kotovalexarian-likes-github/moby--moby
1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
Code Releases Activity

Fix uneccessary calls to volume.Unmount()

Browse source 
Fixes #22564

When an error occurs on mount, there should not be any call later to
unmount. This can throw off refcounting in the underlying driver
unexpectedly.

Consider these two cases:

```
$ docker run -v foo:/bar busybox true
```

```
$ docker run -v foo:/bar -w /foo busybox true
```

In the first case, if mounting `foo` fails, the volume driver will not
get a call to unmount (this is the incorrect behavior).

In the second case, the volume driver will not get a call to unmount
(correct behavior).

This occurs because in the first case, `/bar` does not exist in the
container, and as such there is no call to `volume.Mount()` during the
`create` phase. It will error out during the `start` phase.

In the second case `/bar` is created before dealing with the volume
because of the `-w`. Because of this, when the volume is being setup
docker will try to copy the image path contents in the volume, in which
case it will attempt to mount the volume and fail. This happens during
the `create` phase. This makes it so the container will not be created
(or at least fully created) and the user gets the error on `create`
instead of `start`. The error handling is different in these two phases.

Changed to only send `unmount` if the volume is mounted.

While investigating the cause of the reported issue I found some odd
behavior in unmount calls so I've cleaned those up a bit here as well.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This commit is contained in:
Brian Goff 2016-10-03 13:53:06 -04:00
parent c13bf5ba51
commit 9a2d0bc3ad
7 changed files with 113 additions and 107 deletions
Download patch file Download diff file Expand all files Collapse all files

21
integration-cli/docker_cli_external_volume_driver_unix_test.go
View file

@ -73,6 +73,7 @@ type vol struct {
Mountpoint string
Ninja bool // hack used to trigger a null volume return on `Get`
Status map[string]interface{}
Options map[string]string
}
func (p *volumePlugin) Close() {
@ -130,7 +131,7 @@ func newVolumePlugin(c *check.C, name string) *volumePlugin {
}
_, isNinja := pr.Opts["ninja"]
status := map[string]interface{}{"Hello": "world"}
s.vols[pr.Name] = vol{Name: pr.Name, Ninja: isNinja, Status: status}
s.vols[pr.Name] = vol{Name: pr.Name, Ninja: isNinja, Status: status, Options: pr.Opts}
send(w, nil)
})
@ -212,6 +213,14 @@ func newVolumePlugin(c *check.C, name string) *volumePlugin {
return
}
if v, exists := s.vols[pr.Name]; exists {
// Use this to simulate a mount failure
if _, exists := v.Options["invalidOption"]; exists {
send(w, fmt.Errorf("invalid argument"))
return
}
}
p := hostVolumePath(pr.Name)
if err := os.MkdirAll(p, 0755); err != nil {
send(w, &pluginResp{Err: err.Error()})
@ -562,3 +571,13 @@ func (s *DockerExternalVolumeSuite) TestExternalVolumeDriverOutOfBandDelete(c *c
out, err = s.d.Cmd("volume", "create", "-d", "local", "--name", "test")
c.Assert(err, checker.IsNil, check.Commentf(out))
}
func (s *DockerExternalVolumeSuite) TestExternalVolumeDriverUnmountOnMountFail(c *check.C) {
c.Assert(s.d.StartWithBusybox(), checker.IsNil)
s.d.Cmd("volume", "create", "-d", "test-external-volume-driver", "--opt=invalidOption=1", "--name=testumount")
out, _ := s.d.Cmd("run", "-v", "testumount:/foo", "busybox", "true")
c.Assert(s.ec.unmounts, checker.Equals, 0, check.Commentf(out))
out, _ = s.d.Cmd("run", "-w", "/foo", "-v", "testumount:/foo", "busybox", "true")
c.Assert(s.ec.unmounts, checker.Equals, 0, check.Commentf(out))
}