-26  5:09   ` Eric Biggers
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  5:09 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:58PM -0700, Satya Tangirala wrote:
> Wire up ufshcd.c with the UFS Crypto API, the block layer inline
> encryption additions and the keyslot manager.
> 
> Signed-off-by: Satya Tangirala <satyat@google.com>

Thanks, like the previous patch this looks much better now!

A couple minor nits I noticed while reading this latest version:

> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index eaeb21b9cda24..3af15880e1e36 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -168,6 +168,8 @@ struct ufs_pm_lvl_states {
>   * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
>   * @issue_time_stamp: time stamp for debug purposes
>   * @compl_time_stamp: time stamp for statistics
> + * @crypto_key_slot: the key slot to use for inline crypto

It would be helpful if the comment mentioned the -1 case:

 * @crypto_key_slot: the key slot to use for inline crypto (-1 if none)

> + * @data_unit_num: the data unit number for the first block for inline crypto
>   * @req_abort_skip: skip request abort task flag
>   */
>  struct ufshcd_lrb {
> @@ -192,6 +194,10 @@ struct ufshcd_lrb {
>  	bool intr_cmd;
>  	ktime_t issue_time_stamp;
>  	ktime_t compl_time_stamp;
> +#if IS_ENABLED(CONFIG_SCSI_UFS_CRYPTO)
> +	int crypto_key_slot;
> +	u64 data_unit_num;
> +#endif

Since CONFIG_SCSI_UFS_CRYPTO is a bool this should use #ifdef, not IS_ENABLED().

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 09/11] fscrypt: add inline encryption support
  2020-03-26  3:07 ` [PATCH v9 09/11] fscrypt: add inline encryption support Satya Tangirala
@ 2020-03-26  5:45   ` Eric Biggers
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  5:45 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:07:00PM -0700, Satya Tangirala wrote:
> +/* Enable inline encryption for this file if supported. */
> +void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
> +{
> +	const struct inode *inode = ci->ci_inode;
> +	struct super_block *sb = inode->i_sb;
> +
> +	/* The file must need contents encryption, not filenames encryption */
> +	if (!fscrypt_needs_contents_encryption(inode))
> +		return;
> +
> +	/* blk-crypto must implement the needed encryption algorithm */
> +	if (ci->ci_mode->blk_crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
> +		return;
> +
> +	/* The filesystem must be mounted with -o inlinecrypt */
> +	if (!(sb->s_flags & SB_INLINECRYPT))
> +		return;
> +
> +	ci->ci_inlinecrypt = true;
> +}

A bug I came across last week when writing a new test is that '-o inlinecrypt'
can break some fscrypt settings because it enables blk-crypto even when
CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK is unset and the hardware doesn't support
the algorithm.  For example, adding '-o inlinecrypt' can make Adiantum-encrypted
files stop working, due to the hardware only supporting AES-XTS.

That's undesirable.  Adding '-o inlinecrypt' should just make inline encryption
be used where it can, and not break anything.

To fix this, we should make fscrypt_select_encryption_impl() only set
->ci_inlinecrypt if either blk-crypto-fallback is enabled or if all the
filesystem's devices support the algorithm.

In v7+ of this patchset, this is a bit tricky because now
blk_ksm_crypto_key_supported() takes in a 'struct blk_crypto_key', which
fscrypt_select_encryption_impl() doesn't have available yet.  Perhaps make
blk_ksm_crypto_key_supported() a wrapper around a function like
blk_ksm_crypto_setting_supported() that takes a new struct:

	struct blk_crypto_setting {
	        enum blk_crypto_mode_num crypto_mode;
		unsigned int data_unit_size;
		unsigned int dun_bytes;
	};

Then maybe add blk_crypto_setting_supported() which returns true if either
blk_ksm_crypto_key_supported() *or* blk-crypto-fallback is enabled.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 08/11] fs: introduce SB_INLINECRYPT
  2020-03-26  3:06 ` [PATCH v9 08/11] fs: introduce SB_INLINECRYPT Satya Tangirala
@ 2020-03-26  5:56   ` Eric Biggers
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  5:56 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:59PM -0700, Satya Tangirala wrote:
> Introduce SB_INLINECRYPT, which is set by filesystems that wish to use
> blk-crypto for file content en/decryption.
> 
> Signed-off-by: Satya Tangirala <satyat@google.com>

