tree 6ed932a2333815a31ad1dd565055b0f1f98b6dd5
parent ff67574663fd540ea5f8397efd8fbe5c6f158cc4
author Luis R. Rodriguez <mcgrof@kernel.org> 1507937764 -0700
committer Luis R. Rodriguez <mcgrof@kernel.org> 1528763316 -0700

mkfs.xfs: add configuration file parsing support using our own parser

You may want to stick to specific set of configuration options when
creating filesystems with mkfs.xfs -- sometimes due to pure technical
reasons, but some other times to ensure systems remain compatible as
new features are introduced with older kernels, or if you always want
to take advantage of some new feature which would otherwise typically
be disruptive.

This adds support for parsing a configuration file to override defaults
parameters to be used for mkfs.xfs.

We define an XFS configuration directory, /etc/xfs/mkfs/ and allow for
different configuration files, if none is specified we look for the
default configuration file, /etc/xfs/mkfs/default. You can override
with -c.  For instance, if you specify:

	mkfs.xfs -c experimental -f /dev/loop0

The search path for the configuration file will be:

	1) $PWD/experimental
	2) /etc/xfs/mkfs/experimental

Absolute paths are supported, in which case they will be used directly
and the /etc/xfs/mkfs/ directory is ignored.

To verify what configuration file is used on a system use the typical:

  mkfs.xfs -N

There is only a subset of options allowed to be set on the configuration
file. The default parameters you can override on a configuration file and
their current built-in default settings are:

[data]
noalign=0

[inode]
align=1
projid32bit=1
sparse=0

[log]
lazy-count=1

[metadata]
crc=1
finobt=1
rmapbt=0
reflink=0

[naming]
ftype=1

[rtdev]
noalign=0

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>