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Improve error messages for io::fs

This commit is contained in:
Yehuda Katz 2014-06-03 12:33:18 -07:00 committed by Alex Crichton
parent 2ed4734873
commit 298412a6e8
2 changed files with 244 additions and 64 deletions
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257
src/libstd/io/fs.rs
View File

@ -56,9 +56,9 @@ use io::{FilePermission, Write, UnstableFileStat, Open, FileAccess, FileMode};
use io::{IoResult, IoError, FileStat, SeekStyle, Seek, Writer, Reader};
use io::{Read, Truncate, SeekCur, SeekSet, ReadWrite, SeekEnd, Append};
use io;
use io;
use iter::Iterator;
use kinds::Send;
use libc;
use option::{Some, None, Option};
use owned::Box;
use path::{Path, GenericPath};
@ -138,7 +138,7 @@ impl File {
Write => rtio::Write,
ReadWrite => rtio::ReadWrite,
};
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_open(&path.to_c_str(), mode, access).map(|fd| {
File {
path: path.clone(),
@ -146,7 +146,11 @@ impl File {
last_nread: -1
}
})
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't open file", |e| {
format!("{}; path={}; mode={}; access={}", e, path.display(),
mode_string(mode), access_string(access))
})
}
/// Attempts to open a file in read-only mode. This function is equivalent to
@ -185,6 +189,7 @@ impl File {
/// ```
pub fn create(path: &Path) -> IoResult<File> {
File::open_mode(path, Truncate, Write)
.update_desc("couldn't create file")
}
/// Returns the original path which was used to open this file.
@ -196,7 +201,9 @@ impl File {
/// device. This will flush any internal buffers necessary to perform this
/// operation.
pub fn fsync(&mut self) -> IoResult<()> {
self.fd.fsync().map_err(IoError::from_rtio_error)
let err = self.fd.fsync().map_err(IoError::from_rtio_error);
err.update_err("couldn't fsync file",
|e| format!("{}; path={}", e, self.path.display()))
}
/// This function is similar to `fsync`, except that it may not synchronize
@ -204,7 +211,9 @@ impl File {
/// must synchronize content, but don't need the metadata on disk. The goal
/// of this method is to reduce disk operations.
pub fn datasync(&mut self) -> IoResult<()> {
self.fd.datasync().map_err(IoError::from_rtio_error)
let err = self.fd.datasync().map_err(IoError::from_rtio_error);
err.update_err("couldn't datasync file",
|e| format!("{}; path={}", e, self.path.display()))
}
/// Either truncates or extends the underlying file, updating the size of
@ -216,7 +225,10 @@ impl File {
/// will be extended to `size` and have all of the intermediate data filled
/// in with 0s.
pub fn truncate(&mut self, size: i64) -> IoResult<()> {
self.fd.truncate(size).map_err(IoError::from_rtio_error)
let err = self.fd.truncate(size).map_err(IoError::from_rtio_error);
err.update_err("couldn't truncate file", |e| {
format!("{}; path={}; size={}", e, self.path.display(), size)
})
}
/// Tests whether this stream has reached EOF.
@ -229,10 +241,12 @@ impl File {
/// Queries information about the underlying file.
pub fn stat(&mut self) -> IoResult<FileStat> {
match self.fd.fstat() {
let err = match self.fd.fstat() {
Ok(s) => Ok(from_rtio(s)),
Err(e) => Err(IoError::from_rtio_error(e)),
}
};
err.update_err("couldn't fstat file",
|e| format!("{}; path={}", e, self.path.display()))
}
}
@ -258,9 +272,11 @@ impl File {
/// user lacks permissions to remove the file, or if some other filesystem-level
/// error occurs.
pub fn unlink(path: &Path) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_unlink(&path.to_c_str())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't unlink path",
|e| format!("{}; path={}", e, path.display()))
}
/// Given a path, query the file system to get information about a file,
@ -285,10 +301,12 @@ pub fn unlink(path: &Path) -> IoResult<()> {
/// to perform a `stat` call on the given path or if there is no entry in the
/// filesystem at the provided path.
