github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-01 02:53:36 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

dm-verity-fec: pass down index_in_region instead of rsb

Browse Source 
Replace 'rsb', which is a byte index, with 'index_in_region' which is a
block index.  The block index is slightly easier to compute, it matches
what fec_read_bufs() wants, and it avoids the mismatch between the name
and the units of the variable.  ('rsb' stood for "Reed-Solomon block",
but its units were bytes, not blocks.)

fec_decode_bufs() does want it as a byte index when computing
parity_block, but that's easily handled locally.

As long as the parameters to the log messages are being adjusted, also
eliminate the unnecessary casts to 'unsigned long long'.  %llu is the
correct way to print a u64 in the Linux kernel, as documented in
printk-formats.rst.  There's no PRIu64 macro like there is in userspace.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
This commit is contained in:
Eric Biggers 2026-02-05 20:59:38 -08:00 committed by Mikulas Patocka
parent ca21ed4089
commit b39b3c812e
1 changed files with 26 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
drivers/md/dm-verity-fec.c
View File

@ -49,7 +49,7 @@ static inline u8 *fec_buffer_rs_message(struct dm_verity *v,
* 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,
struct dm_verity_fec_io *fio, u64 index_in_region,
int target_region, unsigned int out_pos, int neras)
{
int r, corrected = 0, res;
@ -67,14 +67,16 @@ 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 + out_pos) * v->fec->roots;
parity_block = ((index_in_region << v->data_dev_block_bits) + 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,
bio->bi_ioprio);
if (IS_ERR(par)) {
DMERR("%s: FEC %llu: parity read failed (block %llu): %ld",
v->data_dev->name, rsb, parity_block, PTR_ERR(par));
v->data_dev->name, index_in_region, parity_block,
PTR_ERR(par));
return PTR_ERR(par);
}
@ -103,8 +105,8 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,
bio->bi_ioprio);
if (IS_ERR(par)) {
DMERR("%s: FEC %llu: parity read failed (block %llu): %ld",
v->data_dev->name, rsb, parity_block,
PTR_ERR(par));
v->data_dev->name, index_in_region,
parity_block, PTR_ERR(par));
return PTR_ERR(par);
}
for (; j < v->fec->roots; j++)
@ -132,10 +134,10 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_io *io,
if (r < 0 && neras)
DMERR_LIMIT("%s: FEC %llu: failed to correct: %d",
v->data_dev->name, (unsigned long long)rsb, r);
v->data_dev->name, index_in_region, r);
else if (r > 0)
DMWARN_LIMIT("%s: FEC %llu: corrected %d errors",
v->data_dev->name, (unsigned long long)rsb, r);
v->data_dev->name, index_in_region, r);
return r;
}
@ -158,14 +160,14 @@ 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, unsigned int out_pos, int *neras)
u64 index_in_region, unsigned int out_pos, int *neras)
{
bool is_zero;
int i, j;
struct dm_buffer *buf;
struct dm_bufio_client *bufio;
struct dm_verity_fec_io *fio = io->fec_io;
u64 block, ileaved;
u64 block;
u8 *bbuf;
u8 want_digest[HASH_MAX_DIGESTSIZE];
unsigned int n, src_pos;
@ -182,8 +184,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
* interleave contents to available bufs
*/
for (i = 0; i < v->fec->rs_k; i++) {
ileaved = rsb + i * (v->fec->region_blocks << v->data_dev_block_bits);
block = ileaved >> v->data_dev_block_bits;
block = i * v->fec->region_blocks + index_in_region;
bufio = v->fec->data_bufio;
if (block >= v->data_blocks) {
@ -203,9 +204,8 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
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,
(unsigned long long)rsb,
(unsigned long long)block, PTR_ERR(bbuf));
v->data_dev->name, index_in_region, block,
PTR_ERR(bbuf));
/* assume the block is corrupted */
if (neras && *neras <= v->fec->roots)
@ -312,11 +312,16 @@ static int fec_decode(struct dm_verity *v, struct dm_verity_io *io,
{
int r, neras = 0;
unsigned int target_region, out_pos;
u64 rsb;
u64 index_in_region;
target_region = div64_u64_rem(
target_block << v->data_dev_block_bits,
v->fec->region_blocks << v->data_dev_block_bits, &rsb);
/*
* Compute 'target_region', the index of the region the target block is
* in; and 'index_in_region', the index of the target block within its
* region. The latter value is also the index within its region of each
* message block that shares its RS codewords with the target block.
*/
target_region = div64_u64_rem(target_block, v->fec->region_blocks,
&index_in_region);
if (WARN_ON_ONCE(target_region >= v->fec->rs_k))
/* target_block is out-of-bounds. Should never happen. */
return -EIO;
@ -324,12 +329,12 @@ static int fec_decode(struct dm_verity *v, struct dm_verity_io *io,
for (out_pos = 0; out_pos < v->fec->block_size;) {
fec_init_bufs(v, fio);
r = fec_read_bufs(v, io, rsb, out_pos,
r = fec_read_bufs(v, io, index_in_region, out_pos,
use_erasures ? &neras : NULL);
if (unlikely(r < 0))
return r;
r = fec_decode_bufs(v, io, fio, rsb, target_region,
r = fec_decode_bufs(v, io, fio, index_in_region, target_region,
out_pos, neras);
if (r < 0)
return r;
@ -344,7 +349,7 @@ static int fec_decode(struct dm_verity *v, struct dm_verity_io *io,
if (memcmp(io->tmp_digest, want_digest, v->digest_size)) {
DMERR_LIMIT("%s: FEC %llu: failed to correct (%d erasures)",
v->data_dev->name, (unsigned long long)rsb, neras);
v->data_dev->name, index_in_region, neras);
return -EILSEQ;
}