Lubomir Rintel [Thu, 30 Aug 2018 14:21:17 +0000 (16:21 +0200)]
iscsi: do not replace the configuration in the host system
ln: failed to create symbolic link '/usr/lib/systemd/system/sockets.target.wants/iscsid.socket': Permission denied
ln: failed to create symbolic link '/usr/lib/systemd/system/sockets.target.wants/iscsiuio.socket': Permission denied
No way. Just ensure the links are there in the initramfs image. In fact,
that is already the case for iscsiuio.socket. Add iscsid.socket too.
If the network module obtained a lease using dhclient, NetworkManager
must be configured to use it too, otherwise it would obtain a different
lease (and could potentially break a connection to the network volume).
Kairui Song [Tue, 11 Sep 2018 11:32:24 +0000 (19:32 +0800)]
Add support for building a squashed initramfs
With all files stored in ramfs, and most of them are not compressed,
the initramfs will take up a lot of memory. Besides, if the file number
is large, each file will waste some memory due to page fragmetation.
This is due to ramfs' design, at least one page will be allocated for
one file however small the file is. On machine with large page size,
this will become worse and waste too many memory.
One approach to reducing the memory usage is to reduce the number of
files that got directly loaded into the root ramfs, and compress files
by put most files will into a read-only squash image and keep a minimum
set of executable and libraries outside as the loader for the squash
image. After the squash image is mounted, the real 'init' will be
executed and then everything behaves as usual.
This patch will introduce a '99squash' module which will never be
included by default. User can force add it, and if it is included,
dracut will perform some extra steps before creating the final image:
For now, "/etc" and "/usr" will be moved into the squashfs image.
"/init" will be renamed to "/init.stock" and replaced by "/init.squash".
Files and folders need to be accessible before mounting the image will
be still avaliable at their original place. And due to squashfs is
readonly, an overlayfs layer will be created on top of squashfs mount
point, as many dracut module require readwrite access to "/etc" and
"/usr", "init.squash" will ultimately call "/init.stock".
An extra systemd service will be installed. This service will umount all
squashfs related mount points right before switch-root to release
resources properly. This service will not actually do anything if
switch-root is not used.
This is very helpful when mem resource is very limited, like Kdump.
According to my tests, this squash module can help save about 35MB of
memory with 64K page size, or about 15MB with 4K page size on an
ordinary kdump capture routine. This module could also help reduce
memory usage for normal boot up process.
Won't change any behavior if squash module is not enabled.
Alexander Tsoy [Sat, 8 Sep 2018 23:47:09 +0000 (02:47 +0300)]
install: avoid non-portable __WORDSIZE
Lets not unnecessarily rely on __WORDSIZE, which is not clearly specified
by any spec. Use explicit size comparisons if we're not interested in the
WORDSIZE, anyway.
Alexander Tsoy [Sat, 8 Sep 2018 14:02:03 +0000 (17:02 +0300)]
Prevent environment leaking into initrd-release
On my system the following initrd-release is generated:
...
VERSION="4 dracut-048 dracut-048"
...
VERSION is not defined in /etc/os-release, so the variable is
concatenated with its previous value:
* "4" comes from the kernel build system since dracut is called from the
kernel install hook ("4" is a major kernel version);
* first "dracut-048" comes from the "systemd-initrd" module;
* second "dracut-048" comes from the "base" module.
98dracut-systemd: Start systemd-vconsole-setup before dracut-cmdline-ask
This is what happened before this patch (edited for brevity):
dracut-cmdline-ask.service in modules.d/98dracut-systemd, which invokes
dracut-cmdline-ask.sh. This script and systemd-vconsole-setup are
started in parallel for the same console (tty1).
Then dracut-cmdline-ask quits immediately without doing anything (unless
rd.cmdline=ask is given). As this is a bash script and it gets tty as
stdin as specified in its *.service, this triggers the hangup of tty1 at
its exit.
Meanwhile systemd-vconsole-setup continues and tries some ioctls after
that, but they fail because of the hung up tty1.
