From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- .../admin-guide/device-mapper/dm-inlinecrypt.rst | 129 +++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst (limited to 'Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst') diff --git a/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst b/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst new file mode 100644 index 000000000..76b3aae21 --- /dev/null +++ b/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst @@ -0,0 +1,129 @@ +============== +dm-inlinecrypt +============== + +Device-Mapper's "inlinecrypt" target provides transparent encryption of block devices +using the inline encryption hardware. + +For a more detailed description of inline encryption, see: +https://docs.kernel.org/block/inline-encryption.html + +Parameters:: + + \ + [<#opt_params> ] + + + Encryption cipher type. + + The cipher specifications format is:: + + cipher + + Examples:: + + aes-xts-plain64 + + The cipher type corresponds to the encryption modes supported by + inline crypto in the block layer. Currently, only + BLK_ENCRYPTION_MODE_AES_256_XTS (i.e. aes-xts-plain64) is supported. + + + Key used for encryption. It is encoded either as a hexadecimal number + or it can be passed as prefixed with single colon + character (':') for keys residing in kernel keyring service. + You can only use key sizes that are valid for the selected cipher. + Note that the size in bytes of a valid key must be in bellow range. + + [BLK_CRYPTO_KEY_TYPE_RAW, BLK_CRYPTO_KEY_TYPE_HW_WRAPPED] + + + The kernel keyring key is identified by string in following format: + ::. + + + The encryption key size in bytes. The kernel key payload size must match + the value passed in . + + + The type of the key inside the kernel keyring. It can be either 'logon', + or 'trusted' kernel key type. + + + The kernel keyring key description inlinecrypt target should look for + when loading key of . + + + The IV offset is a sector count that is added to the sector number + before creating the IV. + + + This is the device that is going to be used as backend and contains the + encrypted data. You can specify it as a path like /dev/xxx or a device + number :. + + + Starting sector within the device where the encrypted data begins. + +<#opt_params> + Number of optional parameters. If there are no optional parameters, + the optional parameters section can be skipped or #opt_params can be zero. + Otherwise #opt_params is the number of following arguments. + + Example of optional parameters section: + keytype:raw allow_discards sector_size:4096 iv_large_sectors + + + The type of the key as seen by the block layer, either standard or + hardware-wrapped. The string is supplied in the table as + or . + +allow_discards + Block discard requests (a.k.a. TRIM) are passed through the inlinecrypt + device. The default is to ignore discard requests. + + WARNING: Assess the specific security risks carefully before enabling this + option. For example, allowing discards on encrypted devices may lead to + the leak of information about the ciphertext device (filesystem type, + used space etc.) if the discarded blocks can be located easily on the + device later. + +sector_size: + Use as the encryption unit instead of 512 bytes sectors. + This option can be in range 512 - 4096 bytes and must be power of two. + Virtual device will announce this size as a minimal IO and logical sector. + +iv_large_sectors + Use -based sector numbers for IV generation instead of + 512-byte sectors. + + For dm-inlinecrypt, this flag must be specified when + is larger than 512 bytes. The legacy 512-byte-based IV behavior is + not supported. + + When specified, if is 4096 bytes, plain64 IV for the + second sector will be 1, and must be a multiple of + (in 512-byte units). + +Example scripts +=============== +Currently, dm-inlinecrypt devices must be set up directly using dmsetup. +There is no userspace support yet to integrate dm-inlinecrypt with LUKS +or cryptsetup. In particular, cryptsetup currently only supports +dm-crypt, and cannot be used to create dm-inlinecrypt mappings. + +The following examples demonstrate how to create dm-inlinecrypt devices +using dmsetup + +:: + + #!/bin/sh + # Create a inlinecrypt device using dmsetup + dmsetup create inlinecrypt1 --table "0 `blockdev --getsz $1` inlinecrypt aes-xts-plain64 babebabebabebabebabebabebabebabebabebabebabebabebabebabebabebabe 0 0 $1 0 1 keytype:raw" + +:: + + #!/bin/sh + # Create a inlinecrypt device using dmsetup when encryption key is stored in keyring service + dmsetup create inlinecrypt2 --table "0 `blockdev --getsz $1` inlinecrypt aes-xts-plain64 :64:logon:fde:dminlinecrypt_test_key 0 0 $1 0 1 keytype:raw" + -- cgit v1.3.1