I've started work on a patchset to add support for directory delegations to the Linux kernel client and server. It's still too rough to post at this point, and for now, I'm just cobbling in a ioctl to drive it. As I started working on some of the client bits, however, I realized that I don't really have a clear picture as to when the client should request a delegation on a directory. It seems like there are a lot of things we could do: One idea: request one on an initial directory readdir. So maybe when the offset is 0 and we don't have a dir delegation already, do: PUTFH:GET_DIR_DELEGATION:READDIR Or, maybe just do it on any readdir when we haven't requested one in a little while? We could also do one on every lookup, when we expect that the result will be a directory. I'm not sure if LOOKUP_DIRECTORY would be a sufficient indicator or if we'd need the vfs to indicate that with a new flag. Would we also want to request one after a mkdir? PUTFH:CREATE:GET_DIR_DELEGATION:GETFH:GET_DIR_DELEGATION:... Assuming we can get this all working, what should drive the client to issues GET_DIR_DELEGATION ops? -- Jeff Layton <jlayton@xxxxxxxxxx>
