Description of problem:

Cannot write a large size file on the NFS mount when using 'dd' utility. 

[root@host ubuntu]# mount -osync -t nfs -o nfsvers=4,noauto,soft,proto=tcp nfs_server:/ nfs1
[root@host ubuntu]# ls nfs1/cephobject/
cephnfs.bucky.0  cephnfs.bucky.1  test

[root@host cephobject]# cd test/
[root@host test]#  dd if=/dev/urandom of=file2 bs=10M count=300
dd: error writing ‘file2’: Input/output error
59+0 records in
58+0 records out
608174080 bytes (608 MB) copied, 29.4651 s, 20.6 MB/s



Version-Release number of selected component (if applicable):

ceph version 12.2.5-37.el7cp
nfs-ganesha-rgw-2.5.5-100.el7cp.x86_64
nfs-ganesha-2.5.5-100.el7cp.x86_64


How reproducible:
2/2

Steps to Reproduce:
1. Configure NFS server on an RGW  and configure NFS client and mount share with NFSv3 or NFSv4.
2. Create a file and write say 3G of data using 'dd'
3. Operation fails with IO error.