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  1. JDK
  2. JDK-8165852

(fs) Mount point not found for a file which is present in overlayfs

    Details

    • Subcomponent:
    • Resolved In Build:
      b01
    • CPU:
      x86_64
    • OS:
      linux
    • Verification:
      Not verified

      Backports

        Description

        FULL PRODUCT VERSION :
        java version "1.8.0_77"
        Java(TM) SE Runtime Environment (build 1.8.0_77-b03)
        Java HotSpot(TM) 64-Bit Server VM (build 25.77-b03, mixed mode)

        ADDITIONAL OS VERSION INFORMATION :
        [root@6b8ab63d2271 /]# uname -a
        Linux 6b8ab63d2271 4.6.0-0.bpo.1-amd64 #1 SMP Debian 4.6.3-1~bpo8+1 (2016-07-13) x86_64 x86_64 x86_64 GNU/Linux

        [root@6b8ab63d2271 /]# cat /etc/redhat-release
        CentOS Linux release 7.2.1511 (Core)

        EXTRA RELEVANT SYSTEM CONFIGURATION :
        Host System: Debian Jessie
        Runs Docker version 1.12.1, build 23cf638 started with --storage-driver=overlay
        Error does occur inside of the docker container which is centos 7

        A DESCRIPTION OF THE PROBLEM :
        When running java inside of a docker container which root fs is an overlayfs

        e.g. from mount: overlay on / type overlay (rw,relatime,lowerdir=/var/lib/docker/overlay/7f380aa866f1411985b0e3d9533e89f0907e11adb81c2c1e20a5733fd3112f33/root,upperdir=/var/lib/docker/overlay/58f650cc4005e9becf01c20b2d8144a372115d11add9e70774322232e3fef590/upper,workdir=/var/lib/docker/overlay/58f650cc4005e9becf01c20b2d8144a372115d11add9e70774322232e3fef590/work)

        And accessing a file like /home/someuser/somefile.txt

        An Exception will be thrown.


        A very similar Case seems to exist with btrfs and subvolumes:
        https://github.com/elastic/elasticsearch/issues/14337 and
        https://github.com/elastic/elasticsearch/issues/12018


        STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
        Start a docker container where dockerd was started with --overlfay and try to access files via Files.getFileStore(path)

        EXPECTED VERSUS ACTUAL BEHAVIOR :
        EXPECTED -
        The Result should be / (if there is no other mount)
        ACTUAL -
        java.io.IOException: Mount point not found

        ERROR MESSAGES/STACK TRACES THAT OCCUR :
        Exception in thread "main" java.io.IOException: Mount point not found
                at sun.nio.fs.LinuxFileStore.findMountEntry(LinuxFileStore.java:91)
                at sun.nio.fs.UnixFileStore.<init>(UnixFileStore.java:65)
                at sun.nio.fs.LinuxFileStore.<init>(LinuxFileStore.java:44)
                at sun.nio.fs.LinuxFileSystemProvider.getFileStore(LinuxFileSystemProvider.java:51)
                at sun.nio.fs.LinuxFileSystemProvider.getFileStore(LinuxFileSystemProvider.java:39)
                at sun.nio.fs.UnixFileSystemProvider.getFileStore(UnixFileSystemProvider.java:368)
                at java.nio.file.Files.getFileStore(Files.java:1461)
                at MyMain.main(MyMain.java:8)

        REPRODUCIBILITY :
        This bug can be reproduced always.

        ---------- BEGIN SOURCE ----------
        import java.io.IOException;
        import java.nio.file.Files;
        import java.nio.file.Paths;

        public class MyMain {

        public static void main(String[] args) throws IOException {
        System.out.println(Files.getFileStore(Paths.get(args[0])));
        }
        }

        ---------- END SOURCE ----------

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                • Assignee:
                  bpb Brian Burkhalter
                  Reporter:
                  webbuggrp Webbug Group
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                  • Created:
                    Updated:
                    Resolved: