internal_hash and journal_mac capabilities.
- Various DM writecache fixes to address performance, fix table output
to match what was provided at table creation, fix writing beyond end
of device when shrinking underlying data device, and a couple other
small cleanups.
- Add DM crypt support for using trusted keys.
- Fix deadlock when swapping to DM crypt device by throttling number
of in-flight REQ_SWAP bios. Implemented in DM core so that other
bio-based targets can opt-in by setting ti->limit_swap_bios.
- Fix various inverted logic bugs in the .iterate_devices callout
functions that are used to assess if specific feature or capability
is supported across all devices being combined/stacked by DM.
- Fix DM era target bugs that exposed users to lost writes or memory
leaks.
- Add DM core support for passing through inline crypto support of
underlying devices. Includes block/keyslot-manager changes that
enable extending this support to DM.
- Various small fixes and cleanups (spelling fixes, front padding
calculation cleanup, cleanup conditional zoned support in targets,
etc).
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Merge tag 'for-5.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Fix DM integrity's HMAC support to provide enhanced security of
internal_hash and journal_mac capabilities.
- Various DM writecache fixes to address performance, fix table output
to match what was provided at table creation, fix writing beyond end
of device when shrinking underlying data device, and a couple other
small cleanups.
- Add DM crypt support for using trusted keys.
- Fix deadlock when swapping to DM crypt device by throttling number of
in-flight REQ_SWAP bios. Implemented in DM core so that other
bio-based targets can opt-in by setting ti->limit_swap_bios.
- Fix various inverted logic bugs in the .iterate_devices callout
functions that are used to assess if specific feature or capability
is supported across all devices being combined/stacked by DM.
- Fix DM era target bugs that exposed users to lost writes or memory
leaks.
- Add DM core support for passing through inline crypto support of
underlying devices. Includes block/keyslot-manager changes that
enable extending this support to DM.
- Various small fixes and cleanups (spelling fixes, front padding
calculation cleanup, cleanup conditional zoned support in targets,
etc).
* tag 'for-5.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (31 commits)
dm: fix deadlock when swapping to encrypted device
dm: simplify target code conditional on CONFIG_BLK_DEV_ZONED
dm: set DM_TARGET_PASSES_CRYPTO feature for some targets
dm: support key eviction from keyslot managers of underlying devices
dm: add support for passing through inline crypto support
block/keyslot-manager: Introduce functions for device mapper support
block/keyslot-manager: Introduce passthrough keyslot manager
dm era: only resize metadata in preresume
dm era: Use correct value size in equality function of writeset tree
dm era: Fix bitset memory leaks
dm era: Verify the data block size hasn't changed
dm era: Reinitialize bitset cache before digesting a new writeset
dm era: Update in-core bitset after committing the metadata
dm era: Recover committed writeset after crash
dm writecache: use bdev_nr_sectors() instead of open-coded equivalent
dm writecache: fix writing beyond end of underlying device when shrinking
dm table: remove needless request_queue NULL pointer checks
dm table: fix zoned iterate_devices based device capability checks
dm table: fix DAX iterate_devices based device capability checks
dm table: fix iterate_devices based device capability checks
...
Introduce blk_ksm_update_capabilities() to update the capabilities of
a keyslot manager (ksm) in-place. The pointer to a ksm in a device's
request queue may not be easily replaced, because upper layers like
the filesystem might access it (e.g. for programming keys/checking
capabilities) at the same time the device wants to replace that
request queue's ksm (and free the old ksm's memory). This function
allows the device to update the capabilities of the ksm in its request
queue directly. Devices can safely update the ksm this way without any
synchronization with upper layers *only* if the updated (new) ksm
continues to support all the crypto capabilities that the old ksm did
(see description below for blk_ksm_is_superset() for why this is so).
Also introduce blk_ksm_is_superset() which checks whether one ksm's
capabilities are a (not necessarily strict) superset of another ksm's.
The blk-crypto framework requires that crypto capabilities that were
advertised when a bio was created continue to be supported by the
device until that bio is ended - in practice this probably means that
a device's advertised crypto capabilities can *never* "shrink" (since
there's no synchronization between bio creation and when a device may
want to change its advertised capabilities) - so a previously
advertised crypto capability must always continue to be supported.