This commit message could use a better explanation.  E.g. this flag maps to the
'-o inlinecrypt' mount option which multiple filesystems will implement, and
code in fs/crypto/ needs to be able to check for this mount option in a
filesystem-independent way.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption
  2020-03-26  3:06 ` [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption Satya Tangirala
@ 2020-03-26  6:22   ` Eric Biggers
  2020-03-27 17:00     ` Christoph Hellwig
  0 siblings, 1 reply; 22+ messages in thread
From: Eric Biggers @ 2020-03-26  6:22 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:52PM -0700, Satya Tangirala wrote:
> Inline Encryption hardware allows software to specify an encryption context
> (an encryption key, crypto algorithm, data unit num, data unit size) along
> with a data transfer request to a storage device, and the inline encryption
> hardware will use that context to en/decrypt the data. The inline
> encryption hardware is part of the storage device, and it conceptually sits
> on the data path between system memory and the storage device.
> 
> Inline Encryption hardware implementations often function around the
> concept of "keyslots". These implementations often have a limited number
> of "keyslots", each of which can hold a key (we say that a key can be
> "programmed" into a keyslot). Requests made to the storage device may have
> a keyslot and a data unit number associated with them, and the inline
> encryption hardware will en/decrypt the data in the requests using the key
> programmed into that associated keyslot and the data unit number specified
> with the request.
> 
> As keyslots are limited, and programming keys may be expensive in many
> implementations, and multiple requests may use exactly the same encryption
> contexts, we introduce a Keyslot Manager to efficiently manage keyslots.
> 
> We also introduce a blk_crypto_key, which will represent the key that's
> programmed into keyslots managed by keyslot managers. The keyslot manager
> also functions as the interface that upper layers will use to program keys
> into inline encryption hardware. For more information on the Keyslot
> Manager, refer to documentation found in block/keyslot-manager.c and
> linux/keyslot-manager.h.
> 
> Co-developed-by: Eric Biggers <ebiggers@google.com>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> Signed-off-by: Satya Tangirala <satyat@google.com>

Thanks, this patch looks much better now.  I don't see any real issues, but as
usual here are a couple nits I noticed while reading through this latest version
:-)

> +/**
> + * blk_ksm_init() - Initialize a keyslot manager
> + * @ksm: The keyslot_manager to initialize.
> + * @dev: Device for runtime power management (NULL if none)
> + * @num_slots: The number of key slots to manage.
> + *
> + * Allocate memory for keyslots and initialize a keyslot manager. Called by
> + * e.g. storage drivers to set up a keyslot manager in their request_queue.
> + *
> + * Return: 0 on success, or else a negative error code.
> + */
> +int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots)

The @dev parameter was removed, so its kerneldoc should be too.

One tip, you can check the validity of kerneldoc comments by running:

$ ./scripts/kernel-doc -v -none block/keyslot-manager.c
block/keyslot-manager.c:67: info: Scanning doc for blk_ksm_init
block/keyslot-manager.c:78: warning: Excess function parameter 'dev' description in 'blk_ksm_init'
block/keyslot-manager.c:180: info: Scanning doc for blk_ksm_get_slot_for_key
block/keyslot-manager.c:198: warning: Function parameter or member 'slot_ptr' not described in 'blk_ksm_get_slot_for_key'
block/keyslot-manager.c:198: warning: Excess function parameter 'keyslot' description in 'blk_ksm_get_slot_for_key'
block/keyslot-manager.c:258: info: Scanning doc for blk_ksm_put_slot
block/keyslot-manager.c:282: info: Scanning doc for blk_ksm_crypto_key_supported
block/keyslot-manager.c:303: info: Scanning doc for blk_ksm_evict_key
block/keyslot-manager.c:343: info: Scanning doc for blk_ksm_reprogram_all_keys
3 warnings

