[PATCH v2 3/5] rust: id_pool: do not supply starting capacity

[Alice Ryhl]

When creating the initial IdPool, Rust Binder simply wants the largest
value that does not allocate. Having to handle allocating error failures
that cannot happen is inconvenient, so make the constructor infallible
by removing the size argument.

Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
---
 rust/kernel/id_pool.rs | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/rust/kernel/id_pool.rs b/rust/kernel/id_pool.rs
index a41a3404213ca92d53b14c80101afff6ac8c416e..126e57f34c3407cb1dab3169417f01917e172dee 100644
--- a/rust/kernel/id_pool.rs
+++ b/rust/kernel/id_pool.rs
@@ -96,16 +96,11 @@ pub fn realloc(&self, flags: Flags) -> Result<PoolResizer, AllocError> {
 
 impl IdPool {
     /// Constructs a new [`IdPool`].
-    ///
-    /// A capacity below [`BITS_PER_LONG`] is adjusted to
-    /// [`BITS_PER_LONG`].
-    ///
-    /// [`BITS_PER_LONG`]: srctree/include/asm-generic/bitsperlong.h
     #[inline]
-    pub fn new(num_ids: usize, flags: Flags) -> Result<Self, AllocError> {
-        let num_ids = core::cmp::max(num_ids, BITS_PER_LONG);
-        let map = BitmapVec::new(num_ids, flags)?;
-        Ok(Self { map })
+    pub fn new() -> Self {
+        Self {
+            map: BitmapVec::new_small(),
+        }
     }
 
     /// Returns how many IDs this pool can currently have.
@@ -224,3 +219,10 @@ pub fn release_id(&mut self, id: usize) {
         self.map.clear_bit(id);
     }
 }
+
+impl Default for IdPool {
+    #[inline]
+    fn default() -> Self {
+        Self::new()
+    }
+}

-- 
2.51.0.869.ge66316f041-goog