--- David Howells <dhowells@xxxxxxxxxx> wrote: > These patches add local caching for network filesystems such as NFS and AFS. > > FS-Cache now runs fully asynchronously as required by Trond Myklebust for > NFS. > > -- > Changes: > [try #3]: > > (*) Added missing file to CacheFiles patch. > > (*) Made new security functions return errors and pass actual return data > via > argument pointer. > > (*) Cleaned up NFS patch. > > (*) The 'fsc' flag must now be passed to NFS mount by the string options. > > (*) Split the NFS patch into three as requested by Trond. > > [try #2]: > > (*) The CacheFiles module no longer accepts directory fds in its cull and > inuse commands from cachefilesd. Instead it uses the current working > directory of the calling process as the basis for looking up the object. > Corollary to this, fget_light() no longer needs to be exported. > How would you expect an LSM that is not SELinux to interface with CacheFiles? You have gone to a great deal of effort to support the requirements of an SELinux system, and that's good, but you have extended the LSM interface to expose SELinux data structures (secids) and require them for the operation of CacheFiles, and that's bad. The data used within an LSM is private to the LSM, and this applies to SELinux as well as to any other LSM that may come along, such as the Smack LSM I'm working on. This applies to task data as well as file data. Further, the behavior of the system in the presence of an LSM should be controlled by the LSM, it is more than a little scary that CacheFiles is enforcing SELinux policy based on secids that may be coming from a different LSM. I applaud the integration of CacheFiles with SELinux. Unfortunately, you've done so using the LSM interface in such a way that an LSM other than SELinux is likely to demonstrate inappropriate behaviors in the presence of CacheFiles because you have so carefully integrated the SELinux requirements. If the integration with SELinux is important to you, and I would expect that it is given the work you've put into it, I suggest that the SELinux specific behaviors be identified so that another LSM can provide the behavior appropriate to the policy it chooses to enforce and put that into SELinux with an LSM interface. I know that you're looking at a significant effort to do that, but I wouldn't think that you'd want CacheFiles to behave badly in the presence of an LSM that doesn't happen to be SELinux. I also know it's tempting to point out the SELinux is the only upstream LSM. I hope to change that before too long, and I know there are others with ambitions as well. I would not like to see CacheFiles have to get excluded in the presence of other LSMs and I doubt you would either. Casey Schaufler casey@xxxxxxxxxxxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
