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 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 | 5 +
block/bio.c | 9 +-
block/blk-core.c | 27 +-
block/blk-crypto-fallback.c | 662 ++++++++++++++++++++++
block/blk-crypto-internal.h | 168 ++++++
block/blk-crypto.c | 429 ++++++++++++++
block/blk-integrity.c | 7 +
block/blk-map.c | 2 +
block/blk-merge.c | 11 +
block/blk-mq.c | 15 +
block/blk.h | 5 +
block/bounce.c | 3 +
block/keyslot-manager.c | 397 +++++++++++++
drivers/md/dm.c | 4 +
drivers/scsi/ufs/Kconfig | 9 +
drivers/scsi/ufs/Makefile | 1 +
drivers/scsi/ufs/ufshcd-crypto.c | 397 +++++++++++++
drivers/scsi/ufs/ufshcd-crypto.h | 68 +++
drivers/scsi/ufs/ufshcd.c | 61 +-
drivers/scsi/ufs/ufshcd.h | 27 +
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/f2fs.h | 3 +
fs/f2fs/super.c | 33 ++
fs/proc_namespace.c | 1 +
include/linux/blk-crypto.h | 130 +++++
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 | 108 ++++
53 files changed, 3622 insertions(+), 90 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
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Satya Tangirala <[email protected]>
---
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 | 108 +++++++++
6 files changed, 544 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 3bc76bb113a0..c04a1d500842 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 1a43750f4b01..ef3a05dcf1f2 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 000000000000..38df0652df80
--- /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 keyslot_manager *ksm;
+};
+
+static inline void blk_ksm_hw_enter(struct 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 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 keyslot_manager *ksm, struct device *dev,
+ 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;
+ ksm->dev = dev;
+
+ 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 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 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 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 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), and BLK_STATUS_IOERR otherwise (and keyslot is
+ * set to NULL).
+ */
+blk_status_t blk_ksm_get_slot_for_key(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ struct blk_ksm_keyslot **slot_ptr)
+{
+ struct blk_ksm_keyslot *slot;
+ int slot_idx;
+ blk_status_t 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 != BLK_STS_OK) {
+ wake_up(&ksm->idle_slots_wait_queue);
+ blk_ksm_hw_exit(ksm);
+ return 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 keyslot_manager *ksm = slot->ksm;
+ unsigned long flags;
+
+ if (!slot)
+ return;
+
+ 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 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 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 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 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 000000000000..b8d54eca1c0d
--- /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 10455b2bbbb4..c447361952d1 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 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 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 000000000000..7f88ed02faee
--- /dev/null
+++ b/include/linux/keyslot-manager.h
@@ -0,0 +1,108 @@
+/* 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 keyslot_manager;
+
+/**
+ * struct keyslot_mgmt_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 keyslot_mgmt_ll_ops {
+ blk_status_t (*keyslot_program)(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot);
+ int (*keyslot_evict)(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot);
+};
+
+struct keyslot_manager {
+ /*
+ * The struct keyslot_mgmt_ll_ops that this keyslot manager will use
+ * to perform operations like programming and evicting keys on the
+ * device
+ */
+ struct keyslot_mgmt_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 keyslot_manager *ksm, struct device *dev,
+ unsigned int num_slots);
+
+blk_status_t blk_ksm_get_slot_for_key(struct 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 keyslot_manager *ksm,
+ const struct blk_crypto_key *key);
+
+int blk_ksm_evict_key(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key);
+
+void blk_ksm_reprogram_all_keys(struct keyslot_manager *ksm);
+
+void blk_ksm_destroy(struct keyslot_manager *ksm);
+
+#endif /* __LINUX_KEYSLOT_MANAGER_H */
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
---
block/Makefile | 2 +-
block/bio.c | 9 +-
block/blk-core.c | 27 ++-
block/blk-crypto-internal.h | 144 +++++++++++++
block/blk-crypto.c | 408 ++++++++++++++++++++++++++++++++++++
block/blk-map.c | 2 +
block/blk-merge.c | 11 +
block/blk-mq.c | 15 ++
block/blk.h | 5 +
block/bounce.c | 3 +
drivers/md/dm.c | 4 +
include/linux/blk-crypto.h | 72 ++++++-
include/linux/blk_types.h | 6 +
include/linux/blkdev.h | 5 +
14 files changed, 706 insertions(+), 7 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 ef3a05dcf1f2..82f42ca3f769 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 94d697217887..9e2542809279 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 +237,9 @@ void bio_uninit(struct bio *bio)
if (bio_integrity(bio))
bio_integrity_free(bio);
+
+ if (bio_has_crypt_ctx(bio))
+ bio_crypt_free_ctx(bio);
}
EXPORT_SYMBOL(bio_uninit);
@@ -664,11 +668,13 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
__bio_clone_fast(b, bio);
+ if (bio_has_crypt_ctx(bio))
+ bio_crypt_clone(b, bio, gfp_mask);
+
if (bio_integrity(bio)) {
int ret;
ret = bio_integrity_clone(b, bio, gfp_mask);
-
if (ret < 0) {
bio_put(b);
return NULL;
@@ -1046,6 +1052,7 @@ 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 089e890ab208..199837d1c15d 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 +619,9 @@ bool bio_attempt_back_merge(struct request *req, struct bio *bio,
req->biotail = bio;
req->__data_len += bio->bi_iter.bi_size;
+ if (bio_has_crypt_ctx(bio))
+ bio_crypt_free_ctx(bio);
+
blk_account_io_start(req, false);
return true;
}
@@ -641,6 +646,9 @@ 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;
+ if (bio_has_crypt_ctx(bio))
+ blk_crypto_rq_bio_prep(req, bio);
+
blk_account_io_start(req, false);
return true;
}
@@ -1066,7 +1074,9 @@ 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 (!bio_has_crypt_ctx(bio) ||
+ !blk_crypto_bio_prep(&bio))
+ ret = q->make_request_fn(q, bio);
blk_queue_exit(q);
@@ -1114,7 +1124,7 @@ 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 +1137,8 @@ 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 (!bio_has_crypt_ctx(bio) || !blk_crypto_bio_prep(&bio))
+ ret = q->make_request_fn(q, bio);
blk_queue_exit(q);
return ret;
}
@@ -1258,6 +1268,10 @@ 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_rq_is_encrypted(rq) &&
+ blk_crypto_insert_cloned_request(rq))
+ return BLK_STS_IOERR;
+
if (blk_queue_io_stat(q))
blk_account_io_start(rq, true);
@@ -1646,6 +1660,9 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
__blk_rq_prep_clone(rq, rq_src);
+ if (blk_crypto_rq_is_encrypted(rq_src))
+ blk_crypto_rq_prep_clone(rq, rq_src);
+
return 0;
free_and_out:
@@ -1813,5 +1830,7 @@ int __init blk_dev_init(void)
blk_debugfs_root = debugfs_create_dir("block", NULL);
#endif
+ bio_crypt_ctx_init();
+
return 0;
}
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
new file mode 100644
index 000000000000..5cdf45167117
--- /dev/null
+++ b/block/blk-crypto-internal.h
@@ -0,0 +1,144 @@
+/* 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
+
+void bio_crypt_ctx_init(void);
+
+void bio_crypt_free_ctx(struct bio *bio);
+
+void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+ unsigned int inc);
+
+void bio_crypt_advance(struct bio *bio, unsigned int bytes);
+
+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);
+}
+
+void blk_crypto_free_request(struct request *rq);
+
+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;
+}
+
+blk_status_t blk_crypto_init_request(struct request *rq, struct bio *bio);
+
+int blk_crypto_bio_prep(struct bio **bio_ptr);
+
+void blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio);
+
+void blk_crypto_rq_prep_clone(struct request *dst, struct request *src);
+
+blk_status_t blk_crypto_insert_cloned_request(struct request *rq);
+
+#else /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+static inline void bio_crypt_ctx_init(void) { }
+
+static inline void bio_crypt_free_ctx(struct bio *bio) { }
+
+static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes) { }
+
+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_free_request(struct request *rq) { }
+
+static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
+
+static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
+{
+ return false;
+}
+
+static inline blk_status_t blk_crypto_init_request(struct request *rq,
+ struct bio *bio)
+{
+ return 0;
+}
+
+static inline int blk_crypto_bio_prep(struct bio **bio_ptr)
+{
+ return 0;
+}
+
+static inline void blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio)
+{ }
+
+static inline void blk_crypto_rq_prep_clone(struct request *dst,
+ struct request *src) { }
+
+static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
+{
+ return 0;
+}
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
new file mode 100644
index 000000000000..1c38de053bb6
--- /dev/null
+++ b/block/blk-crypto.c
@@ -0,0 +1,408 @@
+// 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;
+
+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");
+}
+
+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;
+
+ if (!bc)
+ return;
+
+ 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;
+ inc = ((bc->bc_dun[i] + inc) < inc);
+ i++;
+ }
+
+ return true;
+}
+
+/*
+ * 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 void 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;
+ }
+ }
+}
+
+/**
+ * blk_crypto_init_request - Initializes the request's crypto fields based on
+ * the bio to be added to the request, and prepares
+ * it for hardware inline encryption.
+ *
+ * @rq: The request to init
+ * @bio: The bio 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 bio crypt ctx. Caller must ensure that bio has
+ * a bio_crypt_ctx.
+ *
+ * Return: BLK_STATUS_OK on success, and negative error code otherwise.
+ */
+blk_status_t blk_crypto_init_request(struct request *rq, struct bio *bio)
+{
+ blk_status_t err;
+
+ blk_crypto_rq_set_defaults(rq);
+
+ err = blk_ksm_get_slot_for_key(rq->q->ksm,
+ bio->bi_crypt_context->bc_key,
+ &rq->crypt_keyslot);
+ if (err != BLK_STS_OK)
+ pr_warn_once("Failed to acquire keyslot for %s (err=%d).\n",
+ bio->bi_disk->disk_name, err);
+ return err;
+}
+
+/**
+ * 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: 0 on success; nonzero on error (and bio->bi_status will be set
+ * appropriately, and bio_endio() will have been called so bio
+ * submission should abort).
