Commit 2f9941b6 authored by Olaf Kirch's avatar Olaf Kirch Committed by Linus Torvalds
Browse files

dm crypt: fix remove first_clone 



Get rid of first_clone in dm-crypt

This gets rid of first_clone, which is not really needed.  Apparently, cloned
bios used to share their bvec some time way in the past - this is no longer
the case.  Contrarily, this even hurts us if we try to create a clone off
first_clone after it has completed, and crypt_endio has destroyed its bvec.

Signed-off-by: default avatarOlaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 98221eb7

drivers/md/dm-crypt.c

+6 −28
Original line number Diff line number Diff line
@@ -33,7 +33,6 @@ 
struct crypt_io {

	struct dm_target *target;

	struct bio *base_bio;

	struct bio *first_clone;

	struct work_struct work;

	atomic_t pending;

	int error;
@@ -380,9 +379,8 @@ static int crypt_convert(struct crypt_config *cc, 
 * This should never violate the device limitations

 * May return a smaller bio when running out of pages

 */

static struct bio *

crypt_alloc_buffer(struct crypt_io *io, unsigned int size,

                   struct bio *base_bio, unsigned int *bio_vec_idx)

static struct bio *crypt_alloc_buffer(struct crypt_io *io, unsigned int size,

				      unsigned int *bio_vec_idx)

{

	struct crypt_config *cc = io->target->private;

	struct bio *clone;
@@ -390,12 +388,7 @@ crypt_alloc_buffer(struct crypt_io *io, unsigned int size, 
	gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;

	unsigned int i;



	if (base_bio) {

		clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);

		__bio_clone(clone, base_bio);

	} else

	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);



	if (!clone)

		return NULL;
@@ -498,9 +491,6 @@ static void dec_pending(struct crypt_io *io, int error) 
	if (!atomic_dec_and_test(&io->pending))

		return;



	if (io->first_clone)

		bio_put(io->first_clone);



	bio_endio(io->base_bio, io->base_bio->bi_size, io->error);



	mempool_free(io, cc->io_pool);
@@ -618,8 +608,7 @@ static void process_write(struct crypt_io *io) 
	 * so repeat the whole process until all the data can be handled.

	 */

	while (remaining) {

		clone = crypt_alloc_buffer(io, base_bio->bi_size,

					   io->first_clone, &bvec_idx);

		clone = crypt_alloc_buffer(io, base_bio->bi_size, &bvec_idx);

		if (unlikely(!clone)) {

			dec_pending(io, -ENOMEM);

			return;
@@ -635,21 +624,11 @@ static void process_write(struct crypt_io *io) 
		}



		clone->bi_sector = cc->start + sector;



		if (!io->first_clone) {

			/*

			 * hold a reference to the first clone, because it

			 * holds the bio_vec array and that can't be freed

			 * before all other clones are released

			 */

			bio_get(clone);

			io->first_clone = clone;

		}



		remaining -= clone->bi_size;

		sector += bio_sectors(clone);



		/* prevent bio_put of first_clone */

		/* Grab another reference to the io struct

		 * before we kick off the request */

		if (remaining)

			atomic_inc(&io->pending);
@@ -965,7 +944,6 @@ static int crypt_map(struct dm_target *ti, struct bio *bio, 
	io = mempool_alloc(cc->io_pool, GFP_NOIO);

	io->target = ti;

	io->base_bio = bio;

	io->first_clone = NULL;

	io->error = io->post_process = 0;

	atomic_set(&io->pending, 0);

	kcryptd_queue_io(io);

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