when initializing the devmapper driver, attempt to sync udev and device
mapper. If udev sync is not supported, print a warning. Eventually we'll
likely bail here to avoid unpredictable behavior for users.
Signed-off-by: Vincent Batts <vbatts@redhat.com>
Fixes#9960
This adds the output of a "Backing Filesystem:" entry to `docker info`
to overlay, aufs, and devicemapper graphdrivers. The default list
includes a fairly complete list of common filesystem names from
linux/include/uapi/linux/magic.h, but if the backing filesystem is not
recognized, the code will simply show "<unknown>"
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>
There are a couple of drivers that swallow errors that may occur in
their Put() implementation.
This changes the signature of (*Driver).Put for all the drivers implemented.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
Presenly the "Data file:" shows either the loopback _file_ or the block device.
With this, the "Data file:" will always show the device, and if it is a
loopback, then there will additionally be a "Data loop file:".
(Same for "Metadata file:")
Signed-off-by: Vincent Batts <vbatts@redhat.com>
syscall.Unmount failed sometimes when user interrupted exporting,
for example a Ctrl-C, or pipe to commands which closed the pipe early,
like "docker export <container_name> | file -"; this syscall.Unmount
could sometimes return EBUSY and didn't actually umount the filesystem;
which would cause a following export command fail to mount;
change to lazy Unmount with MNT_DETACH can fix the problem, this is
the same behavior as in Shutdown;
```text
time="2015-01-03T21:27:26Z" level=error msg="Warning: error unmounting device
34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e: device or resource busy"
```
```
$ docker export thirsty_ardinghelli | file -
/dev/stdin: POSIX tar archive
time="2015-01-03T21:58:17Z" level=fatal msg="write /dev/stdout: broken pipe"
$ docker export thirsty_ardinghelli
time="2015-01-03T21:54:33Z" level=fatal msg="Error: thirsty_ardinghelli: Error getting container
34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e from driver devicemapper:
Error mounting '/dev/mapper/docker-253:0-3148372-34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e'
on '/var/lib/docker/devicemapper/mnt/34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e': device or resource busy"
```
Signed-off-by: Derek Che <drc@yahoo-inc.com>
Use transaction logic during device deletion and do rollback if transaction
is not complete. Following is the sequence of events.
- Open transaction and save to metafile
- Delete device from pool
- Delete device metadata file from disk
- Close Transaction
If docker crashes without closing transaction then rollback will take
place upon next docker start.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Finally this patch uses the notion of transaction for device or snapshot
device creation.
Following is sequence of event.
- Open a trasaction and save details in a file.
- Create a new device/snapshot device
- If a new device id is used, refresh transaction with new device id details.
- Create device metadata file
- Close transaction.
If docker crashes anywhere in between without closing transaction, then
upon next start, docker will figure out that there was a pending transaction
and it will roll back transaction. That is it will do following.
- Delete Device from pool
- Delete device metadata file
- Remove transaction file to mark no transaction is pending.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Finally, we seem to have all the bits to keep track of all used device
Ids and find a free device Id to use when creating a new device. Start
using it.
Ideally we should completely move away from retry logic when pool returns
-EEXISTS. For now I have retained that logic and I simply output a warning.
When things are stable, we should be able to get rid of it.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Open code createDevice() and createSnapDevice() and move all the logic
in the caller.
This is a sheer code reorganization so that all device Id allocation
logic is in one function. That way in case of erros, one can easily
cleanup and mark device Id free again. (Later patches benefit from
it).
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now we are accessing devices.NextDeviceId directly and also
incrementing it at various places.
Instead provide a helper function which is responsile for
incrementing NextDeviceId and return next deviceId.
This is just code structuring. This will help later once we
convert this function to find a free device Id and it goes
through a bitmap of used/free device Ids.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
When docker starts, build a used/free Device Id map from the per
device meta files we already have. These meta files have the data
which device Ids are in use. Parse these files and mark device as
used in the map.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Currently devicemapper backend does not keep track of used device Ids in
the pool. It tries a device Id and if that device Id exists in pool, it
tries with a different Id and keeps on doing this in a loop till it succeeds.