+ */
+int blk_crypto_bio_prep(struct bio **bio_ptr)
+{
+ struct bio *bio = *bio_ptr;
+
+ /*
+ * If bio has no data, just pretend it didn't have an encryption
+ * context.
+ */
+ if (!bio_has_data(bio)) {
+ bio_crypt_free_ctx(bio);
+ return 0;
+ }
+
+ bio_crypt_check_alignment(bio);
+ if (bio->bi_status != BLK_STS_OK)
+ 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 0;
+fail:
+ bio_endio(*bio_ptr);
+ return -EIO;
+}
+
+/**
+ * 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)
+{
+ blk_status_t err;
+
+ if (!rq->bio)
+ return 0;
+
+ /*
+ * Pretend that the bio had the encryption ctx before calling
+ * blk_crypto_init_request
+ */
+ rq->bio->bi_crypt_context = rq->crypt_ctx;
+ err = blk_crypto_init_request(rq, rq->bio);
+ /*
+ * blk_crypto_init_request *always* clears the crypto fields in rq to
+ * defaults, so regardless of what err is, restore rq->crypt_ctx.
+ */
+ blk_crypto_rq_bio_prep(rq, rq->bio);
+
+ return err;
+}
+
+/**
+ * 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
+ * @blk_crypto_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 blk_crypto_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 = blk_crypto_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 b0790268ed9d..1c8acc39584d 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -41,6 +41,8 @@ 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;
+ if (bio_has_crypt_ctx(*bio))
+ bio_crypt_free_ctx(*bio);
}
return 0;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 1534ed736363..a0c24b6e0eb3 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 d92088dec6c3..b98dd06daf8f 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 +476,8 @@ 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;
+ if (blk_crypto_rq_is_encrypted(rq))
+ blk_crypto_free_request(rq);
blk_pm_mark_last_busy(rq);
rq->mq_hctx = NULL;
if (rq->tag != -1)
@@ -1971,6 +1975,7 @@ 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 err;
blk_queue_bounce(q, &bio);
__blk_queue_split(q, &bio, &nr_segs);
@@ -2002,6 +2007,16 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
cookie = request_to_qc_t(data.hctx, rq);
+ if (bio_has_crypt_ctx(bio)) {
+ err = blk_crypto_init_request(rq, bio);
+ if (err != BLK_STS_OK) {
+ bio->bi_status = err;
+ bio_endio(bio);
+ blk_mq_end_request(rq, err);
+ 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 0b8884353f6b..35e675ac845d 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 +119,9 @@ static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
if (bio->bi_disk)
rq->rq_disk = bio->bi_disk;
+
+ if (bio_has_crypt_ctx(bio))
+ blk_crypto_rq_bio_prep(rq, bio);
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
diff --git a/block/bounce.c b/block/bounce.c
index f8ed677a1bf7..c345132e91dd 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -267,6 +267,9 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
break;
}
+ if (bio_has_crypt_ctx(bio_src))
+ 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 b89f07ee2eff..d3f8fab33ee2 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 +1305,9 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
__bio_clone_fast(clone, bio);
+ if (bio_has_crypt_ctx(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 b8d54eca1c0d..90a28df26106 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 +44,72 @@ 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];
+};
+
+#ifdef CONFIG_BLOCK
+
+#include <linux/blk_types.h>
+#include <linux/blkdev.h>
+
+struct request;
+struct request_queue;
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+
+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);
+
+static inline bool bio_has_crypt_ctx(struct bio *bio)
+{
+ return bio->bi_crypt_context;
+}
+
+void bio_crypt_clone(struct bio *dst, struct bio *src, 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 blk_crypto_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;
+}
+
+static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
+ gfp_t gfp_mask) { }
+
+#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+
+#endif /* CONFIG_BLOCK */
+
#endif /* __LINUX_BLK_CRYPTO_H */
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 70254ae11769..1996689c51d3 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 c447361952d1..c6ea578c1f79 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;
--
2.25.1.481.gfbce0eb801-goog
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 in the near
future, based on discussion at
https://lore.kernel.org/r/[email protected]/
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, and
through discussions at
https://lore.kernel.org/r/[email protected]/
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 <[email protected]>
---
block/bio-integrity.c | 5 +++++
block/blk-integrity.c | 7 +++++++
block/keyslot-manager.c | 20 ++++++++++++++++++++
include/linux/blkdev.h | 30 ++++++++++++++++++++++++++++++
4 files changed, 62 insertions(+)
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index bf62c25cde8f..a5c57991c6fa 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -42,6 +42,11 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
struct bio_set *bs = bio->bi_pool;
unsigned inline_vecs;
+ if (bio_has_crypt_ctx(bio)) {
+ pr_warn("blk-integrity can't be used together with inline en/decryption.");
+ 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 ff1070edbb40..793ba23e8688 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 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.");
+ blk_ksm_unregister(disk->queue);
+ }
+#endif
}
EXPORT_SYMBOL(blk_integrity_register);
diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
index 38df0652df80..a7970e18a122 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_ksm: " fmt
+
#include <crypto/algapi.h>
#include <linux/keyslot-manager.h>
#include <linux/atomic.h>
@@ -375,3 +378,20 @@ void blk_ksm_destroy(struct keyslot_manager *ksm)
memzero_explicit(ksm, sizeof(*ksm));
}
EXPORT_SYMBOL_GPL(blk_ksm_destroy);
+
+bool blk_ksm_register(struct 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. Won't register keyslot manager with request queue.");
+ return false;
+ }
+ q->ksm = ksm;
+ return true;
+}
+EXPORT_SYMBOL_GPL(blk_ksm_register);
+
+void blk_ksm_unregister(struct request_queue *q)
+{
+ q->ksm = NULL;
+}
+EXPORT_SYMBOL_GPL(blk_ksm_unregister);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c6ea578c1f79..abe886d48cc4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1570,6 +1570,12 @@ 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;
@@ -1650,6 +1656,11 @@ 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;
@@ -1701,6 +1712,25 @@ 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 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 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);
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
---
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 abd0e6b05f79..825d9eb34f10 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4759,6 +4759,8 @@ 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 2ae6c7c8528c..978781c538c4 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 c2961d37cc1c..c0651fe6dbbc 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,
};
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
---
Documentation/block/index.rst | 1 +
Documentation/block/inline-encryption.rst | 195 +++++++
block/Kconfig | 10 +
block/Makefile | 1 +
block/blk-crypto-fallback.c | 662 ++++++++++++++++++++++
block/blk-crypto-internal.h | 24 +
block/blk-crypto.c | 47 +-
include/linux/blk-crypto.h | 17 +-
8 files changed, 943 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 3fa7a52fafa4..026addfc69bc 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 000000000000..3fa475799ecd
--- /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 c04a1d500842..0af387623774 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 82f42ca3f769..9464fb6ae423 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 000000000000..0925325c9433
--- /dev/null
+++ b/block/blk-crypto-fallback.c
@@ -0,0 +1,662 @@
+// 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 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 blk_status_t blk_crypto_keyslot_program(struct 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 BLK_STS_IOERR;
+ }
+ return BLK_STS_OK;
+}
+
+static int blk_crypto_keyslot_evict(struct 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 keyslot_mgmt_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 void 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;
+ }
+
+ 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;
+}
+
+static void 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;
+ }
+ bio_chain(split_bio, bio);
+ generic_make_request(bio);
+ *bio_ptr = split_bio;
+ }
+}
+
+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. Sets bio->bi_status on error.
+ */
+static void 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;
+ int err = 0;
+ blk_status_t blk_st;
+
+ /* Split the bio if it's too big for single page bvec */
+ blk_crypto_split_bio_if_needed(bio_ptr);
+ if ((*bio_ptr)->bi_status != BLK_STS_OK)
+ return;
+
+ 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;
+ }
+
+ /*
+ * 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 */
+ blk_crypto_alloc_cipher_req(src_bio, slot, &ciph_req, &wait);
+ if (src_bio->bi_status != BLK_STS_OK)
+ 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);
+ err = crypto_wait_req(crypto_skcipher_encrypt(ciph_req),
+ &wait);
+ if (err) {
+ 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;
+
+ 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);
+}
+
+/*
+ * 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 */
+ blk_crypto_alloc_cipher_req(bio, slot, &ciph_req, &wait);
+ if (bio->bi_status != BLK_STS_OK)
+ 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).
+ *
+ * Sets bio->bi_status on error.
+ */
+void 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;
+ }
+
+ if (!blk_ksm_crypto_key_supported(&blk_crypto_ksm, bc->bc_key)) {
+ bio->bi_status = BLK_STS_NOTSUPP;
+ return;
+ }
+
+ if (bio_data_dir(bio) == WRITE) {
+ blk_crypto_fallback_encrypt_bio(bio_ptr);
+ return;
+ }
+
+ /*
+ * 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);
+}
+
+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, NULL, 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 5cdf45167117..a8b7c9c4b8da 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
void bio_crypt_ctx_init(void);
@@ -141,4 +143,26 @@ static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
+
+void 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 void 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;
+}
+
+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 1c38de053bb6..3b3beed6560f 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>
@@ -193,7 +197,8 @@ static void bio_crypt_check_alignment(struct bio *bio)
/**
* blk_crypto_init_request - Initializes the request's crypto fields based on
* the bio to be added to the request, and prepares
- * it for hardware inline encryption.
+ * it for hardware inline encryption (as opposed to
+ * using the crypto API fallback).
*
* @rq: The request to init
* @bio: The bio that will (eventually) be added to @rq.
@@ -210,6 +215,10 @@ blk_status_t blk_crypto_init_request(struct request *rq, struct bio *bio)
blk_crypto_rq_set_defaults(rq);
+ /*
+ * We have a bio crypt context here - that means we didn't fallback
+ * to crypto API, so try to program a keyslot now.
+ */
err = blk_ksm_get_slot_for_key(rq->q->ksm,
bio->bi_crypt_context->bc_key,
&rq->crypt_keyslot);
@@ -240,9 +249,16 @@ 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.
*
@@ -268,16 +284,16 @@ int 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 0;
- return 0;
+ blk_crypto_fallback_bio_prep(bio_ptr);
+ if ((*bio_ptr)->bi_status == BLK_STS_OK)
+ return 0;
fail:
bio_endio(*bio_ptr);
return -EIO;
@@ -301,6 +317,10 @@ 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;
}
@@ -395,6 +415,7 @@ 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.