The usual culprit for starting systemd-vconsole-setup early on is
plymouth-start.service, even if plymouth.enable=0 is set.
A popular (and annoying) symptom of this as reported by users was
the inability use their configured keyboard layout in plymouth when
unlocking their crypted block devices.
Kairui Song [Mon, 20 Aug 2018 10:43:19 +0000 (18:43 +0800)]
99base: enable initqueue if extra devices are added
When extra devices are added, initqueue should be enabled to make sure
those devices are present, so following services and routines could
use those devices.
Use multiple lower layer directories in a single OverlayFS mount with
a transient overlay directory.
Tolerate a command line with rd.live.overlay.readonly and NO persistent
overlay by reconfiguring the OverlayFS mount options.
Use more compatible shell syntax for testing symlinks, and use printf
instead of echo -e.
Frederick Grose [Mon, 20 Aug 2018 13:47:50 +0000 (09:47 -0400)]
dmsquash-live: Support a flattened squashfs.img
A simplified root filesystem structure may be provided for OverlayFS
overlays by squashing the root filesystem directly instead of squashing
an embedded image file at /LiveOS/rootfs.img. Detect and configure
such a squashed root filesystem for live booting.
For OverlayFS boots, avoid the read-only Device-mapper linear device
at /dev/mapper/live-base.
Create a consistent device link at /dev/live-base for the read-only
base loop device for all overlayed live root filesystems.
Consistently provide a link at /dev/root for wait_for_dev.
Frederick Grose [Wed, 1 Aug 2018 22:40:20 +0000 (18:40 -0400)]
livenet: Enable OverlayFS overlay in sysroot.mount generator.
Adjust sysroot.mount configuration for rd.live.overlay.overlayfs option.
Use link at /dev/root as a consistent flag for wait_for_dev.
Adjust documentation.
Kairui Song [Wed, 25 Jul 2018 08:47:37 +0000 (16:47 +0800)]
lsinitrd: optimize performance when handling multiple files
Currently, when trying to unpack or print the content of multiple
files, lsinitrd will decompress the image and pipe the decompressed
content to cpio to retrive each file if the image is compressed.
Which mean if we want to extract 10 files the image will be decompressed
10 times, which is a waste of time.
This patch will let lsinitrd decompress the image file to a temp file
first if multiple file names are given, then cpio will read from the
decompressed temp file, which will speed up a lot.
Time consumption test for command:
`lsinitrd initramfs-4.16.15-300.fc28.x86_64.img \
usr/lib/dracut/build-parameter.txt \
usr/lib/dracut/modules.txt \
etc/machine-id \
etc/hostname \
usr/lib/udev/rules.d/99-systemd.rules`
Before the patch:
2.37user 0.33system 0:02.12elapsed
After the patch:
0.50user 0.42system 0:00.72elapsed
There would be a more significant time difference if we try to
extract more files.
Kairui Song [Wed, 25 Jul 2018 08:34:08 +0000 (16:34 +0800)]
lsinitrd: allow to only unpack certain files
Before this patch, "--unpack" will always unpack the whole image.
Make "--unpack" be able to unpack only certain files, it will be
easier to retrieve files from initramfs image.
Kairui Song [Tue, 17 Jul 2018 09:16:07 +0000 (17:16 +0800)]
Record loaded kernel modules when hostonly mode is enabled
A hostonly image will not include every possibly required kernel module,
so if any hardware or configuration changed, the image may fail to boot.
One way to know if there are any hardware change or configuration change
that will require an image rebuild or not is to check the loaded kernel
module list. If the loaded kernel module list differs from last build
time, then the image may require to be rebuilt.
This commit will let dracut record the loaded kernel module list when
the image is being built, so other tools or services can compare this
list with currently loaded kernel modules to decide if dracut should be
called to rebuild the image.
To retrieve the loaded kernel modules list when an image is built, use
lsinitrd command:
projects / thirdparty / dracut.git / log