pub fn stat(path: &Path) -> IoResult<FileStat> {
match LocalIo::maybe_raise(|io| io.fs_stat(&path.to_c_str())) {
let err = match LocalIo::maybe_raise(|io| io.fs_stat(&path.to_c_str())) {
Ok(s) => Ok(from_rtio(s)),
Err(e) => Err(IoError::from_rtio_error(e)),
}
};
err.update_err("couldn't stat path",
|e| format!("{}; path={}", e, path.display()))
}
/// Perform the same operation as the `stat` function, except that this
@ -300,10 +318,12 @@ pub fn stat(path: &Path) -> IoResult<FileStat> {
///
/// See `stat`
pub fn lstat(path: &Path) -> IoResult<FileStat> {
match LocalIo::maybe_raise(|io| io.fs_lstat(&path.to_c_str())) {
let err = match LocalIo::maybe_raise(|io| io.fs_lstat(&path.to_c_str())) {
Ok(s) => Ok(from_rtio(s)),
Err(e) => Err(IoError::from_rtio_error(e)),
}
};
err.update_err("couldn't lstat path",
|e| format!("{}; path={}", e, path.display()))
}
fn from_rtio(s: rtio::FileStat) -> FileStat {
@ -359,9 +379,12 @@ fn from_rtio(s: rtio::FileStat) -> FileStat {
/// permissions to view the contents, or if some other intermittent I/O error
/// occurs.
pub fn rename(from: &Path, to: &Path) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_rename(&from.to_c_str(), &to.to_c_str())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't rename path", |e| {
format!("{}; from={}; to={}", e, from.display(), to.display())
})
}
/// Copies the contents of one file to another. This function will also
@ -393,12 +416,17 @@ pub fn rename(from: &Path, to: &Path) -> IoResult<()> {
/// ensured to not exist, there is nothing preventing the destination from
/// being created and then destroyed by this operation.
pub fn copy(from: &Path, to: &Path) -> IoResult<()> {
fn update_err<T>(result: IoResult<T>, from: &Path, to: &Path) -> IoResult<T> {
result.update_err("couldn't copy path",
|e| format!("{}; from={}; to={}", e, from.display(), to.display()))
}
if !from.is_file() {
return Err(IoError {
return update_err(Err(IoError {
kind: io::MismatchedFileTypeForOperation,
desc: "the source path is not an existing file",
detail: None,
})
detail: None
}), from, to)
}
let mut reader = try!(File::open(from));
@ -409,12 +437,12 @@ pub fn copy(from: &Path, to: &Path) -> IoResult<()> {
let amt = match reader.read(buf) {
Ok(n) => n,
Err(ref e) if e.kind == io::EndOfFile => { break }
Err(e) => return Err(e)
Err(e) => return update_err(Err(e), from, to)
};
try!(writer.write(buf.slice_to(amt)));
}
chmod(to, try!(from.stat()).perm)
chmod(to, try!(update_err(from.stat(), from, to)).perm)
}
/// Changes the permission mode bits found on a file or a directory. This
@ -439,33 +467,45 @@ pub fn copy(from: &Path, to: &Path) -> IoResult<()> {
/// Some possible error situations are not having the permission to
/// change the attributes of a file or the file not existing.
pub fn chmod(path: &Path, mode: io::FilePermission) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_chmod(&path.to_c_str(), mode.bits() as uint)
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't chmod path", |e| {
format!("{}; path={}; mode={}", e, path.display(), mode)
})
}
/// Change the user and group owners of a file at the specified path.
pub fn chown(path: &Path, uid: int, gid: int) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_chown(&path.to_c_str(), uid, gid)
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't chown path", |e| {
format!("{}; path={}; uid={}; gid={}", e, path.display(), uid, gid)
})
}
/// Creates a new hard link on the filesystem. The `dst` path will be a
/// link pointing to the `src` path. Note that systems often require these
/// two paths to both be located on the same filesystem.
pub fn link(src: &Path, dst: &Path) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_link(&src.to_c_str(), &dst.to_c_str())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't link path", |e| {
format!("{}; src={}; dest={}", e, src.display(), dst.display())
})
}
/// Creates a new symbolic link on the filesystem. The `dst` path will be a
/// symlink pointing to the `src` path.
pub fn symlink(src: &Path, dst: &Path) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_symlink(&src.to_c_str(), &dst.to_c_str())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't symlink path", |e| {
format!("{}; src={}; dest={}", e, src.display(), dst.display())
})
}
/// Reads a symlink, returning the file that the symlink points to.