*/
@@ -404,5 +425,5 @@ 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 90a28df26106..9c54bc34044e 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;
@@ -110,6 +110,21 @@ static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
+#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 /* CONFIG_BLOCK */
#endif /* __LINUX_BLK_CRYPTO_H */
--
2.25.1.481.gfbce0eb801-goog
Wire up ufshcd.c with the UFS Crypto API, the block layer inline
encryption additions and the keyslot manager.
Signed-off-by: Satya Tangirala <[email protected]>
---
drivers/scsi/ufs/ufshcd-crypto.c | 27 +++++++++++++++
drivers/scsi/ufs/ufshcd-crypto.h | 14 ++++++++
drivers/scsi/ufs/ufshcd.c | 59 +++++++++++++++++++++++++++++---
drivers/scsi/ufs/ufshcd.h | 8 +++++
4 files changed, 103 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
index 8b6f7c83f77f..37254472326a 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.c
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -368,3 +368,30 @@ void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
{
blk_ksm_destroy(&hba->ksm);
}
+
+int ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
+ struct scsi_cmnd *cmd,
+ struct ufshcd_lrb *lrbp)
+{
+ struct request *rq = cmd->request;
+ struct bio_crypt_ctx *bc = rq->crypt_ctx;
+ unsigned int slot_idx = blk_ksm_get_slot_idx(rq->crypt_keyslot);
+
+ lrbp->crypto_enable = false;
+
+ if (WARN_ON(!(hba->caps & UFSHCD_CAP_CRYPTO))) {
+ /*
+ * Upper layer asked us to do inline encryption
+ * but that isn't enabled, so we fail this request.
+ */
+ return -EINVAL;
+ }
+ if (!ufshcd_keyslot_valid(hba, slot_idx))
+ return -EINVAL;
+
+ lrbp->crypto_enable = true;
+ lrbp->crypto_key_slot = slot_idx;
+ lrbp->data_unit_num = bc->bc_dun[0];
+
+ return 0;
+}
diff --git a/drivers/scsi/ufs/ufshcd-crypto.h b/drivers/scsi/ufs/ufshcd-crypto.h
index 8270c0c5081a..c76f93ede51c 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.h
+++ b/drivers/scsi/ufs/ufshcd-crypto.h
@@ -16,6 +16,15 @@ static inline bool ufshcd_hba_is_crypto_supported(struct ufs_hba *hba)
return hba->crypto_capabilities.reg_val != 0;
}
+int ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
+ struct scsi_cmnd *cmd,
+ struct ufshcd_lrb *lrbp);
+
+static inline bool ufshcd_lrbp_crypto_enabled(struct ufshcd_lrb *lrbp)
+{
+ return lrbp->crypto_enable;
+}
+
void ufshcd_crypto_enable(struct ufs_hba *hba);
void ufshcd_crypto_disable(struct ufs_hba *hba);
@@ -49,6 +58,11 @@ static inline void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
static inline void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
{ }
+static inline bool ufshcd_lrbp_crypto_enabled(struct ufshcd_lrb *lrbp)
+{
+ return false;
+}
+
#endif /* CONFIG_SCSI_UFS_CRYPTO */
#endif /* _UFSHCD_CRYPTO_H */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 825d9eb34f10..3a19966dbee9 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 +817,14 @@ 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_hba_is_crypto_supported(hba)) {
+ ufshcd_crypto_enable(hba);
+ val |= CRYPTO_GENERAL_ENABLE;
+ }
+
+ ufshcd_writel(hba, val, REG_CONTROLLER_ENABLE);
}
/**
@@ -2192,9 +2200,23 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
dword_0 |= UTP_REQ_DESC_INT_CMD;
/* Transfer request descriptor header fields */
+ if (ufshcd_lrbp_crypto_enabled(lrbp)) {
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+ dword_0 |= UTP_REQ_DESC_CRYPTO_ENABLE_CMD;
+ dword_0 |= lrbp->crypto_key_slot;
+ req_desc->header.dword_1 =
+ cpu_to_le32(lower_32_bits(lrbp->data_unit_num));
+ req_desc->header.dword_3 =
+ cpu_to_le32(upper_32_bits(lrbp->data_unit_num));
+#endif /* CONFIG_SCSI_UFS_CRYPTO */
+ } else {
+ /* dword_1 and dword_3 are reserved, hence they are set to 0 */
+ req_desc->header.dword_1 = 0;
+ req_desc->header.dword_3 = 0;
+ }
+
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;
+
/*
* assigning invalid value for command status. Controller
* updates OCS on command completion, with the command
@@ -2202,8 +2224,6 @@ 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->prd_table_length = 0;
}
@@ -2437,6 +2457,20 @@ 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;
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+ if (cmd->request->crypt_keyslot) {
+ err = ufshcd_prepare_lrbp_crypto(hba, cmd, lrbp);
+ if (err) {
+ lrbp->cmd = NULL;
+ ufshcd_release(hba);
+ goto out;
+ }
+ } else {
+ lrbp->crypto_enable = false;
+ }
+#endif
+
lrbp->req_abort_skip = false;
ufshcd_comp_scsi_upiu(hba, lrbp);
@@ -2470,6 +2504,9 @@ 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_enable = false; /* No crypto operations */
+#endif
hba->dev_cmd.type = cmd_type;
return ufshcd_comp_devman_upiu(hba, lrbp);
@@ -4208,6 +4245,8 @@ static inline void ufshcd_hba_stop(struct ufs_hba *hba, bool can_sleep)
{
int err;
+ ufshcd_crypto_disable(hba);
+
ufshcd_writel(hba, CONTROLLER_DISABLE, REG_CONTROLLER_ENABLE);
err = ufshcd_wait_for_register(hba, REG_CONTROLLER_ENABLE,
CONTROLLER_ENABLE, CONTROLLER_DISABLE,
@@ -4624,6 +4663,8 @@ 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;
}
@@ -8304,6 +8345,7 @@ 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);
@@ -8513,6 +8555,13 @@ 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 ee37dd44d5e6..78397864f911 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -168,6 +168,9 @@ 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_enable: whether or not the request needs inline crypto operations
+ * @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 +195,11 @@ struct ufshcd_lrb {
bool intr_cmd;
ktime_t issue_time_stamp;
ktime_t compl_time_stamp;
+#if IS_ENABLED(CONFIG_SCSI_UFS_CRYPTO)
+ bool crypto_enable;
+ u8 crypto_key_slot;
+ u64 data_unit_num;
+#endif /* CONFIG_SCSI_UFS_CRYPTO */
bool req_abort_skip;
};
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
---
drivers/scsi/ufs/Kconfig | 9 +
drivers/scsi/ufs/Makefile | 1 +
drivers/scsi/ufs/ufshcd-crypto.c | 370 +++++++++++++++++++++++++++++++
drivers/scsi/ufs/ufshcd-crypto.h | 54 +++++
drivers/scsi/ufs/ufshcd.h | 14 ++
5 files changed, 448 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 d14c2243e02a..c69f1b49167b 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 94c6c5d7334b..197e178f44bc 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 000000000000..8b6f7c83f77f
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include <linux/keyslot-manager.h>
+#include "ufshcd.h"
+#include "ufshcd-crypto.h"
+
+static inline int ufshcd_num_keyslots(struct ufs_hba *hba)
+{
+ return hba->crypto_capabilities.config_count + 1;
+}
+
+static inline bool ufshcd_keyslot_valid(struct ufs_hba *hba, unsigned int slot)
+{
+ /*
+ * The actual number of configurations supported is (CFGC+1), so slot
+ * numbers range from 0 to config_count inclusive.
+ */
+ return slot < ufshcd_num_keyslots(hba);
+}
+
+static bool ufshcd_cap_idx_valid(struct ufs_hba *hba, unsigned int cap_idx)
+{
+ return cap_idx < hba->crypto_capabilities.num_crypto_cap;
+}
+
+static u8 ufshcd_get_data_unit_size_mask(unsigned int data_unit_size)
+{
+ if (data_unit_size < 512 || data_unit_size > 65536 ||
+ !is_power_of_2(data_unit_size))
+ return 0;
+
+ return data_unit_size / 512;
+}
+
+static size_t ufshcd_get_keysize_bytes(enum ufs_crypto_key_size size)
+{
+ switch (size) {
+ case UFS_CRYPTO_KEY_SIZE_128:
+ return 16;
+ case UFS_CRYPTO_KEY_SIZE_192:
+ return 24;
+ case UFS_CRYPTO_KEY_SIZE_256:
+ return 32;
+ case UFS_CRYPTO_KEY_SIZE_512:
+ return 64;
+ default:
+ return 0;
+ }
+}
+
+/* Blk-crypto modes supported by UFS crypto */
+static const struct {
+ enum ufs_crypto_alg ufs_alg;
+ enum ufs_crypto_key_size ufs_key_size;
+ enum blk_crypto_mode_num blk_mode;
+ bool supported;
+} 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,
+ .blk_mode = BLK_ENCRYPTION_MODE_AES_256_XTS,
+ .supported = true,
+ },
+};
+
+static int ufshcd_crypto_cap_find(struct ufs_hba *hba,
+ enum blk_crypto_mode_num crypto_mode,
+ unsigned int data_unit_size)
+{
+ enum ufs_crypto_alg ufs_alg;
+ u8 data_unit_mask;
+ int cap_idx;
+ enum ufs_crypto_key_size ufs_key_size;
+ union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
+
+ if (!ufshcd_hba_is_crypto_supported(hba))
+ return -EINVAL;
+
+ if (!ufs_crypto_algs[crypto_mode].supported)
+ return -EINVAL;
+
+ ufs_alg = ufs_crypto_algs[crypto_mode].ufs_alg;
+ ufs_key_size = ufs_crypto_algs[crypto_mode].ufs_key_size;
+
+ data_unit_mask = ufshcd_get_data_unit_size_mask(data_unit_size);
+
+ for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
+ cap_idx++) {
+ if (ccap_array[cap_idx].algorithm_id == ufs_alg &&
+ (ccap_array[cap_idx].sdus_mask & data_unit_mask) &&
+ ccap_array[cap_idx].key_size == ufs_key_size)
+ return cap_idx;
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * ufshcd_crypto_cfg_entry_write_key - Write a key into a crypto_cfg_entry
+ *
+ * Writes the key with the appropriate format - for AES_XTS,
+ * the first half of the key is copied as is, the second half is
+ * copied with an offset halfway into the cfg->crypto_key array.
