afs: Get YFS ACLs and information through xattrs

The YFS/AuriStor variant of AFS provides more capable ACLs and provides
per-volume ACLs and per-file ACLs as well as per-directory ACLs.  It also
provides some extra information that can be retrieved through four ACLs:

 (1) afs.yfs.acl

     The YFS file ACL (not the same format as afs.acl).

 (2) afs.yfs.vol_acl

     The YFS volume ACL.

 (3) afs.yfs.acl_inherited

     "1" if a file's ACL is inherited from its parent directory, "0"
     otherwise.

 (4) afs.yfs.acl_num_cleaned

     The number of of ACEs removed from the ACL by the server because the
     PT entries were removed from the PTS database (ie. the subject is no
     longer known).

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 5269824..b800b4e 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1371,6 +1371,19 @@ extern int yfs_fs_inline_bulk_status(struct afs_fs_cursor *, struct afs_net *,
 				     struct afs_callback *, unsigned int,
 				     struct afs_volsync *);
 
+struct yfs_acl {
+	struct afs_acl	*acl;		/* Dir/file/symlink ACL */
+	struct afs_acl	*vol_acl;	/* Whole volume ACL */
+	u32		inherit_flag;	/* True if ACL is inherited from parent dir */
+	u32		num_cleaned;	/* Number of ACEs removed due to subject removal */
+	unsigned int	flags;
+#define YFS_ACL_WANT_ACL	0x01	/* Set if caller wants ->acl */
+#define YFS_ACL_WANT_VOL_ACL	0x02	/* Set if caller wants ->vol_acl */
+};
+
+extern void yfs_free_opaque_acl(struct yfs_acl *);
+extern struct yfs_acl *yfs_fs_fetch_opaque_acl(struct afs_fs_cursor *, unsigned int);
+
 /*
  * Miscellaneous inline functions.
  */