svn commit: r184554 - in head/sys: geom/journal gnu/fs/ext2fs kern nfsclient sys ufs/ffs ufs/ufs

[Attilio Rao]

2008/11/2, Bjoern A. Zeeb <bzeeb-lists at lists.zabbadoz.net>:
> On Sun, 2 Nov 2008, Attilio Rao wrote:
>
>
> > Author: attilio
> > Date: Sun Nov  2 10:15:42 2008
> > New Revision: 184554
> > URL: http://svn.freebsd.org/changeset/base/184554
> >
> > Log:
> >  Improve VFS locking:
> >  - Implement real draining for vfs consumers by not relying on the
> >   mnt_lock and using instead a refcount in order to keep track of lock
> >   requesters.
> >  - Due to the change above, remove the mnt_lock lockmgr because it is now
> >   useless.
> >  - Due to the change above, vfs_busy() is no more linked to a lockmgr.
> >   Change so its KPI by removing the interlock argument and defining 2 new
> >   flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the
> >   old version (which was unlinked from the lockmgr alredy) and
> >   MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx
> >   once the mnt interlock is held (ability still desired by most
> consumers).
> >  - The stub used into vfs_mount_destroy(), that allows to override the
> >   mnt_ref if running for more than 3 seconds, make it totally useless.
> >   Remove it as it was thought to work into older versions.
> >   If a problem of "refcount held never going away" should appear, we will
> >   need to fix properly instead than trust on such hackish solution.
> >  - Fix a bug where returning (with an error) from dounmount() was still
> >   leaving the MNTK_MWAIT flag on even if it the waiters were actually
> >   woken up. Just a place in vfs_mount_destroy() is left because it is
> >   going to recycle the structure in any case, so it doesn't matter.
> >  - Remove the markercnt refcount as it is useless.
> >
> >  This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and
> >  __FreeBSD_version will be modified accordingly.
> >
>
>  So why didn't you update __FreeBSD_version with the same commit that
>  changed the KPI?

I just prefer to split "managing" stuff from the tecnical content.

Attilio


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