Bug 449838

Summary:	sys-apps/coreutils: multiple invocations of 'cp' may suffer a race condition creating directories
Product:	Gentoo Linux	Reporter:	Michał Górny <mgorny>
Component:	[OLD] Core system	Assignee:	Gentoo's Team for Core System packages <base-system>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	http://lists.gnu.org/archive/html/bug-coreutils/2013-01/msg00002.html
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	449760

Description Michał Górny archtester

2013-01-02 22:02:09 UTC

Bug 449760 states a semi-random issue of:

  cp: cannot create directory ‘/var/tmp/portage/dev-python/pyxattr-0.5.1/image/usr’: File exists

which most likely means that copying multiple trees into the same location suffers a race condition when creating necessary directories.

AFAICS, make_dir_parents_private() does fail on every mkdir() failure:

  if (mkdir (dir, mkdir_mode) != 0)
    {
      error (0, errno, _("cannot make directory %s"),
             quote (dir));
      return false;
    }

In this case, it'd be probably enough if it checked for EEXIST and restat()-ed the directory instead. Or just ignored the error and tried to copy/mkdir more waiting for ENOTDIR.

Comment 1 SpanKY gentoo-dev

2013-01-04 01:58:19 UTC

pretty sure it's been this way forever.  not sure if it should bother with stating and forcing the mode bits to the expected if someone is doing things in parallel.  make that the user's problem.

Comment 2 SpanKY gentoo-dev

2013-01-11 06:21:30 UTC

should be all set now in the tree; thanks for the report!

Commit message: Fix parallel recursive cp errors w/mkdir
http://sources.gentoo.org/gentoo/src/patchsets/coreutils/8.20/040_all_coreutils-cp-mkdir-eexist.patch?rev=1.1
http://sources.gentoo.org/sys-apps/coreutils/coreutils-8.20-r2.ebuild?rev=1.1