astrid-runtime/astrid · error

filesystem payload exceeds limit

Error message

filesystem payload exceeds limit

What it means

After decoding a Write payload, decode_operation_v2 checks its length against STORAGE_FILESYSTEM_MAX_IO_BYTES and rejects anything larger with this InvalidData error. This guards the kernel from a single callback frame demanding an oversized write I/O.

Solutions

1. Split large writes into chunks of at most STORAGE_FILESYSTEM_MAX_IO_BYTES before issuing Write operations
2. Check the file/blob size up front and use multiple sequential writes with offsets
3. Raise STORAGE_FILESYSTEM_MAX_IO_BYTES if your workload legitimately needs bigger single I/Os and you control both ends

Example fix

// before
fs.write(path, 0, &huge_blob)?;
// after
for (i, chunk) in huge_blob.chunks(STORAGE_FILESYSTEM_MAX_IO_BYTES as usize).enumerate() {
    fs.write(path, (i * STORAGE_FILESYSTEM_MAX_IO_BYTES as usize) as u64, chunk)?;
}

fn is_within_io_limit(data: &[u8]) -> bool {
    (data.len() as u64) <= STORAGE_FILESYSTEM_MAX_IO_BYTES
}
assert!(is_within_io_limit(&data), "split writes to <= STORAGE_FILESYSTEM_MAX_IO_BYTES");

match result {
    Err(e) if e.to_string() == "filesystem payload exceeds limit" => {
        eprintln!("write too large: chunk into <= {} byte writes", STORAGE_FILESYSTEM_MAX_IO_BYTES);
    }
    other => other?,
}

When it happens

Trigger: A StorageFilesystemOperationV1::Write whose decoded data length (data.len() saturating to u64::MAX) exceeds STORAGE_FILESYSTEM_MAX_IO_BYTES is submitted over the mount callback socket.

Common situations: A filesystem client performs a very large buffered write that the FUSE layer passes through unsplit; a batch tool streams a multi-GB blob in one write call; a malicious/buggy peer sends a huge payload.

Understand the failure class

Background: payload too large / request exceeds maximum size: why libraries cap bytes and how to fix oversize payloads — this error's family across 50 libraries.

Related errors

• mount callback response exceeds limit
• environment value for
• FUSE service launch exceeds limit
• mount callback frame exceeds limit
• mount callback response is too large

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/4aff61a9a69e72e0. Report an issue: GitHub.

Appendix: source

Thrown at crates/astrid-kernel/src/storage_mount.rs:647

            offset,
            length,
        },
        StorageFilesystemOperationV2::Write {
            path,
            offset,
            data_base64,
        } => {
            let data = base64::engine::general_purpose::STANDARD
                .decode(data_base64.as_bytes())
                .map_err(|error| {
                    io::Error::new(
                        io::ErrorKind::InvalidData,
                        format!("invalid base64 filesystem payload: {error}"),
                    )
                })?;
            let data_length = u64::try_from(data.len()).unwrap_or(u64::MAX);
            if data_length > STORAGE_FILESYSTEM_MAX_IO_BYTES {
                return Err(io::Error::new(
                    io::ErrorKind::InvalidData,
                    "filesystem payload exceeds limit",
                ));
            }
            StorageFilesystemOperationV1::Write { path, offset, data }
        },
        StorageFilesystemOperationV2::SetLength { path, length } => {
            StorageFilesystemOperationV1::SetLength { path, length }
        },
        StorageFilesystemOperationV2::Create { path, kind } => {
            StorageFilesystemOperationV1::Create { path, kind }
        },
        StorageFilesystemOperationV2::Remove { path } => {
            StorageFilesystemOperationV1::Remove { path }
        },
        StorageFilesystemOperationV2::Rename { from, to, replace } => {
            StorageFilesystemOperationV1::Rename { from, to, replace }
        },

View on GitHub (pinned to affd8760f4)