Pali Rohár <pali.ro...@gmail.com> writes: > 2014-01-30 Linus Torvalds <torva...@linux-foundation.org>: >> Eric W. Biederman <ebied...@xmission.com> wrote:
>>> These files have been read-only since this code was merged in 2002. >>> Over a decade of not being used seems like a strong indication that no >>> one cares about the write path. >> I think this is a pretty strong argument. Counter-arguments, anybody? The current in-tree AFS module is still something of an experiment and is not widely used by actual clients, essentially all of which are still using the (old, ugly, frustratingly-difficult-to-maintain) out-of-tree module. This is mostly because the in-kernel module is not yet sufficiently mature to support a variety of use cases. I think this is a (minor) step towards making it more mature. > In afs documentation is written that you need to write to these files. See: > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/afs.txt#n82 > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/afs.txt#n159 > Without cells file, you cannot specify other cell servers and you can > use only one rootcell which was specified in kernel cmdline. So for > mounting other server, you need to reboot kernel (if you compiled afs > driver statically) and without cells file there is no other option to > mount more afs servers... (or at least it is not written in that > documentation). So I think without write access it is hard or maybe > impossible to use afs driver. In the AFS world more generally, it is not common to change the root cell without restarting the client. It *is*, however, very common to add configuration for new cells on the fly. The most common implementation, OpenAFS, has a command-line tool for root to do that (fs newcell). The equivalent for the in-tree AFS module would be writing to this file, so to support the fs newcell command with the in-tree module, this file would need to be writable. This is a common action in some use cases. By comparison, there is not a standard fs command to set the current local cell, only to retrieve it. However, I suspect that's primarily due to design limitations in the OpenAFS client. If it's not difficult to support this operation in the in-tree kernel module, I think it would be a good idea to do so early, since it's the kind of thing that could be difficult to retroactively add later. -- Russ Allbery (ea...@eyrie.org) <http://www.eyrie.org/~eagle/> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
