fs/9p: Implement POSIX ACL permission checking function

The ACL value is fetched as a part of inode initialization
from the server and the permission checking function use the
cached value of the ACL

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig
index 7952337..7e05114 100644
--- a/fs/9p/Kconfig
+++ b/fs/9p/Kconfig
@@ -17,3 +17,16 @@
 	  Choose Y here to enable persistent, read-only local
 	  caching support for 9p clients using FS-Cache
 
+
+config 9P_FS_POSIX_ACL
+	bool "9P POSIX Access Control Lists"
+	depends on 9P_FS
+	select FS_POSIX_ACL
+	help
+	  POSIX Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N