+ * For the other supported crypto algs, the key is just copied.
+ *
+ * @cfg: The crypto config to write to
+ * @key: The key to write
+ * @cap: The crypto capability (which specifies the crypto alg and key size)
+ *
+ * Returns BLK_STS_OK on success, or BLK_STS_IOERR on error
+ */
+static blk_status_t ufshcd_crypto_cfg_entry_write_key(
+ union ufs_crypto_cfg_entry *cfg,
+ const u8 *key,
+ union ufs_crypto_cap_entry cap)
+{
+ size_t key_size_bytes = ufshcd_get_keysize_bytes(cap.key_size);
+
+ if (key_size_bytes == 0)
+ return BLK_STS_IOERR;
+
+ switch (cap.algorithm_id) {
+ case UFS_CRYPTO_ALG_AES_XTS:
+ key_size_bytes *= 2;
+ if (key_size_bytes > UFS_CRYPTO_KEY_MAX_SIZE)
+ return BLK_STS_IOERR;
+
+ memcpy(cfg->crypto_key, key, key_size_bytes/2);
+ memcpy(cfg->crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
+ key + key_size_bytes/2, key_size_bytes/2);
+ return BLK_STS_OK;
+ case UFS_CRYPTO_ALG_BITLOCKER_AES_CBC:
+ /* fall through */
+ case UFS_CRYPTO_ALG_AES_ECB:
+ /* fall through */
+ case UFS_CRYPTO_ALG_ESSIV_AES_CBC:
+ memcpy(cfg->crypto_key, key, key_size_bytes);
+ return BLK_STS_OK;
+ }
+
+ return BLK_STS_IOERR;
+}
+
+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 void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
+{
+ union ufs_crypto_cfg_entry cfg = { 0 };
+
+ ufshcd_program_key(hba, &cfg, slot);
+}
+
+/* Clear all keyslots at driver init time */
+static void ufshcd_clear_all_keyslots(struct ufs_hba *hba)
+{
+ int slot;
+
+ for (slot = 0; slot < ufshcd_num_keyslots(hba); slot++)
+ ufshcd_clear_keyslot(hba, slot);
+}
+
+static blk_status_t ufshcd_crypto_keyslot_program(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot)
+{
+ struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+ blk_status_t err = BLK_STS_OK;
+ u8 data_unit_mask;
+ union ufs_crypto_cfg_entry cfg;
+ int cap_idx;
+
+ cap_idx = ufshcd_crypto_cap_find(hba, key->crypto_mode,
+ key->data_unit_size);
+
+ if (!(hba->caps & UFSHCD_CAP_CRYPTO) ||
+ !ufshcd_keyslot_valid(hba, slot) ||
+ !ufshcd_cap_idx_valid(hba, cap_idx))
+ return BLK_STS_IOERR;
+
+ data_unit_mask = ufshcd_get_data_unit_size_mask(key->data_unit_size);
+
+ if (!(data_unit_mask & hba->crypto_cap_array[cap_idx].sdus_mask))
+ return BLK_STS_IOERR;
+
+ memset(&cfg, 0, sizeof(cfg));
+ cfg.data_unit_size = data_unit_mask;
+ cfg.crypto_cap_idx = cap_idx;
+ cfg.config_enable |= UFS_CRYPTO_CONFIGURATION_ENABLE;
+
+ err = ufshcd_crypto_cfg_entry_write_key(&cfg, key->raw,
+ hba->crypto_cap_array[cap_idx]);
+ if (err)
+ return err;
+
+ ufshcd_program_key(hba, &cfg, slot);
+
+ memzero_explicit(&cfg, sizeof(cfg));
+ return BLK_STS_OK;
+}
+
+static int ufshcd_crypto_keyslot_evict(struct keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot)
+{
+ struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+
+ if (!(hba->caps & UFSHCD_CAP_CRYPTO) ||
+ !ufshcd_keyslot_valid(hba, slot))
+ return -EINVAL;
+
+ /*
+ * Clear the crypto cfg on the device. Clearing CFGE
+ * might not be sufficient, so just clear the entire cfg.
+ */
+ ufshcd_clear_keyslot(hba, slot);
+
+ return 0;
+}
+
+void ufshcd_crypto_enable(struct ufs_hba *hba)
+{
+ if (!ufshcd_hba_is_crypto_supported(hba))
+ return;
+
+ hba->caps |= UFSHCD_CAP_CRYPTO;
+
+ /* Reset might clear all keys, so reprogram all the keys. */
+ blk_ksm_reprogram_all_keys(&hba->ksm);
+}
+
+void ufshcd_crypto_disable(struct ufs_hba *hba)
+{
+ hba->caps &= ~UFSHCD_CAP_CRYPTO;
+}
+
+static const struct keyslot_mgmt_ll_ops ufshcd_ksm_ops = {
+ .keyslot_program = ufshcd_crypto_keyslot_program,
+ .keyslot_evict = ufshcd_crypto_keyslot_evict,
+};
+
+static enum blk_crypto_mode_num ufshcd_blk_crypto_mode_num_for_alg_keysize(
+ enum ufs_crypto_alg ufs_crypto_alg,
+ enum ufs_crypto_key_size key_size)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
+ if (ufs_crypto_algs[i].supported &&
+ ufs_crypto_algs[i].ufs_alg == ufs_crypto_alg &&
+ ufs_crypto_algs[i].ufs_key_size == key_size) {
+ return ufs_crypto_algs[i].blk_mode;
+ }
+ }
+ 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;
+
+ /*
+ * Return 0 if crypto support isn't present/not advertised by vendor
+ * specific driver.
+ */
+ if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
+ !(hba->caps & UFSHCD_CAP_CRYPTO))
+ goto out;
+
+ /*
+ * Crypto Capabilities should never be 0, because the
+ * config_array_ptr > 04h. So we use a 0 value to indicate that
+ * crypto init failed, and can't be enabled.
+ */
+ 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;
+ }
+
+ err = blk_ksm_init(&hba->ksm, hba->dev, ufshcd_num_keyslots(hba));
+ 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;
+
+ /*
+ * Store all the capabilities and fill up the keyslot manager's
+ * supported crypto modes.
+ */
+ 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_blk_crypto_mode_num_for_alg_keysize(
+ hba->crypto_cap_array[cap_idx].algorithm_id,
+ hba->crypto_cap_array[cap_idx].key_size);
+ 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;
+ }
+
+ ufshcd_clear_all_keyslots(hba);
+
+ return 0;
+
+out_free_caps:
+ devm_kfree(hba->dev, hba->crypto_cap_array);
+out:
+ /* Indicate that init failed by setting crypto_capabilities to 0 */
+ hba->crypto_capabilities.reg_val = 0;
+ return err;
+}
+
+void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
+ struct request_queue *q)
+{
+ if (!ufshcd_hba_is_crypto_supported(hba) || !q)
+ return;
+
+ 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 000000000000..8270c0c5081a
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd-crypto.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef _UFSHCD_CRYPTO_H
+#define _UFSHCD_CRYPTO_H
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+#include <linux/keyslot-manager.h>
+#include "ufshcd.h"
+#include "ufshci.h"
+
+static inline bool ufshcd_hba_is_crypto_supported(struct ufs_hba *hba)
+{
+ return hba->crypto_capabilities.reg_val != 0;
+}
+
+void 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_hba_is_crypto_supported(struct ufs_hba *hba)
+{
+ return false;
+}
+
+static inline void ufshcd_crypto_enable(struct ufs_hba *hba) { }
+
+static inline void ufshcd_crypto_disable(struct ufs_hba *hba) { }
+
+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 978781c538c4..ee37dd44d5e6 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;
@@ -634,6 +639,7 @@ struct ufs_hba {
* enabled via HCE register.
*/
#define UFSHCI_QUIRK_BROKEN_HCE 0x400
+
unsigned int quirks; /* Deviations from standard UFSHCI spec. */
/* Device deviations from standard UFS device spec. */
@@ -735,6 +741,14 @@ struct ufs_hba {
struct device bsg_dev;
struct request_queue *bsg_queue;
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+ /* crypto */
+ union ufs_crypto_capabilities crypto_capabilities;
+ union ufs_crypto_cap_entry *crypto_cap_array;
+ u32 crypto_cfg_register;
+ struct keyslot_manager ksm;
+#endif /* CONFIG_SCSI_UFS_CRYPTO */
};
/* Returns true if clocks can be gated. Otherwise false */
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Satya Tangirala <[email protected]>
---
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 8046d7c7a3e9..f1f11a6228eb 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 232e2bb5a337..652c7180ec6d 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 4fa18fff9c4e..cec06edd8352 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 1ecaac7ee3cb..263bc676c73d 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 4c212442a8f7..0fca2d7a5645 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 9aae851409e5..2032c81a0675 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 000000000000..9dc0b0694668
--- /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 blk_crypto_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);
+
+ blk_crypto_dun_bytes = 8;
+ if (fscrypt_policy_flags(&ci->ci_policy) &
+ FSCRYPT_POLICY_FLAG_DIRECT_KEY)
+ blk_crypto_dun_bytes += FS_KEY_DERIVATION_NONCE_SIZE;
+
+ err = blk_crypto_init_key(&blk_key->base, raw_key, crypto_mode,
+ blk_crypto_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 ab41b25d4fa1..d8ab33f631ba 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 65cb09fa6ead..fd6cc201b383 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 801b48c0cd7f..59c520b200cb 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 556f4adf5dc5..1d9810eb88b1 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
--
2.25.1.481.gfbce0eb801-goog
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 <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Satya Tangirala <[email protected]>
---
Documentation/filesystems/f2fs.txt | 6 +++
fs/f2fs/compress.c | 2 +-
fs/f2fs/data.c | 68 +++++++++++++++++++++++++-----
fs/f2fs/f2fs.h | 3 ++
fs/f2fs/super.c | 33 +++++++++++++++
5 files changed, 101 insertions(+), 11 deletions(-)
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 4eb3e2ddd00e..300d5843cbe4 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 d8a64be90a50..6ae313ea5432 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 b27b72107911..75dda6735488 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/f2fs.h b/fs/f2fs/f2fs.h
index 5355be6b6755..75817f0dc6f8 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -139,6 +139,9 @@ struct f2fs_mount_info {
int alloc_mode; /* segment allocation policy */
int fsync_mode; /* fsync policy */
bool test_dummy_encryption; /* test dummy encryption */
+#ifdef CONFIG_FS_ENCRYPTION
+ bool inlinecrypt; /* inline encryption enabled */
+#endif
block_t unusable_cap; /* Amount of space allowed to be
* unusable when disabling checkpoint
*/
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a432dfee..aedbf4cae083 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:
@@ -1568,6 +1577,9 @@ static void default_options(struct f2fs_sb_info *sbi)
F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_POSIX;
F2FS_OPTION(sbi).test_dummy_encryption = false;
+#ifdef CONFIG_FS_ENCRYPTION
+ sbi->sb->s_flags &= ~SB_INLINECRYPT;
+#endif
F2FS_OPTION(sbi).s_resuid = make_kuid(&init_user_ns, F2FS_DEF_RESUID);
F2FS_OPTION(sbi).s_resgid = make_kgid(&init_user_ns, F2FS_DEF_RESGID);
F2FS_OPTION(sbi).compress_algorithm = COMPRESS_LZO;
@@ -2415,6 +2427,25 @@ 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 +2455,8 @@ 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
--
2.25.1.481.gfbce0eb801-goog
Introduce SB_INLINECRYPT, which is set by filesystems that wish to use
blk-crypto for file content en/decryption.
