RFR: 8371978: tools/jar/ReproducibleJar.java fails on XFS

[SendaoYan]

On Tue, 18 Nov 2025 08:24:13 GMT, SendaoYan <syan at openjdk.org> wrote:

> Hi all,
> 
> Test tools/jar/ReproducibleJar.java fails when running on a file system that only supports to 2038(e.g. XFS).
> 
> Before this PR, test check if the input test time after "2038-01-19T03:14:07Z" and the extracted time created by jar is equal to "2038-01-19T03:14:07Z", then test will skip that check.
> 
> But the extraced time created by jar equal to "1970-01-01T00:00:00Z" actually. I think the extracted time set to unix epoch time is acceptable, so this PR fix the test make test check skip when the extracted time is unix epoch time.
> 
> Change has been verified locally on XFS file system and ext4 file system.

I create a demo to explain what utimes linux system call works on XFS file system.

When the time value bigger or equals the maximum of signed integer, then the time will set to UNIX epoch time.


#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <stdlib.h>

int main(int argc, char** argv) {
    if (argc != 3) {
        printf("usage: ./a.out file seconds\n");
        return 1;
    }
    const char *filename = argv[1];
    struct timeval times[2];
    long time = atol(argv[2]);

    times[0].tv_sec = time;  // atime
    times[0].tv_usec = 0;
    
    times[1].tv_sec = time;  // mtime
    times[1].tv_usec = 0;
    
    int ret = utimes(filename, times);
    printf("utimes to file %s as %ld return code is %d\n", filename, time, ret);
    
    return 0;
}


Test command and result:


> gcc -Wall -Wextra ~/compiler-test/zzkk/utimes-test.c ; ./a.out a.out 2147483646 ; stat --format %y a.out
utimes to file a.out as 2147483646 return code is 0
2038-01-19 11:14:06.000000000 +0800
> gcc -Wall -Wextra ~/compiler-test/zzkk/utimes-test.c ; ./a.out a.out 2147483647 ; stat --format %y a.out
utimes to file a.out as 2147483647 return code is 0
1970-01-01 08:00:00.000000000 +0800

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PR Comment: https://git.openjdk.org/jdk/pull/28367#issuecomment-3566713777