dm-verity-fec: simplify computation of ileaved

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fec_read_bufs() just iterates over a sequence of message blocks with
step size region_blocks.  At each step, 'ileaved' is just the offset (in
bytes) to one of these blocks.  Compute it in the straightforward way,
eliminating fec_interleave().

In more detail, previously the code computed
'ileaved = (n / k) + (n % k) * (region_blocks * block_size)'
where n = rsb * k + i and 0 <= i < k.  Substituting 'n' gives:

    ileaved = ((rsb * k + i) / k) + ((rsb * k + i) % k) * region_blocks * block_size
            = rsb + (i * region_blocks * block_size)

The result is more efficient and easier to understand.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

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Eric Biggers 2026-02-05 20:59:33 -08:00 • committed by Mikulas Patocka

parent 8ef45923fd

commit 5ef22361fa

1 changed files with 1 additions and 12 deletions

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drivers/md/dm-verity-fec.c

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