git: NULL VFS: store PFS mount points for later use

Francois Tigeot ftigeot at
Wed Dec 14 05:15:44 PST 2011

commit f423d507245621c25de023241e139e13540633ce
Author: Francois Tigeot <ftigeot at>
Date:   Wed Aug 24 22:00:28 2011 +0200

    NULL VFS: store PFS mount points for later use
    * This is a hack to obtain the pfs mount point in vop_write()
    * PFSes use nullfs mounts. Unfortunately, the nullfs implementation
      does not respect the traditional vfs/vnode layers and its vnodes
      may belong to many mount point at once.
    * What's worse, the mount point passed to VFS functions is the one
      of the underlying non-PFS filesystem.
    * We use the namecache layer to put the upper mount point of the
      PFS in a new vnode field to work around this limitation.

Summary of changes:
 sys/kern/vfs_cache.c  |    4 ++++
 sys/kern/vfs_vopops.c |    9 +++++++--
 sys/sys/vnode.h       |    1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

DragonFly BSD source repository

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