rbd_osd_req_create() needs to know the snapshot context size to create a buffer large enough to send it with the message front. It gets this from the img_request, which was not set for the obj_request yet. This resulted in trying to write past the end of the front payload, hitting this BUG: libceph: BUG_ON(p > msg->front.iov_base + msg->front.iov_len); Fix this by associating the obj_request with its img_request immediately after it's created, before the osd request is created. Fixes: http://tracker.ceph.com/issues/5760 Suggested-by: Alex Elder <alex.elder@xxxxxxxxxx> Signed-off-by: Josh Durgin <josh.durgin@xxxxxxxxxxx> --- drivers/block/rbd.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index f8fd7d3..80f787b 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2203,6 +2203,11 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, rbd_segment_name_free(object_name); if (!obj_request) goto out_unwind; + /* + * set obj_request->img_request before creating the + * osd_request so that it gets the right snapc + */ + rbd_img_obj_request_add(img_request, obj_request); if (type == OBJ_REQUEST_BIO) { unsigned int clone_size; @@ -2244,11 +2249,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, obj_request->pages, length, offset & ~PAGE_MASK, false, false); - /* - * set obj_request->img_request before formatting - * the osd_request so that it gets the right snapc - */ - rbd_img_obj_request_add(img_request, obj_request); if (write_request) rbd_osd_req_format_write(obj_request); else -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html