permission: called by the VFS to check for access rights on a POSIX-like
filesystem.
- May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk
- mode, the filesystem must check the permission without blocking or
+ May be called in rcu-walk mode (flags & IPERM_FLAG_RCU). If in rcu-walk
+ mode, the filesystem must check the permission without blocking or
storing to the inode.
If a situation is encountered that rcu-walk cannot handle, return