f125ad88ce
IsLikelyNotMountPoint determines if a directory is not a mountpoint.
It is fast but not necessarily ALWAYS correct. If the path is in fact
a bind mount from one part of a mount to another it will not be detected.
mkdir /tmp/a /tmp/b; mount --bin /tmp/a /tmp/b; IsLikelyNotMountPoint("/tmp/b")
will return true. When in fact /tmp/b is a mount point. So this patch
renames the function and switches it from a positive to a negative (I
could think of a good positive name). This should make future users of
this function aware that it isn't quite perfect, but probably good
enough.
110 lines
3.0 KiB
Go
110 lines
3.0 KiB
Go
/*
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Copyright 2014 The Kubernetes Authors All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// TODO(thockin): This whole pkg is pretty linux-centric. As soon as we have
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// an alternate platform, we will need to abstract further.
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package mount
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import "github.com/golang/glog"
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type Interface interface {
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// Mount mounts source to target as fstype with given options.
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Mount(source string, target string, fstype string, options []string) error
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// Unmount unmounts given target.
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Unmount(target string) error
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// List returns a list of all mounted filesystems. This can be large.
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// On some platforms, reading mounts is not guaranteed consistent (i.e.
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// it could change between chunked reads). This is guaranteed to be
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// consistent.
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List() ([]MountPoint, error)
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// IsLikelyNotMountPoint determines if a directory is a mountpoint.
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IsLikelyNotMountPoint(file string) (bool, error)
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}
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// This represents a single line in /proc/mounts or /etc/fstab.
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type MountPoint struct {
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Device string
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Path string
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Type string
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Opts []string
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Freq int
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Pass int
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}
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// New returns a mount.Interface for the current system.
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func New() Interface {
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return &Mounter{}
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}
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// GetMountRefs finds all other references to the device referenced
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// by mountPath; returns a list of paths.
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func GetMountRefs(mounter Interface, mountPath string) ([]string, error) {
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mps, err := mounter.List()
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if err != nil {
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return nil, err
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}
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// Find the device name.
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deviceName := ""
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for i := range mps {
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if mps[i].Path == mountPath {
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deviceName = mps[i].Device
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break
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}
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}
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// Find all references to the device.
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var refs []string
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if deviceName == "" {
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glog.Warningf("could not determine device for path: %q", mountPath)
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} else {
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for i := range mps {
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if mps[i].Device == deviceName && mps[i].Path != mountPath {
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refs = append(refs, mps[i].Path)
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}
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}
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}
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return refs, nil
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}
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// GetDeviceNameFromMount: given a mnt point, find the device from /proc/mounts
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// returns the device name, reference count, and error code
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func GetDeviceNameFromMount(mounter Interface, mountPath string) (string, int, error) {
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mps, err := mounter.List()
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if err != nil {
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return "", 0, err
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}
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// Find the device name.
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// FIXME if multiple devices mounted on the same mount path, only the first one is returned
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device := ""
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for i := range mps {
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if mps[i].Path == mountPath {
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device = mps[i].Device
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break
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}
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}
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// Find all references to the device.
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refCount := 0
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for i := range mps {
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if mps[i].Device == device {
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refCount++
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}
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}
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return device, refCount, nil
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}
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