Snapshot/Restore: better handle incorrect chunk_size settings in FS repo (#26844)

Specifying a negative value or null as a chunk_size in FS repository can lead to corrupt snapshots.

Closes #26843

Author: imotov

core/src/main/java/org/elasticsearch/index/snapshots/blobstore/BlobStoreIndexShardSnapshot.java

@@ -66,7 +66,7 @@ public FileInfo(String name, StoreFileMetaData metaData, ByteSizeValue partSize)
             this.metadata = metaData;
 
             long partBytes = Long.MAX_VALUE;
-            if (partSize != null) {
+            if (partSize != null && partSize.getBytes() > 0) {
                 partBytes = partSize.getBytes();
             }
 

core/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java

@@ -241,6 +241,10 @@ protected BlobStoreRepository(RepositoryMetaData metadata, Settings globalSettin
             BlobStoreIndexShardSnapshot::fromXContent, namedXContentRegistry, isCompress());
         indexShardSnapshotsFormat = new ChecksumBlobStoreFormat<>(SNAPSHOT_INDEX_CODEC, SNAPSHOT_INDEX_NAME_FORMAT,
             BlobStoreIndexShardSnapshots::fromXContent, namedXContentRegistry, isCompress());
+        ByteSizeValue chunkSize = chunkSize();
+        if (chunkSize != null && chunkSize.getBytes() <= 0) {
+            throw new IllegalArgumentException("the chunk size cannot be negative: [" + chunkSize + "]");
+        }
     }
 
     @Override

core/src/main/java/org/elasticsearch/repositories/fs/FsRepository.java

@@ -54,10 +54,10 @@ public class FsRepository extends BlobStoreRepository {
         new Setting<>("location", "", Function.identity(), Property.NodeScope);
     public static final Setting<String> REPOSITORIES_LOCATION_SETTING =
         new Setting<>("repositories.fs.location", LOCATION_SETTING, Function.identity(), Property.NodeScope);
-    public static final Setting<ByteSizeValue> CHUNK_SIZE_SETTING =
-        Setting.byteSizeSetting("chunk_size", new ByteSizeValue(-1), Property.NodeScope);
-    public static final Setting<ByteSizeValue> REPOSITORIES_CHUNK_SIZE_SETTING =
-        Setting.byteSizeSetting("repositories.fs.chunk_size", new ByteSizeValue(-1), Property.NodeScope);
+    public static final Setting<ByteSizeValue> CHUNK_SIZE_SETTING = Setting.byteSizeSetting("chunk_size",
+            new ByteSizeValue(Long.MAX_VALUE), new ByteSizeValue(5), new ByteSizeValue(Long.MAX_VALUE), Property.NodeScope);
+    public static final Setting<ByteSizeValue> REPOSITORIES_CHUNK_SIZE_SETTING = Setting.byteSizeSetting("repositories.fs.chunk_size",
+        new ByteSizeValue(Long.MAX_VALUE), new ByteSizeValue(5), new ByteSizeValue(Long.MAX_VALUE), Property.NodeScope);
     public static final Setting<Boolean> COMPRESS_SETTING = Setting.boolSetting("compress", false, Property.NodeScope);
     public static final Setting<Boolean> REPOSITORIES_COMPRESS_SETTING =
         Setting.boolSetting("repositories.fs.compress", false, Property.NodeScope);
@@ -95,10 +95,8 @@ public FsRepository(RepositoryMetaData metadata, Environment environment,
         blobStore = new FsBlobStore(settings, locationFile);
         if (CHUNK_SIZE_SETTING.exists(metadata.settings())) {
             this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());
-        } else if (REPOSITORIES_CHUNK_SIZE_SETTING.exists(settings)) {
-            this.chunkSize = REPOSITORIES_CHUNK_SIZE_SETTING.get(settings);
         } else {
-            this.chunkSize = null;
+            this.chunkSize = REPOSITORIES_CHUNK_SIZE_SETTING.get(settings);
         }
         this.compress = COMPRESS_SETTING.exists(metadata.settings()) ? COMPRESS_SETTING.get(metadata.settings()) : REPOSITORIES_COMPRESS_SETTING.get(settings);
         this.basePath = BlobPath.cleanPath();

core/src/test/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreIT.java

@@ -104,6 +104,7 @@
 import static org.elasticsearch.cluster.metadata.IndexMetaData.SETTING_NUMBER_OF_SHARDS;
 import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.elasticsearch.index.IndexSettings.INDEX_REFRESH_INTERVAL_SETTING;
+import static org.elasticsearch.index.query.QueryBuilders.boolQuery;
 import static org.elasticsearch.index.query.QueryBuilders.matchQuery;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAliasesExist;
@@ -135,15 +136,29 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
             MockRepository.Plugin.class);
     }
 
+    private Settings randomRepoSettings() {
+        Settings.Builder repoSettings = Settings.builder();
+        repoSettings.put("location", randomRepoPath());
+        if (randomBoolean()) {
+            repoSettings.put("compress", randomBoolean());
+        }
+        if (randomBoolean()) {
+            repoSettings.put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES);
+        } else {
+            if (randomBoolean()) {
+                repoSettings.put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES);
+            } else {
+                repoSettings.put("chunk_size", (String) null);
+            }
+        }
+        return repoSettings.build();
+    }
+
     public void testBasicWorkFlow() throws Exception {
         Client client = client();
 
         logger.info("-->  creating repository");
-        assertAcked(client.admin().cluster().preparePutRepository("test-repo")
-                .setType("fs").setSettings(Settings.builder()
-                        .put("location", randomRepoPath())
-                        .put("compress", randomBoolean())
-                        .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)));
+        assertAcked(client.admin().cluster().preparePutRepository("test-repo").setType("fs").setSettings(randomRepoSettings()));
 
         createIndex("test-idx-1", "test-idx-2", "test-idx-3");
         ensureGreen();
@@ -308,11 +323,7 @@ public void testFreshIndexUUID() {
         Client client = client();
 
         logger.info("-->  creating repository");
-        assertAcked(client.admin().cluster().preparePutRepository("test-repo")
-                .setType("fs").setSettings(Settings.builder()
-                        .put("location", randomRepoPath())
-                        .put("compress", randomBoolean())
-                        .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)));
+        assertAcked(client.admin().cluster().preparePutRepository("test-repo").setType("fs").setSettings(randomRepoSettings()));
 
         createIndex("test");
         String originalIndexUUID = client().admin().indices().prepareGetSettings("test").get().getSetting("test", IndexMetaData.SETTING_INDEX_UUID);
@@ -356,11 +367,7 @@ public void testRestoreWithDifferentMappingsAndSettings() throws Exception {
         Client client = client();
 
         logger.info("-->  creating repository");
-        assertAcked(client.admin().cluster().preparePutRepository("test-repo")
-                .setType("fs").setSettings(Settings.builder()
-                        .put("location", randomRepoPath())
-                        .put("compress", randomBoolean())
-                        .put("chunk_size", randomIntBetween(100, 1000), ByteSizeUnit.BYTES)));
+        assertAcked(client.admin().cluster().preparePutRepository("test-repo").setType("fs").setSettings(randomRepoSettings()));
 
         logger.info("--> create index with foo type");
         assertAcked(prepareCreate("test-idx", 2, Settings.builder()