git: c4de745c330f - stable/13 - bectl: document the -r flag to bectl

From: Dag-Erling Smørgrav <des_at_FreeBSD.org>
Date: Fri, 22 Mar 2024 09:15:02 UTC
The branch stable/13 has been updated by des:

URL: https://cgit.FreeBSD.org/src/commit/?id=c4de745c330f44c94c6b7e56336b266b1af69c17

commit c4de745c330f44c94c6b7e56336b266b1af69c17
Author:     Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2023-04-20 04:55:07 +0000
Commit:     Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2024-03-22 08:07:34 +0000

    bectl: document the -r flag to bectl
    
    Independent of all of the commands, bectl itself takes an `-r` flag that
    specifies the BE root to use.  This was originally added to facilitate
    testing, but it was later discovered to be incredibly useful in other
    scenarios; e.g., trying to recover some boot environments in rescue
    media.
    
    The "BE root" described here is the parent dataset that holds boot
    environments, but I've no idea if that's an accepted definition for that
    dataset.
    
    Reviewed by:    gallatin, imp, Pau Amma
    MFC after:      1 week
    Differential Review:    https://reviews.freebsd.org/D39710
    
    (cherry picked from commit 4163bae03051839c739c0133605b4ef494ee8f6a)
---
 sbin/bectl/bectl.8 | 39 +++++++++++++++++++++++++++++++++++----
 sbin/bectl/bectl.c | 30 +++++++++++++++---------------
 2 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/sbin/bectl/bectl.8 b/sbin/bectl/bectl.8
index cb06ad9bcaed..2b2dd02bc8ef 100644
--- a/sbin/bectl/bectl.8
+++ b/sbin/bectl/bectl.8
@@ -15,7 +15,7 @@
 .\"
 .\"     @(#)be.1
 .\"
-.Dd March 31, 2022
+.Dd April 26, 2023
 .Dt BECTL 8
 .Os
 .Sh NAME
@@ -23,54 +23,67 @@
 .Nd Utility to manage boot environments on ZFS
 .Sh SYNOPSIS
 .Nm
+.Op Fl r Ar beroot
 .Cm activate
 .Op Fl t | Fl T
 .Ar beName
 .Nm
+.Op Fl r Ar beroot
 .Cm check
 .Nm
+.Op Fl r Ar beroot
 .Cm create
 .Op Fl r
 .Op Fl e Brq Ar nonActiveBe | Ar beName Ns Cm @ Ns Ar snapshot
 .Ar newBeName
 .Nm
+.Op Fl r Ar beroot
 .Cm create
 .Op Fl r
 .Ar beName@snapshot
 .Nm
+.Op Fl r Ar beroot
 .Cm destroy
 .Op Fl \&Fo
 .Ar beName Ns Op Cm @ Ns Ar snapshot
 .Nm
+.Op Fl r Ar beroot
 .Cm export
 .Ar sourceBe
 .Nm
+.Op Fl r Ar beroot
 .Cm import
 .Ar targetBe
 .Nm
+.Op Fl r Ar beroot
 .Cm jail
 .Op Fl bU
 .Oo Bro Fl o Ar key Ns Cm = Ns Ar value | Fl u Ar key Brc Oc Ns ...
 .Ar beName
 .Op Ar utility Op Ar argument ...
 .Nm
+.Op Fl r Ar beroot
 .Cm list
 .Op Fl aDHs
 .Op Fl c Ar property
 .Op Fl C Ar property
 .Oo Bro Fl c Ar property | Fl C Ar property Brc Oc
 .Nm
+.Op Fl r Ar beroot
 .Cm mount
 .Ar beName
 .Op Ar mountpoint
 .Nm
+.Op Fl r Ar beroot
 .Cm rename
 .Ar origBeName
 .Ar newBeName
 .Nm
+.Op Fl r Ar beroot
 .Brq Cm ujail | unjail
 .Brq Ar jailId | jailName | beName
 .Nm
+.Op Fl r Ar beroot
 .Brq Cm umount | unmount
 .Op Fl f
 .Ar beName
@@ -87,6 +100,23 @@ Boot environments
 allow the system to be upgraded, while preserving the old system environment in
 a separate ZFS dataset.
 .Pp
+.Nm
+itself accepts an
+.Fl r
+flag specified before the command to indicate the
+.Ar beroot
+that should be used as the boot environment root, or the dataset whose children
