1 files changed, 47 insertions, 61 deletions

diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index b475200d8586..631a887b487c 100644
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -40,36 +40,25 @@ static inline u64 fec_interleave(struct dm_verity *v, u64 offset)
 }
 
 /*
- * Decode an RS block using Reed-Solomon.
- */
-static int fec_decode_rs8(struct dm_verity *v, struct dm_verity_fec_io *fio,
-			  u8 *data, u8 *fec, int neras)
-{
-	int i;
-	uint16_t par[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN];
-
-	for (i = 0; i < v->fec->roots; i++)
-		par[i] = fec[i];
-
-	return decode_rs8(fio->rs, data, par, v->fec->rsn, NULL, neras,
-			  fio->erasures, 0, NULL);
-}
-
-/*
  * Read error-correcting codes for the requested RS block. Returns a pointer
  * to the data block. Caller is responsible for releasing buf.
  */
 static u8 *fec_read_parity(struct dm_verity *v, u64 rsb, int index,
-			   unsigned int *offset, struct dm_buffer **buf)
+			   unsigned int *offset, unsigned int par_buf_offset,
+			   struct dm_buffer **buf, unsigned short ioprio)
 {
 	u64 position, block, rem;
 	u8 *res;
 
+	/* We have already part of parity bytes read, skip to the next block */
+	if (par_buf_offset)
+		index++;
+
 	position = (index + rsb) * v->fec->roots;
 	block = div64_u64_rem(position, v->fec->io_size, &rem);
-	*offset = (unsigned int)rem;
+	*offset = par_buf_offset ? 0 : (unsigned int)rem;
 
-	res = dm_bufio_read(v->fec->bufio, block, buf);
+	res = dm_bufio_read_with_ioprio(v->fec->bufio, block, buf, ioprio);
 	if (IS_ERR(res)) {
 		DMERR("%s: FEC %llu: parity read failed (block %llu): %ld",
 		      v->data_dev->name, (unsigned long long)rsb,
@@ -121,16 +110,19 @@ static inline unsigned int fec_buffer_rs_index(unsigned int i, unsigned int j)
  * Decode all RS blocks from buffers and copy corrected bytes into fio->output
  * starting from block_offset.
  */
-static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
-			   u64 rsb, int byte_index, unsigned int block_offset,
-			   int neras)
+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)
 {
 	int r, corrected = 0, res;
 	struct dm_buffer *buf;
-	unsigned int n, i, offset;
+	unsigned int n, i, j, offset, par_buf_offset = 0;
+	uint16_t par_buf[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN];
 	u8 *par, *block;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 
-	par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
+	par = fec_read_parity(v, rsb, block_offset, &offset,
+			      par_buf_offset, &buf, bio->bi_ioprio);
 	if (IS_ERR(par))
 		return PTR_ERR(par);
 
@@ -140,7 +132,11 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
 	 */
 	fec_for_each_buffer_rs_block(fio, n, i) {
 		block = fec_buffer_rs_block(v, fio, n, i);
-		res = fec_decode_rs8(v, fio, block, &par[offset], neras);
+		for (j = 0; j < v->fec->roots - par_buf_offset; j++)
+			par_buf[par_buf_offset + j] = par[offset + j];
+		/* Decode an RS block using Reed-Solomon */
+		res = decode_rs8(fio->rs, block, par_buf, v->fec->rsn,
+				 NULL, neras, fio->erasures, 0, NULL);
 		if (res < 0) {
 			r = res;
 			goto error;
@@ -153,12 +149,22 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
 		if (block_offset >= 1 << v->data_dev_block_bits)
 			goto done;
 
-		/* read the next block when we run out of parity bytes */
-		offset += v->fec->roots;
+		/* Read the next block when we run out of parity bytes */
+		offset += (v->fec->roots - par_buf_offset);
+		/* Check if parity bytes are split between blocks */
+		if (offset < v->fec->io_size && (offset + v->fec->roots) > v->fec->io_size) {
+			par_buf_offset = v->fec->io_size - offset;
+			for (j = 0; j < par_buf_offset; j++)
+				par_buf[j] = par[offset + j];
+			offset += par_buf_offset;
+		} else
+			par_buf_offset = 0;
+
 		if (offset >= v->fec->io_size) {
 			dm_bufio_release(buf);
 