@ -475,9 +515,11 @@ pub fn symlink(src: &Path, dst: &Path) -> IoResult<()> {
/// This function will return an error on failure. Failure conditions include
/// reading a file that does not exist or reading a file which is not a symlink.
pub fn readlink(path: &Path) -> IoResult<Path> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
Ok(Path::new(try!(io.fs_readlink(&path.to_c_str()))))
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't resolve symlink for path",
|e| format!("{}; path={}", e, path.display()))
}
/// Create a new, empty directory at the provided path
@ -498,9 +540,12 @@ pub fn readlink(path: &Path) -> IoResult<Path> {
/// This call will return an error if the user lacks permissions to make a new
/// directory at the provided path, or if the directory already exists.
pub fn mkdir(path: &Path, mode: FilePermission) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_mkdir(&path.to_c_str(), mode.bits() as uint)
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't create directory", |e| {
format!("{}; path={}; mode={}", e, path.display(), mode)
})
}
/// Remove an existing, empty directory
@ -520,9 +565,11 @@ pub fn mkdir(path: &Path, mode: FilePermission) -> IoResult<()> {
/// This call will return an error if the user lacks permissions to remove the
/// directory at the provided path, or if the directory isn't empty.
pub fn rmdir(path: &Path) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_rmdir(&path.to_c_str())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't remove directory",
|e| format!("{}; path={}", e, path.display()))
}
/// Retrieve a vector containing all entries within a provided directory
@ -557,11 +604,13 @@ pub fn rmdir(path: &Path) -> IoResult<()> {
/// permissions to view the contents or if the `path` points at a non-directory
/// file
pub fn readdir(path: &Path) -> IoResult<Vec<Path>> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
Ok(try!(io.fs_readdir(&path.to_c_str(), 0)).move_iter().map(|a| {
Path::new(a)
}).collect())
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't read directory",
|e| format!("{}; path={}", e, path.display()))
}
/// Returns an iterator which will recursively walk the directory structure
@ -569,7 +618,11 @@ pub fn readdir(path: &Path) -> IoResult<Vec<Path>> {
/// perform iteration in some top-down order. The contents of unreadable
/// subdirectories are ignored.
pub fn walk_dir(path: &Path) -> IoResult<Directories> {
Ok(Directories { stack: try!(readdir(path)) })
Ok(Directories {
stack: try!(readdir(path).update_err("couldn't walk directory",
|e| format!("{}; path={}",
e, path.display())))
})
}
/// An iterator which walks over a directory
@ -582,7 +635,12 @@ impl Iterator<Path> for Directories {
match self.stack.pop() {
Some(path) => {
if path.is_dir() {
match readdir(&path) {
let result = readdir(&path)
.update_err("couldn't advance Directories iterator",
|e| format!("{}; path={}",
e, path.display()));
match result {
Ok(dirs) => { self.stack.push_all_move(dirs); }
Err(..) => {}
}
@ -614,7 +672,11 @@ pub fn mkdir_recursive(path: &Path, mode: FilePermission) -> IoResult<()> {
for c in comps {
curpath.push(c);
match mkdir(&curpath, mode) {
let result = mkdir(&curpath, mode)
.update_err("couldn't recursively mkdir",
|e| format!("{}; path={}", e, path.display()));
match result {
Err(mkdir_err) => {
// already exists ?
if try!(stat(&curpath)).kind != io::TypeDirectory {
@ -639,8 +701,20 @@ pub fn rmdir_recursive(path: &Path) -> IoResult<()> {
let mut rm_stack = Vec::new();
rm_stack.push(path.clone());
fn rmdir_failed(err: &IoError, path: &Path) -> String {
format!("rmdir_recursive failed; path={}; cause={}",
path.display(), err)
}
fn update_err<T>(err: IoResult<T>, path: &Path) -> IoResult<T> {
err.update_err("couldn't recursively rmdir",
|e| rmdir_failed(e, path))
}
while !rm_stack.is_empty() {
let children = try!(readdir(rm_stack.last().unwrap()));
let children = try!(readdir(rm_stack.last().unwrap())
.update_detail(|e| rmdir_failed(e, path)));
let mut has_child_dir = false;
// delete all regular files in the way and push subdirs
@ -648,17 +722,17 @@ pub fn rmdir_recursive(path: &Path) -> IoResult<()> {
for child in children.move_iter() {
// FIXME(#12795) we should use lstat in all cases
let child_type = match cfg!(windows) {
true => try!(stat(&child)).kind,
false => try!(lstat(&child)).kind
true => try!(update_err(stat(&child), path)),
false => try!(update_err(lstat(&child), path))
};
if child_type == io::TypeDirectory {
if child_type.kind == io::TypeDirectory {
rm_stack.push(child);
has_child_dir = true;
} else {
// we can carry on safely if the file is already gone
// (eg: deleted by someone else since readdir)
match unlink(&child) {
match update_err(unlink(&child), path) {
Ok(()) => (),
Err(ref e) if e.kind == io::FileNotFound => (),
Err(e) => return Err(e)
@ -668,7 +742,8 @@ pub fn rmdir_recursive(path: &Path) -> IoResult<()> {
// if no subdir was found, let's pop and delete
if !has_child_dir {
match rmdir(&rm_stack.pop().unwrap()) {
let result = update_err(rmdir(&rm_stack.pop().unwrap()), path);
match result {
Ok(()) => (),
Err(ref e) if e.kind == io::FileNotFound => (),
Err(e) => return Err(e)
@ -685,18 +760,28 @@ pub fn rmdir_recursive(path: &Path) -> IoResult<()> {
/// be in milliseconds.
