CONFIG_PNFS_FILE_LAYOUT (not configurable)

modulename: nfs_layout_nfsv41_files.ko

configname: CONFIG_PNFS_FILE_LAYOUT

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>PNFS_FILE_LAYOUT
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
source code:
fs/nfs/filelayout/