libceph: bump CEPH_MSG_MAX_DATA_LEN

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>

1 files changed, 7 insertions, 1 deletions

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 49c93b9308d7..68bb09c29ce8 100644
--- 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"