catar/encoder.rs: improve error handling

This commit is contained in:
Dietmar Maurer 2018-12-28 07:45:15 +01:00
parent 0ff559990c
commit d2b03f2397
1 changed files with 43 additions and 19 deletions

View File

@ -6,19 +6,21 @@ use std::io::Write;
use std::os::unix::io::AsRawFd;
use std::os::unix::ffi::OsStrExt;
use std::os::unix::io::RawFd;
use std::path::{Path, PathBuf};
use nix::fcntl::OFlag;
use nix::sys::stat::Mode;
use nix::errno::Errno;
pub struct CaTarEncoder<W: Write> {
current_path: std::path::PathBuf, // used for error reporting
current_path: PathBuf, // used for error reporting
writer: W,
size: usize,
}
impl <W: Write> CaTarEncoder<W> {
pub fn encode(path: std::path::PathBuf, dir: &mut nix::dir::Dir, writer: W) -> Result<(), Error> {
pub fn encode(path: PathBuf, dir: &mut nix::dir::Dir, writer: W) -> Result<(), Error> {
let mut me = Self {
current_path: path,
writer: writer,
@ -32,6 +34,8 @@ impl <W: Write> CaTarEncoder<W> {
Ok(())
}
//fn report_vanished
fn encode_dir(&mut self, dir: &mut nix::dir::Dir) -> Result<(), Error> {
println!("encode_dir: {:?}", self.current_path);
@ -48,7 +52,7 @@ impl <W: Write> CaTarEncoder<W> {
for entry in dir.iter() {
let entry = match entry {
Ok(entry) => entry,
Err(err) => bail!("readir failed - {}", err),
Err(err) => bail!("readir {:?} failed - {}", self.current_path, err),
};
let filename = entry.file_name().to_owned();
@ -57,34 +61,44 @@ impl <W: Write> CaTarEncoder<W> {
if name_len == 2 && name[0] == b'.' && name[1] == 0u8 { continue; }
if name_len == 3 && name[0] == b'.' && name[1] == b'.' && name[2] == 0u8 { continue; }
if let Ok(stat) = nix::sys::stat::fstatat(rawfd, filename.as_ref(), nix::fcntl::AtFlags::AT_SYMLINK_NOFOLLOW) {
//println!("Found {:?}", filename);
name_list.push((filename, stat));
} else {
bail!("fsstat failed");
match nix::sys::stat::fstatat(rawfd, filename.as_ref(), nix::fcntl::AtFlags::AT_SYMLINK_NOFOLLOW) {
Ok(stat) => {
name_list.push((filename, stat));
}
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("fstat {:?} failed - {}", self.current_path, err),
}
}
name_list.sort_unstable_by(|a, b| a.0.cmp(&b.0));
for (filename, stat) in name_list {
//println!("SORTED {:?}", filename);
self.current_path.push(std::ffi::OsStr::from_bytes(filename.as_bytes()));
if (stat.st_mode & libc::S_IFMT) == libc::S_IFDIR {
let mut dir = nix::dir::Dir::openat(
rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty())?;
self.encode_dir(&mut dir)?;
match nix::dir::Dir::openat(rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty()) {
Ok(mut dir) => self.encode_dir(&mut dir)?,
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("open dir {:?} failed - {}", self.current_path, err),
}
} else if (stat.st_mode & libc::S_IFMT) == libc::S_IFREG {
let filefd = nix::fcntl::openat(rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty())?;
self.encode_file(filefd)?;
let _ = nix::unistd::close(filefd); // ignore close errors
match nix::fcntl::openat(rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty()) {
Ok(filefd) => {
let res = self.encode_file(filefd);
let _ = nix::unistd::close(filefd); // ignore close errors
res?;
}
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("open file {:?} failed - {}", self.current_path, err),
}
} else if (stat.st_mode & libc::S_IFMT) == libc::S_IFLNK {
let mut buffer = [0u8; libc::PATH_MAX as usize];
let target = nix::fcntl::readlinkat(rawfd, filename.as_ref(), &mut buffer)?;
self.encode_symlink(&target)?;
match nix::fcntl::readlinkat(rawfd, filename.as_ref(), &mut buffer) {
Ok(target) => self.encode_symlink(&target)?,
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("readlink {:?} failed - {}", self.current_path, err),
}
} else {
bail!("unsupported file type (mode {:o} {:?})", stat.st_mode, self.current_path);
}
@ -108,4 +122,14 @@ impl <W: Write> CaTarEncoder<W> {
Ok(())
}
// the report_XXX method may raise and error - depending on encoder configuration
fn report_vanished_file(&self, path: &Path) -> Result<(), Error> {
eprintln!("WARNING: detected vanished file {:?}", path);
Ok(())
}
}