From: Ilya Dryomov <idryomov@gmail.com>
Date: Wed, 26 Sep 2018 18:03:16 +0200
Subject: libceph: bump CEPH_MSG_MAX_DATA_LEN
Git-commit: 94e6992bb560be8bffb47f287194adf070b57695
Patch-mainline: v4.20-rc1
References: bsc#1114839

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@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
 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
@@ -80,7 +80,13 @@ 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"