Reuse errno_from_ioerror to simplify error handling

src/ctx.rs

@@ -1,5 +1,5 @@
 use crate::fdentry::FdEntry;
-use crate::sys::{dev_null, errno_from_host};
+use crate::sys::{dev_null, errno_from_ioerror};
 use crate::{host, Result};
 use std::borrow::Borrow;
 use std::collections::HashMap;
@@ -92,11 +92,7 @@ impl WasiCtxBuilder {
         // startup code starts looking at fd 3 for preopens
         let mut preopen_fd = 3;
         for (guest_path, dir) in self.preopens {
-            if !dir
-                .metadata()
-                .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?
-                .is_dir()
-            {
+            if !dir.metadata().map_err(errno_from_ioerror)?.is_dir() {
                 return Err(host::__WASI_EBADF);
             }
 

src/fdentry.rs

@@ -1,4 +1,4 @@
-use crate::sys::{errno_from_host, fdentry_impl};
+use crate::sys::{errno_from_ioerror, fdentry_impl};
 use crate::{host, Result};
 
 use std::mem::ManuallyDrop;
@@ -92,7 +92,7 @@ impl FdEntry {
 
     pub fn duplicate(file: &fs::File) -> Result<Self> {
         file.try_clone()
-            .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+            .map_err(errno_from_ioerror)
             .and_then(Self::from)
     }
 

src/hostcalls_impl/fs.rs

@@ -2,7 +2,7 @@
 use crate::ctx::WasiCtx;
 use crate::fdentry::{Descriptor, FdEntry};
 use crate::memory::*;
-use crate::sys::{errno_from_host, host_impl, hostcalls_impl};
+use crate::sys::{errno_from_ioerror, host_impl, hostcalls_impl};
 use crate::{host, wasm32, Result};
 use log::trace;
 use std::io::{self, Read, Seek, SeekFrom, Write};
@@ -32,8 +32,7 @@ pub(crate) fn fd_datasync(wasi_ctx: &WasiCtx, fd: wasm32::__wasi_fd_t) -> Result
         .get_fd_entry(fd, host::__WASI_RIGHT_FD_DATASYNC, 0)
         .and_then(|fe| fe.fd_object.descriptor.as_file())?;
 
-    fd.sync_data()
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    fd.sync_data().map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_pread(
@@ -158,8 +157,7 @@ pub(crate) fn fd_read(
         _ => return Err(host::__WASI_EBADF),
     };
 
-    let host_nread = maybe_host_nread
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?;
+    let host_nread = maybe_host_nread.map_err(errno_from_ioerror)?;
 
     trace!("     | *nread={:?}", host_nread);
 
@@ -242,9 +240,7 @@ pub(crate) fn fd_seek(
         host::__WASI_WHENCE_SET => SeekFrom::Start(offset as u64),
         _ => return Err(host::__WASI_EINVAL),
     };
-    let host_newoffset = fd
-        .seek(pos)
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?;
+    let host_newoffset = fd.seek(pos).map_err(errno_from_ioerror)?;
 
     trace!("     | *newoffset={:?}", host_newoffset);
 
@@ -264,9 +260,7 @@ pub(crate) fn fd_tell(
         .get_fd_entry(fd, host::__WASI_RIGHT_FD_TELL, 0)
         .and_then(|fe| fe.fd_object.descriptor.as_file())?;
 
-    let host_offset = fd
-        .seek(SeekFrom::Current(0))
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?;
+    let host_offset = fd.seek(SeekFrom::Current(0)).map_err(errno_from_ioerror)?;
 
     trace!("     | *newoffset={:?}", host_offset);
 
@@ -348,8 +342,7 @@ pub(crate) fn fd_sync(wasi_ctx: &WasiCtx, fd: wasm32::__wasi_fd_t) -> Result<()>
     let fd = wasi_ctx
         .get_fd_entry(fd, host::__WASI_RIGHT_FD_SYNC, 0)
         .and_then(|fe| fe.fd_object.descriptor.as_file())?;
-    fd.sync_all()
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    fd.sync_all().map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_write(
@@ -383,8 +376,7 @@ pub(crate) fn fd_write(
         Descriptor::Stderr => io::stderr().lock().write_vectored(&iovs),
     };
 
