Re: git: 5a31987d4c39 - main - rc+devd: Add growfs_postboot
- In reply to: Colin Percival : "git: 5a31987d4c39 - main - rc+devd: Add growfs_postboot"
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Mon, 24 Aug 2026 12:25:36 UTC
On Mon 24 Aug 05:02, Colin Percival wrote:
> The branch main has been updated by cperciva:
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=5a31987d4c395ec4d3ed303cbc2e1d12ea54a039
>
> commit 5a31987d4c395ec4d3ed303cbc2e1d12ea54a039
> Author: Colin Percival <cperciva@FreeBSD.org>
> AuthorDate: 2026-07-30 20:20:51 +0000
> Commit: Colin Percival <cperciva@FreeBSD.org>
> CommitDate: 2026-08-24 05:02:16 +0000
>
> rc+devd: Add growfs_postboot
>
> In VM and cloud environments it is often possible to enlarge virtual
> disks; this can be useful, for example, if a system is launched with a
> small root disk and it later becomes clear that more space is needed.
>
> On kernels which support run-time resizing of disks (for NVMe, this was
> added in November 2025; some other disk types have supported this for
> longer) a SIZECHANGE notification is sent to userland via devd.
>
> Add a "nostart" rc.d script (runnable manually but not automatically at
> boot time) and a devd script which invokes it when a notification
> arrives. The rc.d script enlarges the "final partition" on partitioned
> geoms, or the UFS filesystem or zpool device when triggered on a disk
> containing either of those.
>
> Reviewed by: imp, ziaee
> MFC after: 2 weeks
> Relnotes: Disk partitions and filesystems can be enlarged
> automatically when disks grow by setting
> growfs_postboot_enable=YES in /etc/rc.conf.
> Sponsored by: Amazon
> Differential Revision: https://reviews.freebsd.org/D58582
> ---
> libexec/rc/rc.conf | 3 +
> libexec/rc/rc.d/Makefile | 1 +
> libexec/rc/rc.d/growfs_postboot | 116 +++++++++++++++++++++++++++++++++++++++
> sbin/devd/Makefile | 1 +
> sbin/devd/growfs_postboot.conf | 8 +++
> share/man/man5/rc.conf.5 | 1 +
> share/man/man7/Makefile | 1 +
> share/man/man7/growfs.7 | 1 +
> share/man/man7/growfs_postboot.7 | 69 +++++++++++++++++++++++
> 9 files changed, 201 insertions(+)
>
> diff --git a/libexec/rc/rc.conf b/libexec/rc/rc.conf
> index d5d1a198b143..e7ce22822515 100644
> --- a/libexec/rc/rc.conf
> +++ b/libexec/rc/rc.conf
> @@ -122,6 +122,9 @@ background_fsck_delay="60" # Time to wait (seconds) before starting the fsck.
> growfs_enable="NO" # Set to YES to attempt to grow the root filesystem on boot
> growfs_swap_size="" # Set to 0 to disable growfs swap, "" to default size,
> # size in bytes to specify swap size.
> +growfs_postboot_enable="NO" # Set to YES to attempt to grow partitions and
> + # filesystems when devd notifies about disks growing
> + # after the system boots.
> netfs_types="nfs:NFS smbfs:SMB" # Net filesystems.
> extra_netfs_types="NO" # List of network extra filesystem types for delayed
> # mount at startup (or NO).
> diff --git a/libexec/rc/rc.d/Makefile b/libexec/rc/rc.d/Makefile
> index cb94380aff32..f6646208dc03 100644
> --- a/libexec/rc/rc.d/Makefile
> +++ b/libexec/rc/rc.d/Makefile
> @@ -24,6 +24,7 @@ CONFS= DAEMON \
> fsck \
> growfs \
> growfs_fstab \
> + growfs_postboot \
> hostid \
> hostid_save \
> hostname \
> diff --git a/libexec/rc/rc.d/growfs_postboot b/libexec/rc/rc.d/growfs_postboot
> new file mode 100755
> index 000000000000..346c8a0d7162
> --- /dev/null
> +++ b/libexec/rc/rc.d/growfs_postboot
> @@ -0,0 +1,116 @@
> +#!/bin/sh
> +#
> +# Copyright 2026 Colin Percival
> +#
> +# SPDX-License-Identifier: BSD-2-Clause
> +#
> +# PROVIDE: growfs_postboot
> +# KEYWORD: nostart
> +
> +# Triggered by /etc/devd/growfs_postboot.conf: When a disk grows, enlarge the
> +# final partition to fill the available space (if the disk is partitioned) or
> +# enlarge the UFS filesystem or ZFS zpool (if in use for one of those). Note
> +# that in the common case of "a disk is partitioned and one of the partitions
> +# contains a filesystem" this script is invoked twice -- the repartitioning
> +# done on the first call generates a new devd event which triggers the second
> +# invocation.
