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dm crypt: use async crypto
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dm-crypt: Use crypto ablkcipher interface

Move encrypt/decrypt core to async crypto call.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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Milan Broz authored and Alasdair G Kergon committed Feb 8, 2008
1 parent 95497a9 commit 3a7f6c9
Showing 1 changed file with 72 additions and 59 deletions.
131 changes: 72 additions & 59 deletions drivers/md/dm-crypt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,7 @@ struct crypt_config {

char cipher[CRYPTO_MAX_ALG_NAME];
char chainmode[CRYPTO_MAX_ALG_NAME];
struct crypto_blkcipher *tfm;
struct crypto_ablkcipher *tfm;
unsigned long flags;
unsigned int key_size;
u8 key[0];
Expand Down Expand Up @@ -217,7 +217,7 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
return PTR_ERR(essiv_tfm);
}
if (crypto_cipher_blocksize(essiv_tfm) !=
crypto_blkcipher_ivsize(cc->tfm)) {
crypto_ablkcipher_ivsize(cc->tfm)) {
ti->error = "Block size of ESSIV cipher does "
"not match IV size of block cipher";
crypto_free_cipher(essiv_tfm);
Expand Down Expand Up @@ -254,7 +254,7 @@ static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
unsigned bs = crypto_ablkcipher_blocksize(cc->tfm);
int log = ilog2(bs);

/* we need to calculate how far we must shift the sector count
Expand Down Expand Up @@ -318,38 +318,6 @@ static struct crypt_iv_operations crypt_iv_null_ops = {
.generator = crypt_iv_null_gen
};

static int
crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
struct scatterlist *in, unsigned int length,
int write, sector_t sector)
{
u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
struct blkcipher_desc desc = {
.tfm = cc->tfm,
.info = iv,
.flags = CRYPTO_TFM_REQ_MAY_SLEEP,
};
int r;

if (cc->iv_gen_ops) {
r = cc->iv_gen_ops->generator(cc, iv, sector);
if (r < 0)
return r;

if (write)
r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
else
r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
} else {
if (write)
r = crypto_blkcipher_encrypt(&desc, out, in, length);
else
r = crypto_blkcipher_decrypt(&desc, out, in, length);
}

return r;
}

static void crypt_convert_init(struct crypt_config *cc,
struct convert_context *ctx,
struct bio *bio_out, struct bio *bio_in,
Expand All @@ -374,18 +342,25 @@ static void crypt_convert_init(struct crypt_config *cc,
}

static int crypt_convert_block(struct crypt_config *cc,
struct convert_context *ctx)
struct convert_context *ctx,
struct ablkcipher_request *req)
{
struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
struct dm_crypt_request dmreq;
struct dm_crypt_request *dmreq;
u8 *iv;
int r = 0;

sg_init_table(&dmreq.sg_in, 1);
sg_set_page(&dmreq.sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
dmreq = (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
iv = (u8 *)ALIGN((unsigned long)(dmreq + 1),
crypto_ablkcipher_alignmask(cc->tfm) + 1);

sg_init_table(&dmreq->sg_in, 1);
sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
bv_in->bv_offset + ctx->offset_in);

sg_init_table(&dmreq.sg_out, 1);
sg_set_page(&dmreq.sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
sg_init_table(&dmreq->sg_out, 1);
sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
bv_out->bv_offset + ctx->offset_out);

ctx->offset_in += 1 << SECTOR_SHIFT;
Expand All @@ -400,10 +375,21 @@ static int crypt_convert_block(struct crypt_config *cc,
ctx->idx_out++;
}

return crypt_convert_scatterlist(cc, &dmreq.sg_out, &dmreq.sg_in,
dmreq.sg_in.length,
bio_data_dir(ctx->bio_in) == WRITE,
ctx->sector);
if (cc->iv_gen_ops) {
r = cc->iv_gen_ops->generator(cc, iv, ctx->sector);
if (r < 0)
return r;
}

ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
1 << SECTOR_SHIFT, iv);

if (bio_data_dir(ctx->bio_in) == WRITE)
r = crypto_ablkcipher_encrypt(req);
else
r = crypto_ablkcipher_decrypt(req);

return r;
}

static void kcryptd_async_done(struct crypto_async_request *async_req,
Expand All @@ -429,11 +415,27 @@ static int crypt_convert(struct crypt_config *cc,

while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
ctx->idx_out < ctx->bio_out->bi_vcnt) {
r = crypt_convert_block(cc, ctx);
if (r < 0)
break;

ctx->sector++;
crypt_alloc_req(cc, ctx);

r = crypt_convert_block(cc, ctx, cc->req);

switch (r) {
case -EBUSY:
wait_for_completion(&ctx->restart);
INIT_COMPLETION(ctx->restart);
/* fall through*/
case -EINPROGRESS:
atomic_inc(&ctx->pending);
cc->req = NULL;
r = 0;
/* fall through*/
case 0:
ctx->sector++;
continue;
}

break;
}

/*
Expand Down Expand Up @@ -696,9 +698,12 @@ static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)

r = crypt_convert(cc, &io->ctx);

kcryptd_crypt_write_io_submit(io, r, 0);
if (unlikely(r < 0))
return;
if (r != -EINPROGRESS) {
kcryptd_crypt_write_io_submit(io, r, 0);
if (unlikely(r < 0))
return;
} else
atomic_inc(&io->pending);

/* out of memory -> run queues */
if (unlikely(remaining))
Expand Down Expand Up @@ -734,12 +739,17 @@ static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
struct crypt_config *cc = io->target->private;
int r = 0;

atomic_inc(&io->pending);

crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
io->sector);

r = crypt_convert(cc, &io->ctx);

kcryptd_crypt_read_done(io, r);
if (r != -EINPROGRESS)
kcryptd_crypt_read_done(io, r);

crypt_dec_pending(io);
}

static void kcryptd_async_done(struct crypto_async_request *async_req,
Expand Down Expand Up @@ -856,7 +866,7 @@ static int crypt_wipe_key(struct crypt_config *cc)
static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct crypt_config *cc;
struct crypto_blkcipher *tfm;
struct crypto_ablkcipher *tfm;
char *tmp;
char *cipher;
char *chainmode;
Expand Down Expand Up @@ -910,7 +920,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad_cipher;
}

tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0);
if (IS_ERR(tfm)) {
ti->error = "Error allocating crypto tfm";
goto bad_cipher;
Expand Down Expand Up @@ -944,7 +954,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
goto bad_ivmode;

cc->iv_size = crypto_blkcipher_ivsize(tfm);
cc->iv_size = crypto_ablkcipher_ivsize(tfm);
if (cc->iv_size)
/* at least a 64 bit sector number should fit in our buffer */
cc->iv_size = max(cc->iv_size,
Expand All @@ -965,7 +975,10 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}

cc->dmreq_start = sizeof(struct ablkcipher_request);
cc->dmreq_start += crypto_ablkcipher_reqsize(tfm);
cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) &
~(crypto_tfm_ctx_alignment() - 1);

cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
sizeof(struct dm_crypt_request) + cc->iv_size);
Expand All @@ -987,7 +1000,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad_bs;
}

if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) {
ti->error = "Error setting key";
goto bad_device;
}
Expand Down Expand Up @@ -1055,7 +1068,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
bad_ivmode:
crypto_free_blkcipher(tfm);
crypto_free_ablkcipher(tfm);
bad_cipher:
/* Must zero key material before freeing */
memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Expand All @@ -1081,7 +1094,7 @@ static void crypt_dtr(struct dm_target *ti)
kfree(cc->iv_mode);
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
crypto_free_blkcipher(cc->tfm);
crypto_free_ablkcipher(cc->tfm);
dm_put_device(ti, cc->dev);

/* Must zero key material before freeing */
Expand Down

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