X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fmd%2Fdm-crypt.c;h=ab6a61db63ce2248b5553ec43678fab61642e9a7;hb=53ffe3b440aa85af6fc4eda09b2d44bcdd312d4d;hp=44e1aa30e3f66b19300b3689cd7d74679e3c06cc;hpb=899c95d36c896f9fb7bc5f4f03b4abd86bda292c;p=linux-2.6

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 44e1aa30e3..ab6a61db63 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1,11 +1,12 @@
 /*
  * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
  * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
- * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
 
+#include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -31,6 +32,7 @@
  * context holding the current state of a multi-part conversion
  */
 struct convert_context {
+	struct completion restart;
 	struct bio *bio_in;
 	struct bio *bio_out;
 	unsigned int offset_in;
@@ -38,6 +40,7 @@ struct convert_context {
 	unsigned int idx_in;
 	unsigned int idx_out;
 	sector_t sector;
+	atomic_t pending;
 };
 
 /*
@@ -55,6 +58,11 @@ struct dm_crypt_io {
 	sector_t sector;
 };
 
+struct dm_crypt_request {
+	struct scatterlist sg_in;
+	struct scatterlist sg_out;
+};
+
 struct crypt_config;
 
 struct crypt_iv_operations {
@@ -75,15 +83,18 @@ struct crypt_config {
 	sector_t start;
 
 	/*
-	 * pool for per bio private data and
-	 * for encryption buffer pages
+	 * pool for per bio private data, crypto requests and
+	 * encryption requeusts/buffer pages
 	 */
 	mempool_t *io_pool;
+	mempool_t *req_pool;
 	mempool_t *page_pool;
 	struct bio_set *bs;
 
 	struct workqueue_struct *io_queue;
 	struct workqueue_struct *crypt_queue;
+	wait_queue_head_t writeq;
+
 	/*
 	 * crypto related data
 	 */
@@ -96,9 +107,25 @@ struct crypt_config {
 	sector_t iv_offset;
 	unsigned int iv_size;
 
+	/*
+	 * Layout of each crypto request:
+	 *
+	 *   struct ablkcipher_request
+	 *      context
+	 *      padding
+	 *   struct dm_crypt_request
+	 *      padding
+	 *   IV
+	 *
+	 * The padding is added so that dm_crypt_request and the IV are
+	 * correctly aligned.
+	 */
+	unsigned int dmreq_start;
+	struct ablkcipher_request *req;
+
 	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];
@@ -192,7 +219,7 @@ 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);
@@ -229,7 +256,7 @@ 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
@@ -293,38 +320,6 @@ 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,
@@ -337,6 +332,72 @@ static void crypt_convert_init(struct crypt_config *cc,
 	ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
 	ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
 	ctx->sector = sector + cc->iv_offset;
+	init_completion(&ctx->restart);
+	atomic_set(&ctx->pending, 1);
+}
+
+static int crypt_convert_block(struct crypt_config *cc,
+			       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;
+	u8 *iv;
+	int r = 0;
+
+	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,
+		    bv_out->bv_offset + ctx->offset_out);
+
+	ctx->offset_in += 1 << SECTOR_SHIFT;
+	if (ctx->offset_in >= bv_in->bv_len) {
+		ctx->offset_in = 0;
+		ctx->idx_in++;
+	}
+
+	ctx->offset_out += 1 << SECTOR_SHIFT;
+	if (ctx->offset_out >= bv_out->bv_len) {
+		ctx->offset_out = 0;
+		ctx->idx_out++;
+	}
+
+	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,
+			       int error);
+static void crypt_alloc_req(struct crypt_config *cc,
+			    struct convert_context *ctx)
+{
+	if (!cc->req)
+		cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
+	ablkcipher_request_set_tfm(cc->req, cc->tfm);
+	ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+					     CRYPTO_TFM_REQ_MAY_SLEEP,
+					     kcryptd_async_done, ctx);
 }
 
 /*
@@ -345,41 +406,43 @@ static void crypt_convert_init(struct crypt_config *cc,
 static int crypt_convert(struct crypt_config *cc,
 			 struct convert_context *ctx)
 {
-	int r = 0;
+	int r;
 
 	while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
 	      ctx->idx_out < ctx->bio_out->bi_vcnt) {
-		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 scatterlist sg_in, sg_out;
-
-		sg_init_table(&sg_in, 1);
-		sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in);
-
-		sg_init_table(&sg_out, 1);
-		sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out);
-
-		ctx->offset_in += sg_in.length;
-		if (ctx->offset_in >= bv_in->bv_len) {
-			ctx->offset_in = 0;
-			ctx->idx_in++;
-		}
 
