Commit 8cb0defb authored by NeilBrown's avatar NeilBrown Committed by Jens Axboe
Browse files

drbd: use bio_clone_fast() instead of bio_clone() 



drbd does not modify the bi_io_vec of the cloned bio,
so there is no need to clone that part.  So bio_clone_fast()
is the better choice.
For bio_clone_fast() we need to specify a bio_set.
We could use fs_bio_set, which bio_clone() uses, or
drbd_md_io_bio_set, which drbd uses for metadata, but it is
generally best to avoid sharing bio_sets unless you can
be certain that there are no interdependencies.

So create a new bio_set, drbd_io_bio_set, and use bio_clone_fast().

Also remove a "XXX cannot fail ???" comment because it definitely
cannot fail - bio_clone_fast() doesn't fail if the GFP flags allow for
sleeping.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f856dc36

drivers/block/drbd/drbd_int.h

+3 −0
Original line number Diff line number Diff line
@@ -1441,6 +1441,9 @@ extern struct bio_set *drbd_md_io_bio_set; 
/* to allocate from that set */

extern struct bio *bio_alloc_drbd(gfp_t gfp_mask);



/* And a bio_set for cloning */

extern struct bio_set *drbd_io_bio_set;



extern struct mutex resources_mutex;



extern int conn_lowest_minor(struct drbd_connection *connection);

drivers/block/drbd/drbd_main.c

+9 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ mempool_t *drbd_request_mempool; 
mempool_t *drbd_ee_mempool;

mempool_t *drbd_md_io_page_pool;

struct bio_set *drbd_md_io_bio_set;

struct bio_set *drbd_io_bio_set;



/* I do not use a standard mempool, because:

   1) I want to hand out the pre-allocated objects first.
@@ -2098,6 +2099,8 @@ static void drbd_destroy_mempools(void) 


	/* D_ASSERT(device, atomic_read(&drbd_pp_vacant)==0); */



	if (drbd_io_bio_set)

		bioset_free(drbd_io_bio_set);

	if (drbd_md_io_bio_set)

		bioset_free(drbd_md_io_bio_set);

	if (drbd_md_io_page_pool)
@@ -2115,6 +2118,7 @@ static void drbd_destroy_mempools(void) 
	if (drbd_al_ext_cache)

		kmem_cache_destroy(drbd_al_ext_cache);



	drbd_io_bio_set      = NULL;

	drbd_md_io_bio_set   = NULL;

	drbd_md_io_page_pool = NULL;

	drbd_ee_mempool      = NULL;
@@ -2142,6 +2146,7 @@ static int drbd_create_mempools(void) 
	drbd_pp_pool         = NULL;

	drbd_md_io_page_pool = NULL;

	drbd_md_io_bio_set   = NULL;

	drbd_io_bio_set      = NULL;



	/* caches */

	drbd_request_cache = kmem_cache_create(
@@ -2165,6 +2170,10 @@ static int drbd_create_mempools(void) 
		goto Enomem;



	/* mempools */

	drbd_io_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_RESCUER);

	if (drbd_io_bio_set == NULL)

		goto Enomem;



	drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0,

					   BIOSET_NEED_BVECS |

					   BIOSET_NEED_RESCUER);

drivers/block/drbd/drbd_req.h

+1 −1
Original line number Diff line number Diff line
@@ -263,7 +263,7 @@ enum drbd_req_state_bits { 
static inline void drbd_req_make_private_bio(struct drbd_request *req, struct bio *bio_src)

{

	struct bio *bio;

	bio = bio_clone(bio_src, GFP_NOIO); /* XXX cannot fail?? */

	bio = bio_clone_fast(bio_src, GFP_NOIO, drbd_io_bio_set);



	req->private_bio = bio;

CRA Git | Maintained and supported by SUSTech CRA and CCSE