Historically a dynamic misc minor number was registered for the
/dev/zfs device in order to prevent minor number collisions. This
was fine but it prevented us from being able to use the kernel
module auto-loaded which requires a known reserved value.
Resolve this issue by adding a configure test to find an available
misc minor number which can then be used in MODULE_ALIAS_MISCDEV at
build time. By adding this alias the zfs kmod is added to the list
of known static-nodes and the systemd-tmpfiles-setup-dev service
will create a /dev/zfs character device at boot time.
This in turn allows us to update the 90-zfs.rules file to make it
aware this is a static node. The upshot of this is that whenever
a process (zpool, zfs, zed) opens the /dev/zfs the kmods will be
automatic loaded. This even works for unprivileged users so there
is no longer a need to manually load the modules at boot time.
As an additional bonus the zed now no longer needs to start after
the zfs-import.service since it will trigger the module load.
In the unlikely event the minor number we selected conflicts with
another out of tree unregistered minor number the code falls back
to dynamically allocating it. In this case the modules again
must be manually loaded.
Note that due to the change in the method of registering the minor
number the zimport.sh test case may incorrectly fail when the
static node for the installed packages is created instead of the
dynamic one. This issue will only transiently impact zimport.sh
for this single commit when we transition and are mixing and
matching methods.
Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes#7287
* Disable zfs-import-scan.service by default. This ensures that
pools will not be automatically imported unless they appear in
the cache file. When this service is explicitly enabled pools
will be imported with the "cachefile=none" property set. This
prevents the creation of, or update to, an existing cache file.
$ systemctl list-unit-files | grep zfs
zfs-import-cache.service enabled
zfs-import-scan.service disabled
zfs-mount.service enabled
zfs-share.service enabled
zfs-zed.service enabled
zfs.target enabled
* Change services to dynamic from static by adding an [Install]
section and adding 'WantedBy' tags in favor of 'Requires' tags.
This allows for easier customization of the boot behavior.
* Start the zfs-import-cache.service after the root pivot so
the cache file is available in the standard location.
* Start the zfs-mount.service after the systemd-remount-fs.service
to ensure the root fs is writeable and the ZFS filesystems can
create their mount points.
* Change the default behavior to only load the ZFS kernel modules
in zfs-import-*.service or when blkid(8) detects a pool. Users
who wish to unconditionally load the kernel modules must uncomment
the list of modules in /lib/modules-load.d/zfs.conf.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4325Closes#4496Closes#4658Closes#4699
This adds systemd unit files replacing the functionality offered by
the SysV init script found in etc/init.d.
It has been developed and tested on Fedora 19, Fedora 20
and openSuSE 13.1.
Four unit files and one target are offered.
zfs-import-cache.service:
Import pools from /etc/zfs/zpool.cache. This unit will wait for
udev to settle.
zfs-import-scan.service:
Import pools by scanning /dev/disk/by-id for zvols. This unit will
only run if /etc/zfs/zpool.cache is not present. This unit will wait
for udev to settle
zfs-mount.service:
Mount ZFS native filesystems. It contains a dependency to be loaded
before local-fs.target.
zfs-share.service:
Share NFS/SMB filesystems. This unit contains a dependency that
will cause it to be restarted whenever the smb or nfs-server unit
is restarted, restoring the shares added.
zfs.target:
This target pulls in the other units in order to start ZFS. It's
the only unit that can be enabled/disabled, all other services
are static and pulled in by dependencies. It will honour zfs=off
and zfs=no options on the kernel command line.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2108