> +/**
> + * blk_ksm_get_slot_for_key() - Program a key into a keyslot.
> + * @ksm: The keyslot manager to program the key into.
> + * @key: Pointer to the key object to program, including the raw key, crypto
> + *	 mode, and data unit size.
> + * @keyslot: A pointer to return the pointer of the allocated keyslot.
> + *
> + * Get a keyslot that's been programmed with the specified key.  If one already
> + * exists, return it with incremented refcount.  Otherwise, wait for a keyslot
> + * to become idle and program it.
> + *
> + * Context: Process context. Takes and releases ksm->lock.
> + * Return: BLK_STATUS_OK on success (and keyslot is set to the pointer of the
> + *	   allocated keyslot), or some other blk_status_t otherwise (and
> + *	   keyslot is set to NULL).
> + */

It's actually "BLK_STS_OK", not "BLK_STATUS_OK".

> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index f629d40c645cd..27d460d0a8508 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -43,6 +43,7 @@ struct pr_ops;
>  struct rq_qos;
>  struct blk_queue_stats;
>  struct blk_stat_callback;
> +struct blk_keyslot_manager;
>  
>  #define BLKDEV_MIN_RQ	4
>  #define BLKDEV_MAX_RQ	128	/* Default maximum */
> @@ -474,6 +475,11 @@ struct request_queue {
>  	unsigned int		dma_pad_mask;
>  	unsigned int		dma_alignment;
>  
> +#ifdef CONFIG_BLK_INLINE_ENCRYPTION
> +	/* Inline crypto capabilities */
> +	struct blk_keyslot_manager *ksm;
> +#endif

I do still wonder whether the concept of inline crypto support should be more
separated from keyslot management, to be better prepared for device-mapper
passthrough support and for hardware that accepts keys directly.  (Such hardware
exists, though I'm not sure support for it will be upstreamed.)  For example,
the crypto capabilities could be stored in a 'struct blk_crypto_capabilities'
rather than in 'struct blk_keyslot_manager', and the latter could be optional.

What you have now is fine for the functionality in the current patchset though,
so I'm not really complaining.  Just something to think about.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 02/11] block: Inline encryption support for blk-mq
  2020-03-26  3:06 ` [PATCH v9 02/11] block: Inline encryption support for blk-mq Satya Tangirala
@ 2020-03-26 20:05   ` Eric Biggers
  2020-03-27 17:05     ` Christoph Hellwig
  0 siblings, 1 reply; 22+ messages in thread
From: Eric Biggers @ 2020-03-26 20:05 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:53PM -0700, Satya Tangirala wrote:
> diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
> new file mode 100644
> index 0000000000000..1e6d339fe1429
> --- /dev/null
> +++ b/block/blk-crypto-internal.h
> @@ -0,0 +1,172 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2019 Google LLC
> + */
> +
> +#ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
> +#define __LINUX_BLK_CRYPTO_INTERNAL_H
> +
> +#include <linux/bio.h>
> +#include <linux/blkdev.h>
> +
> +/* Represents a crypto mode supported by blk-crypto  */
> +struct blk_crypto_mode {
> +	const char *cipher_str; /* crypto API name (for fallback case) */

Technically, cipher_str shouldn't be added until the patch that adds
blk-crypto-fallback.

> +	unsigned int keysize; /* key size in bytes */
> +	unsigned int ivsize; /* iv size in bytes */
> +};
> +
> +#ifdef CONFIG_BLK_INLINE_ENCRYPTION
> +
> +static inline const struct blk_crypto_key *bio_crypt_key(struct bio *bio)
> +{
> +	if (!bio_has_crypt_ctx(bio))
> +		return NULL;
> +	return bio->bi_crypt_context->bc_key;
> +}


I don't believe bio_crypt_key() is necessary -- see my comment below regarding
blk_mq_make_request().

> +bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc,
> +				 unsigned int bytes,
> +				 u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE])

next_dun should be const.

