The attached patch causes mayflower to use dynamically allocated loop
devices for the rootfs readonly-base, readwrite-overlay, squashfs, and
osmin loop devices, rather than /dev/loop118,119,120&121.
udev rules were updated, and two new ones added, so that
/dev/live-osmin, /dev/live-squashed, /dev/live-osimg, and
/dev/live-overlay links will be created by udev.
Also, the unnecessary mknod calls referencing those devices were removed.
I tested with a minimal spin under qemu, and everything appeared as it
should. I could mount /dev/mapper/live-osimg-min and it looked fine.
I did another minimal spin with --skip-compression. For some reason I
had to hit ctrl-c at to get past udev starting. I'm pretty sure I've
seen this before and it has nothing to do with this patch. After doing
that, and logging in, I verified that it correctly handled the absence
of a squashfs loop device.
Comments?
-dmc
diff -Naur livecd.200709181929/creator/mayflower livecd/creator/mayflower
--- livecd.200709181929/creator/mayflower 2007-09-19 00:29:13.000000000 +0000
+++ livecd/creator/mayflower 2007-09-19 06:40:41.000000000 +0000
@@ -576,13 +576,14 @@
fi
# live cd helper function
-do_live_from_loop121() {
+do_live_from_base_loop() {
# create a sparse file for the overlay
dd if=/dev/null of=/overlay bs=1024 count=1 seek=$((512*1024)) 2> /dev/null
- losetup /dev/loop119 /overlay
+ OVERLAY_LOOPDEV=\$( losetup -f )
+ losetup \$OVERLAY_LOOPDEV /overlay
# set up the snapshot
- echo 0 \`blockdev --getsize /dev/loop121\` snapshot /dev/loop121 /dev/loop119 p 8 | dmsetup create live-rw
+ echo 0 \`blockdev --getsize \$BASE_LOOPDEV\` snapshot \$BASE_LOOPDEV \$OVERLAY_LOOPDEV p 8 | dmsetup create live-rw
# set up new /dev/root symlink
rm -f /dev/root
@@ -619,9 +620,17 @@
echo "KERNEL==\"sd[a-z][0-9]*\", PROGRAM=\"/lib/udev/vol_id -u %N\", RESULT==\"\$UUID\", SYMLINK+=\"live\"" >> /sysroot/etc/udev/rules.d/50-udev*
fi
- # add rules for /dev/live-squashed and /dev/live-osimg
- echo "KERNEL==\"loop120\" SYMLINK+=\"live-squashed\"" >> /sysroot/etc/udev/rules.d/50-udev*
- echo "KERNEL==\"loop121\" SYMLINK+=\"live-osimg\"" >> /sysroot/etc/udev/rules.d/50-udev*
+ # add rules for loop devices created by this mayflower generated init
+ # i.e. /dev/live-osimg, /dev/live-osmin, /dev/live-overlay,
+ # and /dev/live-squashed
+ if [ -b "\$SQUASHED_LOOPDEV" ]; then
+ echo "KERNEL==\"\${SQUASHED_LOOPDEV#/dev/}\" SYMLINK+=\"live-squashed\"" >> /sysroot/etc/udev/rules.d/50-udev*
+ fi
+ if [ -b "\$OSMIN_LOOPDEV" ]; then
+ echo "KERNEL==\"\${OSMIN_LOOPDEV#/dev/}\" SYMLINK+=\"live-osmin\"" >> /sysroot/etc/udev/rules.d/50-udev*
+ fi
+ echo "KERNEL==\"\${BASE_LOOPDEV#/dev/}\" SYMLINK+=\"live-osimg\"" >> /sysroot/etc/udev/rules.d/50-udev*
+ echo "KERNEL==\"\${OVERLAY_LOOPDEV#/dev/}\" SYMLINK+=\"live-overlay\"" >> /sysroot/etc/udev/rules.d/50-udev*
mount -n -o ro,remount /sysroot
}
@@ -636,10 +645,10 @@
fi
if [ -n "\$OSMINGZ" ]; then
- mknod /dev/loop118 b 7 118
# decompress the delta data
gzip -cd \$OSMINGZ > /osmin
- losetup /dev/loop118 /osmin
+ OSMIN_LOOPDEV=\$( losetup -f )
+ losetup \$OSMIN_LOOPDEV /osmin
fi
# we might have an uncompressed embedded ext3 to use as rootfs (uncompressed live)
@@ -655,17 +664,15 @@
echo "setting up embedded ext3 fs "
fi
- mknod /dev/loop119 b 7 119
- mknod /dev/loop120 b 7 120
- mknod /dev/loop121 b 7 121
mkdir -p /dev/mapper
mknod /dev/mapper/control c 10 63
modprobe dm_snapshot
- losetup /dev/loop121 \$EXT3FS
+ BASE_LOOPDEV=\$( losetup -f )
+ losetup \$BASE_LOOPDEV \$EXT3FS
umount -l /sysroot
- do_live_from_loop121
+ do_live_from_base_loop
fi
# we might have an embedded ext3 on squashfs to use as rootfs (compressed live)
@@ -682,9 +689,6 @@
echo "setting up embedded squash -> ext3 fs "
fi
- mknod /dev/loop119 b 7 119
- mknod /dev/loop120 b 7 120
- mknod /dev/loop121 b 7 121
mkdir -p /dev/mapper
mknod /dev/mapper/control c 10 63
modprobe dm_snapshot
@@ -699,24 +703,26 @@
SQUASHED="/squashed.img"
fi
- losetup /dev/loop120 \$SQUASHED
+ SQUASHED_LOOPDEV=\$( losetup -f )
+ losetup \$SQUASHED_LOOPDEV \$SQUASHED
mkdir -p /squashfs
- mount -n -t squashfs -o ro /dev/loop120 /squashfs
+ mount -n -t squashfs -o ro \$SQUASHED_LOOPDEV /squashfs
- losetup /dev/loop121 /squashfs/os.img
+ BASE_LOOPDEV=\$( losetup -f )
+ losetup \$BASE_LOOPDEV /squashfs/os.img
umount -l /squashfs
if [ "\$live_ram" == "0" ] ; then
umount -l /sysroot
fi
- do_live_from_loop121
+ do_live_from_base_loop
fi
if [ -e /osmin ]; then
# set up the devicemapper snapshot device, which will merge
# the normal live fs image, and the delta, into a minimzied fs image
- echo "0 \$( blockdev --getsize /dev/loop121 ) snapshot /dev/loop121 /dev/loop118 p 8" | dmsetup create --readonly live-osimg-min
+ echo "0 \$( blockdev --getsize \$BASE_LOOPDEV ) snapshot \$BASE_LOOPDEV \$OSMIN_LOOPDEV p 8" | dmsetup create --readonly live-osimg-min
fi
if [ "\$eshell" == "1" ] ; then
--
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