On Mon, 2009-06-01 at 00:59 -0400, David Dillow wrote:
> This adds basic support for root on a network block device to
> the netroot framework.
>
> Signed-off-by: David Dillow <dave@xxxxxxxxxxxxxx>
> ---
> modules.d/95nbd/check | 11 ++++
> modules.d/95nbd/install | 7 +++
> modules.d/95nbd/nbd-netroot.sh | 11 ++++
> modules.d/95nbd/nbdroot | 96 ++++++++++++++++++++++++++++++++++++++
> modules.d/95nbd/parse-nbdroot.sh | 49 +++++++++++++++++++
> 5 files changed, 174 insertions(+), 0 deletions(-)
> create mode 100755 modules.d/95nbd/check
> create mode 100755 modules.d/95nbd/install
> create mode 100755 modules.d/95nbd/nbd-netroot.sh
> create mode 100755 modules.d/95nbd/nbdroot
> create mode 100755 modules.d/95nbd/parse-nbdroot.sh
>
> diff --git a/modules.d/95nbd/check b/modules.d/95nbd/check
> new file mode 100755
> index 0000000..f94d63b
> --- /dev/null
> +++ b/modules.d/95nbd/check
> @@ -0,0 +1,11 @@
> +#!/bin/sh
> +# We depend on network modules being loaded
> +[ "$1" = "-d" ] && echo network
> +
> +# If hostonly was requested, fail the check if we are not actually
> +# booting from root.
> +[ "$1" = "-h" ] && ! egrep -q '/ /dev/nbd[0-9]*' /proc/mounts && exit 1
> +
> +# If our prerequisites are not met, fail anyways.
> +which nbd-client >/dev/null 2>&1 || exit 1
> +exit 0
> diff --git a/modules.d/95nbd/install b/modules.d/95nbd/install
> new file mode 100755
> index 0000000..3a80da1
> --- /dev/null
> +++ b/modules.d/95nbd/install
> @@ -0,0 +1,7 @@
> +#!/bin/bash
> +
> +inst nbd-client
> +inst_hook cmdline 90 "$moddir/parse-nbdroot.sh"
> +inst_hook netroot 90 "$moddir/nbd-netroot.sh"
> +inst "$moddir/nbdroot" "/sbin/nbdroot"
> +instmods nbd
> diff --git a/modules.d/95nbd/nbd-netroot.sh b/modules.d/95nbd/nbd-netroot.sh
> new file mode 100755
> index 0000000..74b3da8
> --- /dev/null
> +++ b/modules.d/95nbd/nbd-netroot.sh
> @@ -0,0 +1,11 @@
> +#!/bin/sh # for highlighting
> +
> +if [ "$root" = "dhcp" ]; then
> + if [ -n "$new_root_path" -a -z "${new_root_path%%nbd:*}" ]; then
> + root="$new_root_path"
> + fi
> +fi
> +
> +if [ -z "${root%nbd:*}" ]; then
> + handler=/sbin/nbdroot
> +fi
> diff --git a/modules.d/95nbd/nbdroot b/modules.d/95nbd/nbdroot
> new file mode 100755
> index 0000000..51120c2
> --- /dev/null
> +++ b/modules.d/95nbd/nbdroot
> @@ -0,0 +1,96 @@
> +#!/bin/sh
> +
> +. /lib/dracut-lib
> +
> +PATH=$PATH:/sbin:/usr/sbin
> +
> +# XXX needs error handling like ifup/dhclient-script
> +
> +if getarg rdnetdebug; then
> + exec > /tmp/nbdroot.$1.$$.out
> + exec 2>> /tmp/nbdroot.$1.$$.out
> + set -x
> +fi
> +
> +# root is in the form root=nbd:server:port:fstype:fsopts:nbdopts
> +netif="$1"
> +root="$2"
> +
> +root=${root#nbd:}
> +nbdserver=${root%%:*}; root=${root#*:}
> +nbdport=${root%%:*}; root=${root#*:}
> +nbdfstype=${root%%:*}; root=${root#*:}
> +nbdflags=${root%%:*}
> +nbdopts=${root#*:}
> +
> +if [ "$nbdopts" = "$nbdflags" ]; then
> + unset nbdopts
> +fi
> +if [ "$nbdflags" = "$nbdfstype" ]; then
> + unset nbdflags
> +fi
> +if [ "$nbdfstype" = "$nbdport" ]; then
> + unset nbdfstype
> +fi
> +if [ -z "$nbdfstype" ]; then
> + nbdfstype=auto
> +fi
> +
> +# look through the NBD options and pull out the ones that need to
> +# go before the host etc. Append a ',' so we know we terminate the loop
> +nbdopts=${nbdopts},
> +while [ -n "$nbdopts" ]; do
> + f=${nbdopts%%,*}
> + nbdopts=${nbdopts#*,}
> + if [ -z "$f" ]; then
> + break
> + fi
> + if [ -z "${f%bs=*}" -o -z "${f%timeout=*}" ]; then
> + preopts="$preopts $f"
> + continue
> + fi
> + opts="$opts $f"
> +done
> +
> +# look through the flags and see if any are overridden by the command line
> +nbdflags=${nbdflags},
> +while [ -n "$nbdflags" ]; do
> + f=${nbdflags%%,*}
> + nbdflags=${nbdflags#*,}
> + if [ -z "$f" ]; then
> + break
> + fi
> + if [ "$f" = "ro" -o "$f" = "rw" ]; then
> + nbdrw=$f
> + continue
> + fi
> + fsopts=${fsopts+$fsopts,}$f
> +done
> +
> +getarg ro && nbdrw=ro
> +getarg rw && nbdrw=rw
> +fsopts=${fsopts+$fsopts,}${nbdrw}
> +
> +modprobe nbd || exit 1
> +
> +# XXX better way to wait for the device to be made?
