On Thu, May 17, 2018 at 02:31:21PM -0700, Darrick J. Wong wrote: > On Thu, May 17, 2018 at 12:27:00PM -0700, Luis R. Rodriguez wrote: > > 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/mkfs.xfs.d/ and allow for > > different configuration files, if none is specified we look for the > > default configuration file, /etc/mkfs.xfs.d/default. You can override > > with -c. For instance, if you specify: > > > > mkfs.xfs -c experimental -f /dev/loop0 > > > > The file /etc/mkfs.xfs.d/experimental will be used as your configuration > > file. If you really need to override the full path of the configuration > > file you may use the MKFS_XFS_CONFIG environment variable. > > > > 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, and currently only 1 or 0 are acceptable values. 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 > > Separate patch, but should there be a way to spit out the current mkfs > settings as a config file? Sure, I have that in my mind but definitely separate patch. As can be seen, there are still quite a bit of minor things to wrap up. No point in getting ahead of ourselves. > > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx> > > --- > > include/builddefs.in | 2 + > > man/man5/mkfs.xfs.d.5 | 121 ++++++++++ > > man/man8/mkfs.xfs.8 | 26 +++ > > mkfs/Makefile | 2 +- > > mkfs/xfs_mkfs.c | 47 +++- > > mkfs/xfs_mkfs_common.h | 12 + > > mkfs/xfs_mkfs_config.c | 591 +++++++++++++++++++++++++++++++++++++++++++++++++ > > mkfs/xfs_mkfs_config.h | 11 + > > 8 files changed, 801 insertions(+), 11 deletions(-) > > create mode 100644 man/man5/mkfs.xfs.d.5 > > create mode 100644 mkfs/xfs_mkfs_config.c > > create mode 100644 mkfs/xfs_mkfs_config.h > > > > diff --git a/include/builddefs.in b/include/builddefs.in > > index 8aac06cf90dc..e1ee9f7ba086 100644 > > --- a/include/builddefs.in > > +++ b/include/builddefs.in > > @@ -62,6 +62,7 @@ PKG_LIB_DIR = @libdir@@libdirsuffix@ > > PKG_INC_DIR = @includedir@/xfs > > DK_INC_DIR = @includedir@/disk > > PKG_MAN_DIR = @mandir@ > > +PKG_ETC_DIR = @sysconfdir@ > > PKG_DOC_DIR = @datadir@/doc/@pkg_name@ > > PKG_LOCALE_DIR = @datadir@/locale > > > > @@ -196,6 +197,7 @@ endif > > > > GCFLAGS = $(DEBUG) \ > > -DVERSION=\"$(PKG_VERSION)\" -DLOCALEDIR=\"$(PKG_LOCALE_DIR)\" \ > > + -DROOT_SYSCONFDIR=\"$(PKG_ETC_DIR)\" \ > > -DPACKAGE=\"$(PKG_NAME)\" -I$(TOPDIR)/include -I$(TOPDIR)/libxfs > > > > ifeq ($(ENABLE_GETTEXT),yes) > > diff --git a/man/man5/mkfs.xfs.d.5 b/man/man5/mkfs.xfs.d.5 > > new file mode 100644 > > index 000000000000..5424f730a2e5 > > --- /dev/null > > +++ b/man/man5/mkfs.xfs.d.5 > > @@ -0,0 +1,121 @@ > > +.TH mkfs.xfs.d 5 > > +.SH NAME > > +mkfs.xfs.d \- mkfs.xfs configuration directory > > +.SH DESCRIPTION > > +.B mkfs.xfs (8) > > +uses a set of initial default parameters for configuration. These defaults > > +are conservatively decided by the community as xfsprogs and features for XFS > > +in the kernel advance. One can override these defaults on the > > I'm not sure what the sentence "These defaults...in the kernel advance." > means... is this close to what you meant?: > > "The builtin mkfs defaults are decided by the XFS community. New features > are only enabled by default when the community consider it stable." That reads much better. Amended. > > +.B mkfs.xfs (8) > > +command line, but there are cases where it is desirable for sensible defaults > > +to always be specified by the system where > > "...where it is desirable for the distro or the system administrator to > establish their own supported defaults in a uniform manner." ? Sure, I'll also add at the end: "regardless of the version of mkfs.xfs used" > > +.B mkfs.xfs (8) > > +runs on. This may desirable for example on systems with old kernels where the > > +built-in default parameters on > > +.B mkfs.xfs (8) > > +may not be able to create a filesystem which the old kernel supports and it > > "...where the built-in default mkfs.xfs parameters create a filesystem > that is not supported by the old kernel." > > > +would be unclear what parameters are needed to produce a compatible filesystem. > > +Overriding > > +.B mkfs.xfs (8) > > +built-in defaults may also be desirable if you have a series of systems with > > +different kernels and want to be able to create filesystems which all systems > > +are able to support properly. I've moved this to another sentence as well then: In such situations it would also be unclear what parameters are needed to produce a compatible filesystem, having a configuration file present ensures that if newer versions of .B mkfs.xfs (8) are deployed, creating a filesystem will remain compatible. > > +.PP > > +The XFS configuration directory > > +.B mkfs.xfs.d (5) > > +can be used to define different configuration files which can be used to > > +override the built-in default parameters by > > +.B mkfs.xfs (8). > > +Different configuration files are supported, the default > > +configuration file, > > +.I /etc/mkfs.xfs.d/default > > The "/etc" part of the path should be sysconfdir and replaced by the > build script to match whatever we're encoding into the mkfs.xfs binary. Alrighty .. and all other "etc" references I take it.. sure. > > +, will be looked for first and if present will be used to override > > +.B mkfs.xfs (8) > > +built-in default parameters. You can override the configuration file by > > +specifying its name when using > > +.B mkfs.xfs (8) > > +by using the > > +.B -c > > +parameter. For example: > > +.I mkfs.xfs -c experimental -f /dev/sda1 > > +will make > > +.B mkfs.xfs (8) > > +look for and use the configuration file > > +.I /etc/mkfs.xfs.d/experimental > > +to override > > +.B mkfs.xfs (8) > > +default parameters. If you need to override the full path for a configuration > > +file you can use the > > +.I MKFS_XFS_CONFIG > > +environment variable prior to calling > > +.B mkfs.xfs (8) > > +to define the > > +full path to the configuration file to be used. > > Does the environment variable override -c, or the other way around? The other way around. Will continue the rest tomorrow. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
