git: kernel - Remove kernel-level ccms module (it will be moved into hammer2)

Matthew Dillon dillon at
Sat Jun 2 10:20:52 PDT 2012

commit 5fae12030283a17251f8ba0f78b6802f43dbf98e
Author: Matthew Dillon <dillon at>
Date:   Sat Jun 2 10:15:51 2012 -0700

    kernel - Remove kernel-level ccms module (it will be moved into hammer2)
    * Remove the CCMS kernel layer.  The CCMS module is going to be moved
      directly into hammer2 in order to make hammer2 more portable.  For
      now that means moving the files into vfs/hammer2 in the hammer2 branch.
    * CCMS is a logical cache coherency locking layer that has been in the
      DragonFly tree for a while but was not enabled by default.  Originally
      the plan was to not lock vnodes across operations but to instead acquire
      the appropriate CCMS lock(s), but rewiring all the filesystems proved to
      be too large a task.
    * HAMMER2's cluster work is going to need this layer for real, but nothing
      else does.  What we will do instead (eventually) is add a mount flag to
      allow us to avoid locking vnodes across VNOPS calls which HAMMER2 will be
      able to specify.

Summary of changes:
 sys/kern/kern_ccms.c |  689 --------------------------------------------------
 sys/kern/vfs_lock.c  |    2 -
 sys/kern/vfs_vnops.c |    9 -
 sys/sys/ccms.h       |  281 --------------------
 sys/sys/vnode.h      |    6 +-
 5 files changed, 1 insertions(+), 986 deletions(-)
 delete mode 100644 sys/kern/kern_ccms.c
 delete mode 100644 sys/sys/ccms.h

DragonFly BSD source repository

More information about the Commits mailing list