> +{
> +	int i = 0;
> +	unsigned int inc = bytes >> bc->bc_key->data_unit_size_bits;
> +
> +	while (i < BLK_CRYPTO_DUN_ARRAY_SIZE) {
> +		if (bc->bc_dun[i] + inc != next_dun[i])
> +			return false;
> +		/*
> +		 * If addition of inc to the current entry caused an overflow,
> +		 * then we have to carry "1" for the next entry - so inc
> +		 * needs to be "1" for the next loop iteration). Otherwise,
> +		 * we need inc to be 0 for the next loop iteration. Since
> +		 * overflow can be determined by (bc->bc_dun[i] + inc)  < inc
> +		 * we can do the following.
> +		 */
> +		inc = ((bc->bc_dun[i] + inc)  < inc);
> +		i++;
> +	}

This comment is verbose but doesn't really explain what's going on.
I think it would be much more useful to add comments like:

/*
 * Returns true if @bc_dun plus @bytes converted to data units is equal to
 * @next_dun, treating the DUNs as multi-limb integers.
 */
bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc,
                                 unsigned int bytes,
				 const u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE])

And:


		/*
		 * If the addition in this limb overflowed, then the carry bit
		 * into the next limb is 1.  Else the carry bit is 0.
		 */
		inc = ((bc->bc_dun[i] + inc)  < inc);


> +
> +	/*
> +	 * After going through all the entries in the dun, inc must be 0 for
> +	 * the duns to be contiguous.
> +	 */
> +	return !inc;
> +}

This is new in v9; before it just returned true.

It would be more helpful if this comment was like:

	/* If the DUN wrapped through 0, don't treat it as contiguous. */

> +/**
> + * __blk_crypto_init_request - Initializes the request's crypto fields based on
> + *			       the blk_crypto_key for a bio to be added to the
> + *			       request, and prepares it for hardware inline
> + *			       encryption.
> + *
> + * @rq: The request to init
> + * @key: The blk_crypto_key of bios that will (eventually) be added to @rq.
> + *
> + * Initializes the request's crypto fields to appropriate default values and
> + * tries to get a keyslot for the blk_crypto_key.
> + *
> + * Return: BLK_STATUS_OK on success, and negative error code otherwise.
> + */
> +blk_status_t __blk_crypto_init_request(struct request *rq,
> +				       const struct blk_crypto_key *key)
> +{
> +	return blk_ksm_get_slot_for_key(rq->q->ksm, key, &rq->crypt_keyslot);
> +}

The comment of this function seems outdated.  All it does it get a keyslot, but
the comment talks about initializing "crypto fields" (plural).

> +/**
> + * blk_crypto_evict_key() - Evict a key from any inline encryption hardware
> + *			    it may have been programmed into
> + * @q: The request queue who's keyslot manager this key might have been
> + *     programmed into
> + * @key: The key to evict
> + *
> + * Upper layers (filesystems) should call this function to ensure that a key
> + * is evicted from hardware that it might have been programmed into. This
> + * will call blk_ksm_evict_key on the queue's keyslot manager, if one
> + * exists, and supports the crypto algorithm with the specified data unit size.
> + *
> + * Return: 0 on success or if key is not present in the q's ksm, -err on error.
> + */
> +int blk_crypto_evict_key(struct request_queue *q,
> +			 const struct blk_crypto_key *key)
> +{
> +	if (q->ksm && blk_ksm_crypto_key_supported(q->ksm, key))
> +		return blk_ksm_evict_key(q->ksm, key);
> +
> +	return 0;
> +}

The keyslot manager is really an implementation detail of the block layer.
Therefore when documenting functions like blk_crypto_evict_key() that are the
API for use by upper layers like filesystems, we shouldn't really talk about the
keyslot manager, but rather describe the behavior in higher-level terms like
"evict a key from the inline encryption hardware".

