dm-crypt: support for per-sector NVMe metadata

Support per-sector NVMe metadata in dm-crypt.

This commit changes dm-crypt, so that it can use NVMe metadata to store
authentication information. We can put dm-crypt directly on the top of
NVMe device, without using dm-integrity.

This commit improves write throughput twice, becase the will be no writes
to the dm-integrity journal.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Author: Mikulas Patocka

drivers/md/dm-crypt.c

@@ -214,7 +214,8 @@ struct crypt_config {
 
 	unsigned int integrity_tag_size;
 	unsigned int integrity_iv_size;
-	unsigned int on_disk_tag_size;
+	unsigned int used_tag_size;
+	unsigned int tuple_size;
 
 	/*
 	 * pool for per bio private data, crypto requests,
@@ -256,7 +257,7 @@ static unsigned get_max_request_size(struct crypt_config *cc, bool wrt)
 	val = !wrt ? READ_ONCE(max_read_size) : READ_ONCE(max_write_size);
 	if (likely(!val))
 		val = !wrt ? DM_CRYPT_DEFAULT_MAX_READ_SIZE : DM_CRYPT_DEFAULT_MAX_WRITE_SIZE;
-	if (wrt || cc->on_disk_tag_size) {
+	if (wrt || cc->used_tag_size) {
 		if (unlikely(val > BIO_MAX_VECS << PAGE_SHIFT))
 			val = BIO_MAX_VECS << PAGE_SHIFT;
 	}
@@ -1176,14 +1177,14 @@ static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
 	unsigned int tag_len;
 	int ret;
 
-	if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
+	if (!bio_sectors(bio) || !io->cc->tuple_size)
 		return 0;
 
 	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
 	if (IS_ERR(bip))
 		return PTR_ERR(bip);
 
-	tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
+	tag_len = io->cc->tuple_size * (bio_sectors(bio) >> io->cc->sector_shift);
 
 	bip->bip_iter.bi_sector = io->cc->start + io->sector;
 
@@ -1207,18 +1208,18 @@ static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
 		return -EINVAL;
 	}
 
-	if (bi->tag_size != cc->on_disk_tag_size ||
-	    bi->tuple_size != cc->on_disk_tag_size) {
+	if (bi->tuple_size < cc->used_tag_size) {
 		ti->error = "Integrity profile tag size mismatch.";
 		return -EINVAL;
 	}
+	cc->tuple_size = bi->tuple_size;
 	if (1 << bi->interval_exp != cc->sector_size) {
 		ti->error = "Integrity profile sector size mismatch.";
 		return -EINVAL;
 	}
 
 	if (crypt_integrity_aead(cc)) {
-		cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
+		cc->integrity_tag_size = cc->used_tag_size - cc->integrity_iv_size;
 		DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
 		       cc->integrity_tag_size, cc->integrity_iv_size);
 
@@ -1230,7 +1231,7 @@ static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
 		DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
 		       cc->integrity_iv_size);
 
-	if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
+	if ((cc->integrity_tag_size + cc->integrity_iv_size) > cc->tuple_size) {
 		ti->error = "Not enough space for integrity tag in the profile.";
 		return -EINVAL;
 	}
@@ -1309,7 +1310,7 @@ static void *tag_from_dmreq(struct crypt_config *cc,
 	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
 
 	return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
-		cc->on_disk_tag_size];
+		cc->tuple_size];
 }
 
 static void *iv_tag_from_dmreq(struct crypt_config *cc,
@@ -1390,9 +1391,9 @@ static int crypt_convert_block_aead(struct crypt_config *cc,
 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
 				       cc->sector_size, iv);
 		r = crypto_aead_encrypt(req);
-		if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
+		if (cc->integrity_tag_size + cc->integrity_iv_size != cc->tuple_size)
 			memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
-			       cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
+			       cc->tuple_size - (cc->integrity_tag_size + cc->integrity_iv_size));
 	} else {
 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
 				       cc->sector_size + cc->integrity_tag_size, iv);
@@ -1822,7 +1823,7 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 		return;
 
 	if (likely(!io->ctx.aead_recheck) && unlikely(io->ctx.aead_failed) &&
-	    cc->on_disk_tag_size && bio_data_dir(base_bio) == READ) {
+	    cc->used_tag_size && bio_data_dir(base_bio) == READ) {
 		io->ctx.aead_recheck = true;
 		io->ctx.aead_failed = false;
 		io->error = 0;
@@ -3206,7 +3207,7 @@ static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **ar
 				ti->error = "Invalid integrity arguments";
 				return -EINVAL;
 			}
-			cc->on_disk_tag_size = val;
+			cc->used_tag_size = val;
 			sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
 			if (!strcasecmp(sval, "aead")) {
 				set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
@@ -3418,12 +3419,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		if (ret)
 			goto bad;
 
-		cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
+		cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->tuple_size;
 		if (!cc->tag_pool_max_sectors)
 			cc->tag_pool_max_sectors = 1;
 
 		ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
-			cc->tag_pool_max_sectors * cc->on_disk_tag_size);
+			cc->tag_pool_max_sectors * cc->tuple_size);
 		if (ret) {
 			ti->error = "Cannot allocate integrity tags mempool";
 			goto bad;
@@ -3535,8 +3536,8 @@ static int crypt_map(struct dm_target *ti, struct bio *bio)
 	io = dm_per_bio_data(bio, cc->per_bio_data_size);
 	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
 
-	if (cc->on_disk_tag_size) {
-		unsigned int tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
+	if (cc->tuple_size) {
+		unsigned int tag_len = cc->tuple_size * (bio_sectors(bio) >> cc->sector_shift);
 
 		if (unlikely(tag_len > KMALLOC_MAX_SIZE))
 			io->integrity_metadata = NULL;
@@ -3608,7 +3609,7 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 		num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
 		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)
+		if (cc->used_tag_size)
 			num_feature_args++;
 		if (num_feature_args) {
 			DMEMIT(" %d", num_feature_args);
@@ -3624,8 +3625,8 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 				DMEMIT(" no_read_workqueue");
 			if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
 				DMEMIT(" no_write_workqueue");
-			if (cc->on_disk_tag_size)
-				DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
+			if (cc->used_tag_size)
+				DMEMIT(" integrity:%u:%s", cc->used_tag_size, cc->cipher_auth);
 			if (cc->sector_size != (1 << SECTOR_SHIFT))
 				DMEMIT(" sector_size:%d", cc->sector_size);
 			if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
@@ -3647,9 +3648,9 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 		DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
 		       'y' : 'n');
 
-		if (cc->on_disk_tag_size)
+		if (cc->used_tag_size)
 			DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
-			       cc->on_disk_tag_size, cc->cipher_auth);
+			       cc->used_tag_size, cc->cipher_auth);
 		if (cc->sector_size != (1 << SECTOR_SHIFT))
 			DMEMIT(",sector_size=%d", cc->sector_size);
 		if (cc->cipher_string)
@@ -3757,7 +3758,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version = {1, 26, 0},
+	.version = {1, 27, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,