Commit b4774f9c authored Apr 05, 2016 by David Disseldorp Committed by Sasha Levin Apr 20, 2016

rbd: use GFP_NOIO consistently for request allocations



[ Upstream commit 2224d879c7c0f85c14183ef82eb48bd875ceb599 ]

As of 5a60e87603c4c533492c515b7f62578189b03c9c, RBD object request
allocations are made via rbd_obj_request_create() with GFP_NOIO.
However, subsequent OSD request allocations in rbd_osd_req_create*()
use GFP_ATOMIC.

With heavy page cache usage (e.g. OSDs running on same host as krbd
client), rbd_osd_req_create() order-1 GFP_ATOMIC allocations have been
observed to fail, where direct reclaim would have allowed GFP_NOIO
allocations to succeed.

Cc: stable@vger.kernel.org # 3.18+
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Neil Brown <neilb@suse.com>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 7c134b07

drivers/block/rbd.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1929,7 +1929,7 @@ static struct ceph_osd_request *rbd_osd_req_create(

		osdc = &rbd_dev->rbd_client->client->osdc;
		osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
		GFP_ATOMIC);
		GFP_NOIO);
		if (!osd_req)
		return NULL; /* ENOMEM */

		@@ -1978,7 +1978,7 @@ rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
		rbd_dev = img_request->rbd_dev;
		osdc = &rbd_dev->rbd_client->client->osdc;
		osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
		false, GFP_ATOMIC);
		false, GFP_NOIO);
		if (!osd_req)
		return NULL; /* ENOMEM */

		@@ -2470,7 +2470,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
		bio_chain_clone_range(&bio_list,
		&bio_offset,
		clone_size,
		GFP_ATOMIC);
		GFP_NOIO);
		if (!obj_request->bio_list)
		goto out_unwind;
		} else if (type == OBJ_REQUEST_PAGES) {