> @@ -1971,6 +1974,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
>  	struct request *same_queue_rq = NULL;
>  	unsigned int nr_segs;
>  	blk_qc_t cookie;
> +	blk_status_t ret;
>  
>  	blk_queue_bounce(q, &bio);
>  	__blk_queue_split(q, &bio, &nr_segs);
> @@ -2002,6 +2006,14 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
>  
>  	cookie = request_to_qc_t(data.hctx, rq);
>  
> +	ret = blk_crypto_init_request(rq, bio_crypt_key(bio));
> +	if (ret != BLK_STS_OK) {
> +		bio->bi_status = ret;
> +		bio_endio(bio);
> +		blk_mq_free_request(rq);
> +		return BLK_QC_T_NONE;
> +	}
> +
>  	blk_mq_bio_to_request(rq, bio, nr_segs);

Wouldn't it make a lot more sense to do blk_crypto_init_request() after
blk_mq_bio_to_request() rather than before?

I.e., initialize request::crypt_ctx first, *then* get the keyslot.  Not the
other way around.

That would allow removing the second argument to blk_crypto_init_request() and
removing bio_crypt_key().  blk_crypto_init_request() would only need to take in
the struct request.

> diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
> index b8d54eca1c0d8..4add2e8846fea 100644
> --- a/include/linux/blk-crypto.h
> +++ b/include/linux/blk-crypto.h
> @@ -6,6 +6,8 @@
>  #ifndef __LINUX_BLK_CRYPTO_H
>  #define __LINUX_BLK_CRYPTO_H
>  
> +#include <linux/types.h>
> +
>  enum blk_crypto_mode_num {
>  	BLK_ENCRYPTION_MODE_INVALID,
>  	BLK_ENCRYPTION_MODE_AES_256_XTS,
> @@ -24,7 +26,7 @@ enum blk_crypto_mode_num {
>   *	ciphertext.  This is always a power of 2.  It might be e.g. the
>   *	filesystem block size or the disk sector size.
>   * @data_unit_size_bits: log2 of data_unit_size
> - * @dun_bytes: the number of bytes of DUN used when using this key
> + * @dun_bytes: the maximum number of bytes of DUN used when using this key

This comment update should be folded into the patch that added this.

> +/**
> + * struct bio_crypt_ctx - an inline encryption context
> + * @bc_key: the key, algorithm, and data unit size to use
> + * @bc_dun: the data unit number (starting IV) to use
> + * @bc_keyslot: the keyslot that has been assigned for this key in @bc_ksm,
> + *		or -1 if no keyslot has been assigned yet.
> + * @bc_ksm: the keyslot manager into which the key has been programmed with
> + *	    @bc_keyslot, or NULL if this key hasn't yet been programmed.
> + *
> + * A bio_crypt_ctx specifies that the contents of the bio will be encrypted (for
> + * write requests) or decrypted (for read requests) inline by the storage device
> + * or controller.
> + */
> +struct bio_crypt_ctx {
> +	const struct blk_crypto_key	*bc_key;
> +	u64				bc_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
> +};


Kerneldoc needs to be updated; bc_keyslot and bc_ksm no longer exist.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption
  2020-03-26  3:06 ` [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption Satya Tangirala
@ 2020-03-26 20:28   ` Eric Biggers
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Biggers @ 2020-03-26 20:28 UTC (permalink / raw)
  To: Satya Tangirala
  Cc: linux-block, linux-scsi, linux-fscrypt, linux-fsdevel,
	linux-f2fs-devel, linux-ext4, Barani Muthukumaran, Kuohong Wang,
	Kim Boojin

On Wed, Mar 25, 2020 at 08:06:55PM -0700, Satya Tangirala wrote:
> Blk-crypto delegates crypto operations to inline encryption hardware when
> available. The separately configurable blk-crypto-fallback contains a
> software fallback to the kernel crypto API - when enabled, blk-crypto
> will use this fallback for en/decryption when inline encryption hardware is
> not available. This lets upper layers not have to worry about whether or
> not the underlying device has support for inline encryption before
> deciding to specify an encryption context for a bio, and also allows for
> testing without actual inline encryption hardware. For more details, refer
> to Documentation/block/inline-encryption.rst.
> 
> Signed-off-by: Satya Tangirala <satyat@google.com>

It might be helpful to also mention some real-world examples of how this helps
testing, e.g. it makes it possible to test the inline encryption code in ext4
and f2fs simply by running xfstests with the inlinecrypt mount option.
Therefore it makes it possible for the regular upstream regression testing of
ext4 to cover the inline encryption code paths.

> diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
> new file mode 100644
> index 0000000000000..3fa475799ecd1
> --- /dev/null
> +++ b/Documentation/block/inline-encryption.rst
> @@ -0,0 +1,195 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=================
> +Inline Encryption
> +=================

You may want to consider further improving this documentation file and then
putting it as patch 1 of the series as its own patch to introduce the rest of
the series, rather than "hiding" it in this particular patch.  The documentation
is for blk-crypto as a whole; it's not specific to blk-crypto-fallback.

> +struct bio_fallback_crypt_ctx {
> +	struct bio_crypt_ctx crypt_ctx;
> +	/*
> +	 * Copy of the bvec_iter when this bio was submitted.
> +	 * We only want to en/decrypt the part of the bio as described by the
> +	 * bvec_iter upon submission because bio might be split before being
> +	 * resubmitted
> +	 */
> +	struct bvec_iter crypt_iter;
> +	u64 fallback_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
> +	union {
> +		struct {
> +			struct work_struct work;
> +			struct bio *bio;
> +		};
> +		struct {
> +			void *bi_private_orig;
> +			bio_end_io_t *bi_end_io_orig;
> +		};
> +	};
> +};

Isn't 'fallback_dun' unnecessary now that blk-crypto-fallback uses bi_private?
'fallback_dun' should always be equal to 'crypt_ctx.bc_dun', right?

> +/**
> + * blk_crypto_fallback_bio_prep - Prepare a bio to use fallback en/decryption
> + *
> + * @bio_ptr: pointer to the bio to prepare
> + *
> + * If bio is doing a WRITE operation, we split the bio into two parts, resubmit
> + * the second part. Allocates a bounce bio for the first part, encrypts it, and
> + * update bio_ptr to point to the bounce bio.

This comment is misleading.  The code actually only splits the bio if it's very
large; it doesn't always split it.

> diff --git a/block/blk-crypto.c b/block/blk-crypto.c
> index a52ec4eb153be..41d5e421624e5 100644
> --- a/block/blk-crypto.c
> +++ b/block/blk-crypto.c
> @@ -3,6 +3,10 @@
>   * Copyright 2019 Google LLC
>   */
>  
> +/*
> + * Refer to Documentation/block/inline-encryption.rst for detailed explanation.
> + */
> +
>  #define pr_fmt(fmt) "blk-crypto: " fmt
>  
>  #include <linux/bio.h>
> @@ -206,7 +210,8 @@ static bool bio_crypt_check_alignment(struct bio *bio)
>   * __blk_crypto_init_request - Initializes the request's crypto fields based on
>   *			       the blk_crypto_key for a bio to be added to the
>   *			       request, and prepares it for hardware inline
> - *			       encryption.
> + *			       encryption (as opposed to using the crypto API
> + *			       fallback).
>   *
>   * @rq: The request to init
>   * @key: The blk_crypto_key of bios that will (eventually) be added to @rq.
> @@ -219,6 +224,10 @@ static bool bio_crypt_check_alignment(struct bio *bio)
>  blk_status_t __blk_crypto_init_request(struct request *rq,
>  				       const struct blk_crypto_key *key)
>  {
> +	/*
> +	 * We have a bio crypt context here - that means we didn't fallback
> +	 * to crypto API, so try to program a keyslot now.
> +	 */
>  	return blk_ksm_get_slot_for_key(rq->q->ksm, key, &rq->crypt_keyslot);
>  }

Since the fallback is now transparent to everything below it, we probably
shouldn't leave as many comments like this around that mention the fallback.
Comments are more useful if the code is doing something unexpected, as opposed
to something expected.

