Messages in this thread | | | Date | Wed, 7 Jul 2010 11:05:36 -0400 | From | "J. Bruce Fields" <> | Subject | Re: [PATCH -V14 0/11] Generic name to handle and open by handle syscalls |
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On Wed, Jul 07, 2010 at 01:40:53AM -0600, Andreas Dilger wrote: > On 2010-07-06, at 11:09, Aneesh Kumar K. V wrote: > > On Tue, 6 Jul 2010 12:10:02 -0400, "J. Bruce Fields" <bfields@fieldses.org> wrote: > >> ... I don't understand why both need to come in the same system call. > >> Is it purely an efficiency question? If so, why do you expect this to > >> be significant? > > > > Since we know that system wide file handle should include a file system > > identifier and a file identifier my plan was to retrieve both in the > > same syscall. > > Won't having it be in a separate system call be racy w.r.t. doing the pathname lookup twice?
It'll be rare that a server will want to *just* get a filehandle; normally it will at least want to get some attributes at the same time.
So I think it will always need to open the file first and then do the rest of the operations on the returned filehandle.
--b.
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