Rustify Sys::open and some fs:: error handling.

src/platform/linux/mod.rs

@@ -230,12 +230,12 @@ impl Pal for Sys {
         Self::readlink(CStr::from_bytes_with_nul(&proc_path).unwrap(), out)
     }
 
-    fn fsync(fildes: c_int) -> c_int {
-        e(unsafe { syscall!(FSYNC, fildes) }) as c_int
+    fn fsync(fildes: c_int) -> Result<(), Errno> {
+        e_raw(unsafe { syscall!(FSYNC, fildes) }).map(|_| ())
     }
 
-    fn ftruncate(fildes: c_int, length: off_t) -> c_int {
-        e(unsafe { syscall!(FTRUNCATE, fildes, length) }) as c_int
+    fn ftruncate(fildes: c_int, length: off_t) -> Result<(), Errno> {
+        e_raw(unsafe { syscall!(FTRUNCATE, fildes, length) }).map(|_| ())
     }
 
     #[inline]
@@ -450,8 +450,9 @@ impl Pal for Sys {
         e(unsafe { syscall!(NANOSLEEP, rqtp, rmtp) }) as c_int
     }
 
-    fn open(path: CStr, oflag: c_int, mode: mode_t) -> c_int {
-        e(unsafe { syscall!(OPENAT, AT_FDCWD, path.as_ptr(), oflag, mode) }) as c_int
+    fn open(path: CStr, oflag: c_int, mode: mode_t) -> Result<c_int, Errno> {
+        e_raw(unsafe { syscall!(OPENAT, AT_FDCWD, path.as_ptr(), oflag, mode) })
+            .map(|fd| fd as c_int)
     }
 
     fn pipe2(fildes: &mut [c_int], flags: c_int) -> c_int {

src/platform/pal/mod.rs

@@ -76,9 +76,9 @@ pub trait Pal {
 
     fn fpath(fildes: c_int, out: &mut [u8]) -> ssize_t;
 
-    fn fsync(fildes: c_int) -> c_int;
+    fn fsync(fildes: c_int) -> Result<(), Errno>;
 
-    fn ftruncate(fildes: c_int, length: off_t) -> c_int;
+    fn ftruncate(fildes: c_int, length: off_t) -> Result<(), Errno>;
 
     unsafe fn futex_wait(
         addr: *mut u32,
@@ -179,12 +179,13 @@ pub trait Pal {
 
     fn nanosleep(rqtp: *const timespec, rmtp: *mut timespec) -> c_int;
 
-    fn open(path: CStr, oflag: c_int, mode: mode_t) -> c_int;
+    fn open(path: CStr, oflag: c_int, mode: mode_t) -> Result<c_int, Errno>;
 
     fn pipe2(fildes: &mut [c_int], flags: c_int) -> c_int;
 
     unsafe fn rlct_clone(stack: *mut usize) -> Result<crate::pthread::OsTid, Errno>;
     unsafe fn rlct_kill(os_tid: crate::pthread::OsTid, signal: usize) -> Result<(), Errno>;
+
     fn current_os_tid() -> crate::pthread::OsTid;
 
     fn read(fildes: c_int, buf: &mut [u8]) -> Result<ssize_t, Errno>;

src/platform/redox/epoll.rs

@@ -53,7 +53,7 @@ fn event_flags_to_epoll(flags: syscall::EventFlags) -> c_uint {
 
 impl PalEpoll for Sys {
     fn epoll_create1(flags: c_int) -> c_int {
-        Sys::open(c_str!("/scheme/event"), O_RDWR | flags, 0)
+        Sys::open(c_str!("/scheme/event"), O_RDWR | flags, 0).or_minus_one_errno()
     }
 
     fn epoll_ctl(epfd: c_int, op: c_int, fd: c_int, event: *mut epoll_event) -> c_int {

src/platform/redox/mod.rs

@@ -294,12 +294,14 @@ impl Pal for Sys {
         unsafe { e(libredox::fstatvfs(fildes as usize, buf).map(|()| 0)) as c_int }
     }
 
-    fn fsync(fd: c_int) -> c_int {
-        e(syscall::fsync(fd as usize)) as c_int
+    fn fsync(fd: c_int) -> Result<(), Errno> {
+        syscall::fsync(fd as usize)?;
+        Ok(())
     }
 
-    fn ftruncate(fd: c_int, len: off_t) -> c_int {
-        e(syscall::ftruncate(fd as usize, len as usize)) as c_int
+    fn ftruncate(fd: c_int, len: off_t) -> Result<(), Errno> {
+        syscall::ftruncate(fd as usize, len as usize)?;
+        Ok(())
     }
 
     #[inline]
@@ -777,10 +779,10 @@ impl Pal for Sys {
         }
     }
 
-    fn open(path: CStr, oflag: c_int, mode: mode_t) -> c_int {
-        let path = path_from_c_str!(path);
+    fn open(path: CStr, oflag: c_int, mode: mode_t) -> Result<c_int, Errno> {
+        let path = path.to_str().map_err(|_| Errno(EINVAL))?;
 
-        e(libredox::open(path, oflag, mode)) as c_int
+        Ok(libredox::open(path, oflag, mode)? as c_int)
     }
 
     fn pipe2(fds: &mut [c_int], flags: c_int) -> c_int {