> +#
> +# Enable by setting
> +# growfs_postboot_enable=YES
> +# in /etc/rc.conf. Note that on systems with growfs_enable=YES, it will often
> +# be necessary to set growfs_swap_size=0 in order to disable swap creation;
> +# otherwise the "final partition" is the swap space, not the filesystem and
> +# growing the disk will not cause the most likely desired results.
> +
> +. /etc/rc.subr
> +
> +name="growfs_postboot"
> +desc="automatically grow file systems during runtime"
> +rcvar="growfs_postboot_enable"
> +start_cmd="growfs_postboot_start"
> +
> +disktype() {
> + sysctl -n kern.geom.conftxt | awk -v dev="$1" '
> + BEGIN {
> + partitioned=0
> + indev=0
> + }
> + {
> + if (dev == $3) {
> + indev=1
> + devlevel=$1
> + } else if (devlevel >= $1) {
> + indev=0
> + } else if (indev == 1) {
> + if ($2 == "PART") {
> + partitioned=1
> + }
> + }
> + }
> + END {
> + if (partitioned == 1) {
> + print "partitioned"
> + } else {
> + print "unpartitioned"
> + }
> + }'
> +}
> +
> +growpart() {
> + # Run 'gpart recover' if GPT
> + if gpart list "$1" | grep -qi 'scheme: GPT'; then
> + gpart recover "$1" || true
> + fi
> +
> + # Find the index of the last partition; note that we need to compare
> + # the starting sectors in case partitions are not numbered sensibly.
> + idx=$(gpart backup "$1" | awk '
> + NR == 1 { next }
> + $3 + 0 > start { start = $3 + 0; idx = $1 }
> + END { print idx }')
> + if [ -z "$idx" ]; then
> + echo "Error finding final partition of $1"
> + return 1
> + fi
> +
> + # Expand that partition
> + gpart resize -i "$idx" "$1"
> +}
> +
> +growfilesystem() {
> + case $(fstyp -u "/dev/$1" 2>/dev/null) in
> + ufs) growfs -y "/dev/$1"
> + ;;
> + zfs) zpool list -H -o name |
> + while read -r pool; do
> + zpool list -vH -o name "$pool" |
> + grep "^[[:space:]]" |
> + while read -r dev; do
> + if [ "$dev" = "$1" ]; then
> + zpool online -e "$pool" "$1"
> + fi
> + done
> + done
> + ;;
> + "") # Nothing to grow here
> + ;;
> + *) echo "Don't know how to grow filesystem on /dev/$1"
> + ;;
> + esac
> +}
> +
> +growfs_postboot_start() {
> + # Run either growpart or growfilesystem depending on whether this is
> + # something which is partitioned or not.
> + case $(disktype "$1") in
> + partitioned)
> + growpart "$1"
> + ;;
> + unpartitioned)
> + growfilesystem "$1"
> + ;;
> + esac
> +}
> +
> +load_rc_config $name
> +run_rc_command "$@"
> diff --git a/sbin/devd/Makefile b/sbin/devd/Makefile
> index 78b2b039ac6e..864df3604d64 100644
> --- a/sbin/devd/Makefile
> +++ b/sbin/devd/Makefile
> @@ -5,6 +5,7 @@ PACKAGE=devd
> CONFGROUPS= CONFS DEVD
> CONFS= devd.conf
> DEVD= devmatch.conf
> +DEVD+= growfs_postboot.conf
> DEVDDIR= /etc/devd
> .if ${MK_ACPI} != "no"
> DEVD+= asus.conf
> diff --git a/sbin/devd/growfs_postboot.conf b/sbin/devd/growfs_postboot.conf
> new file mode 100644
> index 000000000000..0c6b817755ec
> --- /dev/null
> +++ b/sbin/devd/growfs_postboot.conf
> @@ -0,0 +1,8 @@
> +# Trigger growfs on GEOM size changes.
> +
> +notify 200 {
> + match "system" "GEOM";
> + match "subsystem" "DEV";
> + match "type" "SIZECHANGE";
> + action "lockf -k /var/run/growfs_postboot.lock /etc/rc.d/growfs_postboot quietstart $cdev 2>&1 | logger -t growfs_postboot &";
> +};
Please avoid calling /etc/rc.d/* directly and prefer using service(8) like all
other devd from base. (beside consistency, it is also simplify my life on rcd)
Best regards,
Bapt