On Thu, Sep 2, 2021 at 6:51 AM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > The reason this touches so many files is that the ->get_acl() method now > gets a "bool rcu" argument. The ->get_acl() API was updated based on > comments from Al and Linus: > > https://lore.kernel.org/linux-fsdevel/CAJfpeguQxpd6Wgc0Jd3ks77zcsAv_bn0q17L3VNnnmPKu11t8A@xxxxxxxxxxxxxx/ That link might have been good in the individual commit message too, but I did it in the merge commit instead. I did notice that we now have a stale comment about ->get_acl() in fs/namei.c: acl = get_cached_acl_rcu(inode, ACL_TYPE_ACCESS); if (!acl) return -EAGAIN; /* no ->get_acl() calls in RCU mode... */ if (is_uncached_acl(acl)) return -ECHILD; but we actually did the RCU-mode ->get_acl() call already in get_cached_acl_rcu(). Of course, get_cached_acl_rcu() only does it for ACL_DONT_CACHE, not for ACL_NOT_CACHED, so RCU mode is still a bit special. At some point we probably should make get_cached_acl_rcu() do the right thing for a successful lookup with ACL_NOT_CACHED set too, and actually install the newly looked-up ACL. But I haven't thought much about locking (but I think it would be ok, we use "cmpxchg" to update the cached entry). This is just a "maybe fixme for the future" note about that comment and about get_cached_acl_rcu() behavior. I've pulled this, and I think we're ok, it's just a small oddity. Linus
