Non-MPSAFE filesystems de-orbit burn schedule

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This page documents proposed schedules for removing infrastructure for non-MPSAFE VFS components and filesystems.

This macro is used in order to conditionally acquire/drop/assert Giant lock in VFS layer, based on the MPSAFETY of the filesystem to be dealt with. The major goal of the project is to make it irrelevant, which means, for instance, locking all the already non-mpsafe filesystems and later on strip off the compat stuff.

Date	Done	Event
27 August 2011	yes	Post MPSAFE VFS plan to arch@.
08 November 2011	yes	Add VFS_ALLOW_NONMPSAFE kernel option and make it the default.
06 March 2012	yes	Remove VFS_ALLOW_NONMPSAFE as the default kernel config.
13 October 2012	yes	FUSE import into base.
28 October 2012	no	Disconnect non-mpsafe filesystems from the tree and remove the Giant-related code.
01 March 2013	no	Garbage collect in-tree non-mpsafe filesystems code.

Filesystem
UFS
ZFS
NFS Client
NFS Server
UnionFS
PseudoFS
TmpFS
NullFS
DevFS
CD9660FS
Ext2FS
FdescFS
FifoFS
MSDOSFS
UDF
ProcFS

Filesystem	Owner	State	Date completed
CodaFS	rwatson	Disconnect
HPFS		Disconnected
NtFS		Non-MPSAFE
NwFS*		Non-MPSAFE
PortalFS		Disconnected
SmbFS*	mav / ixsystems	Non-MPSAFE
ReiserFS	dumbbell	MPSAFE	2012-03-27 (r233575)
XFS		Disconnected

* Please note that locking smbfs and nwfs would also require to lock netsmb and netncp components. Other operating systems got very good results in this (like MacOSX and Solaris) already.

As some of the current filesystems have a very poor in-kernel support but they are actually very useful (with the most notable case being NTFS), in order to not loose their support, we will import in the kernel and actively maintain the FUSE module. At this present stage, most of the bugs from the port seems addressed. Please refer to the following e-mails:

http://lists.freebsd.org/pipermail/freebsd-fs/2012-September/015180.html

http://lists.freebsd.org/pipermail/freebsd-fs/2012-September/015179.html