mount_helper_common.go

Documentation: k8s.io/utils/mount

     1  /*
     2  Copyright 2018 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package mount
    18  
    19  import (
    20  	"fmt"
    21  	"os"
    22  
    23  	"k8s.io/klog/v2"
    24  )
    25  
    26  // CleanupMountPoint unmounts the given path and deletes the remaining directory
    27  // if successful. If extensiveMountPointCheck is true IsNotMountPoint will be
    28  // called instead of IsLikelyNotMountPoint. IsNotMountPoint is more expensive
    29  // but properly handles bind mounts within the same fs.
    30  func CleanupMountPoint(mountPath string, mounter Interface, extensiveMountPointCheck bool) error {
    31  	pathExists, pathErr := PathExists(mountPath)
    32  	if !pathExists {
    33  		klog.Warningf("Warning: Unmount skipped because path does not exist: %v", mountPath)
    34  		return nil
    35  	}
    36  	corruptedMnt := IsCorruptedMnt(pathErr)
    37  	if pathErr != nil && !corruptedMnt {
    38  		return fmt.Errorf("Error checking path: %v", pathErr)
    39  	}
    40  	return doCleanupMountPoint(mountPath, mounter, extensiveMountPointCheck, corruptedMnt)
    41  }
    42  
    43  // doCleanupMountPoint unmounts the given path and
    44  // deletes the remaining directory if successful.
    45  // if extensiveMountPointCheck is true
    46  // IsNotMountPoint will be called instead of IsLikelyNotMountPoint.
    47  // IsNotMountPoint is more expensive but properly handles bind mounts within the same fs.
    48  // if corruptedMnt is true, it means that the mountPath is a corrupted mountpoint, and the mount point check
    49  // will be skipped
    50  func doCleanupMountPoint(mountPath string, mounter Interface, extensiveMountPointCheck bool, corruptedMnt bool) error {
    51  	var notMnt bool
    52  	var err error
    53  	if !corruptedMnt {
    54  		if extensiveMountPointCheck {
    55  			notMnt, err = IsNotMountPoint(mounter, mountPath)
    56  		} else {
    57  			notMnt, err = mounter.IsLikelyNotMountPoint(mountPath)
    58  		}
    59  
    60  		if err != nil {
    61  			return err
    62  		}
    63  
    64  		if notMnt {
    65  			klog.Warningf("Warning: %q is not a mountpoint, deleting", mountPath)
    66  			return os.Remove(mountPath)
    67  		}
    68  	}
    69  
    70  	// Unmount the mount path
    71  	klog.V(4).Infof("%q is a mountpoint, unmounting", mountPath)
    72  	if err := mounter.Unmount(mountPath); err != nil {
    73  		return err
    74  	}
    75  
    76  	if extensiveMountPointCheck {
    77  		notMnt, err = IsNotMountPoint(mounter, mountPath)
    78  	} else {
    79  		notMnt, err = mounter.IsLikelyNotMountPoint(mountPath)
    80  	}
    81  	if err != nil {
    82  		return err
    83  	}
    84  	if notMnt {
    85  		klog.V(4).Infof("%q is unmounted, deleting the directory", mountPath)
    86  		return os.Remove(mountPath)
    87  	}
    88  	return fmt.Errorf("Failed to unmount path %v", mountPath)
    89  }
    90  
    91  // PathExists returns true if the specified path exists.
    92  // TODO: clean this up to use pkg/util/file/FileExists
    93  func PathExists(path string) (bool, error) {
    94  	_, err := os.Stat(path)
    95  	if err == nil {
    96  		return true, nil
    97  	} else if os.IsNotExist(err) {
    98  		return false, nil
    99  	} else if IsCorruptedMnt(err) {
   100  		return true, err
   101  	}
   102  	return false, err
   103  }
   104
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