```
func foo() error {
defer func() {
if err != nil {
...
}
}()
...
}
```
use defer func to do something when err not nil, if foo() not use
named error, `err != nil` can not catch all errors, since when err
re-defined in if condition, it is a new variable.
Signed-off-by: Ace-Tang <aceapril@126.com>
Fixes a bug where a writable transaction may create or make changes to
a directory while the cleanup is running, leading to removal of a
directory which will be referenced.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This function is not called during plugin initialization (#2140),
but should be useful for downstream projects that uses overlayfs
snapshotter as a Go library.
Benchmark result on Ubuntu 17.10, GCE n1-standard-4:
BenchmarkOverlaySupportedOnExt4-4 100 20490598 ns/op
BenchmarkOverlayUnsupportedOnFType0XFS-4 30000 39316 ns/op
BenchmarkOverlaySupportedOnFType1XFS-4 100 19287083 ns/op
BenchmarkOverlayUnsupportedOnFAT-4 100 14217772 ns/op
i.e. the overhead is typically about 20 msec on this machine.
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Allow configuring the overlay snapshotter to synchronously
or asynchronously do cleanup. When the driver is integrated
into a garbage collection system, the asynchronous cleanup
can reduce the time of removal and allow the longer disk
cleanup to be handled without locking the snapshotter.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Updates overlay remove to simply remove the reference, adds
a cleanup method for discarding the directory.
Updates snapshot create to setup the directory structure while
in the transaction, to prevent cleanup from removing directories
which are part of a create.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
