[PATCH 4.18 068/171] libceph: bump CEPH_MSG_MAX_DATA_LEN

From: Greg Kroah-Hartman
Date: Mon Nov 19 2018 - 11:42:18 EST


4.18-stable 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.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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
@@ -81,7 +81,13 @@ 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"