Initramfs scripts for ZoL.

* Supports booting of a ZFS snapshot.
  Do this by cloning the snapshot into a dataset. If this, the resulting
  dataset, already exists, destroy it. Then mount it on root.
  * If snapshot does not exist, use base dataset (the part before '@')
    as boot filesystem instead.
  * If no snapshot is specified on the 'root=' kernel command line, but there
    is an '@', then get a list of snapshots below that filesystem and ask the
    user which to use.
  * Clone with 'mountpoint=none' and 'canmount=noauto' - we mount manually
    and explicitly.
    * For sub-filesystems, that doesn't have a mountpoint property set, we use
      the 'org.zol:mountpoint' to keep track of it's mountpoint.
  * Allow rollback of snapshots instead of clone it and boot from the clone.
* Allow mounting a root- and subfs with mountpoint=legacy set
* Allow mounting a filesystem which is using nativ encryption.
* Support all currently used kernel command line arguments
  All the different distributions have their own standard on what to specify
  on the kernel command line to boot of a ZFS filesystem.
  * Extra options:
    * zfsdebug=(on,yes,1)	Show extra debugging information
    * zfsforce=(on,yes,1)	Force import the pool
    * rollback=(on,yes,1)	Rollback (instead of clone) the snapshot
* Only try to import pool if it haven't already been imported
  * This will negate the need to force import a pool that have not been exported cleanly.
  * Support exclusion of pools to import by setting ZFS_POOL_EXCEPTIONS in /etc/default/zfs.
* Support additional configuration variable ZFS_INITRD_ADDITIONAL_DATASETS
  to mount additional filesystems not located under your root dataset.
* Include /etc/modprobe.d/{zfs,spl}.conf in the initrd if it/they exist.
* Include the udev rule to use by-vdev for pool imports.
* Include the /etc/default/zfs file to the initrd.
* Only try /dev/disk/by-* in the initrd if USE_DISK_BY_ID is set.
  * Use /dev/disk/by-vdev before anything.
  * Add /dev as a last ditch attempt.
  * Fallback to using the cache file if that exist if nothing else worked.
* Use /sbin/modprobe instead of built-in (BusyBox) modprobe.
  This gets rid of the message "modprobe: can't load module zcommon".
  Thanx to pcoultha for finding this.

Signed-off-by: Turbo Fredriksson <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2116
Closes #2114

1 files changed, 21 insertions, 0 deletions

diff --git a/contrib/initramfs/Makefile.am b/contrib/initramfs/Makefile.am
new file mode 100644
index 000000000..fa2b5a283
--- /dev/null
+++ b/contrib/initramfs/Makefile.am
@@ -0,0 +1,21 @@
+initrddir = $(datarootdir)/initramfs-tools
+
+initrd_SCRIPTS = conf-hooks.d/zfs hooks/zfs scripts/zfs
+
+EXTRA_DIST = \
+	$(top_srcdir)/contrib/initramfs/conf-hooks.d/zfs \
+	$(top_srcdir)/contrib/initramfs/hooks/zfs \
+	$(top_srcdir)/contrib/initramfs/scripts/zfs \
+	$(top_srcdir)/contrib/initramfs/README.initramfs.markdown
+
+install-initrdSCRIPTS: $(EXTRA_DIST)
+	for d in conf-hooks.d hooks scripts; do \
+	  $(MKDIR_P) $(DESTDIR)$(initrddir)/$$d; \
+	  cp $(top_srcdir)/contrib/initramfs/$$d/zfs \
+	    $(DESTDIR)$(initrddir)/$$d/; \
+	done
+	if [ -f etc/init.d/zfs ]; then \
+	  $(MKDIR_P) $(DESTDIR)$(DEFAULT_INITCONF_DIR); \
+	  cp $(top_srcdir)/etc/init.d/zfs \
+	    $(DESTDIR)$(DEFAULT_INITCONF_DIR)/; \
+	fi