[8u] RFA: 8165852: (fs) Mount point not found for a file which is present in overlayfs

[Rob McKenna]

Approved

    -Rob

On 24/07/18 15:40, Severin Gehwolf wrote:
> Hi,
> 
> Please approve this backport request for 8u. It fixes an issue on
> certain Linux hosts using docker containers and overlayfs. The patch is
> the same as for JDK 11 modulo some copyright year context adjustments
> and path unshuffeling.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8165852
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8165852/webrev.01/
> Original review thread: http://mail.openjdk.java.net/pipermail/nio-dev/2018-January/004647.html
> 
> Testing: I've manually verified that the problem reproduces on current
> 8u and is fixed by the backport patch. Note that "java" below is
> unpatched. "/java-8-openjdk-u-dev/bin/java" is patched JDK 8.
> 
> [foo at 5755c0f1ee39 ~]$ java Fs $(pwd)/test.txt
> Exception in thread "main" java.io.IOException: Mount point not found
> 	at sun.nio.fs.LinuxFileStore.findMountEntry(LinuxFileStore.java:91)
> 	at sun.nio.fs.UnixFileStore.<init>(UnixFileStore.java:65)
> 	at sun.nio.fs.LinuxFileStore.<init>(LinuxFileStore.java:44)
> 	at sun.nio.fs.LinuxFileSystemProvider.getFileStore(LinuxFileSystemProvider.java:51)
> 	at sun.nio.fs.LinuxFileSystemProvider.getFileStore(LinuxFileSystemProvider.java:39)
> 	at sun.nio.fs.UnixFileSystemProvider.getFileStore(UnixFileSystemProvider.java:368)
> 	at java.nio.file.Files.getFileStore(Files.java:1461)
> 	at Fs.main(Fs.java:8)
> [foo at 5755c0f1ee39 ~]$ /java-8-openjdk-u-dev/bin/java Fs $(pwd)/test.txt
> / (rootfs)
> [foo at 5755c0f1ee39 ~]$ cat Fs.java 
> import java.io.IOException;
> import java.nio.file.Files;
> import java.nio.file.Paths;
> 
> public class Fs {
> 
> public static void main(String[] args) throws IOException {
> System.out.println(Files.getFileStore(Paths.get(args[0])));
> }
> } 
> [foo at 5755c0f1ee39 ~]$ ls
> Fs.class  Fs.java  test.txt
> 
> Thanks,
> Severin
>