zhack.1: modernise

The spacing on zhack    feature stat    pool is a bit iffy(?)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12125

man/man1/zhack.1

@@ -1,4 +1,3 @@
-'\" t
 .\"
 .\" CDDL HEADER START
 .\"
@@ -19,63 +18,108 @@
 .\"
 .\" CDDL HEADER END
 .\"
-.\"
 .\" Copyright 2013 Darik Horn <dajhorn@vanadac.com>. All rights reserved.
 .\"
-.TH ZHACK 1 "Aug 24, 2020" OpenZFS
+.\" lint-ok: WARNING: sections out of conventional order: Sh SYNOPSIS
-
+.\"
-.SH NAME
+.Dd May 26, 2021
-zhack \- libzpool debugging tool
+.Dt ZHACK 1
-.SH DESCRIPTION
+.Os
+.
+.Sh NAME
+.Nm zhack
+.Nd libzpool debugging tool
+.Sh DESCRIPTION
 This utility pokes configuration changes directly into a ZFS pool,
 which is dangerous and can cause data corruption.
-.SH SYNOPSIS
+.Sh SYNOPSIS
-.LP
+.Bl -tag -width Ds
-.BI "zhack [\-c " "cachefile" "] [\-d " "dir" "] <" "subcommand" "> [" "arguments" "]"
+.It Xo
-.SH OPTIONS
+.Nm zhack
-.HP
+.Cm feature stat
-.BI "\-c" " cachefile"
+.Ar pool
-.IP
+.Xc
-Read the \fIpool\fR configuration from the \fIcachefile\fR, which is
-/etc/zfs/zpool.cache by default.
-.HP
-.BI "\-d" " dir"
-.IP
-Search for \fIpool\fR members in the \fIdir\fR path. Can be specified
-more than once.
-.SH SUBCOMMANDS
-.LP
-.BI "feature stat " "pool"
-.IP
 List feature flags.
-.LP
+.
-.BI "feature enable [\-d " "description" "] [\-r] " "pool guid"
+.It Xo
-.IP
+.Nm zhack
-Add a new feature to \fIpool\fR that is uniquely identified by
+.Cm feature enable
-\fIguid\fR, which is specified in the same form as a zfs(8) user
+.Op Fl d Ar description
-property.
+.Op Fl r
-.IP
+.Ar pool
-The \fIdescription\fR is a short human readable explanation of the new
+.Ar guid
+.Xc
+Add a new feature to
+.Ar pool
+that is uniquely identified by
+.Ar guid ,
+which is specified in the same form as a
+.Xr zfs 8
+user property.
+.Pp
+The
+.Ar description
+is a short human readable explanation of the new feature.
+.Pp
+The
+.Fl r
+flag indicates that
+.Ar pool
+can be safely opened in read-only mode by a system that does not understand the
+.Ar guid
 feature.
-.IP
+.
-The \fB\-r\fR switch indicates that \fIpool\fR can be safely opened
+.It Xo
-in read-only mode by a system that does not have the \fIguid\fR
+.Nm zhack
-feature.
+.Cm feature ref
-.LP
+.Op Fl d Ns | Ns Fl m
-.BI "feature ref [\-d|\-m] " "pool guid"
+.Ar pool
-.IP
+.Ar guid
-Increment the reference count of the \fIguid\fR feature in \fIpool\fR.
+.Xc
-.IP
+Increment the reference count of the
-The \fB\-d\fR switch decrements the reference count of the \fIguid\fR
+.Ar guid
-feature in \fIpool\fR.
+feature in
-.IP
+.Ar pool .
-The \fB\-m\fR switch indicates that the \fIguid\fR feature is now
+.Pp
-required to read the pool MOS.
+The
-.SH EXAMPLES
+.Fl d
-.LP
+flag decrements the reference count of the
-.nf
+.Ar guid
+feature in
+.Ar pool
+instead.
+.Pp
+The
+.Fl m
+flag indicates that the
+.Ar guid
+feature is now required to read the pool MOS.
+.El
+.
+.Sh GLOBAL OPTIONS
+The following can be passed to all
+.Nm
+invocations before any subcommand:
+.Bl -tag -width "-d dir"
+.It Fl c Ar cachefile
+Read
+.Ar pool
+configuration from the
+.Ar cachefile ,
+which is
+.Pa /etc/zfs/zpool.cache
+by default.
+.It Fl d Ar dir
+Search for
+.Ar pool
+members in
+.Ar dir .
+Can be specified more than once.
+.El
+.
+.Sh EXAMPLES
+.Bd -literal
 # zhack feature stat tank
-
 for_read_obj:
 	org.illumos:lz4_compress = 0
 for_write_obj:
@@ -85,14 +129,14 @@ descriptions_obj:
 	com.delphix:async_destroy = Destroy filesystems asynchronously.
 	com.delphix:empty_bpobj = Snapshots use less space.
 	org.illumos:lz4_compress = LZ4 compression algorithm support.
-.LP
+
 # zhack feature enable -d 'Predict future disk failures.' \\
     tank com.example:clairvoyance
-.LP
+
 # zhack feature ref tank com.example:clairvoyance
-.SH AUTHORS
+.Ed
-This man page was written by Darik Horn <dajhorn@vanadac.com>.
+.
-.SH SEE ALSO
+.Sh SEE ALSO
-.BR zfs (8),
+.Xr ztest 1 ,
-.BR zpool-features (5),
+.Xr zpool-features 5 ,
-.BR ztest (1)
+.Xr zfs 8