rbd: use GFP_NOIO consistently for request allocations

commit 2224d879c7c0f85c14183ef82eb48bd875ceb599 upstream.

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.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 81ea69f..fbdddd6 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1955,7 +1955,7 @@ 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 */
 
@@ -2004,7 +2004,7 @@ 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 */
 
@@ -2506,7 +2506,7 @@ 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) {