fs.copyFile fails if source is readonly and target is a CIFS volume

Version

v22.21.1

Platform

Linux a7f6d3be6434 5.15.158-2-pve #1 SMP PVE 5.15.158-2 (2024-07-26T13:11Z) x86_64 Linux

Docker: Alpine release 3.22.2

Subsystem

fs

What steps will reproduce the bug?

Hi,

Copying sample.docx fails with EPERM because the source is read-only and the destination is a CIFS share.

Probably related to:

https://github.com/nodejs/node/issues/37284
https://github.com/libuv/libuv/issues/3117
https://github.com/nodejs/node/issues/44261

How often does it reproduce? Is there a required condition?

100% reproducible

What is the expected behavior? Why is that the expected behavior?

/mnt/smb is a CIFS-mounted volume.
sample.docx is a file with read-only permissions for the user running the below code.

Code

import {copyFile} from "fs/promises";

const src = "./sample.docx";
const dest = "/mnt/smb/sample.docx";

await copyFile(src, dest);

console.log("File copied successfully");

The fs.copyFile should be able to succeed in copying the file as long as the destination folder is writable.

What do you see instead?

Error

node:internal/modules/run_main:123
    triggerUncaughtException(
    ^
[Error: EPERM: operation not permitted, copyfile './sample.docx' -> '/mnt/smb/sample.docx'] {
  errno: -1,
  code: 'EPERM',
  syscall: 'copyfile',
  path: './sample.docx',
  dest: '/mnt/smb/sample.docx'
}

Additional information

Works with no error

cp ./sample.docx /mnt/smb/sample.docx

Start at the fs/promises copyFile entry point and reproduce the failure on Linux with a read-only source and writable CIFS destination. Compare Node’s behavior with cp, then read the linked Node.js and libuv issues. Done means copyFile succeeds under the stated permissions without the reported EPERM error.