Signed-off-by: Satya Tangirala <[email protected]>
---
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 273ee82d8aa9..8bf195d3bda6 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 3cd4fe6b845e..08a0395674dd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1370,6 +1370,7 @@ 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) /* inodes in SB use blk-crypto */
#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 */
--
2.25.1.481.gfbce0eb801-goog
From: Eric Biggers <[email protected]>
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 <[email protected]>
Co-developed-by: Satya Tangirala <[email protected]>
Signed-off-by: Satya Tangirala <[email protected]>
---
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 9443fcef1876..ed997e376678 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 b8d28370cfd7..226f1784eda7 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 fa0ff78dc033..5714ff6395a1 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 68b39e75446a..0757145a31b2 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 c1769afbf799..68eac0aeffad 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 0c7c4adb664e..2054da2ddde4 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++)
--
2.25.1.481.gfbce0eb801-goog
On Thu, Mar 12, 2020 at 01:02:42AM -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-v8
I based it on v5.6-rc2 (same base commit as v7) since it still applies cleanly
to it. You can see what changed by:
git diff inline-encryption-v7..inline-encryption-v8
- Eric
On Thu, Mar 12, 2020 at 01:02:52AM -0700, Satya Tangirala wrote:
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 5355be6b6755..75817f0dc6f8 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -139,6 +139,9 @@ struct f2fs_mount_info {
> int alloc_mode; /* segment allocation policy */
> int fsync_mode; /* fsync policy */
> bool test_dummy_encryption; /* test dummy encryption */
> +#ifdef CONFIG_FS_ENCRYPTION
> + bool inlinecrypt; /* inline encryption enabled */
> +#endif
> block_t unusable_cap; /* Amount of space allowed to be
> * unusable when disabling checkpoint
> */
This bool is unused now.
> @@ -1568,6 +1577,9 @@ static void default_options(struct f2fs_sb_info *sbi)
> F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
> F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_POSIX;
> F2FS_OPTION(sbi).test_dummy_encryption = false;
> +#ifdef CONFIG_FS_ENCRYPTION
> + sbi->sb->s_flags &= ~SB_INLINECRYPT;
> +#endif
This really should be CONFIG_FS_ENCRYPTION_INLINE_CRYPT, but actually there's no
need for the #ifdef at all. Just clear the flag unconditionally.
- Eric
On Thu, Mar 12, 2020 at 01:02:51AM -0700, Satya Tangirala wrote:
> +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 blk_crypto_dun_bytes;
'blk_crypto_dun_bytes' is overly verbose. 'dun_bytes' would still be just as
clear.
This comment also applies to the parameter to blk_crypto_init_key().
> +/**
> + * 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);
Nit: the continuation lines for the function arguments aren't aligned.
- Eric
On Thu, Mar 12, 2020 at 01:02:48AM -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.
>
> Signed-off-by: Satya Tangirala <[email protected]>
> ---
> drivers/scsi/ufs/Kconfig | 9 +
> drivers/scsi/ufs/Makefile | 1 +
> drivers/scsi/ufs/ufshcd-crypto.c | 370 +++++++++++++++++++++++++++++++
> drivers/scsi/ufs/ufshcd-crypto.h | 54 +++++
> drivers/scsi/ufs/ufshcd.h | 14 ++
> 5 files changed, 448 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 d14c2243e02a..c69f1b49167b 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 94c6c5d7334b..197e178f44bc 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 000000000000..8b6f7c83f77f
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufshcd-crypto.c
> @@ -0,0 +1,370 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 Google LLC
> + */
> +
> +#include <linux/keyslot-manager.h>
> +#include "ufshcd.h"
> +#include "ufshcd-crypto.h"
Since keyslot-manager.h now has to be included in ufshcd.h anyway since now
there's a struct keyslot_manager embedded in struct ufs_hba, there's no need to
include keyslot-manager.h here and in ufshcd-crypto.h too.
> +
> +static inline int ufshcd_num_keyslots(struct ufs_hba *hba)
> +{
> + return hba->crypto_capabilities.config_count + 1;
> +}
> +
> +static inline bool ufshcd_keyslot_valid(struct ufs_hba *hba, unsigned int slot)
> +{
> + /*
> + * The actual number of configurations supported is (CFGC+1), so slot
> + * numbers range from 0 to config_count inclusive.
> + */
> + return slot < ufshcd_num_keyslots(hba);
> +}
> +
> +static bool ufshcd_cap_idx_valid(struct ufs_hba *hba, unsigned int cap_idx)
> +{
> + return cap_idx < hba->crypto_capabilities.num_crypto_cap;
> +}
ufshcd_cap_idx_valid() isn't needed since it's only used to check the return
value of ufshcd_crypto_cap_find().
> +
> +static u8 ufshcd_get_data_unit_size_mask(unsigned int data_unit_size)
> +{
> + if (data_unit_size < 512 || data_unit_size > 65536 ||
> + !is_power_of_2(data_unit_size))
> + return 0;
> +
> + return data_unit_size / 512;
> +}
ufshcd_get_data_unit_size_mask() isn't needed since it's only used via
ufshcd_crypto_keyslot_program() which already knows it has a data_unit_size the
driver supports. So just do 'ufs_data_unit_size = key->data_unit_size / 512'
> +
> +static size_t ufshcd_get_keysize_bytes(enum ufs_crypto_key_size size)
> +{
> + switch (size) {
> + case UFS_CRYPTO_KEY_SIZE_128:
> + return 16;
> + case UFS_CRYPTO_KEY_SIZE_192:
> + return 24;
> + case UFS_CRYPTO_KEY_SIZE_256:
> + return 32;
> + case UFS_CRYPTO_KEY_SIZE_512:
> + return 64;
> + default:
> + return 0;
> + }
> +}
ufshcd_get_keysize_bytes() isn't needed since it's only used via
ufshcd_crypto_keyslot_program() which already has access to key->size.
> +
> +/* Blk-crypto modes supported by UFS crypto */
> +static const struct {
> + enum ufs_crypto_alg ufs_alg;
> + enum ufs_crypto_key_size ufs_key_size;
> + enum blk_crypto_mode_num blk_mode;
> + bool supported;
> +} 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,
> + .blk_mode = BLK_ENCRYPTION_MODE_AES_256_XTS,
> + .supported = true,
> + },
> +};
The '.blk_mode' field is unnecessary since it's the same as the array index.
I was also confused by the '.supported' field and under what circumstances it
would be set to false. It's actually just used to indicate that the array entry
is used. That's not necessary since UFS_CRYPTO_KEY_SIZE_INVALID == 0. (To make
the assumption clear, we can add BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0))
> +static int ufshcd_crypto_cap_find(struct ufs_hba *hba,
> + enum blk_crypto_mode_num crypto_mode,
> + unsigned int data_unit_size)
> +{
> + enum ufs_crypto_alg ufs_alg;
> + u8 data_unit_mask;
> + int cap_idx;
> + enum ufs_crypto_key_size ufs_key_size;
> + union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
> +
> + if (!ufshcd_hba_is_crypto_supported(hba))
> + return -EINVAL;
> +
> + if (!ufs_crypto_algs[crypto_mode].supported)
> + return -EINVAL;
> +
> + ufs_alg = ufs_crypto_algs[crypto_mode].ufs_alg;
> + ufs_key_size = ufs_crypto_algs[crypto_mode].ufs_key_size;
> +
> + data_unit_mask = ufshcd_get_data_unit_size_mask(data_unit_size);
> +
> + for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
> + cap_idx++) {
> + if (ccap_array[cap_idx].algorithm_id == ufs_alg &&
> + (ccap_array[cap_idx].sdus_mask & data_unit_mask) &&
> + ccap_array[cap_idx].key_size == ufs_key_size)
> + return cap_idx;
> + }
> +
> + return -EINVAL;
> +}
This is only called once. It would be simpler to just inline it into the
caller. The ufshcd_hba_is_crypto_supported() and
ufs_crypto_algs[crypto_mode].supported checks are also unnecessary.
> +
> +/**
> + * ufshcd_crypto_cfg_entry_write_key - Write a key into a crypto_cfg_entry
> + *
> + * Writes the key with the appropriate format - for AES_XTS,
> + * the first half of the key is copied as is, the second half is
> + * copied with an offset halfway into the cfg->crypto_key array.
> + * For the other supported crypto algs, the key is just copied.
