zfs discuss - Sep 2007 - question about modification of dd_parent_obj during COW

>From the online document of ZFS On-Disk Specification, I found there is a
field named  "dd_parent_obj" in dsl_dir_phys_t. will this field be
modified or kept unchanged during snapshot COW?
   For example, consider a ZFS filesytem mounted on /myzfs, which contains 2
subdirs(A and B). If we do the following steps:
  1) create a snapshot named /myzfs at now.
  2) rename /myzfs/A to /myzfs/A1.

  I think the directory objects of /myzfs/A and /myzfs will be COW''d
during the rename operation.

  Now we can access dirctory B by specifing either "/myzfs/B "  or 
"/myzfs at now/B".
 
  The problems are:
   1)  What is the parent of B?  will "dd_parent_obj" of B be changed
during the COW of dirctory object /myzfs?
   2)  If we remove /myzfs/B thereafter, will "dd_parent_obj"  of of
/myzfs at now/B be changed?

  Thanks.
 
 
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