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path: root/drivers/md/dm-verity-fec.h
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2021-04-14dm verity fec: fix misaligned RS roots IOJaegeuk Kim1-0/+1
commit df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to block size") introduced the possibility for misaligned roots IO relative to the underlying device's logical block size. E.g. Android's default RS roots=2 results in dm_bufio->block_size=1024, which causes the following EIO if the logical block size of the device is 4096, given v->data_dev_block_bits=12: E sd 0 : 0:0:0: [sda] tag#30 request not aligned to the logical block size E blk_update_request: I/O error, dev sda, sector 10368424 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 E device-mapper: verity-fec: 254:8: FEC 9244672: parity read failed (block 18056): -5 Fix this by onlu using f->roots for dm_bufio blocksize IFF it is aligned to v->data_dev_block_bits. Fixes: df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to block size") Cc: stable@vger.kernel.org Signed-off-by: Jaegeuk Kim <jaegeuk@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30dm: convert to bioset_init()/mempool_init()Kent Overstreet1-4/+4
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>
2017-03-16dm verity fec: limit error correction recursionSami Tolvanen1-0/+4
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+
2015-12-10dm verity: add support for forward error correctionSami Tolvanen1-0/+152
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>