> + *
> + * @cfg: The crypto config to write to
> + * @key: The key to write
> + * @cap: The crypto capability (which specifies the crypto alg and key size)
> + *
> + * Returns BLK_STS_OK on success, or BLK_STS_IOERR on error
> + */
> +static blk_status_t ufshcd_crypto_cfg_entry_write_key(
> + union ufs_crypto_cfg_entry *cfg,
> + const u8 *key,
> + union ufs_crypto_cap_entry cap)
> +{
> + size_t key_size_bytes = ufshcd_get_keysize_bytes(cap.key_size);
> +
> + if (key_size_bytes == 0)
> + return BLK_STS_IOERR;
> +
> + switch (cap.algorithm_id) {
> + case UFS_CRYPTO_ALG_AES_XTS:
> + key_size_bytes *= 2;
> + if (key_size_bytes > UFS_CRYPTO_KEY_MAX_SIZE)
> + return BLK_STS_IOERR;
> +
> + memcpy(cfg->crypto_key, key, key_size_bytes/2);
> + memcpy(cfg->crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
> + key + key_size_bytes/2, key_size_bytes/2);
> + return BLK_STS_OK;
> + case UFS_CRYPTO_ALG_BITLOCKER_AES_CBC:
> + /* fall through */
> + case UFS_CRYPTO_ALG_AES_ECB:
> + /* fall through */
> + case UFS_CRYPTO_ALG_ESSIV_AES_CBC:
> + memcpy(cfg->crypto_key, key, key_size_bytes);
> + return BLK_STS_OK;
> + }
> +
> + return BLK_STS_IOERR;
> +}
Likewise, this is only called once, and the error checks are unnecessary as this
is only called from ufshcd_crypto_keyslot_program() where we know the algorithm
is supported by the UFS driver. It would be much simpler to just inline this
into the caller.
The switch statement can also be simplified to an 'if', since XTS is the only
algorithm that requires special handling and it's likely to remain that way.
The "two keys" thing is pretty unique to XTS.
> +
> +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 void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
> +{
> + union ufs_crypto_cfg_entry cfg = { 0 };
> +
> + ufshcd_program_key(hba, &cfg, slot);
> +}
It may make sense to move ufshcd_clear_keyslot() to just above
ufshcd_crypto_keyslot_evict(), so that the key eviction code is grouped
together.
> +/* Clear all keyslots at driver init time */
> +static void ufshcd_clear_all_keyslots(struct ufs_hba *hba)
> +{
> + int slot;
> +
> + for (slot = 0; slot < ufshcd_num_keyslots(hba); slot++)
> + ufshcd_clear_keyslot(hba, slot);
> +}
This is only called once. It would be simpler to just inline it into
ufshcd_hba_init_crypto().
> +static blk_status_t ufshcd_crypto_keyslot_program(struct keyslot_manager *ksm,
> + const struct blk_crypto_key *key,
> + unsigned int slot)
> +{
> + struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
> + blk_status_t err = BLK_STS_OK;
> + u8 data_unit_mask;
> + union ufs_crypto_cfg_entry cfg;
> + int cap_idx;
> +
> + cap_idx = ufshcd_crypto_cap_find(hba, key->crypto_mode,
> + key->data_unit_size);
> +
> + if (!(hba->caps & UFSHCD_CAP_CRYPTO) ||
> + !ufshcd_keyslot_valid(hba, slot) ||
> + !ufshcd_cap_idx_valid(hba, cap_idx))
> + return BLK_STS_IOERR;
> +
> + data_unit_mask = ufshcd_get_data_unit_size_mask(key->data_unit_size);
> +
> + if (!(data_unit_mask & hba->crypto_cap_array[cap_idx].sdus_mask))
> + return BLK_STS_IOERR;
> +
> + memset(&cfg, 0, sizeof(cfg));
> + cfg.data_unit_size = data_unit_mask;
> + cfg.crypto_cap_idx = cap_idx;
> + cfg.config_enable |= UFS_CRYPTO_CONFIGURATION_ENABLE;
> +
> + err = ufshcd_crypto_cfg_entry_write_key(&cfg, key->raw,
> + hba->crypto_cap_array[cap_idx]);
> + if (err)
> + return err;
> +
> + ufshcd_program_key(hba, &cfg, slot);
> +
> + memzero_explicit(&cfg, sizeof(cfg));
> + return BLK_STS_OK;
> +}
ufshcd_crypto_keyslot_program() is much more complicated than necessary. It
calls several functions that are only called once, and could be simplified if
inlined. It also does lots of checks that are unnecessary because the block
layer already guarantees that it's called with a valid keyslot and a
(crypto_mode, data unit_size) pair the driver supports.
I also don't see any benefit to the change from errno to blk_status_t here.
It's inconsistent with keyslot_evict(), which is going to cause confusion. It
also doesn't match what blk-crypto-fallback wants. It seems it would be better
to just have blk_ksm_get_slot_for_key() use errno_to_blk_status() instead.
So how about something like the following:
static int ufshcd_crypto_keyslot_program(struct 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 *ccaps = hba->crypto_cap_array;
const struct ufs_crypto_alg_entry *alg =
&ufs_crypto_algs[key->crypto_mode];
unsigned int ufs_data_unit_size = key->data_unit_size / 512;
int cap_idx;
union ufs_crypto_cfg_entry cfg = { 0 };
/* Find the corresponding crypto capability */
for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
cap_idx++) {
if (ccaps[cap_idx].algorithm_id == alg->ufs_alg &&
ccaps[cap_idx].key_size == alg->ufs_key_size &&
(ccaps[cap_idx].sdus_mask & ufs_data_unit_size))
break;
}
if (WARN_ON(cap_idx == hba->crypto_capabilities.num_crypto_cap))
return -EOPNOTSUPP;
if (alg->ufs_alg == UFS_CRYPTO_ALG_AES_XTS) {
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);
}
cfg.data_unit_size = ufs_data_unit_size;
cfg.crypto_cap_idx = cap_idx;
cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
ufshcd_program_key(hba, &cfg, slot);
memzero_explicit(&cfg, sizeof(cfg));
return 0;
}
That does make ufshcd_crypto_keyslot_program() slightly longer, but it
eliminates lots of other functions. So overall it makes the code much shorter
and easier to understand.
> +static int ufshcd_crypto_keyslot_evict(struct keyslot_manager *ksm,
> + const struct blk_crypto_key *key,
> + unsigned int slot)
> +{
> + struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
> +
> + if (!(hba->caps & UFSHCD_CAP_CRYPTO) ||
> + !ufshcd_keyslot_valid(hba, slot))
> + return -EINVAL;
Similarly, there's need for these checks, since the block layer ensures this is
only called with a valid keyslot.
> +
> + /*
> + * Clear the crypto cfg on the device. Clearing CFGE
> + * might not be sufficient, so just clear the entire cfg.
> + */
> + ufshcd_clear_keyslot(hba, slot);
This comment seems to be in the wrong place. It should be in
ufshcd_clear_keyslot(), where the cfg is actually initialized to 0.
> +void ufshcd_crypto_enable(struct ufs_hba *hba)
> +{
> + if (!ufshcd_hba_is_crypto_supported(hba))
> + return;
> +
> + hba->caps |= UFSHCD_CAP_CRYPTO;
> +
> + /* Reset might clear all keys, so reprogram all the keys. */
> + blk_ksm_reprogram_all_keys(&hba->ksm);
> +}
> +
> +void ufshcd_crypto_disable(struct ufs_hba *hba)
> +{
> + hba->caps &= ~UFSHCD_CAP_CRYPTO;
> +}
What's the point of setting and clearing UFSHCD_CAP_CRYPTO every time the host
controller is stopped / started? The block layer already ensures that the host
controller is runtime-resumed before calling any of the keyslot manager
functions. So the crypto support isn't going to transiently go away.
Also, UFSHCD_CAP_CRYPTO is now the means by which the vendor driver indicates
that crypto is supported. So what's the point of both
ufshcd_hba_is_crypto_supported() and UFSHCD_CAP_CRYPTO? Why not just
consistently use UFSHCD_CAP_CRYPTO?
I.e., remove ufshcd_crypto_disable(), and ufshcd_crypto_enable() would be:
void ufshcd_crypto_enable(struct ufs_hba *hba)
{
/* Reset might clear all keys, so reprogram all the keys. */
if (hba->caps & UFSHCD_CAP_CRYPTO)
blk_ksm_reprogram_all_keys(&hba->ksm);
}
ufshcd_hba_init_crypto() would then clear UFSHCD_CAP_CRYPTO if crypto
initialization failed / isn't supported. ufshcd_hba_init_crypto() would be the
only place that checks the crypto capabilities register.
That all would be much simpler. Any reason not to do that?
> +static enum blk_crypto_mode_num ufshcd_blk_crypto_mode_num_for_alg_keysize(
> + enum ufs_crypto_alg ufs_crypto_alg,
> + enum ufs_crypto_key_size key_size)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
> + if (ufs_crypto_algs[i].supported &&
> + ufs_crypto_algs[i].ufs_alg == ufs_crypto_alg &&
> + ufs_crypto_algs[i].ufs_key_size == key_size) {
> + return ufs_crypto_algs[i].blk_mode;
> + }
> + }
> + return BLK_ENCRYPTION_MODE_INVALID;
> +}
This function name is far too long. Also, the 'supported' and 'blk_mode' fields
are unnecessary as I mentioned above. Also, it would be simpler to pass in
'union ufs_crypto_cap_entry'. So how about:
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;
> +
> + /*
> + * Return 0 if crypto support isn't present/not advertised by vendor
> + * specific driver.
> + */
> + if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
> + !(hba->caps & UFSHCD_CAP_CRYPTO))
> + goto out;
People will be confused by the difference between capabilities and caps.
This comment could use some elaboration, like:
/*
* 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.
*/
> +
> + /*
> + * Crypto Capabilities should never be 0, because the
> + * config_array_ptr > 04h. So we use a 0 value to indicate that
> + * crypto init failed, and can't be enabled.
> + */
This comment would become unnecessary if we were to stop using the cached
hardware crypto capabilities register to indicate whether crypto is supported,
but rather just UFSHCD_CAP_CRYPTO -- as I suggested above.
> + 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);
The arguments to devm_kcalloc() can fit on two lines.
