Commit 298a9fa0 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm crypt: use per-bio data 



Change dm-crypt so that it uses auxiliary data allocated with the bio.

Dm-crypt requires two allocations per request - struct dm_crypt_io and
struct ablkcipher_request (with other data appended to it).  It
previously only used mempool allocations.

Some requests may require more dm_crypt_ios and ablkcipher_requests,
however most requests need just one of each of these two structures to
complete.

This patch changes it so that the first dm_crypt_io and ablkcipher_request
are allocated with the bio (using target per_bio_data_size option).  If
the request needs additional values, they are allocated from the mempool.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 6a241483

drivers/md/dm-crypt.c

+27 −14
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ struct dm_crypt_io { 
	int error;

	sector_t sector;

	struct dm_crypt_io *base_io;

};

} CRYPTO_MINALIGN_ATTR;



struct dm_crypt_request {

	struct convert_context *ctx;
@@ -162,6 +162,8 @@ struct crypt_config { 
	 */

	unsigned int dmreq_start;



	unsigned int per_bio_data_size;



	unsigned long flags;

	unsigned int key_size;

	unsigned int key_parts;      /* independent parts in key buffer */
@@ -895,6 +897,15 @@ static void crypt_alloc_req(struct crypt_config *cc, 
	    kcryptd_async_done, dmreq_of_req(cc, ctx->req));

}



static void crypt_free_req(struct crypt_config *cc,

			   struct ablkcipher_request *req, struct bio *base_bio)

{

	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);



	if ((struct ablkcipher_request *)(io + 1) != req)

		mempool_free(req, cc->req_pool);

}



/*

 * Encrypt / decrypt data from one bio to another one (can be the same one)

 */
@@ -1008,12 +1019,9 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 
	}

}



static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc,

static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,

			  struct bio *bio, sector_t sector)

{

	struct dm_crypt_io *io;



	io = mempool_alloc(cc->io_pool, GFP_NOIO);

	io->cc = cc;

	io->base_bio = bio;

	io->sector = sector;
@@ -1021,8 +1029,6 @@ static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc, 
	io->base_io = NULL;

	io->ctx.req = NULL;

	atomic_set(&io->io_pending, 0);



	return io;

}



static void crypt_inc_pending(struct dm_crypt_io *io)
@@ -1046,7 +1052,8 @@ static void crypt_dec_pending(struct dm_crypt_io *io) 
		return;



	if (io->ctx.req)

		mempool_free(io->ctx.req, cc->req_pool);

		crypt_free_req(cc, io->ctx.req, base_bio);

	if (io != dm_per_bio_data(base_bio, cc->per_bio_data_size))

		mempool_free(io, cc->io_pool);



	if (likely(!base_io))
@@ -1255,8 +1262,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 
		 * between fragments, so switch to a new dm_crypt_io structure.

		 */

		if (unlikely(!crypt_finished && remaining)) {

			new_io = crypt_io_alloc(io->cc, io->base_bio,

						sector);

			new_io = mempool_alloc(cc->io_pool, GFP_NOIO);

			crypt_io_init(new_io, io->cc, io->base_bio, sector);

			crypt_inc_pending(new_io);

			crypt_convert_init(cc, &new_io->ctx, NULL,

					   io->base_bio, sector);
@@ -1325,7 +1332,7 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, 
	if (error < 0)

		io->error = -EIO;



	mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);

	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);



	if (!atomic_dec_and_test(&ctx->cc_pending))

		return;
@@ -1728,6 +1735,10 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		goto bad;

	}



	cc->per_bio_data_size = ti->per_bio_data_size =

				sizeof(struct dm_crypt_io) + cc->dmreq_start +

				sizeof(struct dm_crypt_request) + cc->iv_size;



	cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);

	if (!cc->page_pool) {

		ti->error = "Cannot allocate page mempool";
@@ -1824,7 +1835,9 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) 
		return DM_MAPIO_REMAPPED;

	}



	io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));

	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));

	io->ctx.req = (struct ablkcipher_request *)(io + 1);



	if (bio_data_dir(io->base_bio) == READ) {

		if (kcryptd_io_read(io, GFP_NOWAIT))

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