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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
dm-verity-fec: improve comments for fec_read_bufs()
Update the comments in and above fec_read_bufs() to more clearly
describe what it does.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
authored by
Eric Biggers
and committed by
Mikulas Patocka
4f6d6fb3
d0829329
+22
-8
+22
-8
drivers/md/dm-verity-fec.c
+22
-8
drivers/md/dm-verity-fec.c
···
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}
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/*
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* Read data blocks that are part of the RS block and deinterleave as much as
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* fits into buffers. Check for erasure locations if @neras is non-NULL.
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* Read the message block at index @index_in_region within each of the
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* @v->fec->rs_k regions and deinterleave their contents into @io->fec_io->bufs.
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*
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* @target_block gives the index of specific block within this sequence that is
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* being corrected, relative to the start of all the FEC message blocks.
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*
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* @out_pos gives the current output position, i.e. the position in (each) block
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* from which to start the deinterleaving. Deinterleaving continues until
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* either end-of-block is reached or there's no more buffer space.
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*
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* If @neras is non-NULL, then also use verity hashes and the presence/absence
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* of I/O errors to determine which of the message blocks in the sequence are
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* likely to be incorrect. Write the number of such blocks to *@neras and the
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* indices of the corresponding RS message bytes in [0, k - 1] to
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* @io->fec_io->erasures, up to a limit of @v->fec->roots + 1 such blocks.
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*/
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static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
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u64 target_block, u64 index_in_region,
···
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if (WARN_ON(v->digest_size > sizeof(want_digest)))
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return -EINVAL;
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/*
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* read each of the rs_k data blocks that are part of the RS block, and
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* interleave contents to available bufs
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*/
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for (i = 0; i < v->fec->rs_k; i++) {
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/*
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* Read the block from region i. It contains the i'th message
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* byte of the target block's RS codewords.
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*/
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block = i * v->fec->region_blocks + index_in_region;
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bufio = v->fec->data_bufio;
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···
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}
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/*
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* deinterleave and copy the bytes that fit into bufs,
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* starting from out_pos
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* Deinterleave the bytes of the block, starting from 'out_pos',
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* into the i'th byte of the RS message buffers. Stop when
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* end-of-block is reached or there are no more buffers.
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*/
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src_pos = out_pos;
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fec_for_each_buffer_rs_message(fio, n, j) {