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

diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index 4aee948dde5d7a3fe13cdc5ff37c1a91eeea53e8..6dee48858ed6e00a90699a67c8726d2ac1202604 100644 (file)
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -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 */