[RHEL5 / RHEL6] The "scp -r" command fails on NFSv4, or open fails with EISDIR

Issue

• build tool that issues nmake randomly fails. When an strace is taken of the failing process, we see open failing with EISDIR as follows: open("/foo/bar/include", O_RDONLY) = -1 EISDIR (Is a directory). If he disables parallel compilation, he does not notice any issue with the build process.

• The "scp -r" command fails if NFSv4 contains a directory.

  # scp -rp root NFSv4 client :/mnt/nfs ./tmp/.  
  scp: /mnt/nfs/dir1: Is a directory
  

• The strace and the tcpdump show open() for directory fails with "EISDIR" as the following.

 (5.6z)           (5.6z)          (5.6z)
 client        NFSv4 client     NFSv4 server
   |               |               |
   |               | NFSv4 mount   |
   | scp  NG       | --------------|
   |-------------- |               | set EISDIR