NFS ls -l or stat (GETATTR) stalls while write is in progress

Issue

• NFS getattr hangs while write is in progress
• nfs_getattr() hangs during heavy write workloads
• NFS: ls stalls when big files are written
• While simultaneous writes to nfs share are going on, "ls -l" or other commands hang on getattr(), the processes remain in D state till the writes are over.
• ls command hangs during heavy write workloads on NFS mounts
• NFS clients using RHEL5.x shows a pause during heavy I/O