diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2026-02-05 20:59:27 -0800 |
|---|---|---|
| committer | Mikulas Patocka <mpatocka@redhat.com> | 2026-03-09 15:11:59 +0100 |
| commit | 82fbd6a3e29a329d439690cd7ccc4162c9cd8db6 (patch) | |
| tree | e17aabd138ee8fc74afe83772bdd06116813de82 | |
| parent | 05777b2800b060585d601705a8d1bb5afadc2f11 (diff) | |
dm-verity-fec: replace {MAX,MIN}_RSN with {MIN,MAX}_ROOTS
Every time DM_VERITY_FEC_{MAX,MIN}_RSN are used, they are subtracted
from DM_VERITY_FEC_RSM to get the bounds on the number of roots.
Therefore, replace these with {MIN,MAX}_ROOTS constants which are more
directly useful. (Note the inversion, where MAX_RSN maps to MIN_ROOTS
and MIN_RSN maps to MAX_ROOTS.) No functional change.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
| -rw-r--r-- | drivers/md/dm-verity-fec.c | 6 | ||||
| -rw-r--r-- | drivers/md/dm-verity-fec.h | 7 |
2 files changed, 6 insertions, 7 deletions
diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index 7a5ca1186af0..0622b7496b8d 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -73,7 +73,7 @@ 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, j, parity_pos, to_copy; - uint16_t par_buf[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN]; + uint16_t par_buf[DM_VERITY_FEC_MAX_ROOTS]; u8 *par, *block; u64 parity_block; struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); @@ -572,8 +572,8 @@ int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS)) { if (sscanf(arg_value, "%hhu%c", &num_c, &dummy) != 1 || !num_c || - num_c < (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MAX_RSN) || - num_c > (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN)) { + num_c < DM_VERITY_FEC_MIN_ROOTS || + num_c > DM_VERITY_FEC_MAX_ROOTS) { ti->error = "Invalid " DM_VERITY_OPT_FEC_ROOTS; return -EINVAL; } diff --git a/drivers/md/dm-verity-fec.h b/drivers/md/dm-verity-fec.h index 32ca2bfee1db..d8d0e81da270 100644 --- a/drivers/md/dm-verity-fec.h +++ b/drivers/md/dm-verity-fec.h @@ -13,8 +13,8 @@ /* Reed-Solomon(M, N) parameters */ #define DM_VERITY_FEC_RSM 255 -#define DM_VERITY_FEC_MAX_RSN 253 -#define DM_VERITY_FEC_MIN_RSN 231 /* ~10% space overhead */ +#define DM_VERITY_FEC_MIN_ROOTS 2 /* RS(255, 253): ~0.8% space overhead */ +#define DM_VERITY_FEC_MAX_ROOTS 24 /* RS(255, 231): ~10% space overhead */ /* buffers for deinterleaving and decoding */ #define DM_VERITY_FEC_BUF_RS_BITS 4 /* 1 << RS blocks per buffer */ @@ -47,8 +47,7 @@ struct dm_verity_fec { /* per-bio data */ struct dm_verity_fec_io { struct rs_control *rs; /* Reed-Solomon state */ - /* erasures for decode_rs8 */ - int erasures[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN + 1]; + int erasures[DM_VERITY_FEC_MAX_ROOTS + 1]; /* erasures for decode_rs8 */ u8 *output; /* buffer for corrected output */ unsigned int level; /* recursion level */ unsigned int nbufs; /* number of buffers allocated */ |