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dm crypt: use shifts instead of sector_div

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sector_div is very slow, so we introduce a variable sector_shift and
use shift instead of sector_div.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mikulas Patocka 2017-03-23 10:23:14 -04:00 committed by Mike Snitzer
parent c2bcb2b702
commit ff3af92b44
1 changed files with 10 additions and 7 deletions
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17
drivers/md/dm-crypt.c
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@ -172,7 +172,8 @@ struct crypt_config {
} iv_gen_private;
sector_t iv_offset;
unsigned int iv_size;
unsigned int sector_size;
unsigned short int sector_size;
unsigned char sector_shift;
/* ESSIV: struct crypto_cipher *essiv_tfm */
void *iv_private;
@ -1062,7 +1063,7 @@ static int crypt_convert_block_aead(struct crypt_config *cc,
dmreq = dmreq_of_req(cc, req);
dmreq->iv_sector = ctx->cc_sector;
if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
sector_div(dmreq->iv_sector, cc->sector_size >> SECTOR_SHIFT);
dmreq->iv_sector >>= cc->sector_shift;
dmreq->ctx = ctx;
*org_tag_of_dmreq(cc, dmreq) = tag_offset;
@ -1155,7 +1156,7 @@ static int crypt_convert_block_skcipher(struct crypt_config *cc,
dmreq = dmreq_of_req(cc, req);
dmreq->iv_sector = ctx->cc_sector;
if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
sector_div(dmreq->iv_sector, cc->sector_size >> SECTOR_SHIFT);
dmreq->iv_sector >>= cc->sector_shift;
dmreq->ctx = ctx;
*org_tag_of_dmreq(cc, dmreq) = tag_offset;
@ -1290,7 +1291,7 @@ static int crypt_convert(struct crypt_config *cc,
struct convert_context *ctx)
{
unsigned int tag_offset = 0;
unsigned int sector_step = cc->sector_size / (1 << SECTOR_SHIFT);
unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
int r;
atomic_set(&ctx->cc_pending, 1);
@ -2575,13 +2576,14 @@ static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **ar
cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
if (!cc->cipher_auth)
return -ENOMEM;
} else if (sscanf(opt_string, "sector_size:%u%c", &cc->sector_size, &dummy) == 1) {
} else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
if (cc->sector_size < (1 << SECTOR_SHIFT) ||
cc->sector_size > 4096 ||
(1 << ilog2(cc->sector_size) != cc->sector_size)) {
(cc->sector_size & (cc->sector_size - 1))) {
ti->error = "Invalid feature value for sector_size";
return -EINVAL;
}
cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
} else if (!strcasecmp(opt_string, "iv_large_sectors"))
set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
else {
@ -2625,6 +2627,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
cc->key_size = key_size;
cc->sector_size = (1 << SECTOR_SHIFT);
cc->sector_shift = 0;
ti->private = cc;
@ -2870,7 +2873,7 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
num_feature_args += !!ti->num_discard_bios;
num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
num_feature_args += (cc->sector_size != (1 << SECTOR_SHIFT)) ? 1 : 0;
num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
if (cc->on_disk_tag_size)
num_feature_args++;