Re: [fuse-devel] [RFC] fuse: Support posix ACLs

["Jean-Pierre André" <jean-pierre.andre@wanadoo.fr>]

ebiederm@xmission.com (Eric W. Biederman) wrote:
> "Michael j Theall" <mtheall@us.ibm.com> writes:
>
>> Going by the patch I posted a couple of years ago:
>> https://sourceforge.net/p/fuse/mailman/message/33033653/
>>
>> The only hole I see in your patch is that in setattr() you are not
>> updating the cached acl if the ATTR_MODE is updated. The other major
>> difference is that my version uses the get_acl/set_acl inode
>> operations but you use that plus the xattr handlers. I'm not
>> up-to-speed on the kernel so I'm not sure if you actually need to
>> implement both.
>
> That makes an interesting question.  Is it desirable to keep
> inode->i_mode in sync with the posix acls in fuse or should a filesystem
> that supports posix acls worry about that?

Using a former implementation of ACLs within fuse at the
kernel level, I got the result below.
File systems expect consistency.

# Using the low level interface of fuse, with use of ACLs
# intended to be checked in the kernel, but not related to
# access control
rm -rf trydir
mkdir trydir
echo file > trydir/file
ls -l trydir/file
setfacl -m 'u::7,g::5,o::5' trydir/file
ls -l trydir/file
sleep 1
ls -l trydir/file

-rw-r--r-- 1 root root 5 2009-09-12 12:02 trydir/file
-rw-r--r-- 1 root root 5 2009-09-12 12:02 trydir/file
-rwxr-xr-x 1 root root 5 2009-09-12 12:02 trydir/file

Jean-Pierre