The previous version used a verbose `match` to get
`current`, which may be slightly confusing at first
glance.
This change makes it shorter and more clearly expresses
the intent: prefer `next` if available, otherwise fall
back to `prev`.
Signed-off-by: Onur Özkan <work@onurozkan.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://lore.kernel.org/r/20250708075850.25789-1-work@onurozkan.dev
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In Rust Binder I need to be able to determine whether a red/black tree
is empty. Thus, add a method for that operation to replace
rbtree.iter().next().is_none()
This is terrible, so add a method for this purpose. We do not add a
RBTree::len method because computing the number of elements requires
iterating the entire tree, but checking whether it is empty can be done
cheaply.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250616-rbtree-is-empty-v1-1-61f7cfb012e3@google.com
[ Adjusted title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Avoid casting the input pointer to `*const _`, allowing the output
pointer to be `*mut` if the input is `*mut`. This allows a number of
`*const` to `*mut` conversions to be removed at the cost of slightly
worse ergonomics when the macro is used with a reference rather than a
pointer; the only example of this was in the macro's own doctest.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250409-container-of-mutness-v1-1-64f472b94534@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Several safety comments in the RBTree implementation still refer to
"Box::from_raw" and "Box::into_raw", but the code actually uses KBox.
These comments were not updated when the implementation transitioned
from using Box to KBox.
Fixes: 8373147ce4 ("rust: treewide: switch to our kernel `Box` type")
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250315-rbtree-comment-fixes-v1-1-51f72c420ff0@posteo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.86.0 (to be released 2025-04-03), Clippy will have
a new lint, `doc_overindented_list_items` [1], which catches cases of
overindented list items.
The lint has been added by Yutaro Ohno, based on feedback from the kernel
[2] on a patch that fixed a similar case -- commit 0c5928dead ("rust:
block: fix formatting in GenDisk doc").
Clippy reports a few cases in the kernel, apart from the one already
fixed in the commit above. One is this one:
error: doc list item overindented
--> rust/kernel/rbtree.rs:1152:5
|
1152 | /// null, it is a pointer to the root of the [`RBTree`].
| ^^^^ help: try using ` ` (2 spaces)
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#doc_overindented_list_items
= note: `-D clippy::doc-overindented-list-items` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::doc_overindented_list_items)]`
Thus clean it up.
Cc: Yutaro Ohno <yutaro.ono.418@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs).
Fixes: a335e95914 ("rust: rbtree: add `RBTree::entry`")
Link: https://github.com/rust-lang/rust-clippy/pull/13711 [1]
Link: https://github.com/rust-lang/rust-clippy/issues/13601 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Yutaro Ohno <yutaro.ono.418@gmail.com>
Link: https://lore.kernel.org/r/20250206232022.599998-1-ojeda@kernel.org
[ There are a few other cases, so updated message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Remove `unwrap` in asserts and replace it with `Option::Some`
matching. By doing it this way, the examples are more
descriptive, so it disambiguates the return type of
the `get(...)` and `next(...)`, because the `unwrap(...)`
can also be called on `Result`.
Signed-off-by: Daniel Sedlak <daniel@sedlak.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241123095033.41240-3-daniel@sedlak.dev
[ Reworded title slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we got the kernel `Box` type in place, convert all existing
`Box` users to make use of it.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-13-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The tag `SAFETY` is used for safety comments, i.e. `// SAFETY`, while a
`Safety` section is used for safety preconditions in code documentation,
i.e. `/// # Safety`.
Fix the three instances recently added in `rbtree` that Clippy would
have normally caught in a public item, so that we can enable checking
of private items in one of the following commits.
Fixes: 98c14e40e0 ("rust: rbtree: add cursor")
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-14-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This mirrors the entry API [1] from the Rust standard library on
`RBTree`. This API can be used to access the entry at a specific key and
make modifications depending on whether the key is vacant or occupied.
This API is useful because it can often be used to avoid traversing the
tree multiple times.
This is used by binder to look up and conditionally access or insert a
value, depending on whether it is there or not [2].
Link: https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html [1]
Link: https://android-review.googlesource.com/c/kernel/common/+/2849906 [2]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-5-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a cursor interface to `RBTree`, supporting the following use cases:
- Inspect the current node pointed to by the cursor, inspect/move to
it's neighbors in sort order (bidirectionally).
- Mutate the tree itself by removing the current node pointed to by the
cursor, or one of its neighbors.
Add functions to obtain a cursor to the tree by key:
- The node with the smallest key
- The node with the largest key
- The node matching the given key, or the one with the next larger key
The cursor abstraction is needed by the binder driver to efficiently
search for nodes and (conditionally) modify them, as well as their
neighbors [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-4-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add mutable Iterator implementation for `RBTree`,
allowing iteration over (key, value) pairs in key order. Only values are
mutable, as mutating keys implies modifying a node's position in the tree.
Mutable iteration is used by the binder driver during shutdown to
clean up the tree maintained by the "range allocator" [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-3-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
- 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-v1-17-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-2-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The rust rbtree exposes a map-like interface over keys and values,
backed by the kernel red-black tree implementation. Values can be
inserted, deleted, and retrieved from a `RBTree` by key.
This base abstraction is used by binder to store key/value
pairs and perform lookups, for example the patch
"[PATCH RFC 03/20] rust_binder: add threading support"
in the binder RFC [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-3-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-1-014561758a57@google.com
[ Updated link to docs.kernel.org. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