-    let host_nwritten = maybe_host_nwritten
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?;
+    let host_nwritten = maybe_host_nwritten.map_err(errno_from_ioerror)?;
 
     trace!("     | *nwritten={:?}", host_nwritten);
 
@@ -432,9 +424,7 @@ pub(crate) fn fd_allocate(
         .get_fd_entry(fd, host::__WASI_RIGHT_FD_ALLOCATE, 0)
         .and_then(|fe| fe.fd_object.descriptor.as_file())?;
 
-    let metadata = fd
-        .metadata()
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?;
+    let metadata = fd.metadata().map_err(errno_from_ioerror)?;
 
     let current_size = metadata.len();
     let wanted_size = offset.checked_add(len).ok_or(host::__WASI_E2BIG)?;
@@ -443,8 +433,7 @@ pub(crate) fn fd_allocate(
     }
 
     if wanted_size > current_size {
-        fd.set_len(wanted_size)
-            .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+        fd.set_len(wanted_size).map_err(errno_from_ioerror)
     } else {
         Ok(())
     }

src/sys/unix/fdentry_impl.rs

@@ -1,5 +1,5 @@
 use crate::fdentry::Descriptor;
-use crate::sys::errno_from_host;
+use crate::sys::{errno_from_host, errno_from_ioerror};
 use crate::{host, Result};
 use std::io;
 use std::os::unix::prelude::{AsRawFd, FileTypeExt, FromRawFd, RawFd};
@@ -51,10 +51,7 @@ pub(crate) fn determine_type_rights<Fd: AsRawFd>(
         // we just make a `File` here for convenience; we don't want it to close when it drops
         let file =
             std::mem::ManuallyDrop::new(unsafe { std::fs::File::from_raw_fd(fd.as_raw_fd()) });
-        let ft = file
-            .metadata()
-            .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?
-            .file_type();
+        let ft = file.metadata().map_err(errno_from_ioerror)?.file_type();
         if ft.is_block_device() {
             (
                 host::__WASI_FILETYPE_BLOCK_DEVICE,

src/sys/unix/hostcalls_impl/fs.rs

@@ -6,7 +6,7 @@ use crate::fdentry::FdEntry;
 use crate::helpers::systemtime_to_timestamp;
 use crate::sys::fdentry_impl::determine_type_rights;
 use crate::sys::host_impl;
-use crate::sys::{errno_from_host, errno_from_ioerror};
+use crate::sys::{errno_from_ioerror};
 use crate::{host, wasm32, Result};
 use nix::libc::{self, c_long, c_void, off_t};
 use std::convert::TryInto;
@@ -20,13 +20,11 @@ pub(crate) fn fd_pread(
     buf: &mut [u8],
     offset: host::__wasi_filesize_t,
 ) -> Result<usize> {
-    file.read_at(buf, offset)
-        .map_err(|e| e.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    file.read_at(buf, offset).map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_pwrite(file: &File, buf: &[u8], offset: host::__wasi_filesize_t) -> Result<usize> {
-    file.write_at(buf, offset)
-        .map_err(|e| e.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    file.write_at(buf, offset).map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_fdstat_get(fd: &File) -> Result<host::__wasi_fdflags_t> {

src/sys/unix/hostcalls_impl/fs_helpers.rs

@@ -1,7 +1,7 @@
 #![allow(non_camel_case_types)]
 #![allow(unused_unsafe)]
 
-use crate::sys::errno_from_host;
+use crate::sys::errno_from_ioerror;
 use crate::sys::host_impl;
 use crate::{host, Result};
 use nix::libc::{self, c_long};
@@ -24,10 +24,7 @@ pub(crate) fn path_get(
         return Err(host::__WASI_EILSEQ);
     }
 
-    let dirfd = dirfd.try_clone().map_err(|err| {
-        err.raw_os_error()
-            .map_or(host::__WASI_EBADF, errno_from_host)
-    })?;
+    let dirfd = dirfd.try_clone().map_err(errno_from_ioerror)?;
 