-		ctx->offset_out += sg_out.length;
-		if (ctx->offset_out >= bv_out->bv_len) {
-			ctx->offset_out = 0;
-			ctx->idx_out++;
+		crypt_alloc_req(cc, ctx);
+
+		atomic_inc(&ctx->pending);
+
+		r = crypt_convert_block(cc, ctx, cc->req);
+
+		switch (r) {
+		/* async */
+		case -EBUSY:
+			wait_for_completion(&ctx->restart);
+			INIT_COMPLETION(ctx->restart);
+			/* fall through*/
+		case -EINPROGRESS:
+			cc->req = NULL;
+			ctx->sector++;
+			continue;
+
+		/* sync */
+		case 0:
+			atomic_dec(&ctx->pending);
+			ctx->sector++;
+			cond_resched();
+			continue;
+
+		/* error */
+		default:
+			atomic_dec(&ctx->pending);
+			return r;
 		}
-
-		r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
-			bio_data_dir(ctx->bio_in) == WRITE, ctx->sector);
-		if (r < 0)
-			break;
-
-		ctx->sector++;
 	}
 
-	return r;
+	return 0;
 }
 
 static void dm_crypt_bio_destructor(struct bio *bio)
@@ -555,6 +618,11 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
 
 static void kcryptd_io_write(struct dm_crypt_io *io)
 {
+	struct bio *clone = io->ctx.bio_out;
+	struct crypt_config *cc = io->target->private;
+
+	generic_make_request(clone);
+	wake_up(&cc->writeq);
 }
 
 static void kcryptd_io(struct work_struct *work)
@@ -575,7 +643,8 @@ static void kcryptd_queue_io(struct dm_crypt_io *io)
 	queue_work(cc->io_queue, &io->work);
 }
 
-static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
+static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
+					  int error, int async)
 {
 	struct bio *clone = io->ctx.bio_out;
 	struct crypt_config *cc = io->target->private;
@@ -593,8 +662,12 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
 	clone->bi_sector = cc->start + io->sector;
 	io->sector += bio_sectors(clone);
 
-	atomic_inc(&io->pending);
-	generic_make_request(clone);
+	if (async)
+		kcryptd_queue_io(io);
+	else {
+		atomic_inc(&io->pending);
+		generic_make_request(clone);
+	}
 }
 
 static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
@@ -622,13 +695,21 @@ 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);
-		if (unlikely(r < 0))
-			return;
+		if (atomic_dec_and_test(&io->ctx.pending)) {
+			/* processed, no running async crypto  */
+			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))
+		if (unlikely(remaining)) {
+			/* wait for async crypto then reinitialize pending */
+			wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
+			atomic_set(&io->ctx.pending, 1);
 			congestion_wait(WRITE, HZ/100);
+		}
 	}
 }
 
@@ -660,12 +741,40 @@ 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 (atomic_dec_and_test(&io->ctx.pending))
+		kcryptd_crypt_read_done(io, r);
+
+	crypt_dec_pending(io);
+}
+
+static void kcryptd_async_done(struct crypto_async_request *async_req,
+			       int error)
+{
+	struct convert_context *ctx = async_req->data;
+	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
+	struct crypt_config *cc = io->target->private;
+
+	if (error == -EINPROGRESS) {
+		complete(&ctx->restart);
+		return;
+	}
+
+	mempool_free(ablkcipher_request_cast(async_req), cc->req_pool);
+
+	if (!atomic_dec_and_test(&ctx->pending))
+		return;
+
+	if (bio_data_dir(io->base_bio) == READ)
+		kcryptd_crypt_read_done(io, error);
+	else
+		kcryptd_crypt_write_io_submit(io, error, 1);
 }
 
 static void kcryptd_crypt(struct work_struct *work)
@@ -759,7 +868,7 @@ 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;
@@ -813,7 +922,7 @@ 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;
@@ -847,7 +956,7 @@ 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,
@@ -867,6 +976,20 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_slab_pool;
 	}
 
+	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);
+	if (!cc->req_pool) {
+		ti->error = "Cannot allocate crypt request mempool";
+		goto bad_req_pool;
+	}
+	cc->req = NULL;
+
 	cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
 	if (!cc->page_pool) {
 		ti->error = "Cannot allocate page mempool";
@@ -879,7 +1002,7 @@ 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;
 	}
@@ -926,6 +1049,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_crypt_queue;
 	}
 
+	init_waitqueue_head(&cc->writeq);
 	ti->private = cc;
 	return 0;
 
@@ -940,12 +1064,14 @@ bad_device:
 bad_bs:
 	mempool_destroy(cc->page_pool);
 bad_page_pool:
+	mempool_destroy(cc->req_pool);
+bad_req_pool:
 	mempool_destroy(cc->io_pool);
 bad_slab_pool:
 	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));
@@ -960,14 +1086,18 @@ static void crypt_dtr(struct dm_target *ti)
 	destroy_workqueue(cc->io_queue);
 	destroy_workqueue(cc->crypt_queue);
 
+	if (cc->req)
+		mempool_free(cc->req, cc->req_pool);
+
 	bioset_free(cc->bs);
 	mempool_destroy(cc->page_pool);
+	mempool_destroy(cc->req_pool);
 	mempool_destroy(cc->io_pool);
 
 	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 */