cvs commit: src/sys/kern vfs_lookup.c

[Jeff Roberson]

jeff        2005-04-09 11:53:16 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             vfs_lookup.c 
  Log:
   - If we vrele() a dvp while the child is locked we can potentially deadlock
     when vrele() acquires the directory lock in the wrong order.  Fix this
     via the following changes:
   - Keep the directory locked after VOP_LOOKUP() until we've determined
     what we're going to do with the child.  This allows us to remove the
     complicated post LOOKUP code which determins whether we should lock or
     unlock the parent.  This means we may have to vput() in the appropriate
     cases later, rather than doing an unsafe vrele.
   - in NDFREE() keep two flags to indicate whether we need to unlock vp or
     dvp.  This allows us to vput rather than vrele in the appropriate
     cases without rechecking the flags.  Move the code to handle dvp after
     we handle vp.
   - Remove some dead code from namei() that was the result of changes to
     VFS_LOCK_GIANT().
  
  Sponsored by:   Isilon Systems, Inc.
  
  Revision  Changes    Path
  1.78      +60 -51    src/sys/kern/vfs_lookup.c