| Submitter | Scott Garman |
|---|---|
| Date | March 23, 2012, 4:43 a.m. |
| Message ID | <cover.1332453478.git.scott.a.garman@intel.com> |
| Download | mbox |
| Permalink | /patch/24239/ |
| State | New |
| Headers | show |
Pull-request
git://git.pokylinux.org/poky-contrib sgarman/useradd-lock-fix-oeComments
On Thu, 2012-03-22 at 21:43 -0700, Scott Garman wrote: > Hello, > > This pull request fixes two race conditions related to the useradd code. > > Yocto bug #2127 describes how when using the RPM package manager, the > order of package installation during generatin of the rootfs did not > guarantee that base-passwd and shadow would be installed before other > packages which need to install custom users/groups in their postinstall > functions. This fix ensures that when base-passwd and/or shadow are > part of an image, they will be installed first during image generation. > > The second race condition is described in Yocto bug #1794, and can occur > if two build steps try to update the sysroot passwd/group files at the > same time. Since the shadow utilities enforce file locking, the commands > will fail to run. The fix for this involves checking for failure and > retrying the commands up to 10 times, with a 1s delay between attempts > before giving up. > > Verifying these fixes involved creating numerous images and useradd-based > packages repeatedly on a build host with high parallelism, and also doing > so from a pre-populated sstate-cache. I was able to reliably simulate the > file locking behavior by making the passwd/group files read only when > developing the fix for #1794. > > Scott > > The following changes since commit 87e581bb7da9f1530d190cd023fcf892c8b858f5: > > ddimage: Add script for writing images to boot media (2012-03-22 19:17:54 +0000) > > are available in the git repository at: > git://git.pokylinux.org/poky-contrib sgarman/useradd-lock-fix-oe > http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=sgarman/useradd-lock-fix-oe > > Scott Garman (2): > package_rpm.bbclass: ensure base-passwd and shadow get installed > first > useradd.bbclass: retry useradd/groupadd commands to avoid lock race > issues Merged to master, thanks! Richard
Hello, This pull request fixes two race conditions related to the useradd code. Yocto bug #2127 describes how when using the RPM package manager, the order of package installation during generatin of the rootfs did not guarantee that base-passwd and shadow would be installed before other packages which need to install custom users/groups in their postinstall functions. This fix ensures that when base-passwd and/or shadow are part of an image, they will be installed first during image generation. The second race condition is described in Yocto bug #1794, and can occur if two build steps try to update the sysroot passwd/group files at the same time. Since the shadow utilities enforce file locking, the commands will fail to run. The fix for this involves checking for failure and retrying the commands up to 10 times, with a 1s delay between attempts before giving up. Verifying these fixes involved creating numerous images and useradd-based packages repeatedly on a build host with high parallelism, and also doing so from a pre-populated sstate-cache. I was able to reliably simulate the file locking behavior by making the passwd/group files read only when developing the fix for #1794. Scott The following changes since commit 87e581bb7da9f1530d190cd023fcf892c8b858f5: ddimage: Add script for writing images to boot media (2012-03-22 19:17:54 +0000) are available in the git repository at: git://git.pokylinux.org/poky-contrib sgarman/useradd-lock-fix-oe http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=sgarman/useradd-lock-fix-oe Scott Garman (2): package_rpm.bbclass: ensure base-passwd and shadow get installed first useradd.bbclass: retry useradd/groupadd commands to avoid lock race issues meta/classes/package_rpm.bbclass | 9 ++++++++- meta/classes/useradd.bbclass | 36 ++++++++++++++++++++++++++++++++++-- 2 files changed, 42 insertions(+), 3 deletions(-)