Date: Thu, 20 Nov 2008 16:27:58 -0500 From: John Baldwin <jhb@freebsd.org> To: current@freebsd.org Cc: scottl@freebsd.org Subject: [PATCH] Make udf(4) MPSAFE and use shared lookups Message-ID: <200811201627.58289.jhb@freebsd.org>
next in thread | raw e-mail | index | archive | help
So this patch is fairly minimal since udf(4) is currently read-only. The changes include: * Set VV_ROOT in udf_vget() if we ever return a vnode instead of doing it only in udf_root(). This matches the behavior of other operating systems and correctly tags the root vnode with VV_ROOT in the unlikely case that we create the vnode during a call to ufs_vget() that does not come from ufs_root(). * If the hash lookup in ufs_vget() fails, ensure an exclusive vnode lock is used while creating the new vnode (same as UFS). * Allow lock recursion (XXX: not really sure this is needed actually). * Allow shared vnode locks on non-fifos. * Honor the requested locking flags (shared vs exclusive) instead of always using exclusive vnode locks during a lookup operation. * Handle "." lookups the same way other filesystems do by just bumping the reference on 'dvp' rather than calling udf_vget(). http://www.FreeBSD.org/~jhb/patches/udf_mpsafe.patch I have only verified that this compiles and would appreciate it if some folks could test this, preferable with INVARIANTS and DEBUG_VFS_LOCKS enabled. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200811201627.58289.jhb>