// FIXME(#10301) these arguments should not be u64
pub fn change_file_times(path: &Path, atime: u64, mtime: u64) -> IoResult<()> {
LocalIo::maybe_raise(|io| {
let err = LocalIo::maybe_raise(|io| {
io.fs_utime(&path.to_c_str(), atime, mtime)
}).map_err(IoError::from_rtio_error)
}).map_err(IoError::from_rtio_error);
err.update_err("couldn't change_file_times",
|e| format!("{}; path={}", e, path.display()))
}
impl Reader for File {
fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
match self.fd.read(buf) {
fn update_err<T>(result: IoResult<T>, file: &File) -> IoResult<T> {
result.update_err("couldn't read file",
|e| format!("{}; path={}",
e, file.path.display()))
}
let result: IoResult<int> = update_err(self.fd.read(buf), self);
match result {
Ok(read) => {
self.last_nread = read;
match read {
0 => Err(io::standard_error(io::EndOfFile)),
0 => update_err(Err(standard_error(io::EndOfFile)), self),
_ => Ok(read as uint)
}
},
@ -707,13 +792,17 @@ impl Reader for File {
impl Writer for File {
fn write(&mut self, buf: &[u8]) -> IoResult<()> {
self.fd.write(buf).map_err(IoError::from_rtio_error)
let err = self.fd.write(buf).map_err(IoError::from_rtio_error)
err.update_err("couldn't write to file",
|e| format!("{}; path={}", e, self.path.display()))
}
}
impl Seek for File {
fn tell(&self) -> IoResult<u64> {
self.fd.tell().map_err(IoError::from_rtio_error)
let err = self.fd.tell().map_err(IoError::from_rtio_error);
err.update_err("couldn't retrieve file cursor (`tell`)",
|e| format!("{}; path={}", e, self.path.display()))
}
fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
@ -722,14 +811,16 @@ impl Seek for File {
SeekCur => rtio::SeekCur,
SeekEnd => rtio::SeekEnd,
};
match self.fd.seek(pos, style) {
let err = match self.fd.seek(pos, style) {
Ok(_) => {
// successful seek resets EOF indicator
self.last_nread = -1;
Ok(())
}
Err(e) => Err(IoError::from_rtio_error(e)),
}
};
err.update_err("couldn't seek in file",
|e| format!("{}; path={}", e, self.path.display()))
}
}
@ -779,6 +870,22 @@ impl path::Path {
}
}
fn mode_string(mode: FileMode) -> &'static str {
match mode {
super::Open => "open",
super::Append => "append",
super::Truncate => "truncate"
}
}
fn access_string(access: FileAccess) -> &'static str {
match access {
super::Read => "read",
super::Write => "write",
super::ReadWrite => "readwrite"
}
}
#[cfg(test)]
#[allow(unused_imports)]
mod test {
@ -801,6 +908,14 @@ mod test {
}
) )
macro_rules! error( ($e:expr, $s:expr) => (
match $e {
Ok(val) => fail!("Should have been an error, was {:?}", val),
Err(ref err) => assert!(err.to_str().as_slice().contains($s.as_slice()),
format!("`{}` did not contain `{}`", err, $s))
}
) )
struct TempDir(Path);
impl TempDir {
@ -856,13 +971,21 @@ mod test {
let tmpdir = tmpdir();
let filename = &tmpdir.join("file_that_does_not_exist.txt");
let result = File::open_mode(filename, Open, Read);
assert!(result.is_err());
error!(result, "couldn't open file");
error!(result, "no such file or directory");
error!(result, format!("path={}; mode=open; access=read", filename.display()));
})
iotest!(fn file_test_iounlinking_invalid_path_should_raise_condition() {
let tmpdir = tmpdir();
let filename = &tmpdir.join("file_another_file_that_does_not_exist.txt");
assert!(unlink(filename).is_err());
let result = unlink(filename);
error!(result, "couldn't unlink path");
error!(result, "no such file or directory");
error!(result, format!("path={}", filename.display()));
})
iotest!(fn file_test_io_non_positional_read() {
@ -1091,6 +1214,22 @@ mod test {
assert!(dir.is_dir())
})
iotest!(fn recursive_mkdir_failure() {
let tmpdir = tmpdir();
