- simplify mds auth tracking?
- use caps instead?
- unwind writeback start error in addr.c (see fixme)... by redirtying pages?
-- inotify for updates from other clients?
-- optional or no fill_trace?
- flock, fnctl locks
-- async xattrs
-- avoid pinning inodes with expireable caps?
- ACLs
- make writepages maybe skip pages with errors?
- EIO, or ENOSPC?
- ... writeback vs ENOSPC vs flush vs close()... hrm...
- set mapping bits for ENOSPC, EIO?
+- should we try to ref CAP_PIN on special inodes that are open?
- fix readdir vs fragment race by keeping a separate frag pos, and ignoring dentries below it
- reconnect after being disconnected from the mds
-- should we try to ref CAP_PIN on special inodes that are open?
+- inotify for updates from other clients?
vfs issues
- real_lookup() race: