Commit 3ad2b952 authored by Eric Biggers's avatar Eric Biggers Committed by Mikulas Patocka
Browse files

dm-verity-fec: rename block_offset to out_pos 



The current position in the output block buffer is called 'pos' in
fec_decode_rsb(), and 'block_offset' in fec_read_bufs() and
fec_decode_bufs().  These names aren't very clear, especially
'block_offset' which is easily confused with the offset of a message or
parity block or the position in the current parity block.

Rename it to 'out_pos'.

Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
parent 96dfabe7

drivers/md/dm-verity-fec.c

+13 −15
Original line number Diff line number Diff line
@@ -46,11 +46,11 @@ static inline u8 *fec_buffer_rs_message(struct dm_verity *v, 


/*

 * Decode all RS codewords whose message bytes were loaded into fio->bufs.  Copy

 * the corrected bytes into fio->output starting from block_offset.

 * the corrected bytes into fio->output starting from out_pos.

 */

static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,

			   struct dm_verity_fec_io *fio, u64 rsb, int byte_index,

			   unsigned int block_offset, int neras)

			   unsigned int out_pos, int neras)

{

	int r, corrected = 0, res;

	struct dm_buffer *buf;
@@ -67,7 +67,7 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io, 
	 * block_size is always a power of 2, but roots might not be.  Note that

	 * when it's not, a codeword's parity bytes can span a block boundary.

	 */

	parity_block = (rsb + block_offset) * v->fec->roots;

	parity_block = (rsb + out_pos) * v->fec->roots;

	parity_pos = parity_block & (v->fec->block_size - 1);

	parity_block >>= v->data_dev_block_bits;

	par = dm_bufio_read_with_ioprio(v->fec->bufio, parity_block, &buf,
@@ -120,10 +120,9 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io, 
		}



		corrected += res;

		fio->output[block_offset] = msg_buf[byte_index];

		fio->output[out_pos++] = msg_buf[byte_index];



		block_offset++;

		if (block_offset >= v->fec->block_size)

		if (out_pos >= v->fec->block_size)

			goto done;

	}

done:
@@ -159,8 +158,7 @@ static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io, 
 * fits into buffers. Check for erasure locations if @neras is non-NULL.

 */

static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,

			 u64 rsb, u64 target, unsigned int block_offset,

			 int *neras)

			 u64 rsb, u64 target, unsigned int out_pos, int *neras)

{

	bool is_zero;

	int i, j, target_index = -1;
@@ -243,9 +241,9 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io, 


		/*

		 * deinterleave and copy the bytes that fit into bufs,

		 * starting from block_offset

		 * starting from out_pos

		 */

		src_pos = block_offset;

		src_pos = out_pos;

		fec_for_each_buffer_rs_message(fio, n, j) {

			if (src_pos >= v->fec->block_size)

				goto done;
@@ -317,21 +315,21 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io, 
			  const u8 *want_digest, bool use_erasures)

{

	int r, neras = 0;

	unsigned int pos;

	unsigned int out_pos;



	for (pos = 0; pos < v->fec->block_size;) {

	for (out_pos = 0; out_pos < v->fec->block_size;) {

		fec_init_bufs(v, fio);



		r = fec_read_bufs(v, io, rsb, offset, pos,

		r = fec_read_bufs(v, io, rsb, offset, out_pos,

				  use_erasures ? &neras : NULL);

		if (unlikely(r < 0))

			return r;



		r = fec_decode_bufs(v, io, fio, rsb, r, pos, neras);

		r = fec_decode_bufs(v, io, fio, rsb, r, out_pos, neras);

		if (r < 0)

			return r;



		pos += fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS;

		out_pos += fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS;

	}



	/* Always re-validate the corrected block against the expected hash */