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fix(libfuse): fix flags in ReplyOpen & fix set_creds logic #250

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Merged
merged 1 commit into from
Nov 5, 2025
+52 −11
Merged

fix(libfuse): fix flags in ReplyOpen & fix set_creds logic #250

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11 changes: 11 additions & 0 deletions project/libfuse-fs/examples/overlay.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -111,6 +111,17 @@ async fn main() -> Result<(), std::io::Error> {

set_log(&args);

let file = std::fs::OpenOptions::new()
.create(true)
.write(true)
.truncate(true)
.open("/tmp/overlayfs.log")?;
use std::os::unix::io::AsRawFd;
unsafe {
libc::dup2(file.as_raw_fd(), libc::STDOUT_FILENO);
libc::dup2(file.as_raw_fd(), libc::STDERR_FILENO);
}

let mut mount_handle = libfuse_fs::overlayfs::mount_fs(OverlayArgs {
name: Some(args.name),
mountpoint: args.mountpoint,
Expand Down
2 changes: 1 addition & 1 deletion project/libfuse-fs/examples/overlayfs_example.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ struct Args {
#[arg(long)]
lowerdir: Vec<String>,
/// Use privileged mount instead of unprivileged (default false)
#[arg(long, default_value_t = true)]
#[arg(long, default_value_t = false)]
privileged: bool,
/// Options, currently contains uid/gid mapping info
#[arg(long, short)]
Expand Down
11 changes: 9 additions & 2 deletions project/libfuse-fs/src/overlayfs/async_io.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -366,11 +366,18 @@ impl Filesystem for OverlayFs {

self.handles.lock().await.insert(hd, Arc::new(handle_data));

let mut opts = OpenOptions::empty();
match self.config.cache_policy {
CachePolicy::Never => opts |= OpenOptions::DIRECT_IO,
CachePolicy::Always => opts |= OpenOptions::KEEP_CACHE,
_ => {}
}

trace!("OPEN: returning handle: {hd}");

Ok(ReplyOpen {
fh: hd,
flags: flags as u32,
flags: opts.bits(),
})
}

Expand Down Expand Up @@ -837,8 +844,8 @@ impl Filesystem for OverlayFs {
let mut opts = OpenOptions::empty();
match self.config.cache_policy {
CachePolicy::Never => opts |= OpenOptions::DIRECT_IO,
CachePolicy::Auto => opts |= OpenOptions::DIRECT_IO,
CachePolicy::Always => opts |= OpenOptions::KEEP_CACHE,
_ => {}
}

Ok(ReplyCreated {
Expand Down
39 changes: 31 additions & 8 deletions project/libfuse-fs/src/passthrough/async_io.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -491,6 +491,7 @@ impl<S: BitmapSlice + Send + Sync> PassthroughFs<S> {
uid.unwrap_or(self.cfg.mapping.get_uid(req.uid)),
gid.unwrap_or(self.cfg.mapping.get_gid(req.gid)),
)?;
// Maybe buggy because `open_file` may call `open_by_handle_at`, which requires CAP_DAC_READ_SEARCH.
data.open_file(final_flags, &self.proc_self_fd)?
}
}
Expand Down Expand Up @@ -560,14 +561,14 @@ impl<S: BitmapSlice + Send + Sync> PassthroughFs<S> {
self.validate_path_component(name)?;

let data = self.inode_map.get(parent).await?;
let file = data.get_file()?;

let res = {
let _guard = set_creds(
uid.unwrap_or(self.cfg.mapping.get_uid(req.uid)),
gid.unwrap_or(self.cfg.mapping.get_gid(req.gid)),
)?;

let file = data.get_file()?;
// Safe because this doesn't modify any memory and we check the return value.
unsafe { libc::mkdirat(file.as_raw_fd(), name.as_ptr(), mode & !umask) }
};
Expand Down Expand Up @@ -617,14 +618,14 @@ impl<S: BitmapSlice + Send + Sync> PassthroughFs<S> {
self.validate_path_component(name)?;

let data = self.inode_map.get(parent).await?;
let file = data.get_file()?;

let res = {
let _guard = set_creds(
uid.unwrap_or(self.cfg.mapping.get_uid(req.uid)),
gid.unwrap_or(self.cfg.mapping.get_gid(req.gid)),
)?;

let file = data.get_file()?;
// Safe because this doesn't modify any memory and we check the return value.
unsafe { libc::symlinkat(link.as_ptr(), file.as_raw_fd(), name.as_ptr()) }
};
Expand Down Expand Up @@ -1097,8 +1098,14 @@ impl Filesystem for PassthroughFs {
buf.truncate(bytes_read); // Adjust the buffer size
}
} else {
error!("read error: {ret}");
return Err(Errno::from(ret as i32));
let e = io::Error::last_os_error();
// if e.raw_os_error() == Some(libc::EINVAL) {
// // Handle EINVAL for sparse files by returning zeroed data
// buf.clear();
// } else {
error!("read error: {e:?}");
return Err(Errno::from(e.raw_os_error().unwrap_or(-1)));
// }
}
}
}
Expand Down Expand Up @@ -1145,6 +1152,17 @@ impl Filesystem for PassthroughFs {
let size = data.len();

self.check_fd_flags(&handle_data, raw_fd, flags).await?;
// // Debug for O_DIRECT alignment issues
// if (flags & libc::O_DIRECT as u32) != 0 {
// let block_size = 512;
// debug!(
// "Alignment check (block_size={}): offset_ok={}, len_ok={}, addr_ok={}",
// block_size,
// offset % block_size as u64 == 0,
// size % block_size == 0,
// (data.as_ptr() as usize) % block_size == 0
// );
// }
let ret = unsafe {
libc::pwrite(
raw_fd as c_int,
Expand All @@ -1156,8 +1174,9 @@ impl Filesystem for PassthroughFs {
if ret >= 0 {
ret
} else {
error!("write error: {ret}");
return Err(Errno::from(ret as i32));
let e = io::Error::last_os_error();
error!("write error: {e:?}");
return Err(Errno::from(e.raw_os_error().unwrap_or(-1)));
}
}
};
Expand Down Expand Up @@ -1313,7 +1332,9 @@ impl Filesystem for PassthroughFs {
)
};
if res < 0 {
return Err(io::Error::last_os_error().into());
let e = io::Error::last_os_error();
// error!("getxattr error: {e:?}");
return Err(e.into());
}

if size == 0 {
Expand Down Expand Up @@ -1351,7 +1372,9 @@ impl Filesystem for PassthroughFs {
)
};
if res < 0 {
return Err(io::Error::last_os_error().into());
let e = io::Error::last_os_error();
// error!("listxattr error: {e:?}");
return Err(e.into());
}

if size == 0 {
Expand Down
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