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path: root/drivers/md/dm-verity-fec.c
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Diffstat (limited to 'drivers/md/dm-verity-fec.c')
-rw-r--r--drivers/md/dm-verity-fec.c93
1 files changed, 36 insertions, 57 deletions
diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index e46aee6f932e..0c41949db784 100644
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -40,35 +40,23 @@ 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 short ioprio)
+ 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_with_ioprio(v->fec->bufio, block, buf, ioprio);
if (IS_ERR(res)) {
@@ -128,11 +116,13 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,
{
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, bio_prio(bio));
+ par = fec_read_parity(v, rsb, block_offset, &offset,
+ par_buf_offset, &buf, bio->bi_ioprio);
if (IS_ERR(par))
return PTR_ERR(par);
@@ -142,7 +132,11 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,
*/
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;
@@ -155,12 +149,22 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,
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, bio_prio(bio));
+ par = fec_read_parity(v, rsb, block_offset, &offset,
+ par_buf_offset, &buf, bio->bi_ioprio);
if (IS_ERR(par))
return PTR_ERR(par);
}
@@ -186,8 +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;
@@ -251,7 +254,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
bufio = v->bufio;
}
- bbuf = dm_bufio_read_with_ioprio(bufio, block, &buf, bio_prio(bio));
+ 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,
@@ -388,8 +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;
@@ -404,24 +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);
@@ -471,12 +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--;
@@ -746,10 +728,7 @@ 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,
generated by cgit (git 2.34.1) at 2025-07-24 22:43:21 +0000