>  void __blk_crypto_rq_prep_clone(struct request *dst, struct request *src)
>  {
> +	/* Don't clone crypto info if src uses fallback en/decryption */
> +	if (!src->crypt_keyslot)
> +		return;
> +
>  	dst->crypt_ctx = src->crypt_ctx;
>  }

Isn't this part unnecessary?  If the fallback was used, there is no crypt
context anymore.

- Eric

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption
  2020-03-26  6:22   ` Eric Biggers
@ 2020-03-27 17:00     ` Christoph Hellwig
  0 siblings, 0 replies; 22+ messages in thread
From: Christoph Hellwig @ 2020-03-27 17:00 UTC (permalink / raw)
  To: Eric Biggers
  Cc: Satya Tangirala, linux-block, linux-scsi, linux-fscrypt,
	linux-fsdevel, linux-f2fs-devel, linux-ext4, Barani Muthukumaran,
	Kuohong Wang, Kim Boojin

On Wed, Mar 25, 2020 at 11:22:13PM -0700, Eric Biggers wrote:
> > +#ifdef CONFIG_BLK_INLINE_ENCRYPTION
> > +	/* Inline crypto capabilities */
> > +	struct blk_keyslot_manager *ksm;
> > +#endif
> 
> I do still wonder whether the concept of inline crypto support should be more
> separated from keyslot management, to be better prepared for device-mapper
> passthrough support and for hardware that accepts keys directly.  (Such hardware
> exists, though I'm not sure support for it will be upstreamed.)  For example,
> the crypto capabilities could be stored in a 'struct blk_crypto_capabilities'
> rather than in 'struct blk_keyslot_manager', and the latter could be optional.
> 
> What you have now is fine for the functionality in the current patchset though,
> so I'm not really complaining.  Just something to think about.

I'd rather keep things simple (aka as-is) for now.  If needed we can
change it. I doubt we'll even have a handful drivers with inline
crypto in the next years..

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v9 02/11] block: Inline encryption support for blk-mq
  2020-03-26 20:05   ` Eric Biggers
@ 2020-03-27 17:05     ` Christoph Hellwig
  0 siblings, 0 replies; 22+ messages in thread
From: Christoph Hellwig @ 2020-03-27 17:05 UTC (permalink / raw)
  To: Eric Biggers
  Cc: Satya Tangirala, linux-block, linux-scsi, linux-fscrypt,
	linux-fsdevel, linux-f2fs-devel, linux-ext4, Barani Muthukumaran,
	Kuohong Wang, Kim Boojin

On Thu, Mar 26, 2020 at 01:05:11PM -0700, Eric Biggers wrote:
> > +{
> > +	int i = 0;
> > +	unsigned int inc = bytes >> bc->bc_key->data_unit_size_bits;
> > +
> > +	while (i < BLK_CRYPTO_DUN_ARRAY_SIZE) {
> > +		if (bc->bc_dun[i] + inc != next_dun[i])
> > +			return false;
> > +		/*
> > +		 * If addition of inc to the current entry caused an overflow,
> > +		 * then we have to carry "1" for the next entry - so inc
> > +		 * needs to be "1" for the next loop iteration). Otherwise,
> > +		 * we need inc to be 0 for the next loop iteration. Since
> > +		 * overflow can be determined by (bc->bc_dun[i] + inc)  < inc
> > +		 * we can do the following.
> > +		 */
> > +		inc = ((bc->bc_dun[i] + inc)  < inc);
> > +		i++;
> > +	}
> 
> This comment is verbose but doesn't really explain what's going on.
> I think it would be much more useful to add comments like:

Also the code is still weird.  Odd double whitespaces, expression that
evaluate to bool.

