2010-09-09 21:16:03

by Orion Poplawski

Subject: locking and setgid files

Is this expected?

$ ls -l /data/sw/svn/dombroski/supergran_paper/db/txn-current-lock
-rw-rwSr--. 1 dombroski superg 0 Aug 30 16:27 txn-current-lock

$ id
uid=6412(aaronb) gid=1001(cora) groups=1001(cora),1041(superg)
context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

open("/data/sw/svn/dombroski/supergran_paper/db/txn-current-lock", O_RDWR) = 3
fcntl64(3, F_GETLK, {type=F_WRLCK, whence=SEEK_SET, start=0, len=0,
pid=10771680}) = -1 ENOLCK (No locks available)

I guess I could somewhat understand it, though the fcntl64() call succeeds on
the server (CentOS 5.5).

2010-09-09 21:43:50

by Trond Myklebust

Subject: Re: locking and setgid files

On Thu, 2010-09-09 at 21:15 +0000, Orion Poplawski wrote:
> Is this expected?
>
> $ ls -l /data/sw/svn/dombroski/supergran_paper/db/txn-current-lock
> -rw-rwSr--. 1 dombroski superg 0 Aug 30 16:27 txn-current-lock
>
> $ id
> uid=6412(aaronb) gid=1001(cora) groups=1001(cora),1041(superg)
> context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
>
> open("/data/sw/svn/dombroski/supergran_paper/db/txn-current-lock", O_RDWR) = 3
> fcntl64(3, F_GETLK, {type=F_WRLCK, whence=SEEK_SET, start=0, len=0,
> pid=10771680}) = -1 ENOLCK (No locks available)
>
> I guess I could somewhat understand it, though the fcntl64() call succeeds on
> the server (CentOS 5.5).

It is quite conceivable that your CentOS 5.5 NFS server lacks the proper
support for mandatory posix locking. We only test regularly with
advisory locks.

Cheers
Trond