fs.move fails with chmod error when disk under heavy use

Using fs-extra v2.0.0 I noticed that fs.move, which uses /lib/copy/ncp under the hood, fails with a chmod error when the disk is under heavy use.

{ Error: ENOENT: no such file or directory, chmod '/the/path-a/file'
  errno: -2,
  code: 'ENOENT',
  syscall: 'chmod',
  path: '/the/path-b/file' }

In this case I’m moving a very large directory of a few files. I’m using pify on fs.move:

const binary = (func) => (a, b) => func(a, b)
const move = binary(pify(fs.move))
// ...
move('/the/path-a', '/the/path-b')

With this error on the move operation what ends up happening is that path-a will still exist with one or so of its files left but path-b is created and contains all files (at least it contains a copy of the file remaining in path-a).

Related to #326. \cc @nicks.

[RyanZim]

@jdalton fs-extra uses fs.rename when possible, if that’s not possible it uses ncp and deletes the source.

@manidlou We don’t use node-mv as a dependency; lib/move/index.js is a fork of node-mv.

@jdalton We don’t want to shell out to mv for a few reasons:

• child_process is kinda slow
• It introduces additional cross-platform issues
• Shelling out is a security issue; without some kind of escaping, malicious filenames could possibly call arbitrary commands on the shell.

[jprichardson]

@jdalton thanks for checking back to let us know!! Much appreciated.