From 14fd63a5c8e2d7b0eab2970699c2b4a407200cec Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Fri, 24 Feb 2023 10:38:52 +0000
Subject: [PATCH 1/2] Add test for pread and pwrite

---
 tests/fs.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/fs.md b/tests/fs.md
index 63a1c7e72..c62d4f4fc 100644
--- a/tests/fs.md
+++ b/tests/fs.md
@@ -8,6 +8,7 @@
 
 ```ocaml
 
+module Int63 = Optint.Int63
 module Path = Eio.Path
 
 let () = Eio.Exn.Backend.show := false
@@ -512,3 +513,22 @@ Unconfined:
 +write <cwd:stat_reg> -> ok
 - : unit = ()
 ```
+
+# pread/pwrite
+
+Check reading and writing vectors at arbitrary offsets:
+
+```ocaml
+# run @@ fun env ->
+  let cwd = Eio.Stdenv.cwd env in
+  let path = cwd / "test.txt" in
+  Path.with_open_out path ~create:(`Exclusive 0o600) @@ fun file ->
+  Eio.Flow.copy_string "+-!" file;
+  Eio.File.pwrite_all file ~file_offset:(Int63.of_int 2) Cstruct.[of_string "abc"; of_string "123"];
+  let buf1 = Cstruct.create 3 in
+  let buf2 = Cstruct.create 4 in
+  Eio.File.pread_exact file ~file_offset:(Int63.of_int 1) [buf1; buf2];
+  traceln" %S/%S" (Cstruct.to_string buf1) (Cstruct.to_string buf2);;
++ "-ab"/"c123"
+- : unit = ()
+```

From 76ffd669efcefbb18a4c2ede85f9192cfdb1290c Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Mon, 27 Feb 2023 13:23:25 +0000
Subject: [PATCH 2/2] Add test for readdir with no access

Report the error as `Permission_denied`.
---
 lib_eio_linux/eio_linux.ml |  2 +-
 lib_eio_luv/eio_luv.ml     |  1 +
 tests/fs.md                | 14 ++++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib_eio_linux/eio_linux.ml b/lib_eio_linux/eio_linux.ml
index 1706fc788..3a5387faf 100644
--- a/lib_eio_linux/eio_linux.ml
+++ b/lib_eio_linux/eio_linux.ml
@@ -47,7 +47,7 @@ let wrap_error_fs code name arg =
   match code with
   | Unix.EEXIST -> Eio.Fs.err (Already_exists e)
   | Unix.ENOENT -> Eio.Fs.err (Not_found e)
-  | Unix.EXDEV -> Eio.Fs.err (Permission_denied e)
+  | Unix.EXDEV | EPERM | EACCES -> Eio.Fs.err (Permission_denied e)
   | _ -> wrap_error code name arg
 
 module FD = struct
diff --git a/lib_eio_luv/eio_luv.ml b/lib_eio_luv/eio_luv.ml
index f0e645b40..ed6f5a575 100644
--- a/lib_eio_luv/eio_luv.ml
+++ b/lib_eio_luv/eio_luv.ml
@@ -45,6 +45,7 @@ let wrap_error_fs e =
   match e with
   | `EEXIST -> Eio.Fs.err (Already_exists (Luv_error e))
   | `ENOENT -> Eio.Fs.err (Not_found (Luv_error e))
+  | `EPERM | `EACCES -> Eio.Fs.err (Permission_denied (Luv_error e))
   | e -> wrap_error e
 
 let or_raise = function
diff --git a/tests/fs.md b/tests/fs.md
index c62d4f4fc..0a9fce31c 100644
--- a/tests/fs.md
+++ b/tests/fs.md
@@ -377,6 +377,20 @@ Reading directory entries under `cwd` and outside of `cwd`.
 - : unit = ()
 ```
 
+An error from the underlying directory, not the sandbox:
+
+```ocaml
+# Unix.mkdir "test-no-access" 0;
+- : unit = ()
+# run @@ fun env ->
+  let cwd = Eio.Stdenv.cwd env in
+  try_read_dir (cwd / "test-no-access");;
++Eio.Io Fs Permission_denied _, reading directory <cwd:test-no-access>
+- : unit = ()
+# Unix.chmod "test-no-access" 0o700;
+- : unit = ()
+```
+
 Can use `fs` to access absolute paths:
 
 ```ocaml