"Ara.T.Howard" wrote:
>O_EXCL is broken on nfs:
>
>   O_EXCL When used with O_CREAT, if the file  already  exists  it  is  an 
> error
>   and  the open will fail. In this context, a symbolic link exists, 
> regardless of
>   where its points to.  O_EXCL is broken  on NFS file systems, programs which
>   rely on it for performing lock- ing tasks will contain a race 
> condition.  The
>   solution for  per- forming  atomic  file  locking  using  a lockfile is to
>   create a unique file on the same 
> fs  (e.g.,  incorporating  hostname  and pid),
>   use  link(2)  to  make  a link to the lockfile. If link() returns 0, 
> the lock
>   is successful.  Otherwise,  use  stat(2)  on the  unique  file to check 
> if its
>   link count has increased to 2, in which case the lock is also successful.

... And I barely understood a word of that. `.`

Does that mean it won't properly perform the "don't clobber an existing file"
purpose I'm using it for?

-Morgan 


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