This moves base device creation function in a separate function. Pure
code reorganization. Makes reading code little easier.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
This patch does three things. Following are the descriptions.
===
Create a separate function for delete transactions so that parent function
is little smaller.
Also close transaction if an error happens.
===
When docker is being shutdown, save deviceset metadata first before
trying to remove the devices. Generally caller gives only 10 seconds
for shutdown to complete and then kills it after that. So if some device
is busy, we will wait 20 seconds for it removal and never be able to save
metadata. So first save metadata and then deal with device removal.
===
Move issue discard operation in a separate function. This makes reading code
little easier.
Also don't issue discards if device is still open. That means devices is
still probably being used and issuing discards is not a good idea.
This is especially true in case of deferred deletion. We want to issue
discards when device is not open. At that time device can be deleted too.
Otherwise we will issue discards and deletion will actually fail. Later
we will try deletion again and issue discards again and deletion will
fail again as device is open and busy.
So this will ensure that discards are issued once when device is not open
and it can actually be deleted.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Right now we seem to have 3 locks.
- devinfo.lock
This is a per device lock
- metaData.devicesLock
This is supposedely protecting map of devices.
- Global DeviceSet lock
This is protecting map of devices as well as serializing calls to libdevmapper.
Semantics of per devices lock and global deviceset lock seem to be very clear.
Even ordering between these two locks has been defined properly.
What is not clear is the need and ordering of metaData.devicesLock. Looks like
this lock is not necessary and global DeviceSet lock should be used to
protect map of devices as it is part of DeviceSet.
This patchset gets rid of metaData.devicesLock and instead uses DeviceSet
lock to protect map of devices.
Also at couple of places during initialization takes devices.Lock(). That
is not strictly necessary as there is supposed to be one thread of execution
during initializaiton. Still it makes the code clearer.
I think this makes code more clear and easier to understand and easier to
make further changes.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
maxDeviceID is upper limit on device Id thin pool can support. Right now
we have this check only during startup. It is a good idea to move this
check in loadMetadata so that any time a device file is loaded and if it
is corrupted and device Id is more than maxDevieceID, it will be detected
right then and there.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Use deactivateDevice() instead of removeDevice() directly. This will make
sure for device deletion, deferred removal is used if user has configured
it in. Also this makes reading code litle easier as there is single function
to remove a device and that is deactivateDevice().
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
If a device is still mounted at the time of DeleteDevice(), that means
higher layers have not called Put() properly on the device and are trying
to delete it. This is a bug in the code where Get() and Put() have not been
properly paired up. Fail device deletion if it is still mounted.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Exists() and HasDevice() just check if device file exists or not. It does
not say anything about if device is mounted or not. Fix comments.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
device has map (device.Devices), contains valid devices and we skip all
the files which are not device files. transaction metadata file is not
device file. Skip this file when devices files are being read and loaded
into map.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
This fixes the case where directory is removed in
aufs and then the same layer is imported to a
different graphdriver.
Currently when you do `rm -rf /foo && mkdir /foo`
in a layer in aufs the files under `foo` would
only be be hidden on aufs.
The problems with this fix:
1) When a new diff is recreated from non-aufs driver
the `opq` files would not be there. This should not
mean layer differences for the user but still
different content in the tar (one would have one
`opq` file, the others would have `.wh.*` for every
file inside that folder). This difference also only
happens if the tar-split file isn’t stored for the
layer.
2) New files that have the filenames before `.wh..wh..opq`
when they are sorted do not get picked up by non-aufs
graphdrivers. Fixing this would require a bigger
refactoring that is planned in the future.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Signed-off-by: Stefan J. Wernli <swernli@microsoft.com>
Windows: add support for images stored in alternate location.
Signed-off-by: Stefan J. Wernli <swernli@microsoft.com>
Commit e27c904 added a wrong and misleading comment
to GetMetadata(). Fix it using the wording from
commit 407a626 which introduced GetMetadata().
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
These functions are not part of the graphdriver.Driver
interface and should therefore be private.
Also, remove comments added by commit e27c904 as they are
* pretty obvious
* no longer required by golint
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Ploop graph driver provides its own ext4 filesystem to every
container. It so happens that ext4 root comes with lost+found
directory, causing failures from DriverTestCreateEmpty() and
DriverTestCreateBase() tests on ploop.
While I am not yet ready to submit ploop graph driver for review,
this change looks simple enough to push.
Note that filtering is done without any additional allocations,
as described in https://github.com/golang/go/wiki/SliceTricks.
[v2: added a comment about lost+found]
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
TL;DR: check for IsExist(err) after a failed MkdirAll() is both
redundant and wrong -- so two reasons to remove it.
Quoting MkdirAll documentation:
> MkdirAll creates a directory named path, along with any necessary
> parents, and returns nil, or else returns an error. If path
> is already a directory, MkdirAll does nothing and returns nil.
This means two things:
1. If a directory to be created already exists, no error is returned.
2. If the error returned is IsExist (EEXIST), it means there exists
a non-directory with the same name as MkdirAll need to use for
directory. Example: we want to MkdirAll("a/b"), but file "a"
(or "a/b") already exists, so MkdirAll fails.
The above is a theory, based on quoted documentation and my UNIX
knowledge.
3. In practice, though, current MkdirAll implementation [1] returns
ENOTDIR in most of cases described in #2, with the exception when
there is a race between MkdirAll and someone else creating the
last component of MkdirAll argument as a file. In this very case
MkdirAll() will indeed return EEXIST.
Because of #1, IsExist check after MkdirAll is not needed.
Because of #2 and #3, ignoring IsExist error is just plain wrong,
as directory we require is not created. It's cleaner to report
the error now.
Note this error is all over the tree, I guess due to copy-paste,
or trying to follow the same usage pattern as for Mkdir(),
or some not quite correct examples on the Internet.
[v2: a separate aufs commit is merged into this one]
[1] https://github.com/golang/go/blob/f9ed2f75/src/os/path.go
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
