Hi Mike, thanks for implementation. After the MFC and the new -STABLE snapshots I am really looking forward to try this out an my RPi4B.
--Gordon On Sat, Dec 10, 2022 at 07:41:13PM +0000, Mike Karels wrote: > The branch main has been updated by karels: > > URL: > https://cgit.FreeBSD.org/src/commit/?id=4a30d7bb373c08f42f953b9cd1e793e236b4cd92 > > commit 4a30d7bb373c08f42f953b9cd1e793e236b4cd92 > Author: Mike Karels <kar...@freebsd.org> > AuthorDate: 2022-12-10 19:38:36 +0000 > Commit: Mike Karels <kar...@freebsd.org> > CommitDate: 2022-12-10 19:38:36 +0000 > > growfs script: add swap partition as well as growing root > > Add the ability to create a swap partition in the course of growing > the root file system on first boot, enabling by default. The default > rules are: add swap if the disk is at least 15 GB (decimal), and the > existing root is less than 40% of the disk. The default size is 10% > of the disk, but is limited by the memory size. The limit is twice > memory size up to 4 GB, 8 GB up to 8 GB memory, and memory size over > 8 GB memory. Swap size is clamped at vm.swap_maxpages/2 as well. > The new swap partition is labeled as "growfs_swap". > > The default behavior can be overridden by setting growfs_swap_size in > /etc/rc.conf or in the kernel environment, with kenv taking priority. > A value of 0 inhibits the addition of swap, an empty value specifies > the default, and other values indicate a swap size in bytes. > > By default, addition of swap is inhibited if a swap partition is found > in the output of the sysctl kern.geom.conftxt before the current root > partition, usually meaning that there is another disk present. > Swap space is not added if one is already present in /etc/fstab. > > The root partition is read-only when growfs runs, so /etc/fstab can > not be modified. That step is handled by a new growfs_fstab script, > added in a separate commit. Set the value "growfs_swap_pdev" in kenv > to indicate that this should be done, as well as for internal use. > > There is optional verbose output meant for debugging; it can only be > enabled by modifying the script (in two places, for sh and awk). > This should be removed before release, after testing on -current. > > Discussed with: cperciva > Reviewed by: imp (previous version) > Differential Revision: https://reviews.freebsd.org/D37462 > --- > libexec/rc/rc.d/growfs | 178 > +++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 172 insertions(+), 6 deletions(-) > > diff --git a/libexec/rc/rc.d/growfs b/libexec/rc/rc.d/growfs > index 5402bd442279..3c48a7dca6b2 100755 > --- a/libexec/rc/rc.d/growfs > +++ b/libexec/rc/rc.d/growfs > @@ -1,5 +1,6 @@ > #!/bin/sh > # > +# Copyright 2022 Michael J. Karels > # Copyright 2014 John-Mark Gurney > # All rights reserved. > # > @@ -32,8 +33,9 @@ > # BEFORE: root > # KEYWORD: firstboot > > -# This allows us to distribute an image > -# and have it work on essentially any size drive. > +# Grow root partition to fill available space, optionally adding a swap > +# partition at the end. This allows us to distribute an image and > +# have it work on essentially any size drive. > > # Note that this uses awk(1), and thus will not work if /usr is on a separate > # filesystem. We need to run early, because there might be not enough free > @@ -48,7 +50,7 @@ start_cmd="growfs_start" > stop_cmd=":" > rcvar="growfs_enable" > > -growfs_get_diskdev () > +growfs_get_diskdev() > { > local _search=${1} > sysctl -b kern.geom.conftxt | > @@ -61,8 +63,51 @@ growfs_get_diskdev () > done > } > > -growfs_start () > +# Compute upper bound on swap partition size (if added), based on physmem > +# and vm.swap_maxpages / 2 (the limit that elicits a warning). > +# Rule for swap size based on memory size: > +# up to 4 GB twice memory size > +# 4 GB - 8 GB 8 GB > +# over 8 GB memory size > +growfs_swap_max() > { > + memsize=$(sysctl -n hw.physmem) > + memsizeMB=$(($memsize / (1024 * 1024))) > + > + if [ $memsizeMB -lt 4096 ] > + then > + swapmax=$(($memsize * 2)) > + elif [ $memsizeMB -lt 8192 ] > + then > + swapmax=$((8192 * 1024 * 1024)) > + else > + swapmax=$memsize > + fi > + > + pagesize=$(sysctl -n hw.pagesize) > + vm_swap_max=$(($(sysctl -n vm.swap_maxpages) / 2 * $pagesize)) > + > + if [ $swapmax -gt $vm_swap_max ] > + then > + $swapmax=$vm_swap_max > + fi > + echo -n "$swapmax" > +} > + > +# Find newly-added swap partition on parent device ($1). > +growfs_last_swap() > +{ > + swapdev=$(gpart list $1 | awk ' > + $2 == "Name:" { dev = $3 } > + $1 == "type:" && $2 == "freebsd-swap" { swapdev = dev } > + END { print swapdev } > + ') > + echo -n $swapdev > +} > + > +growfs_start() > +{ > + verbose=0 > echo "Growing root partition to fill device" > FSTYPE=$(mount -p | awk '{ if ( $2 == "/") { print $3 }}') > FSDEV=$(mount -p | awk '{ if ( $2 == "/") { print $1 }}') > @@ -100,19 +145,126 @@ growfs_start () > diskdev=${rootdev} > fi > > + # Check kenv for growfs_swap_size; if not present, > + # check $growfs_swap_size from /etc/rc.conf. > + # A value of 0 suppresses swap addition, > + # "" (or unset) specifies the default; > + # other values indicate the size in bytes. > + # If default, check whether swap is already in fstab; > + # if so, don't add another. > + addswap=1 > + swapsize="$(kenv -q growfs_swap_size 2>/dev/null)" > + case "$swapsize" in > + "0") addswap=0 > + ;; > + "") case "$growfs_swap_size" in > + "0") addswap=0 > + ;; > + "") > + if ! awk ' > + /^#/ { next } > + $3 == "swap" { exit 1 } > + ' < /etc/fstab > + then > + addswap=0 > + fi > + ;; > + *) swapsize="$growfs_swap_size" > + ;; > + esac > + ;; > + *) ;; > + esac > + > + swaplim=$(growfs_swap_max) > + > + [ $verbose -eq 1 ] && { > + echo "diskdev is $diskdev" > + echo "search is $search" > + echo "swapsize is $swapsize" > + echo "swaplim is $swaplim" > + } > + > sysctl -b kern.geom.conftxt | awk ' > { > + verbose = 0 > lvl=$1 > device[lvl] = $3 > type[lvl] = $2 > idx[lvl] = $7 > + offset[lvl] = $9 > parttype[lvl] = $13 > + size[lvl] = $4 > + if (verbose) print lvl, type[lvl], $3 > + if (type[lvl] == "DISK") { > + disksize = size[lvl] > + if (verbose) > + print "disksize ", disksize > + # Don't add swap on disks under 15 GB (decimal) by default. > + if (addswap == 1 && (size[lvl] > 15000000000 || swapsize > 0)) > + doing_swap = 1 > + else > + doing_swap = 0 > + } else if (type[lvl] == "PART" && $11 == "freebsd-swap" && \ > + int(swapsize) == 0) { > + # This finds swap only if it precedes root, e.g. preceding disk. > + addswap = 0 > + doing_swap = 0 > + print "swap device exists, not adding swap" > + } > if (dev == $3) { > for (i = 1; i <= lvl; i++) { > # resize > if (type[i] == "PART") { > pdev = device[i - 1] > - cmd[i] = "gpart resize -i " idx[i] " " pdev > + if (verbose) > + print i, pdev, addswap, disksize, \ > + doing_swap > + swapcmd = "" > + # Allow swap if current root is < 40% of disk. > + if (parttype[i] != "MBR" && doing_swap == 1 && \ > + (size[i] / disksize < 0.4 || \ > + swapsize > 0)) { > + print "Adding swap partition" > + if (int(swapsize) == 0) { > + swapsize = int(disksize / 10) > + if (swapsize > swaplim) > + swapsize = swaplim > + } > + sector = $5 > + swapsize /= sector > + if (verbose) > + print "swapsize sectors", > + swapsize > + align = 4 * 1024 * 1024 / sector > + > + # Estimate offset for swap; let > + # gpart compute actual start and size. > + # Assume expansion all goes into this > + # partition for MBR case. > + if (parttype[i - 1] == "MBR") { > + if (verbose) > + print "sz ", size[i - 1], \ > + " off ", offset[i - 1] > + expand = size[0] - \ > + (size[i - 1] + offset[i - 1]) > + } else { > + if (verbose) > + print "sz ", size[i], \ > + " off ", offset[i] > + expand = size[0] - \ > + (size[i] + offset[i]) > + } > + if (verbose) > + print "expand ", expand, \ > + " sz ", size[i] > + swapbase = (expand + size[i]) / sector > + swapbase -= swapsize + align > + swapcmd = "gpart add -t freebsd-swap -a > " align " -b " swapbase " " pdev "; kenv growfs_swap_pdev=" pdev " > >/dev/null; " > + if (verbose) > + swapcmd = "set -x; " swapcmd > + } > + cmd[i] = swapcmd "gpart resize -i " idx[i] " " > pdev > if (parttype[i] == "GPT") > cmd[i] = "gpart recover " pdev " ; " > cmd[i] > } else if (type[i] == "LABEL") { > @@ -128,7 +280,7 @@ growfs_start () > } > exit 0 > } > -}' dev="$search" > +}' dev="$search" addswap="$addswap" swapsize="$swapsize" swaplim="$swaplim" > gpart commit "$diskdev" 2> /dev/null > case "$FSTYPE" in > ufs) > @@ -138,6 +290,20 @@ growfs_start () > zpool online -e $pool $rootdev > ;; > esac > + > + # Get parent device of swap partition if one was added; > + # if so, find swap device and label it. > + pdev=$(kenv -q growfs_swap_pdev) > + if [ -n "$pdev" ] > + then > + dev=$(growfs_last_swap "$pdev") > + if [ -z "$dev" ] > + then > + echo "Swap partition not found on $pdev" > + exit 0 > + fi > + glabel label -v growfs_swap $dev > + fi > } > > load_rc_config $name > --
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