> 
> 		/*
> 		 * If the addition in this limb overflowed, then the carry bit
> 		 * into the next limb is 1.  Else the carry bit is 0.
> 		 */
> 		inc = ((bc->bc_dun[i] + inc)  < inc);

		if (bc->bc_dun[i] + carry < carry)
			carry = 1;
		else
			carry = 0;

> 
> > +blk_status_t __blk_crypto_init_request(struct request *rq,
> > +				       const struct blk_crypto_key *key)
> > +{
> > +	return blk_ksm_get_slot_for_key(rq->q->ksm, key, &rq->crypt_keyslot);
> > +}
> 
> The comment of this function seems outdated.  All it does it get a keyslot, but
> the comment talks about initializing "crypto fields" (plural).

This is a classic case where I think the top of the function comment
is entirely useless. If there is a single caller in core code and the
function is completely trivial, there really is no point in a multi-line
comment.  Comment should explain something unexpected or non-trivial,
while much of the comments in this series are just boilerplate making
the code harder to read.

> >  	blk_queue_bounce(q, &bio);
> >  	__blk_queue_split(q, &bio, &nr_segs);
> > @@ -2002,6 +2006,14 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> >  
> >  	cookie = request_to_qc_t(data.hctx, rq);
> >  
> > +	ret = blk_crypto_init_request(rq, bio_crypt_key(bio));
> > +	if (ret != BLK_STS_OK) {
> > +		bio->bi_status = ret;
> > +		bio_endio(bio);
> > +		blk_mq_free_request(rq);
> > +		return BLK_QC_T_NONE;
> > +	}
> > +
> >  	blk_mq_bio_to_request(rq, bio, nr_segs);
> 
> Wouldn't it make a lot more sense to do blk_crypto_init_request() after
> blk_mq_bio_to_request() rather than before?
> 
> I.e., initialize request::crypt_ctx first, *then* get the keyslot.  Not the
> other way around.
> 
> That would allow removing the second argument to blk_crypto_init_request() and
> removing bio_crypt_key().  blk_crypto_init_request() would only need to take in
> the struct request.

And we can fail just the request on an error, so yes this doesn't
seem too bad.

^ permalink raw reply	[flat|nested] 22+ messages in thread

end of thread, back to index

Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-26  3:06 [PATCH v9 00/11] Inline Encryption Support Satya Tangirala
2020-03-26  3:06 ` [PATCH v9 01/11] block: Keyslot Manager for Inline Encryption Satya Tangirala
2020-03-26  6:22   ` Eric Biggers
2020-03-27 17:00     ` Christoph Hellwig
2020-03-26  3:06 ` [PATCH v9 02/11] block: Inline encryption support for blk-mq Satya Tangirala
2020-03-26 20:05   ` Eric Biggers
2020-03-27 17:05     ` Christoph Hellwig
2020-03-26  3:06 ` [PATCH v9 03/11] block: Make blk-integrity preclude hardware inline encryption Satya Tangirala
2020-03-26  3:06 ` [PATCH v9 04/11] block: blk-crypto-fallback for Inline Encryption Satya Tangirala
2020-03-26 20:28   ` Eric Biggers
2020-03-26  3:06 ` [PATCH v9 05/11] scsi: ufs: UFS driver v2.1 spec crypto additions Satya Tangirala
2020-03-26  3:06 ` [PATCH v9 06/11] scsi: ufs: UFS crypto API Satya Tangirala
2020-03-26  5:07   ` Eric Biggers
2020-03-26  3:06 ` [PATCH v9 07/11] scsi: ufs: Add inline encryption support to UFS Satya Tangirala
2020-03-26  5:09   ` Eric Biggers
2020-03-26  3:06 ` [PATCH v9 08/11] fs: introduce SB_INLINECRYPT Satya Tangirala
2020-03-26  5:56   ` Eric Biggers
2020-03-26  3:07 ` [PATCH v9 09/11] fscrypt: add inline encryption support Satya Tangirala
2020-03-26  5:45   ` Eric Biggers
2020-03-26  3:07 ` [PATCH v9 10/11] f2fs: " Satya Tangirala
2020-03-26  3:07 ` [PATCH v9 11/11] ext4: " Satya Tangirala
2020-03-26  3:32 ` [PATCH v9 00/11] Inline Encryption Support Eric Biggers

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