     // Stack of directory file descriptors. Index 0 always corresponds with the directory provided
     // to this function. Entering a directory causes a file descriptor to be pushed, while handling

src/sys/unix/mod.rs

@@ -2,16 +2,15 @@ pub(crate) mod fdentry_impl;
 pub(crate) mod host_impl;
 pub(crate) mod hostcalls_impl;
 
-use crate::sys::errno_from_host;
-use crate::{host, Result};
+use crate::sys::errno_from_ioerror;
+use crate::Result;
 use std::fs::File;
 use std::path::Path;
 
 pub(crate) fn dev_null() -> Result<File> {
-    File::open("/dev/null")
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    File::open("/dev/null").map_err(errno_from_ioerror)
 }
 
 pub fn preopen_dir<P: AsRef<Path>>(path: P) -> Result<File> {
-    File::open(path).map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    File::open(path).map_err(errno_from_ioerror)
 }

src/sys/windows/hostcalls_impl/fs.rs

@@ -4,9 +4,9 @@ use super::fs_helpers::*;
 use crate::ctx::WasiCtx;
 use crate::fdentry::FdEntry;
 use crate::helpers::systemtime_to_timestamp;
-use crate::sys::{errno_from_ioerror, errno_from_host};
 use crate::sys::fdentry_impl::determine_type_rights;
 use crate::sys::host_impl;
+use crate::sys::{errno_from_host, errno_from_ioerror};
 use crate::{host, Result};
 use std::convert::TryInto;
 use std::fs::{File, Metadata};
@@ -39,13 +39,11 @@ pub(crate) fn fd_pread(
     buf: &mut [u8],
     offset: host::__wasi_filesize_t,
 ) -> Result<usize> {
-    read_at(file, buf, offset)
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    read_at(file, buf, offset).map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_pwrite(file: &File, buf: &[u8], offset: host::__wasi_filesize_t) -> Result<usize> {
-    write_at(file, buf, offset)
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    write_at(file, buf, offset).map_err(errno_from_ioerror)
 }
 
 pub(crate) fn fd_fdstat_get(fd: &File) -> Result<host::__wasi_fdflags_t> {

src/sys/windows/hostcalls_impl/fs_helpers.rs

@@ -1,7 +1,7 @@
 #![allow(non_camel_case_types)]
 #![allow(unused_unsafe)]
 
-use crate::sys::errno_from_host;
+use crate::sys::errno_from_ioerror;
 use crate::sys::host_impl;
 use crate::{host, Result};
 use std::fs::File;
@@ -20,10 +20,7 @@ pub(crate) fn path_get(
         return Err(host::__WASI_EILSEQ);
     }
 
-    let dirfd = dirfd.try_clone().map_err(|err| {
-        err.raw_os_error()
-            .map_or(host::__WASI_EBADF, errno_from_host)
-    })?;
+    let dirfd = dirfd.try_clone().map_err(errno_from_ioerror)?;
 
     // Stack of directory handles. Index 0 always corresponds with the directory provided
     // to this function. Entering a directory causes a handle to be pushed, while handling

src/sys/windows/mod.rs

@@ -2,13 +2,13 @@ pub(crate) mod fdentry_impl;
 pub(crate) mod host_impl;
 pub(crate) mod hostcalls_impl;
 
-use crate::sys::errno_from_host;
+use crate::sys::errno_from_ioerror;
 use crate::{host, Result};
 use std::fs::File;
 use std::path::Path;
 
 pub(crate) fn dev_null() -> Result<File> {
-    File::open("NUL").map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+    File::open("NUL").map_err(errno_from_ioerror)
 }
 
 pub fn preopen_dir<P: AsRef<Path>>(path: P) -> Result<File> {
@@ -25,5 +25,5 @@ pub fn preopen_dir<P: AsRef<Path>>(path: P) -> Result<File> {
         .read(true)
         .attributes(FILE_FLAG_BACKUP_SEMANTICS)
         .open(path)
-        .map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
+        .map_err(errno_from_ioerror)
 }