[Linux-cluster] lock issue with gfs and gfs2

[Steven Whitehouse]

Hi,

Please file a bug at  bugzilla.redhat.com,

Steve.

On Tue, 2008-10-14 at 21:33 -0700, Vipin Sharma wrote:
> Hi,
> 
> Let me try to explain my issue with gfs/gfs2 filesystem. I have two
> node cluster and a shared gfs filesystem which is mounted on both the
> nodes at the same time. I can access the filesystem from both nodes. 
> 1. From node A I put a lock on a file called testfile and tried to put
> the lock on testfile from node B. I get message, file is already
> locked, which is good since file is locked from ndoe A.
> 2. Now unmount the filesystem on node B while lock is still there on
> testfile from node A and mount it back. Now try to put lock on the
> testfile from node B which is locked from node A. Expected result
> would be not to succeed in puting lock from node B, but "NO" I am able
> to put the lock from node B.
> 3. Node B does not know that there is some lock on testfile form node
> A but now if you release the lock from node A and put it again and
> then try to put lock on testfile from node B it works as expected
> means you will not be able to put lock on testfile. It says file is
> already locked.
> 
> It does not make any difference if I use gfs or gfs2 test works same
> way I tried on Oracle enterprise linux 5.1 and 5.2, which is nothing
> but redhat. Also node A or node B test results are same.
> 
> I have lock file which is compiled one but the following program also
> works the same way.
> ===========================================================================
> /*
> ** lockdemo.c -- shows off your system's file locking.  Rated R.
> */
> 
> #include <stdio.h>
> #include <stdlib.h>
> #include <errno.h>
> #include <fcntl.h>
> #include <unistd.h>
> 
> int main(int argc, char *argv[])
> {
>                      /* l_type   l_whence  l_start  l_len  l_pid   */
>     struct flock fl = { F_WRLCK, SEEK_SET, 0,       0,     0 };
>     int fd;
> 
>     fl.l_pid = getpid();
> 
>     if (argc > 1)
>         fl.l_type = F_RDLCK;
> 
>     if ((fd = open("lockdemo.c", O_RDWR)) == -1) {
>         perror("open");
>         exit(1);
>     }
> 
>     printf("Press <RETURN> to try to get lock: ");
>     getchar();
>     printf("Trying to get lock...");
> 
>     if (fcntl(fd, F_SETLKW, &fl) == -1) {
>         perror("fcntl");
>         exit(1);
>     }
> 
>     printf("got lock\n");
>     printf("Press <RETURN> to release lock: ");
>     getchar();
> 
>     fl.l_type = F_UNLCK;  /* set to unlock same region */
> 
>     if (fcntl(fd, F_SETLK, &fl) == -1) {
>         perror("fcntl");
>         exit(1);
>     }
> 
>     printf("Unlocked.\n");
> 
>     close(fd);
> }
> 
> =============================================================================
> 
> I will be happy to provide more details as requested.
> 
> TIA
> vip
> 
> 
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