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path: root/drivers/md/dm-verity-fec.c
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2018-09-14dm: Remove VLA usage from hashesKees Cook1-1/+4
In the quest to remove all stack VLA usage from the kernel[1], this uses the new HASH_MAX_DIGESTSIZE from the crypto layer to allocate the upper bounds on stack usage. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-06-05Merge tag 'rslib-v4.18-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull reed-salomon library updates from Kees Cook: "Refactors rslib and callers to provide a per-instance allocation area instead of performing VLAs on the stack" * tag 'rslib-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: rslib: Allocate decoder buffers to avoid VLAs mtd: rawnand: diskonchip: Allocate rs control per instance rslib: Split rs control struct rslib: Simplify error path rslib: Remove GPL boilerplate rslib: Add SPDX identifiers rslib: Cleanup top level comments rslib: Cleanup whitespace damage dm/verity_fec: Use GFP aware reed solomon init rslib: Add GFP aware init function
2018-05-31dm: convert to bioset_init()/mempool_init()Kent Overstreet1-27/+28
Convert dm to embedded bio sets. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-25dm/verity_fec: Use GFP aware reed solomon initThomas Gleixner1-1/+1
Allocations from the rs_pool can invoke init_rs() from the mempool allocation callback. This is problematic in fec_alloc_bufs() which invokes mempool_alloc() with GFP_NOIO to prevent a swap deadlock because init_rs() uses GFP_KERNEL allocations. Switch it to init_rs_gfp() and invoke it with the gfp_t flags which are handed in from the allocator. Note: This is not a problem today because the rs control struct is shared between the instances and its created when the mempool is initialized. But the upcoming changes which switch to a rs_control struct per instance to embed decoder buffers will trigger the swap vs. GFP_KERNEL issue. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-07-26dm verity fec: fix GFP flags used with mempool_alloc()NeilBrown1-16/+5
mempool_alloc() cannot fail for GFP_NOIO allocation, so there is no point testing for failure. One place the code tested for failure was passing "0" as the GFP flags. This is most unusual and is probably meant to be GFP_NOIO, so that is changed. Also, allocation from ->extra_pool and ->prealloc_pool are repeated before releasing the previous allocation. This can deadlock if the code is servicing a write under high memory pressure. To avoid deadlocks, change these to use GFP_NOWAIT and leave the error handling in place. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-03Merge tag 'for-4.12/dm-changes' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - A major update for DM cache that reduces the latency for deciding whether blocks should migrate to/from the cache. The bio-prison-v2 interface supports this improvement by enabling direct dispatch of work to workqueues rather than having to delay the actual work dispatch to the DM cache core. So the dm-cache policies are much more nimble by being able to drive IO as they see fit. One immediate benefit from the improved latency is a cache that should be much more adaptive to changing workloads. - Add a new DM integrity target that emulates a block device that has additional per-sector tags that can be used for storing integrity information. - Add a new authenticated encryption feature to the DM crypt target that builds on the capabilities provided by the DM integrity target. - Add MD interface for switching the raid4/5/6 journal mode and update the DM raid target to use it to enable aid4/5/6 journal write-back support. - Switch the DM verity target over to using the asynchronous hash crypto API (this helps work better with architectures that have access to off-CPU algorithm providers, which should reduce CPU utilization). - Various request-based DM and DM multipath fixes and improvements from Bart and Christoph. - A DM thinp target fix for a bio structure leak that occurs for each discard IFF discard passdown is enabled. - A fix for a possible deadlock in DM bufio and a fix to re-check the new buffer allocation watermark in the face of competing admin changes to the 'max_cache_size_bytes' tunable. - A couple DM core cleanups. * tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits) dm bufio: check new buffer allocation watermark every 30 seconds dm bufio: avoid a possible ABBA deadlock dm mpath: make it easier to detect unintended I/O request flushes dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit() dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH dm: introduce enum dm_queue_mode to cleanup related code dm mpath: verify __pg_init_all_paths locking assumptions at runtime dm: verify suspend_locking assumptions at runtime dm block manager: remove an unused argument from dm_block_manager_create() dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue() dm mpath: delay requeuing while path initialization is in progress dm mpath: avoid that path removal can trigger an infinite loop dm mpath: split and rename activate_path() to prepare for its expanded use dm ioctl: prevent stack leak in dm ioctl call dm integrity: use previously calculated log2 of sectors_per_block dm integrity: use hex2bin instead of open-coded variant dm crypt: replace custom implementation of hex2bin() dm crypt: remove obsolete references to per-CPU state dm verity: switch to using asynchronous hash crypto API dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues ...
2017-04-24dm verity: switch to using asynchronous hash crypto APIGilad Ben-Yossef1-2/+2
Use of the synchronous digest API limits dm-verity to using pure CPU based algorithm providers and rules out the use of off CPU algorithm providers which are normally asynchronous by nature, potentially freeing CPU cycles. This can reduce performance per Watt in situations such as during boot time when a lot of concurrent file accesses are made to the protected volume. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> CC: Eric Biggers <ebiggers3@gmail.com> CC: Ondrej Mosnáček <omosnacek+linux-crypto@gmail.com> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-31dm verity fec: fix bufio leaksSami Tolvanen1-3/+3
Buffers read through dm_bufio_read() were not released in all code paths. Fixes: a739ff3f543a ("dm verity: add support for forward error correction") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-16dm verity fec: limit error correction recursionSami Tolvanen1-1/+11
If the hash tree itself is sufficiently corrupt in addition to data blocks, it's possible for error correction to end up in a deep recursive loop, which eventually causes a kernel panic. This change limits the recursion to a reasonable level during a single I/O operation. Fixes: a739ff3f543a ("dm verity: add support for forward error correction") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v4.5+
2016-07-02dm verity fec: fix block calculationSami Tolvanen1-3/+1
do_div was replaced with div64_u64 at some point, causing a bug with block calculation due to incompatible semantics of the two functions. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Fixes: a739ff3f543a ("dm verity: add support for forward error correction") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-02-23dm: rename target's per_bio_data_size to per_io_data_sizeMike Snitzer1-1/+1
Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm verity: add ignore_zero_blocks featureSami Tolvanen1-1/+7
If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks matching a zero hash without validating the content. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm verity: add support for forward error correctionSami Tolvanen1-0/+812
Add support for correcting corrupted blocks using Reed-Solomon. This code uses RS(255, N) interleaved across data and hash blocks. Each error-correcting block covers N bytes evenly distributed across the combined total data, so that each byte is a maximum distance away from the others. This makes it possible to recover from several consecutive corrupted blocks with relatively small space overhead. In addition, using verity hashes to locate erasures nearly doubles the effectiveness of error correction. Being able to detect corrupted blocks also improves performance, because only corrupted blocks need to corrected. For a 2 GiB partition, RS(255, 253) (two parity bytes for each 253-byte block) can correct up to 16 MiB of consecutive corrupted blocks if erasures can be located, and 8 MiB if they cannot, with 16 MiB space overhead. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>