From: Stephen Smalley <sds@epoch.ncsc.mil>

This patch against 2.5.69 adds a security_inode_post_setxattr hook so that
security modules can update the inode security structure after a successful
setxattr, and it moves the existing security_inode_setxattr hook call after
the taking the inode semaphore so that atomicity is provided for the
security check and the update to the inode security structure.