Internal dd Error: Seek amount greater than signed 64-bit in

Error message

Internal dd Error: Seek amount greater than signed 64-bit integer

What it means

Error "Internal dd Error: Seek amount greater than signed 64-bit integer" thrown in uutils/coreutils.

Source

Thrown at src/uu/dd/src/dd.rs:747

}

/// Decide whether the given buffer is all zeros.
fn is_sparse(buf: &[u8]) -> bool {
    buf.iter().all(|&e| e == 0u8)
}

/// Handle O_DIRECT write errors by temporarily removing the flag and retrying.
/// This follows GNU dd behavior for partial block writes with O_DIRECT.
#[cfg(any(target_os = "linux", target_os = "android"))]
fn handle_o_direct_write(f: &mut File, buf: &[u8], original_error: io::Error) -> io::Result<usize> {
    use rustix::fs::{OFlags, fcntl_getfl, fcntl_setfl};

    // Get current flags
    let Ok(oflags) = fcntl_getfl(&*f) else {
        return Err(original_error);
    };

    // If O_DIRECT is set, try removing it temporarily
    if oflags.contains(OFlags::DIRECT) {
        let flags_without_direct = oflags & !OFlags::DIRECT;

        // Remove O_DIRECT flag
        fcntl_setfl(&*f, flags_without_direct).map_err(|_| original_error)?;

        // Retry the write without O_DIRECT
        let write_result = f.write(buf);

        // Restore O_DIRECT flag (GNU doesn't restore it, but we'll be safer)
        // Log any restoration errors without failing the operation
        if let Err(e) = fcntl_setfl(&*f, oflags).map_err(io::Error::from) {
            // Just log the error, don't fail the whole operation
            show_error!("Failed to restore O_DIRECT flag: {e}");
        }

        write_result
    } else {

View on GitHub (pinned to 9ff4114e82)

Solutions

Use seek/skip values that fit in a signed 64-bit integer.
Split very large offsets into multiple smaller seek operations.

When it happens

Trigger: Occurs when dd computes a seek amount exceeding the range of a signed 64-bit integer.

Common situations: Using enormous seek/skip values multiplied by a large block size, overflowing i64.

AI-assisted analysis of uutils/coreutils@9ff4114e82 (2026-08-19). Data as JSON: /api/errors/1b30064e48005451. Report an issue: GitHub.