We are building new bootonce mechanism (previously zfs bootnext) and it is based on this OpenZFS change. Since this patch is nicely self contained, I am commiting it as is, and we can stack our changes. Original patch description follows: Modern bootloaders leverage data stored in the root filesystem to enable some of their powerful features. GRUB specifically has a grubenv file which can store large amounts of configuration data that can be read and written at boot time and during normal operation. This allows sysadmins to configure useful features like automated failover after failed boot attempts. Unfortunately, due to the Copy-on-Write nature of ZFS, the standard behavior of these tools cannot handle writing to ZFS files safely at boot time. We need an alternative way to store data that allows the bootloader to make changes to the data. This work is very similar to work that was done on Illumos to enable similar functionality in the FreeBSD bootloader. This patch is different in that the data being stored is a raw grubenv file; this file can store arbitrary variables and values, and the scripting provided by grub is powerful enough that special structures are not required to implement advanced behavior. We repurpose the second padding area in each label to store the grubenv file, protected by an embedded checksum. We add two ioctls to get and set this data, and libzfs_core and libzfs functions to access them more easily. There are no direct command line interfaces to these functions; these will be added directly to the bootloader utilities. Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes #10009 Obtained from: OpenZFS Sponsored by: Netflix, Klara Inc. |
||
---|---|---|
bin | ||
cddl | ||
contrib | ||
crypto | ||
etc | ||
gnu | ||
include | ||
kerberos5 | ||
lib | ||
libexec | ||
release | ||
rescue | ||
sbin | ||
secure | ||
share | ||
stand | ||
sys | ||
targets | ||
tests | ||
tools | ||
usr.bin | ||
usr.sbin | ||
.arcconfig | ||
.arclint | ||
.cirrus.yml | ||
.clang-format | ||
.gitattributes | ||
.gitignore | ||
COPYRIGHT | ||
LOCKS | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc1 | ||
Makefile.libcompat | ||
Makefile.sys.inc | ||
ObsoleteFiles.inc | ||
README | ||
README.md | ||
RELNOTES | ||
UPDATING |
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.
Source Roadmap:
bin System/user commands.
cddl Various commands and libraries under the Common Development
and Distribution License.
contrib Packages contributed by 3rd parties.
crypto Cryptography stuff (see crypto/README).
etc Template files for /etc.
gnu Various commands and libraries under the GNU Public License.
Please see gnu/COPYING* for more information.
include System include files.
kerberos5 Kerberos5 (Heimdal) package.
lib System libraries.
libexec System daemons.
release Release building Makefile & associated tools.
rescue Build system for statically linked /rescue utilities.
sbin System commands.
secure Cryptographic libraries and commands.
share Shared resources.
stand Boot loader sources.
sys Kernel sources.
sys/<arch>/conf Kernel configuration files. GENERIC is the configuration
used in release builds. NOTES contains documentation of
all possible entries.
tests Regression tests which can be run by Kyua. See tests/README
for additional information.
tools Utilities for regression testing and miscellaneous tasks.
usr.bin User commands.
usr.sbin System administration commands.
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see:
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/current-stable.html