3.16.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ilya Dryomov <idryomov@xxxxxxxxx> commit 94e6992bb560be8bffb47f287194adf070b57695 upstream. If the read is large enough, we end up spinning in the messenger: libceph: osd0 192.168.122.1:6801 io error libceph: osd0 192.168.122.1:6801 io error libceph: osd0 192.168.122.1:6801 io error This is a receive side limit, so only reads were affected. Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- include/linux/ceph/libceph.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/include/linux/ceph/libceph.h +++ b/include/linux/ceph/libceph.h @@ -67,7 +67,13 @@ struct ceph_options { #define CEPH_MSG_MAX_FRONT_LEN (16*1024*1024) #define CEPH_MSG_MAX_MIDDLE_LEN (16*1024*1024) -#define CEPH_MSG_MAX_DATA_LEN (16*1024*1024) + +/* + * Handle the largest possible rbd object in one message. + * There is no limit on the size of cephfs objects, but it has to obey + * rsize and wsize mount options anyway. + */ +#define CEPH_MSG_MAX_DATA_LEN (32*1024*1024) #define CEPH_AUTH_NAME_DEFAULT "guest"