remove need for virt_preopens

crates/wasi-common/src/ctx.rs

@@ -63,8 +63,7 @@ impl PendingCString {
 /// A builder allowing customizable construction of `WasiCtx` instances.
 pub struct WasiCtxBuilder {
     fds: HashMap<wasi::__wasi_fd_t, PendingFdEntry>,
-    preopens: Vec<(PathBuf, File)>,
-    virt_preopens: Vec<(PathBuf, Box<dyn VirtualFile>)>,
+    preopens: Vec<(PathBuf, fdentry::File)>,
     args: Vec<PendingCString>,
     env: HashMap<PendingCString, PendingCString>,
 }
@@ -75,7 +74,6 @@ impl WasiCtxBuilder {
         let mut builder = Self {
             fds: HashMap::new(),
             preopens: Vec::new(),
-            virt_preopens: Vec::new(),
             args: vec![],
             env: HashMap::new(),
         };
@@ -186,20 +184,20 @@ impl WasiCtxBuilder {
         self
     }
 
-    /// Add a preopened directory.
+    /// Add a preopened OS directory.
     pub fn preopened_dir<P: AsRef<Path>>(mut self, dir: File, guest_path: P) -> Self {
-        self.preopens.push((guest_path.as_ref().to_owned(), dir));
+        self.preopens.push((guest_path.as_ref().to_owned(), fdentry::File::OsHandle(OsHandle::from(dir))));
         self
     }
 
-    /// Add a thunk that will prooduce some FdEntry.
+    /// Add a preopened virtual directory.
     pub fn preopened_virt<P: AsRef<Path>>(
         mut self,
         dir: Box<dyn VirtualFile>,
         guest_path: P,
     ) -> Self {
-        self.virt_preopens
-            .push((guest_path.as_ref().to_owned(), dir));
+        self.preopens
+            .push((guest_path.as_ref().to_owned(), fdentry::File::VirtualFile(dir)));
         self
     }
 
@@ -257,43 +255,25 @@ impl WasiCtxBuilder {
             // unnecessarily if we have exactly the maximum number of file descriptors.
             preopen_fd = preopen_fd.checked_add(1).ok_or(Error::ENFILE)?;
 
-            if !dir.metadata()?.is_dir() {
-                return Err(Error::EBADF);
-            }
-
-            // We don't currently allow setting file descriptors other than 0-2, but this will avoid
-            // collisions if we restore that functionality in the future.
-            while fds.contains_key(&preopen_fd) {
-                preopen_fd = preopen_fd.checked_add(1).ok_or(Error::ENFILE)?;
-            }
-            let mut fe = FdEntry::from(fdentry::File::OsHandle(OsHandle::from(dir)))?;
-            fe.preopen_path = Some(guest_path);
-            log::debug!("WasiCtx inserting ({:?}, {:?})", preopen_fd, fe);
-            fds.insert(preopen_fd, fe);
-            log::debug!("WasiCtx fds = {:?}", fds);
-        }
-
-        for (guest_path, virt_dir) in self.virt_preopens {
-            // We do the increment at the beginning of the loop body, so that we don't overflow
-            // unnecessarily if we have exactly the maximum number of file descriptors.
-            preopen_fd = preopen_fd.checked_add(1).ok_or(Error::ENFILE)?;
-
-            /*
-            if !dir.metadata()?.is_dir() {
-                return Err(Error::EBADF);
+            match &dir {
+                fdentry::File::OsHandle(handle) => {
+                    if !handle.metadata()?.is_dir() {
+                        return Err(Error::EBADF);
+                    }
+                },
+                fdentry::File::VirtualFile(virt) => {
+                    if virt.get_file_type() != wasi::__WASI_FILETYPE_DIRECTORY {
+                        return Err(Error::EBADF);
+                    }
+                }
             }
-            */
 
             // We don't currently allow setting file descriptors other than 0-2, but this will avoid
             // collisions if we restore that functionality in the future.
             while fds.contains_key(&preopen_fd) {
                 preopen_fd = preopen_fd.checked_add(1).ok_or(Error::ENFILE)?;
             }
-            let mut fe = FdEntry::virtual_from(virt_dir)?;
-            fe.file_type = wasi::__WASI_FILETYPE_DIRECTORY;
-            fe.rights_base = wasi::RIGHTS_DIRECTORY_BASE;
-            fe.rights_inheriting = wasi::RIGHTS_DIRECTORY_INHERITING;
-            fe.file_type = wasi::__WASI_FILETYPE_DIRECTORY;
+            let mut fe = FdEntry::from(dir)?;
             fe.preopen_path = Some(guest_path);
             log::debug!("WasiCtx inserting ({:?}, {:?})", preopen_fd, fe);
             fds.insert(preopen_fd, fe);