From nobody Mon Feb 9 12:25:12 2026 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4802F1B2EE1 for ; Wed, 21 Aug 2024 17:42:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724262134; cv=none; b=Dwfjt7z5yVDtyy3ur9du9R5Wt7qhIzPdPo207BbwsUeYO0e4NrdLipHSk3SIK4tcyDruimO/swbyXVwvGIxH3KcMnpb2Ax/1zbC9tZeTGAlqeHWRGxhgLueAZfGfgAhdQPu40/9NUdgFQfJbY4rsQLk8aQI9IMbFONlTocsvrHM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724262134; c=relaxed/simple; bh=prbzF9A7rp/G33IcXNJKm6tZRhmAfexWxJAHcXVXlYc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=OVNlkgmUPq+GsLPO16k1dQx2k+Xp/omNcBWfiORBW1OxAwOvwmgt+vUHL3pAJVGAROgDgEqMnl7PQs4w2BgTv03ZQPLkTDFFBVumj8tY8QKEN8FJWEidNTorfXt7FoiY9KWSY+zE8+oEcNv+ZgCZ4ivcuzxw2IZ3nx0id4lArww= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mattgilbride.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Cs2uIKFb; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--mattgilbride.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Cs2uIKFb" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6b052c5939cso11419317b3.1 for ; Wed, 21 Aug 2024 10:42:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1724262131; x=1724866931; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=CYBGbx/uYLeIyT2X3cGbSQ5xZpFImUAaykVOvmQ6VX8=; b=Cs2uIKFbL2NNxj9RjDNLlp9l1PgbnbZZ8Vo+ahygh0fZPPSOt5HklTtG9DE0Ki+0ft y1h5yuIC84iIK6gm+dT1+3glt/dRW0mR5FZEG+hJx+WbMXgLxtSPXMLCfbEIMkeWYAOc zk5syfY/sfSqI87G4k18H+FUS3ZNbxQaWtUp3acs9sq9KAYlVLTElgBG8RqKINfSN2dY TCct1m/3cB4+J3SWLiqJxzC4gMxgqKcnucJQ7x6Rfc1ovs/wcejJeqtHr45oJmjgCUjA WO+S+bLSr4IyVSzhzf/8H17eGOptMWRHzFQ0lObXvPwUxKupkBgXj1T4tcLu5LZ4KGnW 6hXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724262131; x=1724866931; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CYBGbx/uYLeIyT2X3cGbSQ5xZpFImUAaykVOvmQ6VX8=; b=KAsvOUcy4mvlNIis50rz87gcEZQuOPNq7b3hPtfenuEVt77z5nYSlbDMe26P70wSMI QKninRxWvvbRK1rBZIJMtDgfZ4LgNf6RTWEulyW34RAXHviapzM9kF9d2UrUOwxKHvWT +WASuEmiCI46/vfLJy0NmdXSzs3yGfnGa2TspHrvFMgTA0qIA0XKvYpCGalOKZJV9xMz BeSGCnXUyH4QzACc8i7zaM9wdm791+Xnbf7HfPKuJPv0h0WQm5wAPLkAZfRhz3cgAiUo JjEqwxAu2H+Ue7qHXUfJK25yWexWAXJhW6UACtwLdBrziHsSJ37fq1bqjfY/qtjR1eoz y2mw== X-Forwarded-Encrypted: i=1; AJvYcCXUd1EutlppnTb8ptlnjncp38gndlx3gdBHeyOKMee9fPa44WR/rM+QN3a5rXvvj6MiT2/UWobZPD/Vq6g=@vger.kernel.org X-Gm-Message-State: AOJu0YykZ3x7cyw5OwVotKIWS7/X4BcFGetw81HzOU6XwdxWZxXZAsxe Nx5M5zdaM8a3pmQPD74t10VcSpZWU1rIxX7pcOWQslx6qT3aKyE5ZFVEwnq6FOwaV+Hefq989Ig Eq2LQBt/l2Pnr0BunLRpnIP8DNA== X-Google-Smtp-Source: AGHT+IEINZ4v/d1WW6Yp74ioaOYj+iYeZ3vNSgjypCuHeDr9hlI1StxoI6laD74+nWt/F0LZIxtyzEfuZrIVISG8hNI= X-Received: from mattgilbride.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:2ac5]) (user=mattgilbride job=sendgmr) by 2002:a05:690c:7406:b0:665:7b0d:ed27 with SMTP id 00721157ae682-6c303b0b5c4mr248297b3.2.1724262131250; Wed, 21 Aug 2024 10:42:11 -0700 (PDT) Date: Wed, 21 Aug 2024 17:42:08 +0000 In-Reply-To: <20240821-b4-rbtree-v11-0-2ddc66f26972@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240821-b4-rbtree-v11-0-2ddc66f26972@google.com> X-Mailer: b4 0.13.0 Message-ID: <20240821-b4-rbtree-v11-2-2ddc66f26972@google.com> Subject: [PATCH v11 2/5] rust: rbtree: add iterator From: Matt Gilbride To: Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , "=?utf-8?q?Bj=C3=B6rn_Roy_Baron?