MMapFile: File locking failed with error code 37

[gaf-mNDKBlG2WHs at public.gmane.org (Jerry Feldman)]

On 01/27/2009 04:15 PM, Nuno Sucena Almeida wrote:
> Hi Jerry,=20
>
> I remember having locking problems with one of the rpc daemon about a
> year ago, maybe stat, that would cause havoc with the nfs mounted
> clients. When I looked at it, I traced to a flaw in some of the kernel
> code which was corrected in some newer kernel version. Right now I'm
> running 2.6.24 or above. I don't know how difficult is to try a new
> kernel on your system, but maybe you can give it a try.
>  =20
I have a bit more information. I was able to find the lines of code, and =

it has nothing to do with mmap(2). The problem is with fcntl, and only=20
when the NFS server is RHEL 5.2 Kernel 2.6.18-92. Works fine on a local=20
file (eg. /tmp or on a file served by RHEL 4.6 kernel 2.6.9-67. I handed =

the problem off to our IT person to file a bug on RHEL 5.2. I should be=20
able to get the latest kernel for my NFS server, but it might be=20
difficult to get the time to reboot while people are doing work and have =

some processes that run for hours or days (CPU bound, not I/O bound).

  fd =3D open(fileName, O_RDWR | O_CREAT, 0644);
  fl.l_type =3D F_WRLCK;
  fl.l_start =3D 0;
  fl.l_whence =3D SEEK_SET;
  fl.l_len =3D 0;
  fl.l_pid =3D getpid();
  int fcnt =3D fcntl(fd, F_SETLK, &fl); /* fails when NFS server is RHEL =

5.2 */

--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
PGP key id: 537C5846
PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB  CA3B 4607 4319 537C 5846