From: Ilya Dryomov <idryomov@gmail.com>

Date: Sat, 20 Jan 2018 10:30:10 +0100

Subject: rbd: don't (ab)use obj_req->pages for stat requests

Git-commit: 06fbb6993504974db6334a80b6796d6522ad45eb

Patch-mainline: v4.17-rc1

References: FATE#324714

obj_req->pages is for provided data buffers.  stat requests are

internal and should be NODATA.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Reviewed-by: Alex Elder <elder@linaro.org>

Acked-by: Luis Henriques <lhenriques@suse.com>

---

 drivers/block/rbd.c |   15 +++++----------

 1 file changed, 5 insertions(+), 10 deletions(-)

--- a/drivers/block/rbd.c

+++ b/drivers/block/rbd.c

@@ -2636,11 +2636,9 @@ static int rbd_img_obj_exists_submit(str

 	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;

 	struct rbd_obj_request *stat_request;

 	struct page **pages;

-	u32 page_count;

-	size_t size;

 	int ret;

-	stat_request = rbd_obj_request_create(OBJ_REQUEST_PAGES);

+	stat_request = rbd_obj_request_create(OBJ_REQUEST_NODATA);

 	if (!stat_request)

 		return -ENOMEM;

@@ -2661,22 +2659,19 @@ static int rbd_img_obj_exists_submit(str

 	 *         le32 tv_nsec;

 	 *     } mtime;

 	 */

-	size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);

-	page_count = (u32)calc_pages_for(0, size);

-	pages = ceph_alloc_page_vector(page_count, GFP_NOIO);

+	pages = ceph_alloc_page_vector(1, GFP_NOIO);

 	if (IS_ERR(pages)) {

 		ret = PTR_ERR(pages);

 		goto fail_stat_request;

 	}

 	osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);

-	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,

-				     false, false);

+	osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages,

+				     8 + sizeof(struct ceph_timespec),

+				     0, false, true);

 	rbd_obj_request_get(obj_request);

 	stat_request->obj_request = obj_request;

-	stat_request->pages = pages;

-	stat_request->page_count = page_count;

 	stat_request->callback = rbd_img_obj_exists_callback;

 	rbd_obj_request_submit(stat_request);