XID confusions with servers that cache them over a long period and
with clients that reboot quickly.
Problems: because of the sanity check that is done by comparing the system
time with filesystem time, XIDs will start at 0 until root is mounted,
which means it isn't completely safe for diskless setups. But it's clearly
better than it was. It would also be cleaner if all XID handling (more
generally, all RPC handling) within the kernel went through the
same functions.
This takes care of two related problems:
- `umount -f' wouldn't work if someone's working directory is
the filesystem root.
- vfs_unmountall() would complain about a busy `/' on a
diskless setup.
* Never change the NQNFS flag and/or version when just doing an update mount.
Fixes a problem that made diskless booting impossible under some
circumstances.
* Make 2nd and 3rd args timespecs, not timevals.
* Consistently pass a Boolean as the 4th arg (except in LFS).
Also, fix ffs_update() and lfs_update() to actually change the nsec fields.
device and a printable "external name" (name + unit number), thus eliminating
if_name and if_unit. Updated interface to (*if_watchdog)() and (*if_reset)()
to take a struct ifnet *, rather than a unit number.
directory problems.
XXX There is no clean solution to the cookie/cookieverifier validity mess.
Together with the disabled strict cookie check, this puts us back at
what v2 did in this case. Slightly better solution possible by
consequently storing 64bit cookies in other places too.
* Change the argument names to vop_link so they actually make sense.
* Implement vop_link and vop_symlink for all file systems, so they do proper
cleanup.
* Require the file system to decide whether or not linking and unlinking of
directories is allowed, and disable it for all current file systems.
(Also, remove the cross-device link check, that was moved into the file
systems some time ago.)
* Change the argument names to vop_link so they actually make sense.
* Implement vop_link and vop_symlink for all file systems, so they do proper
cleanup.
* Require the file system to decide whether or not linking and unlinking of
directories is allowed, and disable it for all current file systems.
each entry, and read them out in nfs_readdir().
Caveat: our current caching method for directory blocks uses the
server offset of the first directory entry as an identifier, so a
Linux emulation getdirentries() will wind up retrieving one block from
the NFS server for each directory entry, unnecessarily thrashing the
cache. The situation isn't as bad for other emulations.
Instead of getblk(), we need to write a routine to scan each cache
block associated with vp to find a cookie that matches at some
directory entry. Some later time.
