On Mon, Aug 11, 2014 at 03:08:38PM -0400, J. Bruce Fields wrote: > On Sat, Aug 09, 2014 at 02:44:00PM +0100, Ross Lagerwall wrote: > > When creating a file that already exists in a read-only directory with > > O_EXCL, the NFSv3 server returns EACCES rather than EEXIST (which local > > files and the NFSv4 server return). Fix this by checking the MAY_CREATE > > permission only if the file does not exist. Since this already happens > > in do_nfsd_create, the check in nfsd3_proc_create can simply be removed. > > Thanks. > > From a look at the history I believe the server has behaved this way > since the beginning. Is this creating a practical problem for you? How > did you notice it? I help maintain GNOME's gvfs and so I have a bunch of test programs which I run to check for conformance. I noticed that: gvfs-save /mnt/dir/file fails with a permission denied error when file is on an NFSv3 mount and dir is read-only. Basically, gvfs-save first tries to create the file. If it already exists, then it just truncates it. But on NFSv3, the first creation generates a permission denied error so the operation is aborted. Not really a practical problem, but it is possible to see this with various real-world programs which do a similar dance when saving like this: open(path, O_WRONLY|O_CREAT|O_EXCL) if EEXIST: open(path, O_WRONLY|O_CREAT|O_TRUNC) else: bail() (For Linux NFS clients, the kernel does its own client-side caching so if you do: ls /mnt/dir; gvfs-save /mnt/dir/file it magically works!) > > Inclined to apply it just for consistency as you suggest. And because > it removes some unnecessary code. But as a low priority: for 3.18 and > not stable. > OK, your decision. That is OK with me. Cheers, -- Ross Lagerwall -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
