diff --git a/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java b/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java index 33cb70a0d0ba9..7bb1e51cd2372 100644 --- a/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java +++ b/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java @@ -137,7 +137,7 @@ private double addDouble(double current, double other) { } public void add(Path path) { - total = addLong(total, path.total); + total = FsProbe.adjustForHugeFilesystems(addLong(total, path.total)); free = addLong(free, path.free); available = addLong(available, path.available); if (path.spins != null && path.spins.booleanValue()) { diff --git a/core/src/main/java/org/elasticsearch/monitor/fs/FsProbe.java b/core/src/main/java/org/elasticsearch/monitor/fs/FsProbe.java index d079a7201686f..1fdae49a6f16b 100644 --- a/core/src/main/java/org/elasticsearch/monitor/fs/FsProbe.java +++ b/core/src/main/java/org/elasticsearch/monitor/fs/FsProbe.java @@ -136,7 +136,11 @@ List readProcDiskStats() throws IOException { } /* See: https://bugs.openjdk.java.net/browse/JDK-8162520 */ - private static long adjustForHugeFilesystems(long bytes) { + /** + * Take a large value intended to be positive, and if it has overflowed, + * return {@code Long.MAX_VALUE} instead of a negative number. + */ + static long adjustForHugeFilesystems(long bytes) { if (bytes < 0) { return Long.MAX_VALUE; } diff --git a/core/src/test/java/org/elasticsearch/monitor/fs/FsProbeTests.java b/core/src/test/java/org/elasticsearch/monitor/fs/FsProbeTests.java index 007b6ce1fc776..3d4903e04724d 100644 --- a/core/src/test/java/org/elasticsearch/monitor/fs/FsProbeTests.java +++ b/core/src/test/java/org/elasticsearch/monitor/fs/FsProbeTests.java @@ -40,6 +40,7 @@ import static org.hamcrest.CoreMatchers.equalTo; import static org.hamcrest.Matchers.greaterThan; import static org.hamcrest.Matchers.greaterThanOrEqualTo; +import static org.hamcrest.Matchers.lessThan; import static org.hamcrest.Matchers.isEmptyOrNullString; import static org.hamcrest.Matchers.not; @@ -91,6 +92,29 @@ public void testFsInfo() throws IOException { } } + public void testFsInfoOverflow() throws Exception { + FsInfo.Path pathStats = new FsInfo.Path("/foo/bar", null, + randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong()); + + // While not overflowing, keep adding + FsInfo.Path pathToAdd = new FsInfo.Path("/foo/baz", null, + randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong()); + while ((pathStats.total + pathToAdd.total) > 0) { + // Add itself as a path, to increase the total bytes until it overflows + logger.info("--> adding {} bytes to {}, will be: {}", pathToAdd.total, pathStats.total, pathToAdd.total + pathStats.total); + pathStats.add(pathToAdd); + pathToAdd = new FsInfo.Path("/foo/baz", null, + randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong()); + } + + logger.info("--> adding {} bytes to {}, will be: {}", pathToAdd.total, pathStats.total, pathToAdd.total + pathStats.total); + assertThat(pathStats.total + pathToAdd.total, lessThan(0L)); + pathStats.add(pathToAdd); + + // Even after overflowing, it should not be negative + assertThat(pathStats.total, greaterThan(0L)); + } + public void testIoStats() { final AtomicReference> diskStats = new AtomicReference<>(); diskStats.set(Arrays.asList(