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
ZFS allows for specific permissions to be delegated to normal users
with the `zfs allow` and `zfs unallow` commands. In addition, non-
privileged users should be able to run all of the following commands:
* zpool [list | iostat | status | get]
* zfs [list | get]
Historically this functionality was not available on Linux. In order
to add it the secpolicy_* functions needed to be implemented and mapped
to the equivalent Linux capability. Only then could the permissions on
the `/dev/zfs` be relaxed and the internal ZFS permission checks used.
Even with this change some limitations remain. Under Linux only the
root user is allowed to modify the namespace (unless it's a private
namespace). This means the mount, mountpoint, canmount, unmount,
and remount delegations cannot be supported with the existing code. It
may be possible to add this functionality in the future.
This functionality was validated with the cli_user and delegation test
cases from the ZFS Test Suite. These tests exhaustively verify each
of the supported permissions which can be delegated and ensures only
an authorized user can perform it.
Two minor bug fixes were required for test-running.py. First, the
Timer() object cannot be safely created in a `try:` block when there
is an unconditional `finally` block which references it. Second,
when running as a normal user also check for scripts using the
both the .ksh and .sh suffixes.
Finally, existing users who are simulating delegations by setting
group permissions on the /dev/zfs device should revert that
customization when updating to a version with this change.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#362Closes#434Closes#4100Closes#4394Closes#4410Closes#4487
One of the side effects of calling zvol_create_minors() in
zvol_init() is that all pools listed in the cache file will
be opened. Depending on the state and contents of your pool
this operation can take a considerable length of time.
Doing this at load time is undesirable because the kernel
is holding a global module lock. This prevents other modules
from loading and can serialize an otherwise parallel boot
process. Doing this after module inititialization also
reduces the chances of accidentally introducing a race
during module init.
To ensure that /dev/zvol/<pool>/<dataset> devices are
still automatically created after the module load completes
a udev rules has been added. When udev notices that the
/dev/zfs device has been create the 'zpool list' command
will be run. This then will cause all the pools listed
in the zpool.cache file to be opened.
Because this process in now driven asynchronously by udev
there is the risk of problems in downstream distributions.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #756
Issue #1020
Issue #1234
This rule does not need to be dracut specific. Automatically loading
the zfs module stack when a zfs device is detected is usually desirable.
My only concern is that this might cause trouble for large pools where
we don't want to automatically import the pool until all the disks are
available. However, we'll cross that bridge when we come to it.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