This function can be used to check that a new ksm is a valid
replacement for an old ksm.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The device mapper may map over devices that have inline encryption
capabilities, and to make use of those capabilities, the DM device must
itself advertise those inline encryption capabilities. One way to do this
would be to have the DM device set up a keyslot manager with a
"sufficiently large" number of keyslots, but that would use a lot of
memory. Also, the DM device itself has no "keyslots", and it doesn't make
much sense to talk about "programming a key into a DM device's keyslot
manager", so all that extra memory used to represent those keyslots is just
wasted. All a DM device really needs to be able to do is advertise the
crypto capabilities of the underlying devices in a coherent manner and
expose a way to evict keys from the underlying devices.
There are also devices with inline encryption hardware that do not
have a limited number of keyslots. One can send a raw encryption key along
with a bio to these devices (as opposed to typical inline encryption
hardware that require users to first program a raw encryption key into a
keyslot, and send the index of that keyslot along with the bio). These
devices also only need the same things from the keyslot manager that DM
devices need - a way to advertise crypto capabilities and potentially a way
to expose a function to evict keys from hardware.
So we introduce a "passthrough" keyslot manager that provides a way to
represent a keyslot manager that doesn't have just a limited number of
keyslots, and for which do not require keys to be programmed into keyslots.
DM devices can set up a passthrough keyslot manager in their request
queues, and advertise appropriate crypto capabilities based on those of the
underlying devices. Blk-crypto does not attempt to program keys into any
keyslots in the passthrough keyslot manager. Instead, if/when the bio is
resubmitted to the underlying device, blk-crypto will try to program the
key into the underlying device's keyslot manager.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add a resource-managed variant of blk_ksm_init() so that drivers don't
have to worry about calling blk_ksm_destroy().
Note that the implementation uses a custom devres action to call
blk_ksm_destroy() rather than switching the two allocations to be
directly devres-managed, e.g. with devm_kmalloc(). This is because we
need to keep zeroing the memory containing the keyslots when it is
freed, and also because we want to continue using kvmalloc() (and there
is no devm_kvmalloc()).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20210121082155.111333-2-ebiggers@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If there is only one keyslot, then blk_ksm_init() computes
slot_hashtable_size=1 and log_slot_ht_size=0. This causes
blk_ksm_find_keyslot() to crash later because it uses
hash_ptr(key, log_slot_ht_size) to find the hash bucket containing the
key, and hash_ptr() doesn't support the bits == 0 case.
Fix this by making the hash table always have at least 2 buckets.
Tested by running:
kvm-xfstests -c ext4 -g encrypt -m inlinecrypt \
-o blk-crypto-fallback.num_keyslots=1
Fixes: 1b26283970 ("block: Keyslot Manager for Inline Encryption")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make blk_ksm_destroy() use the kvfree_sensitive() function (which was
introduced in v5.8-rc1) instead of open-coding it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Whenever a device supports blk-integrity, make the kernel pretend that
the device doesn't support inline encryption (essentially by setting the
keyslot manager in the request queue to NULL).
There's no hardware currently that supports both integrity and inline
encryption. However, it seems possible that there will be such hardware
in the near future (like the NVMe key per I/O support that might support
both inline encryption and PI).
But properly integrating both features is not trivial, and without
real hardware that implements both, it is difficult to tell if it will
be done correctly by the majority of hardware that support both.
So it seems best not to support both features together right now, and
to decide what to do at probe time.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Inline Encryption hardware allows software to specify an encryption context
(an encryption key, crypto algorithm, data unit num, data unit size) along
with a data transfer request to a storage device, and the inline encryption
hardware will use that context to en/decrypt the data. The inline
encryption hardware is part of the storage device, and it conceptually sits
on the data path between system memory and the storage device.
Inline Encryption hardware implementations often function around the
concept of "keyslots". These implementations often have a limited number
of "keyslots", each of which can hold a key (we say that a key can be
"programmed" into a keyslot). Requests made to the storage device may have
a keyslot and a data unit number associated with them, and the inline
encryption hardware will en/decrypt the data in the requests using the key
programmed into that associated keyslot and the data unit number specified
with the request.
As keyslots are limited, and programming keys may be expensive in many
implementations, and multiple requests may use exactly the same encryption
contexts, we introduce a Keyslot Manager to efficiently manage keyslots.
We also introduce a blk_crypto_key, which will represent the key that's
programmed into keyslots managed by keyslot managers. The keyslot manager
also functions as the interface that upper layers will use to program keys
into inline encryption hardware. For more information on the Keyslot
Manager, refer to documentation found in block/keyslot-manager.c and
linux/keyslot-manager.h.
Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds
Satya Tangirala
Eric Biggers