Commit e5524e12 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm crypt: use dm_submit_bio_remap 



Care was taken to support kcryptd_io_read being called from crypt_map
or workqueue.  Use of an intermediate CRYPT_MAP_READ_GFP gfp_t
(defined as GFP_NOWAIT) should protect from maintenance burden if that
flag were to change for some reason.

Reviewed-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 0fbb4d93

drivers/md/dm-crypt.c

+8 −5
Original line number Diff line number Diff line
@@ -1828,6 +1828,8 @@ static void crypt_endio(struct bio *clone) 
	crypt_dec_pending(io);

}



#define CRYPT_MAP_READ_GFP GFP_NOWAIT



static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)

{

	struct crypt_config *cc = io->cc;
@@ -1855,7 +1857,7 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 
		return 1;

	}



	submit_bio_noacct(clone);

	dm_submit_bio_remap(io->base_bio, clone, (gfp != CRYPT_MAP_READ_GFP));

	return 0;

}
@@ -1881,7 +1883,7 @@ static void kcryptd_io_write(struct dm_crypt_io *io) 
{

	struct bio *clone = io->ctx.bio_out;



	submit_bio_noacct(clone);

	dm_submit_bio_remap(io->base_bio, clone, true);

}



#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
@@ -1960,7 +1962,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 


	if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||

	    test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {

		submit_bio_noacct(clone);

		dm_submit_bio_remap(io->base_bio, clone, true);

		return;

	}
@@ -3363,6 +3365,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 


	ti->num_flush_bios = 1;

	ti->limit_swap_bios = true;

	ti->accounts_remapped_io = true;



	dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);

	return 0;
@@ -3431,7 +3434,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) 
		io->ctx.r.req = (struct skcipher_request *)(io + 1);



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

		if (kcryptd_io_read(io, GFP_NOWAIT))

		if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))

			kcryptd_queue_read(io);

	} else

		kcryptd_queue_crypt(io);
@@ -3626,7 +3629,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 


static struct target_type crypt_target = {

	.name   = "crypt",

	.version = {1, 23, 0},

	.version = {1, 24, 0},

	.module = THIS_MODULE,

	.ctr    = crypt_ctr,

	.dtr    = crypt_dtr,