From 770a1234154c19ba75e00ae0e4c26496f854af3b Mon Sep 17 00:00:00 2001
From: LI Qing <geding.lq@antgroup.com>
Date: Thu, 16 May 2024 14:59:09 +0800
Subject: [PATCH] Change the return value of dup() for Vmo<Rights>

---
 kernel/aster-nix/src/fs/exfat/dentry.rs       |  2 +-
 kernel/aster-nix/src/fs/utils/page_cache.rs   |  2 +-
 .../process/program_loader/elf/load_elf.rs    |  2 +-
 kernel/aster-nix/src/vm/vmo/options.rs        |  4 ++--
 kernel/aster-nix/src/vm/vmo/static_cap.rs     | 19 ++++++++-----------
 5 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/kernel/aster-nix/src/fs/exfat/dentry.rs b/kernel/aster-nix/src/fs/exfat/dentry.rs
index 84119bfd9..63d7bbe8c 100644
--- a/kernel/aster-nix/src/fs/exfat/dentry.rs
+++ b/kernel/aster-nix/src/fs/exfat/dentry.rs
@@ -270,7 +270,7 @@ impl ExfatDentrySet {
     }
 
     pub(super) fn read_from(page_cache: Vmo<Full>, offset: usize) -> Result<Self> {
-        let mut iter = ExfatDentryIterator::new(page_cache.dup().unwrap(), offset, None)?;
+        let mut iter = ExfatDentryIterator::new(page_cache, offset, None)?;
         let primary_dentry_result = iter.next();
 
         if primary_dentry_result.is_none() {
diff --git a/kernel/aster-nix/src/fs/utils/page_cache.rs b/kernel/aster-nix/src/fs/utils/page_cache.rs
index 31eda2d2a..4e8fef4c2 100644
--- a/kernel/aster-nix/src/fs/utils/page_cache.rs
+++ b/kernel/aster-nix/src/fs/utils/page_cache.rs
@@ -45,7 +45,7 @@ impl PageCache {
     // TODO: The capability is too high，restrict it to eliminate the possibility of misuse.
     //       For example, the `resize` api should be forbidded.
     pub fn pages(&self) -> Vmo<Full> {
-        self.pages.dup().unwrap()
+        self.pages.dup()
     }
 
     /// Evict the data within a specified range from the page cache and persist
diff --git a/kernel/aster-nix/src/process/program_loader/elf/load_elf.rs b/kernel/aster-nix/src/process/program_loader/elf/load_elf.rs
index 0d32b21d5..f8ae19381 100644
--- a/kernel/aster-nix/src/process/program_loader/elf/load_elf.rs
+++ b/kernel/aster-nix/src/process/program_loader/elf/load_elf.rs
@@ -325,7 +325,7 @@ fn init_segment_vmo(program_header: &ProgramHeader64, elf_file: &Dentry) -> Resu
             start..end
         };
         debug_assert!(vmo_size >= (program_header.file_size as usize).align_up(PAGE_SIZE));
-        page_cache_vmo.new_cow_child(parent_range)?.alloc()?
+        page_cache_vmo.new_cow_child(parent_range).alloc()?
     };
 
     let anonymous_map_size: usize = if vmo_size > segment_vmo.size() {
diff --git a/kernel/aster-nix/src/vm/vmo/options.rs b/kernel/aster-nix/src/vm/vmo/options.rs
index 5328baddf..2d2ae374c 100644
--- a/kernel/aster-nix/src/vm/vmo/options.rs
+++ b/kernel/aster-nix/src/vm/vmo/options.rs
@@ -513,7 +513,7 @@ mod test {
     #[ktest]
     fn slice_child() {
         let parent = VmoOptions::<Full>::new(2 * PAGE_SIZE).alloc().unwrap();
-        let parent_dup = parent.dup().unwrap();
+        let parent_dup = parent.dup();
         let slice_child = VmoChildOptions::new_slice(parent_dup, 0..PAGE_SIZE)
             .alloc()
             .unwrap();
@@ -530,7 +530,7 @@ mod test {
         let parent = VmoOptions::<Full>::new(2 * PAGE_SIZE).alloc().unwrap();
         parent.write_val(1, &42u8).unwrap();
         parent.write_val(2, &16u8).unwrap();
-        let parent_dup = parent.dup().unwrap();
+        let parent_dup = parent.dup();
         let cow_child = VmoChildOptions::new_cow(parent_dup, 0..10 * PAGE_SIZE)
             .alloc()
             .unwrap();
diff --git a/kernel/aster-nix/src/vm/vmo/static_cap.rs b/kernel/aster-nix/src/vm/vmo/static_cap.rs
index ffa23f877..8b07f8eb6 100644
--- a/kernel/aster-nix/src/vm/vmo/static_cap.rs
+++ b/kernel/aster-nix/src/vm/vmo/static_cap.rs
@@ -36,9 +36,9 @@ impl<R: TRights> Vmo<TRightSet<R>> {
     pub fn new_slice_child(
         &self,
         range: Range<usize>,
-    ) -> Result<VmoChildOptions<TRightSet<R>, VmoSliceChild>> {
-        let dup_self = self.dup()?;
-        Ok(VmoChildOptions::new_slice(dup_self, range))
+    ) -> VmoChildOptions<TRightSet<R>, VmoSliceChild> {
+        let dup_self = self.dup();
+        VmoChildOptions::new_slice(dup_self, range)
     }
 
     /// Creates a new COW VMO through a set of VMO child options.
@@ -62,12 +62,9 @@ impl<R: TRights> Vmo<TRightSet<R>> {
     /// The child will be given the access rights of the parent
     /// plus the Write right.
     #[require(R > Dup)]
-    pub fn new_cow_child(
-        &self,
-        range: Range<usize>,
-    ) -> Result<VmoChildOptions<TRightSet<R>, VmoCowChild>> {
-        let dup_self = self.dup()?;
-        Ok(VmoChildOptions::new_cow(dup_self, range))
+    pub fn new_cow_child(&self, range: Range<usize>) -> VmoChildOptions<TRightSet<R>, VmoCowChild> {
+        let dup_self = self.dup();
+        VmoChildOptions::new_cow(dup_self, range)
     }
 
     /// commit a page at specific offset
@@ -135,8 +132,8 @@ impl<R: TRights> Vmo<TRightSet<R>> {
     ///
     /// The method requires the Dup right.
     #[require(R > Dup)]
-    pub fn dup(&self) -> Result<Self> {
-        Ok(Vmo(self.0.clone(), self.1))
+    pub fn dup(&self) -> Self {
+        Vmo(self.0.clone(), self.1)
     }
 
     /// Strict the access rights.