> +i=0
> +while [ ! -b /dev/nbd0 ]; do
> + [ $i -ge 20 ] && exit 1
> + sleep 0.1
> + i=$(( $i + 1))
> +done
> +
> +# XXX netroot expects to have the handler mount things, but we should
> +# XXX allow LVM, LUKS, etc over nbd
> +
> +nbd-client $preopts "$nbdserver" "$nbdport" /dev/nbd0 $opts || exit 1
Ah, but we are not really a netroot in the sense that NFS is -- all we
are doing is attaching a block device. Once it is attached the usual
root-on-block-device rules should kick in as soon as udev sees the block
devices.
> +if ! mount -t $nbdfstype -o$fsopts /dev/nbd0 $NEWROOT; then
> + # Mount failed, clean up after ourselves so if we try a different
> + # interface it can succeed
> + nbd-client -d /dev/nbd0
> + exit 1
> +fi
why not just poke udev with udevadm trigger if there is any doubt?
> +exit 0
> diff --git a/modules.d/95nbd/parse-nbdroot.sh b/modules.d/95nbd/parse-nbdroot.sh
> new file mode 100755
> index 0000000..4bedaab
> --- /dev/null
> +++ b/modules.d/95nbd/parse-nbdroot.sh
> @@ -0,0 +1,49 @@
> +#!/bin/dash
> +
> +# It'd be nice if this could share rules with 99-block.sh, but since
> +# the kernel side adds nbd{1..16} when the module is loaded -- before
> +# they are associated with a server -- we cannot use the udev add rule
> +# to find it
> +#
> +# XXX actually we could, if we move to root=XXX and netroot=XXX, then
> +# you could do root=LABEL=/ nbdroot=XXX, or netroot=nbd:XXX
> +#
> +# However, we need to be 90-nbd.sh to catch root=/dev/nbd*
> +#
> +# Preferred format:
> +# root=nbd:srv:port[:fstype[:rootflags[:nbdopts]]]
> +#
> +# nbdopts is a comma seperated list of options to give to nbd-client
> +#
> +#
> +# Legacy formats:
> +# nbdroot=srv,port
> +# nbdroot=srv:port[:fstype[:rootflags[:nbdopts]]]
> +# root=dhcp nbdroot=srv:port[:fstype[:rootflags[:nbdopts]]]
> +# root=nbd nbdroot=srv:port[:fstype[:rootflags[:nbdopts]]]
> +#
> +
> +case "$root" in
> + nbd|dhcp|'')
> + if getarg nbdroot= > /dev/null; then
> + root=nbd:$(getarg nbdroot=)
> + fi
> + ;;
> +esac
> +
> +# Convert the Debian style to our syntax, but avoid matches on fs arguments
> +case "$root" in
> + nbd:*,*)
> + if check_occurances "$root" ',' 1 && check_occurances "$root" ':' 1;
> + then
> + root=${root%*,}:${root#*,}
> + fi
> + ;;
> +esac
> +
> +if [ "${root%%:*}" = "nbd" ]; then
> + # XXX validate options here?
> + # XXX generate udev rules?
> + rootok=1
> + netroot=nbd
> +fi
--
Victor Lowther
RHCE# 805008539634727
LPIC-2# LPI000140019
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