git: kernel - Fix cluster_awrite() race

Matthew Dillon dillon at
Sat Oct 28 15:16:36 PDT 2017

commit c3c895a62193e0eb34749eb6e20a7957eb66ea40
Author: Matthew Dillon <dillon at>
Date:   Sat Oct 28 15:14:02 2017 -0700

    kernel - Fix cluster_awrite() race
    * Fix a race between cluster_awrite() and vnode destruction.  We
      have to finish working the cluster pbuf before disposing of the
      component elements.  b_vp in the cluster pbuf is held only by
      the presence of the components.
    * Fixes NULL pointer indirection panic associated with heavy
      paging during tmpfs operations.  This typically only occurs
      when maxvnodes is set to a relatively low value, but it can
      eventually occur in any modestly paging environment when
      tmpfs is used.

Summary of changes:
 sys/kern/vfs_cluster.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

DragonFly BSD source repository

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