Fix root scheme order by using indexmap (tmp).

Cargo.lock

@@ -103,9 +103,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.2.5"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b0b929d511467233429c45a44ac1dcaa21ba0f5ba11e4879e6ed28ddb4f9df4"
+checksum = "68b900aa2f7301e21c36462b170ee99994de34dff39a4a6a528e80e7376d07e5"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -123,6 +123,7 @@ dependencies = [
  "fdt",
  "goblin",
  "hashbrown",
+ "indexmap",
  "linked_list_allocator 0.9.1",
  "log",
  "raw-cpuid",

Cargo.toml

@@ -23,6 +23,8 @@ spinning_top = { version = "0.3", features = ["arc_lock"] }
 rmm = { path = "rmm", default-features = false }
 arrayvec = { version = "0.7.4", default-features = false }
 slab = { version = "0.4", default-features = false }
+# TODO: Remove
+indexmap = { version = "2.5.0", default-features = false }
 
 [dependencies.goblin]
 version = "0.2.1"

src/scheme/mod.rs

@@ -6,9 +6,12 @@
 //! The kernel validates paths and file descriptors before they are passed to schemes,
 //! also stripping the scheme identifier of paths if necessary.
 
+// TODO: Move handling of the global namespace to userspace.
+
 use alloc::{boxed::Box, collections::BTreeMap, string::ToString, sync::Arc, vec::Vec};
-use core::sync::atomic::AtomicUsize;
-use hashbrown::HashMap;
+use core::{hash::BuildHasherDefault, sync::atomic::AtomicUsize};
+use hashbrown::{hash_map::DefaultHashBuilder, HashMap};
+use indexmap::IndexMap;
 use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
 use syscall::{EventFlags, MunmapFlags, SendFdFlags};
 
@@ -89,7 +92,7 @@ int_like!(SchemeId, usize);
 int_like!(FileHandle, AtomicFileHandle, usize, AtomicUsize);
 
 pub struct SchemeIter<'a> {
-    inner: Option<hashbrown::hash_map::Iter<'a, Box<str>, SchemeId>>,
+    inner: Option<indexmap::map::Iter<'a, Box<str>, SchemeId>>,
 }
 
 impl<'a> Iterator for SchemeIter<'a> {
@@ -103,7 +106,7 @@ impl<'a> Iterator for SchemeIter<'a> {
 /// Scheme list type
 pub struct SchemeList {
     map: HashMap<SchemeId, KernelSchemes>,
-    pub(crate) names: HashMap<SchemeNamespace, HashMap<Box<str>, SchemeId>>,
+    pub(crate) names: HashMap<SchemeNamespace, IndexMap<Box<str>, SchemeId, DefaultHashBuilder>>,
     next_ns: usize,
     next_id: usize,
 }
@@ -157,7 +160,8 @@ impl SchemeList {
     /// Initialize the null namespace
     fn new_null(&mut self) {
         let ns = SchemeNamespace(0);
-        self.names.insert(ns, HashMap::new());
+        self.names
+            .insert(ns, IndexMap::with_hasher(BuildHasherDefault::default()));
 
         //TODO: Only memory: is in the null namespace right now. It should be removed when
         //anonymous mmap's are implemented
@@ -172,7 +176,8 @@ impl SchemeList {
     fn new_ns(&mut self) -> SchemeNamespace {
         let ns = SchemeNamespace(self.next_ns);
         self.next_ns += 1;
-        self.names.insert(ns, HashMap::new());
+        self.names
+            .insert(ns, IndexMap::with_hasher(BuildHasherDefault::default()));
 
         self.insert(ns, "", |scheme_id| {
             KernelSchemes::Root(Arc::new(RootScheme::new(ns, scheme_id)))

src/scheme/root.rs

@@ -254,15 +254,16 @@ impl KernelScheme for RootScheme {
         let mut buf = DirentBuf::new(buf, header_size).ok_or(Error::new(EIO))?;
         {
             let schemes = scheme::schemes();
-            for (name, scheme_id) in schemes
+            for (i, (name, _)) in schemes
                 .iter_name(ens)
-                .filter(|(_, s)| opaque <= s.get() as u64)
+                .enumerate()
+                .skip_while(|(i, _)| (*i as u64) < opaque)
             {
                 buf.entry(DirEntry {
                     kind: DirentKind::Unspecified,
                     name,
                     inode: 0,
-                    next_opaque_id: scheme_id.get() as u64 + 1,
+                    next_opaque_id: i as u64 + 1,
                 })?;
             }
         }