J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > > One of these is the call to manage local caching on a file or volume. > > This, however, doesn't really need to be limited to AFS, but could also be > > applicable to NFS, CIFS, etc. - and possibly even to local filesystems. > > Do you have a summary of the AFS interface to give an idea what's > needed? I have the pioctls listed here that I need to emulate: https://www.infradead.org/~dhowells/kafs/user_interface.html along with my thoughts on how to do that. For cache wangling, I was thinking of something like: fcachectl(int dirfd, const char *pathname, unsigned atflags, const char *cmd, char *result, size_t *result_len); The relevant pioctls are: (*) VIOCGETCACHEPARMS Get the size of the cache. (*) VIOCSETCACHESIZE Set the cache size. (*) VIOCFLUSH Invalidate the cached information for an object, both the inode/dentry structs and anything in the local cache. (*) VIOCFLUSHCB Invalidate any callbacks/leases outstanding on an object. This might make more sense to be done via the same mechanism as lease/lock management. (*) VIOC_FLUSHVOLUME Flush all cached state for a volume, both from RAM and local disk cache as far as possible. Files that are open aren't necessarily affected. (*) VIOC_FLUSHALL FLush all cached state for all volumes. (*) VIOCPREFETCH Prefetch a file into the cache. So, maybe: fcachectl(AT_FDCWD, "/afs/user/dhowells", 0, "flush volume", NULL, NULL); to flush an AFS volume containing my home directory. Note that doing this by fcntl() or ioctl() has potential difficulties as it would have to work on non-file objects such as device files or symlinks. Other functions that this could be used for are cache pinning and fixup/integration should we ever want disconnected operation. David -- 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