-			par = fec_read_parity(v, rsb, block_offset, &offset, &buf);
+			par = fec_read_parity(v, rsb, block_offset, &offset,
+					      par_buf_offset, &buf, bio->bi_ioprio);
 			if (IS_ERR(par))
 				return PTR_ERR(par);
 		}
@@ -184,8 +190,7 @@ error:
 static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io,
 			  u8 *want_digest, u8 *data)
 {
-	if (unlikely(verity_hash(v, verity_io_hash_req(v, io),
-				 data, 1 << v->data_dev_block_bits,
+	if (unlikely(verity_hash(v, io, data, 1 << v->data_dev_block_bits,
 				 verity_io_real_digest(v, io), true)))
 		return 0;
 
@@ -210,6 +215,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
 	u8 *bbuf, *rs_block;
 	u8 want_digest[HASH_MAX_DIGESTSIZE];
 	unsigned int n, k;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 
 	if (neras)
 		*neras = 0;
@@ -248,7 +254,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
 			bufio = v->bufio;
 		}
 
-		bbuf = dm_bufio_read(bufio, block, &buf);
+		bbuf = dm_bufio_read_with_ioprio(bufio, block, &buf, bio->bi_ioprio);
 		if (IS_ERR(bbuf)) {
 			DMWARN_LIMIT("%s: FEC %llu: read failed (%llu): %ld",
 				     v->data_dev->name,
@@ -377,7 +383,7 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
 		if (unlikely(r < 0))
 			return r;
 
-		r = fec_decode_bufs(v, fio, rsb, r, pos, neras);
+		r = fec_decode_bufs(v, io, fio, rsb, r, pos, neras);
 		if (r < 0)
 			return r;
 
@@ -385,8 +391,7 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
 	}
 
 	/* Always re-validate the corrected block against the expected hash */
-	r = verity_hash(v, verity_io_hash_req(v, io), fio->output,
-			1 << v->data_dev_block_bits,
+	r = verity_hash(v, io, fio->output, 1 << v->data_dev_block_bits,
 			verity_io_real_digest(v, io), true);
 	if (unlikely(r < 0))
 		return r;
@@ -401,24 +406,9 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
 	return 0;
 }
 
-static int fec_bv_copy(struct dm_verity *v, struct dm_verity_io *io, u8 *data,
-		       size_t len)
-{
-	struct dm_verity_fec_io *fio = fec_io(io);
-
-	memcpy(data, &fio->output[fio->output_pos], len);
-	fio->output_pos += len;
-
-	return 0;
-}
-
-/*
- * Correct errors in a block. Copies corrected block to dest if non-NULL,
- * otherwise to a bio_vec starting from iter.
- */
+/* Correct errors in a block. Copies corrected block to dest. */
 int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
-		      enum verity_block_type type, sector_t block, u8 *dest,
-		      struct bvec_iter *iter)
+		      enum verity_block_type type, sector_t block, u8 *dest)
 {
 	int r;
 	struct dm_verity_fec_io *fio = fec_io(io);
@@ -468,12 +458,7 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
 			goto done;
 	}
 
-	if (dest)
-		memcpy(dest, fio->output, 1 << v->data_dev_block_bits);
-	else if (iter) {
-		fio->output_pos = 0;
-		r = verity_for_bv_block(v, io, iter, fec_bv_copy);
-	}
+	memcpy(dest, fio->output, 1 << v->data_dev_block_bits);
 
 done:
 	fio->level--;
@@ -608,6 +593,10 @@ int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
 	(*argc)--;
 
 	if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV)) {
+		if (v->fec->dev) {
+			ti->error = "FEC device already specified";
+			return -EINVAL;
+		}
 		r = dm_get_device(ti, arg_value, BLK_OPEN_READ, &v->fec->dev);
 		if (r) {
 			ti->error = "FEC device lookup failed";
@@ -743,10 +732,7 @@ int verity_fec_ctr(struct dm_verity *v)
 		return -E2BIG;
 	}
 
-	if ((f->roots << SECTOR_SHIFT) & ((1 << v->data_dev_block_bits) - 1))
-		f->io_size = 1 << v->data_dev_block_bits;
-	else
-		f->io_size = v->fec->roots << SECTOR_SHIFT;
+	f->io_size = 1 << v->data_dev_block_bits;
 
 	f->bufio = dm_bufio_client_create(f->dev->bdev,
 					  f->io_size,