> + if (!hba->crypto_cap_array) {
> + err = -ENOMEM;
> + goto out;
> + }
> +
> + err = blk_ksm_init(&hba->ksm, hba->dev, ufshcd_num_keyslots(hba));
> + if (err)
> + goto out_free_caps;
If the unnecessary checks are removed from other places in this file, this would
be the only remaining caller of ufshcd_num_keyslots(), which could then be
removed and the comment about the off-by-one quirk could be moved to here:
/* The actual number of configurations supported is (CFGC+1) */
num_keyslots = hba->crypto_capabilities.config_count + 1;
err = blk_ksm_init(&hba->ksm, hba->dev, num_keyslots);
...
/* Clear all keyslots at driver init time */
for (slot = 0; slot < num_keyslots; slot++)
ufshcd_clear_keyslot(hba, slot);
> +
> + hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
> + /* UFS only supports 8 bytes for any DUN */
> + hba->ksm.max_dun_bytes_supported = 8;
> +
> + /*
> + * Store all the capabilities and fill up the keyslot manager's
> + * supported crypto modes.
> + */
"fill up the keyslot manager's supported crypto modes" is what the code does,
but in comments it's better to describe the goal at a higher level, like
/*
* 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_blk_crypto_mode_num_for_alg_keysize(
> + hba->crypto_cap_array[cap_idx].algorithm_id,
> + hba->crypto_cap_array[cap_idx].key_size);
As I mentioned above, this could simply pass the capability directly.
> + 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;
> + }
> +
> + ufshcd_clear_all_keyslots(hba);
> +
> + return 0;
> +
> +out_free_caps:
> + devm_kfree(hba->dev, hba->crypto_cap_array);
> +out:
> + /* Indicate that init failed by setting crypto_capabilities to 0 */
> + hba->crypto_capabilities.reg_val = 0;
> + return err;
> +}
As I mentioned above, why not clear UFSHCD_CAP_CRYPTO here instead of
crypto_capabilities, and use UFSHCD_CAP_CRYPTO consistently everywhere?
> +
> +void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
> + struct request_queue *q)
> +{
> + if (!ufshcd_hba_is_crypto_supported(hba) || !q)
> + return;
> +
> + blk_ksm_register(&hba->ksm, q);
> +}
> +
> +void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
> +{
> + blk_ksm_destroy(&hba->ksm);
> +}
q can't be NULL here.
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 978781c538c4..ee37dd44d5e6 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;
> @@ -634,6 +639,7 @@ struct ufs_hba {
> * enabled via HCE register.
> */
> #define UFSHCI_QUIRK_BROKEN_HCE 0x400
> +
> unsigned int quirks; /* Deviations from standard UFSHCI spec. */
Unnecessary whitespace change.
>
> /* Device deviations from standard UFS device spec. */
> @@ -735,6 +741,14 @@ struct ufs_hba {
>
> struct device bsg_dev;
> struct request_queue *bsg_queue;
> +
> +#ifdef CONFIG_SCSI_UFS_CRYPTO
> + /* crypto */
> + union ufs_crypto_capabilities crypto_capabilities;
> + union ufs_crypto_cap_entry *crypto_cap_array;
> + u32 crypto_cfg_register;
> + struct keyslot_manager ksm;
> +#endif /* CONFIG_SCSI_UFS_CRYPTO */
These two comments don't really add anything. It's already obviously "crypto"
fields based on the #ifdef and variable names. And a 4 line #ifdef isn't long
enough for a comment on the #endif to be helpful.
- Eric
On Thu, Mar 12, 2020 at 01:02:49AM -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 <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd-crypto.c | 27 +++++++++++++++
> drivers/scsi/ufs/ufshcd-crypto.h | 14 ++++++++
> drivers/scsi/ufs/ufshcd.c | 59 +++++++++++++++++++++++++++++---
> drivers/scsi/ufs/ufshcd.h | 8 +++++
> 4 files changed, 103 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
> index 8b6f7c83f77f..37254472326a 100644
> --- a/drivers/scsi/ufs/ufshcd-crypto.c
> +++ b/drivers/scsi/ufs/ufshcd-crypto.c
> @@ -368,3 +368,30 @@ void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
> {
> blk_ksm_destroy(&hba->ksm);
> }
> +
> +int ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
> + struct scsi_cmnd *cmd,
> + struct ufshcd_lrb *lrbp)
> +{
> + struct request *rq = cmd->request;
> + struct bio_crypt_ctx *bc = rq->crypt_ctx;
> + unsigned int slot_idx = blk_ksm_get_slot_idx(rq->crypt_keyslot);
> +
> + lrbp->crypto_enable = false;
> +
> + if (WARN_ON(!(hba->caps & UFSHCD_CAP_CRYPTO))) {
> + /*
> + * Upper layer asked us to do inline encryption
> + * but that isn't enabled, so we fail this request.
> + */
> + return -EINVAL;
> + }
> + if (!ufshcd_keyslot_valid(hba, slot_idx))
> + return -EINVAL;
> +
> + lrbp->crypto_enable = true;
> + lrbp->crypto_key_slot = slot_idx;
> + lrbp->data_unit_num = bc->bc_dun[0];
> +
> + return 0;
> +}
> diff --git a/drivers/scsi/ufs/ufshcd-crypto.h b/drivers/scsi/ufs/ufshcd-crypto.h
> index 8270c0c5081a..c76f93ede51c 100644
> --- a/drivers/scsi/ufs/ufshcd-crypto.h
> +++ b/drivers/scsi/ufs/ufshcd-crypto.h
> @@ -16,6 +16,15 @@ static inline bool ufshcd_hba_is_crypto_supported(struct ufs_hba *hba)
> return hba->crypto_capabilities.reg_val != 0;
> }
>
> +int ufshcd_prepare_lrbp_crypto(struct ufs_hba *hba,
> + struct scsi_cmnd *cmd,
> + struct ufshcd_lrb *lrbp);
> +
> +static inline bool ufshcd_lrbp_crypto_enabled(struct ufshcd_lrb *lrbp)
> +{
> + return lrbp->crypto_enable;
> +}
> +
> void ufshcd_crypto_enable(struct ufs_hba *hba);
>
> void ufshcd_crypto_disable(struct ufs_hba *hba);
> @@ -49,6 +58,11 @@ static inline void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
> static inline void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
> { }
>
> +static inline bool ufshcd_lrbp_crypto_enabled(struct ufshcd_lrb *lrbp)
> +{
> + return false;
> +}
> +
> #endif /* CONFIG_SCSI_UFS_CRYPTO */
>
> #endif /* _UFSHCD_CRYPTO_H */
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 825d9eb34f10..3a19966dbee9 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 +817,14 @@ 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_hba_is_crypto_supported(hba)) {
> + ufshcd_crypto_enable(hba);
> + val |= CRYPTO_GENERAL_ENABLE;
> + }
> +
> + ufshcd_writel(hba, val, REG_CONTROLLER_ENABLE);
> }
>
> /**
> @@ -2192,9 +2200,23 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
> dword_0 |= UTP_REQ_DESC_INT_CMD;
>
> /* Transfer request descriptor header fields */
> + if (ufshcd_lrbp_crypto_enabled(lrbp)) {
> +#ifdef CONFIG_SCSI_UFS_CRYPTO
> + dword_0 |= UTP_REQ_DESC_CRYPTO_ENABLE_CMD;
> + dword_0 |= lrbp->crypto_key_slot;
> + req_desc->header.dword_1 =
> + cpu_to_le32(lower_32_bits(lrbp->data_unit_num));
> + req_desc->header.dword_3 =
> + cpu_to_le32(upper_32_bits(lrbp->data_unit_num));
> +#endif /* CONFIG_SCSI_UFS_CRYPTO */
> + } else {
> + /* dword_1 and dword_3 are reserved, hence they are set to 0 */
> + req_desc->header.dword_1 = 0;
> + req_desc->header.dword_3 = 0;
> + }
> +
> 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;
> +
> /*
> * assigning invalid value for command status. Controller
> * updates OCS on command completion, with the command
> @@ -2202,8 +2224,6 @@ 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->prd_table_length = 0;
> }
> @@ -2437,6 +2457,20 @@ 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;
> +
> +#ifdef CONFIG_SCSI_UFS_CRYPTO
> + if (cmd->request->crypt_keyslot) {
> + err = ufshcd_prepare_lrbp_crypto(hba, cmd, lrbp);
> + if (err) {
> + lrbp->cmd = NULL;
> + ufshcd_release(hba);
> + goto out;
> + }
> + } else {
> + lrbp->crypto_enable = false;
> + }
> +#endif
> +
> lrbp->req_abort_skip = false;
>
> ufshcd_comp_scsi_upiu(hba, lrbp);
> @@ -2470,6 +2504,9 @@ 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_enable = false; /* No crypto operations */
> +#endif
> hba->dev_cmd.type = cmd_type;
>
> return ufshcd_comp_devman_upiu(hba, lrbp);
This is all much more complicated than needed.
- We don't need the 'crypto_enable' field. Just make 'crypto_key_slot' an int
and use 'crypto_key_slot = -1' instead.
- ufshcd_lrbp_crypto_enabled() isn't needed since it's only used in one place
which uses an ifdef anyway. It can simply check crypto_key_slot >= 0.
- The checks in ufshcd_prepare_lrbp_crypto() are unneeded, as the block layer
already ensures that a valid keyslot is provided.
So for the per-command code, all we actually need is:
#ifdef CONFIG_SCSI_UFS_CRYPTO
static inline void ufshcd_prepare_lrbp_crypto(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;
}
}
...
#else
static inline void ufshcd_prepare_lrbp_crypto(struct scsi_cmnd *cmd,
struct ufshcd_lrb *lrbp)
{
}
...
#endif
Then in ufshcd_queuecommand():
...
lrbp->intr_cmd = !ufshcd_is_intr_aggr_allowed(hba) ? true : false;
lrbp->req_abort_skip = false;
ufshcd_prepare_lrbp_crypto(cmd, lrbp);
ufshcd_comp_scsi_upiu(hba, lrbp);
...
Then in ufshcd_prepare_req_desc_hdr():
u32 dword_1 = 0;
u32 dword_3 = 0;
...