This worked fine so far but now we are moving to transaction based
device creation and deletion. We will keep deviceId information in
transaction which will be rolled back if docker crashed before transaction
was complete.
If we store a deviceId in transaction and later figure out it already
existed in pool and docker crashed, then we will rollback and remove
that existing device Id from pool (which we should not have).
That means, we should know free device Id in pool in advance before
we put that device Id in transaction.
Hence this patch creates a bitmap (one bit each for a deviceId), and
sets the bit if device Id is used otherwise resets it. This patch
is just preparing the ground right now. Actual usage will follow
in later patches.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now setupBaseImage() uses deleteDevice() to delete uninitialized
base image while rest of the code uses DeleteDevice(). Change it and
use a common function everywhere for the sake of uniformity.
I can't see what harm can be done by doing little extra locking done
by DeleteDevice().
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Very soon we will have the notion of an open transaction and keep its
details in a metafile.
When a new transaction is opened, we allocate a new transaction Id,
do the device creation/deletion and then we will close the transaction.
I thought that OpenTransactionId better represents the semantics of
transaction Id associated with an open transaction instead of NewtransactionId.
This patch just does the renaming. No functionality change.
I have also introduced a structure "Transaction" which will keep all
the details associated with a transaction. Later patches will add more
fields in this structure.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Currently new transaction Id is created using allocateTransactionId()
function. This function takes NewTransactionId and bumps up by one
to create NewTransactionId.
I think ideally we should be bumping up devices.TransactionId by 1
to come up with NewTransactionId. Because idea is that devices.TransactionId
contains the current pool transaction Id and to come up with a new
transaction Id bump it up by one.
Current code is not wrong as we are keeping NewTransactionId and
TransactionId in sync. But it will be more direct if we look at
devices.TransactionId to come up with NewTransactionId. That way
we don't have to even initialize NewTransactionId during startup
as first time somebody wants to do a transaction, it will be
allocated fresh.
So simplify the code a bit. No functionality change.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Currently updatePoolTransactionId() checks if NewTransactionId and
TransactionId are not same only then update the transaction Id in pool. This
check is redundant. Currently we call updatePoolTransactionId() only from
two places and both of these first allocate a new transaction Id.
Also updatePoolTransactionId() should only be called after allocating
new transaction Id otherwise it does not make any sense.
Remove the redundant check and reduce confusion.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Create two new helper functions for device and snap device creation. These
functions will not only create the device and also register the device.
Again, makes the code structure better and keeps all transaction logic
contained to functions instead of spilling over into functions like
setupBaseImage or AddDevice().
Just the code reorganization. No functionality change.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Currently registerDevice() adds a device to in-memory table, saves metadata
and also updates the pool transaction ID.
Now move transaciton Id update out of registerDevice() and provide a new
function unregisterDevice() which does the reverse of registerDevice().
This will simplify some code down the line and make it more structured.
This is just code reorganization and should not change functionality.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Currently devicemapper CreateDevice and CreateSnapDevice keep on retrying
device creation till a suitable device id is found.
With new transaction mechanism we need to store device id in transaction
before it has been created.
So change the logic in such a way that caller decides the devices Id to
use. If that device Id is not available, caller bumps up the device Id
and retries.
That way caller can update transaciton too when it tries a new Id. Transaction
related patches will come later in the series.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
When we are deleting a device, we also delete associated metadata file. If
that file removal fails, we are adding back the device in in-memory
table. I really can't see what's the point. When next lookup takes place
it will be automatically loaded if need be. Remove that code.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now initMetaData() first queries the pool for current transaciton Id
and then it migrates the old metafile.
Move pool transaction Id query and file migration in separate functions
for better code reuse and organization.
Given we have removed device transaction Id dependency from saveMetaData(),
we don't have to query pool transaction Id before migrating files.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Anes Hasicic
Arnaud Porterie
Deng Guangxing
Qiang Huang
Alexander Morozov
Jessie Frazelle
Phil Estes
Mabin
Vincent Batts
Peter Volpe
Sven Dowideit
Vivek Goyal
Vincent Batts
Phil Estes
Alexander Morozov
unclejack
Derek
Michael Crosby