Messages in this thread | | | From | "Aneesh Kumar K. V" <> | Subject | Re: [PATCH -V18 04/13] vfs: Allow handle based open on symlinks | Date | Tue, 24 Aug 2010 16:04:32 +0530 |
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On Tue, 24 Aug 2010 17:21:55 +1000, Nick Piggin <npiggin@kernel.dk> wrote: > On Sat, Aug 21, 2010 at 03:12:15PM +0530, Aneesh Kumar K. V wrote: > > On Sat, 21 Aug 2010 18:30:24 +1000, Nick Piggin <npiggin@kernel.dk> wrote: > > > Thanks, I had both of the same concerns as Christoph with API > > > change and exposing symlink fds last time I looked at the patces, > > > actually. > > > > > > But they can probably be worked around or avoided. I think the more > > > important thing is whether it is worth supporting. This is > > > all restricted to root (or CAP_DAC_READ_SEARCH) only, right, and > > > what exact semantics they want. I would like to see more discussion > > > of what this enables and some results. > > > > > > For the case of avoiding expensive network revalidations in path name > > > lookup, do we even need to open symlinks? Could the security issues be > > > avoided by always having handle attached to an open fd? > > > > > > > For implementing a userspace file server that use handle for > > representing files (like NFS) we would require to have the ability to do > > different file system operations that can operate on symlink to work on > > handle too. > > Right. Is this a really important goal, I'm wondering? Is it realistic > (ie. to be able to remove the nfs server from the kernel)? >
The feature is also needed to implement a 9p virtio pass through file system in Qemu http://thread.gmane.org/gmane.comp.emulators.qemu/68992
-aneesh
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