#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
req_desc->header.dword_0 = cpu_to_le32(dword_0);
req_desc->header.dword_1 = cpu_to_le32(dword_1);
...
req_desc->header.dword_2 =
cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
req_desc->header.dword_3 = cpu_to_le32(dword_3);
On Thu, Mar 12, 2020 at 01:02:49AM -0700, Satya Tangirala wrote:
> @@ -2470,6 +2504,9 @@ 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_enable = false; /* No crypto operations */
> +#endif
> hba->dev_cmd.type = cmd_type;
Doesn't this need to be initialized in ufshcd_issue_devman_upiu_cmd() too?
On Thu, Mar 12, 2020 at 01:02:50AM -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 <[email protected]>
> ---
> 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 273ee82d8aa9..8bf195d3bda6 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 3cd4fe6b845e..08a0395674dd 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1370,6 +1370,7 @@ 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) /* inodes in SB use blk-crypto */
"inodes use blk-crypto" isn't very clear. It could be misunderstand as meaning
something like "does the filesystem contain any encrypted files". I think the
following would be a bit clearer:
/* Use blk-crypto for encrypted files */
(And these flags are obviously per-sb, so there's no need to write "in SB".)
On Thu, Mar 12, 2020 at 01:02:43AM -0700, Satya Tangirala wrote:
> +/**
> + * 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 keyslot_manager *ksm, struct device *dev,
> + 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;
> + ksm->dev = dev;
Seems that now that keyslot_manager::dev is an unconditional field and callers
initialize other fields of the keyslot_manager, the 'dev' parameter should be
removed from blk_ksm_init() and the caller should be responsible for setting
'dev' if they need runtime power management.
> +/**
> + * 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), and BLK_STATUS_IOERR otherwise (and keyslot is
> + * set to NULL).
> + */
There can be other errors besides BLK_STATUS_IOERR returned.
> +/**
> + * 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 keyslot_manager *ksm = slot->ksm;
> + unsigned long flags;
> +
> + if (!slot)
> + return;
> +
> + if (atomic_dec_and_lock_irqsave(&slot->slot_refs,
> + &ksm->idle_slots_lock, flags)) {
> + list_add_tail(&slot->idle_slot_node,
> + &ksm->idle_slots);
Nit: the arguments to list_add_tail() fit on one line
> diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h
> new file mode 100644
> index 000000000000..7f88ed02faee
> --- /dev/null
> +++ b/include/linux/keyslot-manager.h
> @@ -0,0 +1,108 @@
> +/* 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 keyslot_manager;
> +
> +/**
> + * struct keyslot_mgmt_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 keyslot_mgmt_ll_ops {
> + blk_status_t (*keyslot_program)(struct keyslot_manager *ksm,
> + const struct blk_crypto_key *key,
> + unsigned int slot);
> + int (*keyslot_evict)(struct keyslot_manager *ksm,
> + const struct blk_crypto_key *key,
> + unsigned int slot);
> +};
As I mentioned on one of the UFS patches, I'm not sure it's better to make
keyslot_program return blk_status_t rather than errno as it did before.
blk_ksm_get_slot_for_key() could just do the translation to blk_status_t.
> +struct keyslot_manager {
Now that the "blk_" prefix has been added to all the functions, perhaps the
actual struct should be renamed to "blk_keyslot_manager" too?
And likewise "blk_keyslot_mgmt_ll_ops".
On Thu, Mar 12, 2020 at 01:02:45AM -0700, Satya Tangirala wrote:
> diff --git a/block/blk-integrity.c b/block/blk-integrity.c
> index ff1070edbb40..793ba23e8688 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 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.");
> + blk_ksm_unregister(disk->queue);
> + }
> +#endif
> }
> EXPORT_SYMBOL(blk_integrity_register);
This ifdef is wrong, it should be CONFIG_BLK_INLINE_ENCRYPTION.
Also the log message is missing a trailing newline.
>
> diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
> index 38df0652df80..a7970e18a122 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_ksm: " fmt
People aren't going to know what "blk_ksm" means in the logs.
I think just use "blk-crypto" instead.
> +
> #include <crypto/algapi.h>
> #include <linux/keyslot-manager.h>
> #include <linux/atomic.h>
> @@ -375,3 +378,20 @@ void blk_ksm_destroy(struct keyslot_manager *ksm)
> memzero_explicit(ksm, sizeof(*ksm));
> }
> EXPORT_SYMBOL_GPL(blk_ksm_destroy);
> +
> +bool blk_ksm_register(struct 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. Won't register keyslot manager with request queue.");
> + return false;
> + }
> + q->ksm = ksm;
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(blk_ksm_register);
People reading the logs won't know what a keyslot manager is and why they should
care that one wasn't registered. It would be better to say that hardware inline
encryption is being disabled.
Ideally the device name would be included in the message too.
> +
> +void blk_ksm_unregister(struct request_queue *q)
> +{
> + q->ksm = NULL;
> +}
> +EXPORT_SYMBOL_GPL(blk_ksm_unregister);
blk_ksm_unregister() doesn't need to be exported.
On Thu, Mar 12, 2020 at 01:02:44AM -0700, Satya Tangirala wrote:
> + if (bio_has_crypt_ctx(bio))
> + bio_crypt_clone(b, bio, gfp_mask);
FYI, what I had tried to suggest when moving the the bio_has_crypt_ctx
checks out was not to open code them, but to have inline functions.
E.g. your current bio_crypt_clone becomes __bio_crypt_clone,
and then a wrapper is added ala:
static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
gfp_t gfp_mask)
{
if (bio_has_crypt_ctx(bio))
__bio_crypt_clone(dst, src, gfp_mask);
}
Which also means in all the headers you can now declare everything
unconditional as long as bio_has_crypt_ctx is stubbed out for the case
where blk crypto is disabled.
> if (bio_integrity(bio)) {
> int ret;
>
> ret = bio_integrity_clone(b, bio, gfp_mask);
> -
> if (ret < 0) {
> bio_put(b);
> return NULL;
Spurious whitespace change.
> free_and_out:
> @@ -1813,5 +1830,7 @@ int __init blk_dev_init(void)
> blk_debugfs_root = debugfs_create_dir("block", NULL);
> #endif
>
> + bio_crypt_ctx_init();
> +
Is there any good reason to explicitly call bio_crypt_ctx_init vs just
making it a local subsys_initcall?
> +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;
> + inc = ((bc->bc_dun[i] + inc) < inc);
Besides the bracing and double whitespace issue this code looks weird
to me.
So inc starts out as the number of bytes shifted to the dun size.
We then check if it matches the next dun for every entry in the
array.
But then inc is turned into a bollean for the next iteration. At that
point I'm a little lost, can you add comments or make the code more
explicit?
> + blk_crypto_rq_set_defaults(rq);
> +
> + err = blk_ksm_get_slot_for_key(rq->q->ksm,
> + bio->bi_crypt_context->bc_key,
> + &rq->crypt_keyslot);
> + if (err != BLK_STS_OK)
> + pr_warn_once("Failed to acquire keyslot for %s (err=%d).\n",
> + bio->bi_disk->disk_name, err);
> + return err;
Is this error really that important? If someone prints an error here
I'd expect the low-level driver to do that, as that is the only place
knowing what kind of error we could have here.
> +int blk_crypto_bio_prep(struct bio **bio_ptr)
> +{
> + struct bio *bio = *bio_ptr;
> +
> + /*
> + * If bio has no data, just pretend it didn't have an encryption
> + * context.
> + */
> + if (!bio_has_data(bio)) {
> + bio_crypt_free_ctx(bio);
> + return 0;
> + }
Shouldn't a submitted bio without data but with a crypt context be a
hard error?
> + bio_crypt_check_alignment(bio);
> + if (bio->bi_status != BLK_STS_OK)
> + goto fail;
Weird calling convention. Why doesn't bio_crypt_check_alignment
return a bool, and then this becomes the much more obvious:
if (!bio_crypt_check_alignment(bio)) {
bio->bi_status = BLK_STS_IOERR;
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 0;
> +fail:
> + bio_endio(*bio_ptr);
> + return -EIO;
Weird calling convention again. If the actual error is in the bio,
this should just be a bool.
> +void blk_crypto_rq_prep_clone(struct request *dst, struct request *src)
> +{
> + dst->crypt_ctx = src->crypt_ctx;
> +}
This seems reasonable to inline in the header..
> + blk_status_t err;
>
> blk_queue_bounce(q, &bio);
> __blk_queue_split(q, &bio, &nr_segs);
> @@ -2002,6 +2007,16 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
>
> cookie = request_to_qc_t(data.hctx, rq);
>
> + if (bio_has_crypt_ctx(bio)) {
> + err = blk_crypto_init_request(rq, bio);
> + if (err != BLK_STS_OK) {
The err declaration can go into this scope. I'd also rather call it
ret as err is usually used for errno codes.
Also blk_crypto_init_request doesn't really need the bio, but just the
key. So I'd rather pass the key to avoid confusion what this function
might do with the bio.
> + bio->bi_status = err;
> + bio_endio(bio);
> + blk_mq_end_request(rq, err);
> + return BLK_QC_T_NONE;
Shoudn't the blk_mq_end_request just be a blk_mq_free_request here?
> +#ifdef CONFIG_BLOCK
> +
> +#include <linux/blk_types.h>
> +#include <linux/blkdev.h>
> +
> +struct request;
> +struct request_queue;
> +
> +#ifdef CONFIG_BLK_INLINE_ENCRYPTION
Does the #ifdef CONFIG_BLOCK buy us anything?
On Thu, Mar 12, 2020 at 01:02:45AM -0700, Satya Tangirala wrote:
> There's no hardware currently that supports both integrity and inline
> encryption. However, it seems possible that there will be in the near
> future, based on discussion at
> https://lore.kernel.org/r/[email protected]/
> 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, and
> through discussions at
> https://lore.kernel.org/r/[email protected]/
> it seems best not to support both features together right now, and
> to decide what to do at probe time.
Please don't reference web links, just inline the important information.
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index bf62c25cde8f..a5c57991c6fa 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -42,6 +42,11 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
> struct bio_set *bs = bio->bi_pool;
> unsigned inline_vecs;
>
> + if (bio_has_crypt_ctx(bio)) {
> + pr_warn("blk-integrity can't be used together with inline en/decryption.");
> + return ERR_PTR(-EOPNOTSUPP);
> + }
This is a hard error and should just be a WARN_ON_ONCE.
I'm also not sure we need the register time warnings at all.