The ability to save and verify base device UUID (#13896) introduced a
situation where the initialization would panic when removing the device
returns EBUSY.
Functions `verifyBaseDeviceUUID` and `saveBaseDeviceUUID` now take the
lock on the `DeviceSet`, which solves the problem as `removeDevice`
assumes it owns the lock.
Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
DeviceMapper must be explicitly selected because the Docker binary might not be linked to the right devmapper library.
With this change, Docker fails fast if the driver detection finds the devicemapper directory but the driver is not the default option.
The option `override_udev_sync_check` doesn't make sense anymore, since the user must be explicit to select devicemapper, so it's being removed.
Docker fails to use devicemapper only if Docker has been built statically unless the option was explicit.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Export metadata for container and image in docker-inspect when overlay
graphdriver is in use. Right now it is done only for devicemapper graph
driver.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
It is easy for one to use docker for a while, shut it down and restart
docker with different set of storage options for device mapper driver
which will effectively change the thin pool. That means any of the
metadata stored in /var/lib/docker/devicemapper/metadata/ is not valid
for the new pool and user will run into various kind of issues like
container not found in the pool etc.
Users think that their images or containers are lost but it might just
be the case of configuration issue. People might use wrong metadata
with wrong pool.
To detect such situations, save UUID of base image and once docker
starts later, query and compare the UUID of base image with the
stored one. If they don't match, fail the initialization with the
error that UUID failed to match.
That way user will be forced to cleanup /var/lib/docker/ directory
and start docker again.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Export image/container metadata stored in graph driver. Right now 3 fields
DeviceId, DeviceSize and DeviceName are being exported from devicemapper.
Other graph drivers can export fields as they see fit.
This data can be used to mount the thin device outside of docker and tools
can look into image/container and do some kind of inspection.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Previously the cache was only updated once on startup, because the graph
code only check for filesystems on startup. However this breaks the API as it
was supposed and so unit tests.
Fixes#13142
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
The docker graph call driver.Exists() on initialisation for each filesystem in
the graph. This results will results in a lot `zfs get all` commands. To reduce
this, retrieve all descend filesystem at startup and cache it for later checks
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
instead of let zfs automaticly mount datasets, mount them on demand using mount(2).
This speed up this graph driver in 2 ways:
- less zfs processes needed to start a container
- /proc/mounts get smaller, so zfs userspace tools has less to read (which can
a significant amount of data as the number of layer grows)
This ways it can be also ensured that the correct mountpoint is always used.
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
Right now devicemapper mounts thin device using online discards by default
and passes mount option "discard". Generally people discourage usage of
online discards as they can be a drain on performance. Instead it is
recommended to use fstrim once in a while to reclaim the space.
In case of containers, we recommend to keep data volumes separate. So
there might not be lot of rm, unlink operations going on and there might
not be lot of space being freed by containers. So it might not matter
much if we don't reclaim that free space in pool.
User can still pass mount option explicitly using dm.mountopt=discard to
enable discards if they would like to.
So this is more like setting the containers by default for better performance
instead of better space efficiency in pool. And user can change the behavior
if they don't like default behavior.
Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
If device is being reactivated before it could go away and deferred
deactivation is scheduled on it, cancel it.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
This will help with debugging as one could just do "docker info" and figure
out of deferred removal is enabled or not.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Provide a new command line knob dm.deferred_device_removal which will enable
deferred device deactivation if driver and library support it.
This patch also checks for library support and driver version.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Before this, a storage driver would be defaulted to based on the
priority list, and only print a warning if there is state from other
drivers.
This meant a reordering of priority list would "break" users in an
upgrade of docker, such that there images in the prior driver's state
were now invisible.
With this change, prior state is scanned, and if present that driver is
preferred.
As such, we can reorder the priority list, and after an upgrade,
existing installs with prior drivers can have a contiguous experience,
while fresh installs may default to a driver in the new priority list.
Ref: https://github.com/docker/docker/pull/11962#issuecomment-88274858
Signed-off-by: Vincent Batts <vbatts@redhat.com>
Signed-off-by: Megan Kostick <mkostick@us.ibm.com>
Alphabetize FSMagic list to make more human-readable.
Signed-off-by: Megan Kostick <mkostick@us.ibm.com>
John Howard
Arnaud Porterie
Jessie Frazelle
David Calavera
Mary Anthony
Vivek Goyal
Vincent Batts
Brian Goff
Jörg Thalheim
Tibor Vass
mapk0y
Alexey Guskov
Alexander Morozov
Michael Crosby
Lei Jitang
Alexander Morozov
Burke Libbey
unclejack
Antonio Murdaca
Megan Kostick
Vincent Batts