zfs discuss - Apr 2009 - facl_getat() needed for extended file (XATTR) acls?

Hi,

	I''ve been working on an improved bart(1M) that is supposed to address 
open issues including XATTR support.  In writing the XATTR support the 
only MT appropriate solution I''ve found that doesn''t make bad
privilege
assumptions for performing a stat depends on openat() to get the 
parent''s attribute directory and fstatat() to get the stat. There is 
however no corresponding way to request a file''s acls.

	With the current interfaces, I must either have the file open or be 
able to reference to it by path.  But this creates a choice between 
having the file open to get acls despite read permission explicitly not 
being a requirement for reading a file''s acls or performing a chdir() 
which impacts the entire process.

	It looks like fstatat() was a recognized need of XATTR support as it 
was included in "PSARC/1999/209 Extended File Attributes" but a 
corresponding "faclat()" was not added and "2002/240 ZFS"
added
(f)acl_get() but did not add a corresponding facl_getat().
	-Will