let dir = tmpdir.join("d1");
let file = dir.join("f1");
check!(mkdir_recursive(&dir, io::UserRWX));
check!(File::create(&file));
let result = mkdir_recursive(&file, io::UserRWX);
error!(result, "couldn't recursively mkdir");
error!(result, "couldn't create directory");
error!(result, "mode=FilePermission { bits: 448 }");
error!(result, format!("path={}", file.display()));
})
iotest!(fn recursive_mkdir_slash() {
check!(mkdir_recursive(&Path::new("/"), io::UserRWX));
})
@ -1147,6 +1286,12 @@ mod test {
iotest!(fn copy_file_does_not_exist() {
let from = Path::new("test/nonexistent-bogus-path");
let to = Path::new("test/other-bogus-path");
error!(copy(&from, &to),
format!("couldn't copy path (the source path is not an \
existing file; from={}; to={})",
from.display(), to.display()));
match copy(&from, &to) {
Ok(..) => fail!(),
Err(..) => {

51
src/libstd/io/mod.rs
View File

@ -232,7 +232,7 @@ use owned::Box;
use result::{Ok, Err, Result};
use rt::rtio;
use slice::{Vector, MutableVector, ImmutableVector};
use str::{StrSlice, StrAllocating};
use str::{Str, StrSlice, StrAllocating};
use str;
use string::String;
use uint;
@ -309,6 +309,7 @@ impl IoError {
/// struct is filled with an allocated string describing the error
/// in more detail, retrieved from the operating system.
pub fn from_errno(errno: uint, detail: bool) -> IoError {
#[cfg(windows)]
fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
match errno {
@ -388,8 +389,8 @@ impl IoError {
IoError {
kind: kind,
desc: desc,
detail: if detail {
Some(os::error_string(errno))
detail: if detail && kind == OtherIoError {
Some(os::error_string(errno).as_slice().chars().map(|c| c.to_lowercase()).collect())
} else {
None
},
@ -420,10 +421,13 @@ impl IoError {
impl fmt::Show for IoError {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
try!(write!(fmt, "{}", self.desc));
match self.detail {
Some(ref s) => write!(fmt, " ({})", *s),
None => Ok(())
match *self {
IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
write!(fmt, "{}", detail),
IoError { detail: None, desc, .. } =>
write!(fmt, "{}", desc),
IoError { detail: Some(ref detail), desc, .. } =>
write!(fmt, "{} ({})", desc, detail)
}
}
}
@ -484,6 +488,37 @@ pub enum IoErrorKind {
NoProgress,
}
/// A trait that lets you add a `detail` to an IoError easily
trait UpdateIoError<T> {
/// Returns an IoError with updated description and detail
fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> Self;
/// Returns an IoError with updated detail
fn update_detail(self, detail: |&IoError| -> String) -> Self;
/// Returns an IoError with update description
fn update_desc(self, desc: &'static str) -> Self;
}
impl<T> UpdateIoError<T> for IoResult<T> {
fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> IoResult<T> {
self.map_err(|mut e| {
let detail = detail(&e);
e.desc = desc;
e.detail = Some(detail);
e
})
}
fn update_detail(self, detail: |&IoError| -> String) -> IoResult<T> {
self.map_err(|mut e| { e.detail = Some(detail(&e)); e })
}
fn update_desc(self, desc: &'static str) -> IoResult<T> {
self.map_err(|mut e| { e.desc = desc; e })
}
}
static NO_PROGRESS_LIMIT: uint = 1000;
/// A trait for objects which are byte-oriented streams. Readers are defined by
@ -1577,7 +1612,7 @@ pub fn standard_error(kind: IoErrorKind) -> IoError {
ConnectionAborted => "connection aborted",
NotConnected => "not connected",
BrokenPipe => "broken pipe",
PathAlreadyExists => "file exists",
PathAlreadyExists => "file already exists",
PathDoesntExist => "no such file",
MismatchedFileTypeForOperation => "mismatched file type",
ResourceUnavailable => "resource unavailable",