libceph: bump CEPH_MSG_MAX_DATA_LEN

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@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 3e3799c..9b9fe05 100644 (file)
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -72,7 +72,13 @@ 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"