Functionality we probably won't ever support

[marcinslusarz]

This issue lists features we currently don't plan to support. If you want to discuss support for any of them please file separate issue and remove it from here.

Almost definitely not:

• O_ASYNC flag for open
• mandatory locking
• signal management using fcntl (F_GETOWN, F_SETOWN, F_GETOWN_EX, F_SETOWN_EX, F_GETSIG, F_SETSIG)
• RENAME_WHITEOUT flag for renameat2

Probably not:

• dnotify (F_NOTIFY flag for fctnl)
• inotify
• fanotify
• leases (F_SETLEASE, F_GETLEASE flags for fcntl)
• file sealing (F_ADD_SEALS, F_GET_SEALS flags for fcntl)
• select / pselect / poll / ppoll / epoll