+are all boot environments.
+Normally this information is derived from the bootfs property of the pool that
+is mounted at
+.Pa / ,
+but it is useful when the system has not been booted into a ZFS root or a
+different pool should be operated on.
+For instance, booting into the recovery media and manually importing a pool from
+one of the system's resident disks will require the
+.Fl r
+flag to work.
+.Pp
 The following commands are supported by
 .Nm :
 .Bl -tag -width activate
@@ -139,11 +169,13 @@ flag is specified, the new environment will be cloned from the given
 .Ar nonActiveBe
 or
 .Ar beName Ns Cm @ Ns Ar snapshot .
-Otherwise, the new environment will be created from the currently booted environment.
+Otherwise, the new environment will be created from the currently booted
+environment.
 .Pp
 If
 .Nm
-is creating from another boot environment, a snapshot of that boot environment will be created to clone from.
+is creating from another boot environment, a snapshot of that boot environment
+will be created to clone from.
 .It Xo
 .Cm create
 .Op Fl r
@@ -274,7 +306,6 @@ is used on next boot once
 .Pq Em \&T ;
 or combination of
 .Pq Em \&NRT .
-.Pp
 .Bl -tag -width indent
 .It Fl a
 Display all datasets.
diff --git a/sbin/bectl/bectl.c b/sbin/bectl/bectl.c
index a2b300a4bb44..f2ea8b241b14 100644
--- a/sbin/bectl/bectl.c
+++ b/sbin/bectl/bectl.c
@@ -67,23 +67,23 @@ usage(bool explicit)
 	fprintf(fp, "%s",
 	    "Usage:\tbectl {-h | -? | subcommand [args...]}\n"
 #if SOON
-	    "\tbectl add (path)*\n"
+	    "\tbectl [-r beroot] add (path)*\n"
 #endif
-	    "\tbectl activate [-t] beName\n"
-	    "\tbectl activate [-T]\n"
-	    "\tbectl check\n"
-	    "\tbectl create [-r] [-e {nonActiveBe | beName@snapshot}] beName\n"
-	    "\tbectl create [-r] beName@snapshot\n"
-	    "\tbectl destroy [-Fo] {beName | beName@snapshot}\n"
-	    "\tbectl export sourceBe\n"
-	    "\tbectl import targetBe\n"
-	    "\tbectl jail [-bU] [{-o key=value | -u key}]... beName\n"
+	    "\tbectl [-r beroot] activate [-t] beName\n"
+	    "\tbectl [-r beroot] activate [-T]\n"
+	    "\tbectl [-r beroot] check\n"
+	    "\tbectl [-r beroot] create [-r] [-e {nonActiveBe | beName@snapshot}] beName\n"
+	    "\tbectl [-r beroot] create [-r] beName@snapshot\n"
+	    "\tbectl [-r beroot] destroy [-Fo] {beName | beName@snapshot}\n"
+	    "\tbectl [-r beroot] export sourceBe\n"
+	    "\tbectl [-r beroot] import targetBe\n"
+	    "\tbectl [-r beroot] jail [-bU] [{-o key=value | -u key}]... beName\n"
 	    "\t      [utility [argument ...]]\n"
-	    "\tbectl list [-aDHs] [{-c property | -C property}]\n"
-	    "\tbectl mount beName [mountpoint]\n"
-	    "\tbectl rename origBeName newBeName\n"
-	    "\tbectl {ujail | unjail} {jailID | jailName | beName}\n"
-	    "\tbectl {umount | unmount} [-f] beName\n");
+	    "\tbectl [-r beroot] list [-aDHs] [{-c property | -C property}]\n"
+	    "\tbectl [-r beroot] mount beName [mountpoint]\n"
+	    "\tbectl [-r beroot] rename origBeName newBeName\n"
+	    "\tbectl [-r beroot] {ujail | unjail} {jailID | jailName | beName}\n"
+	    "\tbectl [-r beroot] {umount | unmount} [-f] beName\n");
 
 	return (explicit ? 0 : EX_USAGE);
 }