From ff3af92b4461be773337111daea80bb91b2cd545 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 23 Mar 2017 10:23:14 -0400 Subject: dm crypt: use shifts instead of sector_div sector_div is very slow, so we introduce a variable sector_shift and use shift instead of sector_div. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-crypt.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'drivers/md/dm-crypt.c') diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 05acc42bdd38..ccbc7f36bb2e 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -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++; -- cgit v1.2.3