ostree/man/ostree-checkout.xml
Colin Walters 558720e7aa checkout: Don't hardlink zero sized files
Alternative to https://github.com/ostreedev/ostree/pull/2197

Python's (usually) zero-sized `__init__.py` files can provoke
us hitting the hardlink limits on some filesystems (`EMLINK`).
At least one Fedora rpm-ostree user hit this.

The benefits of hardlinking here are quite marginal; lots
of hardlinks can behave suboptimally in particular filesystems
like BTRFS too.

This builds on prior code which made this an option, introduced
in 673cacd633
Now we just do it uncondtionally.

Also this provoked a different bug in a very obscure user mode checkout
case; when the "real" permissions were different from the "physical"
permissions, we would still hardlink.  Fix the test case for this.
2020-10-01 16:47:07 -04:00

218 lines
7.3 KiB
XML

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
Copyright 2014 Anne LoVerso <anne.loverso@students.olin.edu>
SPDX-License-Identifier: LGPL-2.0+
This library is free software; you can redistribute it and/or
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
-->
<refentry id="ostree">
<refentryinfo>
<title>ostree checkout</title>
<productname>OSTree</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Colin</firstname>
<surname>Walters</surname>
<email>walters@verbum.org</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>ostree checkout</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>ostree-checkout</refname>
<refpurpose>Check out a commit into a filesystem</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>ostree checkout</command> <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMIT</arg> <arg choice="opt">DESTINATION</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
Checks out the given commit into the filesystem under directory DESTINATION. If DESTINATION is not specified, the COMMIT will become the destination checkout target. If COMMIT destination already exists, command will error unless <option>--union</option> option is selected.
</para>
</refsect1>
<refsect1>
<title>Options</title>
<variablelist>
<varlistentry>
<term><option>--user-mode</option>, <option>-U</option></term>
<listitem><para>
Do not change file ownership or initialize extended attributes.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--subpath</option>="PATH"</term>
<listitem><para>
Checkout sub-directory PATH.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--union</option></term>
<listitem><para>
Keep existing directories and unchanged files, overwrite existing files.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--union-add</option></term>
<listitem><para>
Keep existing directories and files.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--union-identical</option></term>
<listitem><para>Like <literal>--union</literal>, but error out
if a file would be replaced with a different file. Add new files
and directories, ignore identical files, and keep existing
directories. Requires <literal>-H</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--whiteouts</option></term>
<listitem><para>
Process whiteout files (Docker style).
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--allow-noent</option></term>
<listitem><para>
Do nothing if specified path does not exist.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--from-stdin</option></term>
<listitem><para>
Process many checkouts from standard input.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--from-file</option>="FILE"</term>
<listitem><para>
Process many checkouts from input file.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--fsync</option>="POLICY"</term>
<listitem><para>
POLICY is a boolean which specifies whether fsync should be
used or not. Default to true.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--require-hardlinks</option>,
<option>-H</option></term>
<listitem><para>
Do not fall back to full copies if hardlinking fails.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--force-copy-zerosized</option>,
<option>-z</option></term>
<listitem><para>
This option does nothing; the functionality is now always on by default.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--force-copy</option>, <option>-C</option></term>
<listitem><para>
Never hardlink (but may reflink if available).
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--bareuseronly-dirs</option>,
<option>-M</option></term>
<listitem><para>
Suppress mode bits outside of 0775 for directories (suid,
world writable, etc.).
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--skip-list</option>="FILE"</term>
<listitem><para>
Skip checking out the absolute file paths listed in FILE,
one per line.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--selinux-policy</option></term>
<listitem><para>
Set SELinux labels based on policy in root filesystem PATH
(may be /). This implies <literal>--force-copy</literal>.
</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<!-- check this example for accuracy-->
<refsect1>
<title>Example</title>
<para><command>$ ostree checkout my-branch</command></para>
<para><command>$ ls</command></para>
<programlisting>
file1&nbsp;&nbsp;&nbsp;&nbsp;file2&nbsp;&nbsp;&nbsp;&nbsp;<emphasis>my-branch</emphasis>
</programlisting>
</refsect1>
</refentry>