=" , Benno Lossin , Andreas Hindborg , Alice Ryhl , Greg Kroah-Hartman , "=?utf-8?q?Arve_Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Martijn Coenen , Joel Fernandes , Carlos Llamas , Suren Baghdasaryan , Christian Brauner Cc: Rob Landley , Davidlohr Bueso , Michel Lespinasse , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Matt Gilbride Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Wedson Almeida Filho - Add Iterator implementation for `RBTree`, allowing iteration over (key, value) pairs in key order. - Add individual `keys()` and `values()` functions to iterate over keys or values alone. - Update doctests to use iteration instead of explicitly getting items. Iteration is needed by the binder driver to enumerate all values in a tree for oneway spam detection [1]. Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-17-08b= a9197f637@google.com/ [1] Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Tested-by: Alice Ryhl Reviewed-by: Benno Lossin Reviewed-by: Boqun Feng Signed-off-by: Matt Gilbride --- rust/kernel/rbtree.rs | 130 +++++++++++++++++++++++++++++++++++++++++++---= ---- 1 file changed, 112 insertions(+), 18 deletions(-) diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs index 51c53a25bc7d..29e7a0795266 100644 --- a/rust/kernel/rbtree.rs +++ b/rust/kernel/rbtree.rs @@ -42,14 +42,30 @@ /// assert_eq!(tree.get(&30).unwrap(), &300); /// } /// +/// // Iterate over the nodes we just inserted. +/// { +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &100)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert_eq!(iter.next().unwrap(), (&30, &300)); +/// assert!(iter.next().is_none()); +/// } +/// +/// // Print all elements. +/// for (key, value) in &tree { +/// pr_info!("{} =3D {}\n", key, value); +/// } +/// /// // Replace one of the elements. /// tree.try_create_and_insert(10, 1000, flags::GFP_KERNEL)?; /// /// // Check that the tree reflects the replacement. /// { -/// assert_eq!(tree.get(&10).unwrap(), &1000); -/// assert_eq!(tree.get(&20).unwrap(), &200); -/// assert_eq!(tree.get(&30).unwrap(), &300); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &1000)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert_eq!(iter.next().unwrap(), (&30, &300)); +/// assert!(iter.next().is_none()); /// } /// /// // Change the value of one of the elements. @@ -57,9 +73,11 @@ /// /// // Check that the tree reflects the update. /// { -/// assert_eq!(tree.get(&10).unwrap(), &1000); -/// assert_eq!(tree.get(&20).unwrap(), &200); -/// assert_eq!(tree.get(&30).unwrap(), &3000); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &1000)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert_eq!(iter.next().unwrap(), (&30, &3000)); +/// assert!(iter.next().is_none()); /// } /// /// // Remove an element. @@ -67,9 +85,10 @@ /// /// // Check that the tree reflects the removal. /// { -/// assert_eq!(tree.get(&10), None); -/// assert_eq!(tree.get(&20).unwrap(), &200); -/// assert_eq!(tree.get(&30).unwrap(), &3000); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert_eq!(iter.next().unwrap(), (&30, &3000)); +/// assert!(iter.next().is_none()); /// } /// /// # Ok::<(), Error>(()) @@ -109,9 +128,11 @@ /// /// // Check the nodes we just inserted. /// { -/// assert_eq!(tree.get(&10).unwrap(), &100); -/// assert_eq!(tree.get(&20).unwrap(), &200); -/// assert_eq!(tree.get(&30).unwrap(), &300); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &100)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert_eq!(iter.next().unwrap(), (&30, &300)); +/// assert!(iter.next().is_none()); /// } /// /// // Remove a node, getting back ownership of it. @@ -119,9 +140,10 @@ /// /// // Check that the tree reflects the removal. /// { -/// assert_eq!