diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index 0304e36af329..9bf48d34ef0f 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -60,14 +60,19 @@ static int fec_decode_rs8(struct dm_verity *v, struct dm_verity_fec_io *fio, * 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) { 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); if (IS_ERR(res)) { @@ -127,10 +132,11 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio, { int r, corrected = 0, res; struct dm_buffer *buf; - unsigned int n, i, offset; - u8 *par, *block; + unsigned int n, i, offset, par_buf_offset = 0; + u8 *par, *block, par_buf[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN]; - par = fec_read_parity(v, rsb, block_offset, &offset, &buf); + par = fec_read_parity(v, rsb, block_offset, &offset, + par_buf_offset, &buf); if (IS_ERR(par)) return PTR_ERR(par); @@ -140,7 +146,8 @@ 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); + memcpy(&par_buf[par_buf_offset], &par[offset], v->fec->roots - par_buf_offset); + res = fec_decode_rs8(v, fio, block, par_buf, neras); if (res < 0) { r = res; goto error; @@ -153,12 +160,21 @@ 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; + memcpy(par_buf, &par[offset], par_buf_offset); + 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); if (IS_ERR(par)) return PTR_ERR(par); } @@ -743,10 +759,7 @@ 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,