Re: [PATCH 2/2] mkfs: add "-m" options to the man page

Brian Foster
2014-06-19T13:02:05Z

On Thu, Jun 19, 2014 at 03:33:52PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Because they are missing.
>
> Reported-by: Matthias Schniedermeyer <ms@citd.de>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---
> man/man8/mkfs.xfs.8 | 47 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 47 insertions(+)
>
> diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
> index 8184e10..4ba07bf 100644
> --- a/man/man8/mkfs.xfs.8
> +++ b/man/man8/mkfs.xfs.8
> @@ -7,6 +7,9 @@ mkfs.xfs \- construct an XFS filesystem
> .B \-b
> .I block_size
> ] [
> +.B \-m
> +.I global_metadata_options
> +] [
> .B \-d
> .I data_section_options
> ] [
> @@ -125,6 +128,50 @@ The default value is 4096 bytes (4 KiB), the minimum is 512, and the
> maximum is 65536 (64 KiB).
> XFS on Linux currently only supports pagesize or smaller blocks.
> .TP
> +.BI \-m " global_metadata_options"
> +These options specify metadata format options that either apply to the entire
> +filesystem or aren't easily characterised by a specific functionality group. The
> +valid
> +.I global_metadata_options
> +are:
> +.RS 1.2i
> +.TP
> +.BI crc= value
> +This is used to create a filesystem which maintains and checks CRC information
> +in all metadata objects on disk. The value is either 0 to disable the feature,
> +or 1 to enable the use of CRCs.
> +.IP
> +CRCs enable enhanced error detection due to
> +hardware issues, whilst the format changes also improves crash recovery
> +algorithms and the ability of various tools to validate and repair metadata
^ extra space

The rest looks good to me. Thanks for writing up the finobt bits!

Reviewed-by: Brian Foster <bfoster@redhat.com>

> +corruptions when they are found.
> +The CRC algorithm used is CRC32c, so the overhead is dependent on CPU
> +architecture as some CPUs have hardware acceleration of this algorithm.
> +Typically the overhead of calculating and checking the CRCs is not noticable in
> +normal operation.
> +.IP
> +By default,
> +.B mkfs.xfs
> +will not enable metadata CRCs.
> +.TP
> +.BI finobt= value
> +This option enables the use of a separate free inode btree index in each
> +allocation group. The value is either 0 to disable the feature, or 1 to create
> +a free inode btree in each allocation group.
> +.IP
> +The free inode btree mirrors the existing allocated inode btree index which
> +indexes both used and free inodes. The free inode btree does not index used
> +inodes, allowing faster, more consistent inode allocation performance as
> +filesystems age.
> +.IP
> +By default,
> +.B mkfs.xfs
> +will not create free inode btrees. This feature is also currently only available
> +for filesystems created with the
> +.B \-m crc=1
> +option set.
> +.RE
> +.TP
> .BI \-d " data_section_options"
> These options specify the location, size, and other parameters of the
> data section of the filesystem. The valid
> --
> 2.0.0
>
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