(tree.get(&10).unwrap(), &100); -/// assert_eq!(tree.get(&20).unwrap(), &200); -/// assert_eq!(tree.get(&30), None); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &100)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert!(iter.next().is_none()); /// } /// /// // Create a preallocated reservation that we can re-use later. @@ -133,9 +155,11 @@ /// /// // Check that the tree reflect the new insertion. /// { -/// assert_eq!(tree.get(&10).unwrap(), &100); -/// assert_eq!(tree.get(&15).unwrap(), &150); -/// assert_eq!(tree.get(&20).unwrap(), &200); +/// let mut iter =3D tree.iter(); +/// assert_eq!(iter.next().unwrap(), (&10, &100)); +/// assert_eq!(iter.next().unwrap(), (&15, &150)); +/// assert_eq!(iter.next().unwrap(), (&20, &200)); +/// assert!(iter.next().is_none()); /// } /// /// # Ok::<(), Error>(()) @@ -167,6 +191,26 @@ pub fn new() -> Self { _p: PhantomData, } } + + /// Returns an iterator over the tree nodes, sorted by key. + pub fn iter(&self) -> Iter<'_, K, V> { + // INVARIANT: `bindings::rb_first` returns a valid pointer to a tr= ee node given a valid pointer to a tree root. + Iter { + _tree: PhantomData, + // SAFETY: `self.root` is a valid pointer to the tree root. + next: unsafe { bindings::rb_first(&self.root) }, + } + } + + /// Returns an iterator over the keys of the nodes in the tree, in sor= ted order. + pub fn keys(&self) -> impl Iterator { + self.iter().map(|(k, _)| k) + } + + /// Returns an iterator over the values of the nodes in the tree, sort= ed by key. + pub fn values(&self) -> impl Iterator { + self.iter().map(|(_, v)| v) + } } =20 impl RBTree @@ -358,6 +402,56 @@ fn drop(&mut self) { } } =20 +impl<'a, K, V> IntoIterator for &'a RBTree { + type Item =3D (&'a K, &'a V); + type IntoIter =3D Iter<'a, K, V>; + + fn into_iter(self) -> Self::IntoIter { + self.iter() + } +} + +/// An iterator over the nodes of a [`RBTree`]. +/// +/// Instances are created by calling [`RBTree::iter`]. +/// +/// # Invariants +/// - `self.next` is a valid pointer. +/// - `self.next` points to a node stored inside of a valid `RBTree`. +pub struct Iter<'a, K, V> { + _tree: PhantomData<&'a RBTree>, + next: *mut bindings::rb_node, +} + +// SAFETY: The [`Iter`] gives out immutable references to K and V, so it h= as the same +// thread safety requirements as immutable references. +unsafe impl<'a, K: Sync, V: Sync> Send for Iter<'a, K, V> {} + +// SAFETY: The [`Iter`] gives out immutable references to K and V, so it h= as the same +// thread safety requirements as immutable references. +unsafe impl<'a, K: Sync, V: Sync> Sync for Iter<'a, K, V> {} + +impl<'a, K, V> Iterator for Iter<'a, K, V> { + type Item =3D (&'a K, &'a V); + + fn next(&mut self) -> Option { + if self.next.is_null() { + return None; + } + + // SAFETY: By the type invariant of `Iter`, `self.next` is a valid= node in an `RBTree`, + // and by the type invariant of `RBTree`, all nodes point to the l= inks field of `Node` objects. + let cur =3D unsafe { container_of!(self.next, Node, links) }; + + // SAFETY: `self.next` is a valid tree node by the type invariants. + self.next =3D unsafe { bindings::rb_next(self.next) }; + + // SAFETY: By the same reasoning above, it is safe to dereference = the node. Additionally, + // it is ok to return a reference to members because the iterator = must outlive it. + Some(unsafe { (&(*cur).key, &(*cur).value) }) + } +} + /// A memory reservation for a red-black tree node. /// /// --=20 2.46.0.184.g6999bdac58-goog