Feature: Implement fields capable_ext and want_ext

jfuse-api/src/main/java/org/cryptomator/jfuse/api/FuseConnInfo.java

@@ -323,6 +323,7 @@ public interface FuseConnInfo {
 	 * Capability flags that the kernel supports (read-only)
 	 *
 	 * @return {@code capable} value
+	 * @apiNote Since libFUSE 3.17, this field is deprecated left over for ABI compatibility, use capable_ext
 	 */
 	int capable();
 
@@ -333,13 +334,17 @@ public interface FuseConnInfo {
 	 * reasonable default values before calling the init() handler.
 	 *
 	 * @return {@code want} value
+	 * @apiNote Since libFUSE 3.17, this field is deprecated left over for ABI compatibility.
+	 * Use want_ext with the helper functions fuse_set_feature_flag() / fuse_unset_feature_flag()
 	 */
 	int want();
 
 	/**
 	 * Sets the {@link #want()} value.
 	 *
 	 * @param wanted {@code want} value
+	 * @apiNote Since libFUSE 3.17, this field is deprecated left over for ABI compatibility.
+	 * Use want_ext with the helper functions fuse_set_feature_flag() / fuse_unset_feature_flag()
 	 */
 	void setWant(int wanted);
 
@@ -499,4 +504,87 @@ default int asyncRead() {
 	default void setAsyncRead(int asyncRead) {
 		//no-op
 	}
+
+	/**
+	 * Extended capability flags that the kernel supports (read-only)
+	 * This field provides full 64-bit capability support.
+	 * <p>
+	 * If the version of the loaded FUSE library is below 3.17, this method does nothing.
+	 *
+	 * @implSpec The default implementation always returns 0.
+	 * @since libFUSE 3.17
+	 */
+	default long capableExt() {
+		return 0;
+	}
+
+	/**
+	 * Extended capability flags that the filesystem wants to enable.
+	 * This field provides full 64-bit capability support.
+	 * <p>
+	 * Don't set this field directly, but use the helper functions
+	 * fuse_set_feature_flag() / fuse_unset_feature_flag()
+	 * <p>
+	 * If the version of the loaded FUSE library is below 3.17, this method does nothing.
+	 *
+	 * @implSpec The default implementation always returns 0.
+	 * @see #setFeatureFlag(long)
+	 * @see #unsetFeatureFlag(long)
+	 * @since libFUSE 3.17
+	 */
+	default long wantExt() {
+		return 0;
+	}
+
+	/**
+	 * Sets the {@link #wantExt()} value.
+	 * <p>
+	 * Deprecated way of setting the wantExt field. Use {@link #setFeatureFlag(long)} instead.
+	 * If the version of the loaded FUSE library is below 3.17, this method does nothing.
+	 *
+	 * @param wantExt {@code want_ext} value
+	 * @implSpec The default implementation is a no-op.
+	 * @since libFUSE 3.17
+	 */
+	default void setWantExt(long wantExt) {
+		//no-op
+	}
+
+	/**
+	 * Set a feature flag in the want_ext field of fuse_conn_info.
+	 *
+	 * @param flag feature flag to be set
+	 * @return {@code true} if the flag was set, {@code false} if the flag is not supported
+	 * @throws UnsupportedOperationException if the loaded fuse library does not implement the method
+	 * @implSpec The default implementation throws {@link UnsupportedOperationException}
+	 * @since libFUSE 3.17
+	 */
+	default boolean setFeatureFlag(long flag) throws UnsupportedOperationException {
+		throw new UnsupportedOperationException("Loaded library does not implement fuse_set_feature_flag");
+	}
+
+	/**
+	 * Unset a feature flag in the want_ext field of fuse_conn_info.
+	 *
+	 * @param flag feature flag to be unset
+	 * @throws UnsupportedOperationException if the loaded fuse library does not implement the method
+	 * @implSpec The default implementation throws {@link UnsupportedOperationException}
+	 * @since libFUSE 3.17
+	 */
+	default void unsetFeatureFlag(long flag) throws UnsupportedOperationException {
+		throw new UnsupportedOperationException("Loaded library does not implement fuse_unset_feature_flag");
+	}
+
+	/**
+	 * Get the value of a feature flag in the want_ext field of fuse_conn_info.
+	 *
+	 * @param flag feature flag to be checked
+	 * @return {@code true} if the flag is set, {@code false} otherwise
+	 * @throws UnsupportedOperationException if the loaded fuse library does not implement the method
+	 * @implSpec The default implementation throws {@link UnsupportedOperationException}
+	 * @since libFUSE 3.17
+	 */
+	default boolean getFeatureFlag(long flag) throws UnsupportedOperationException {
+		throw new UnsupportedOperationException("Loaded library does not implement fuse_get_feature_flag");
+	}
 }

jfuse-linux-aarch64/src/main/java/org/cryptomator/jfuse/linux/aarch64/FuseConnInfoImpl.java

@@ -3,10 +3,20 @@
 import org.cryptomator.jfuse.api.FuseConnInfo;
 import org.cryptomator.jfuse.linux.aarch64.extr.fuse3.fuse_conn_info;
 
-import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
 
-record FuseConnInfoImpl(MemorySegment segment) implements FuseConnInfo {
+class FuseConnInfoImpl implements FuseConnInfo {
+
+	protected final MemorySegment segment;
+
+	FuseConnInfoImpl(MemorySegment segment) {
+		this.segment = segment;
+	}
+
+	//mimic record behaviour
+	public MemorySegment segment() {
+		return segment;
+	}
 
 	@Override
 	public int protoMajor() {

jfuse-linux-aarch64/src/main/java/org/cryptomator/jfuse/linux/aarch64/FuseConnInfoImpl317.java

@@ -0,0 +1,43 @@
+package org.cryptomator.jfuse.linux.aarch64;
+
+import org.cryptomator.jfuse.linux.aarch64.extr.fuse3.fuse_conn_info;
+
+import java.lang.foreign.MemorySegment;
+
+class FuseConnInfoImpl317 extends FuseConnInfoImpl {
+
+	FuseConnInfoImpl317(MemorySegment segment) {
+		super(segment);
+	}
+
+	@Override
+	public long capableExt() {
+		return fuse_conn_info.capable_ext(segment);
+	}
+
+	@Override
+	public long wantExt() {
+		return fuse_conn_info.want_ext(segment);
+	}
+
+	@Override
+	public void setWantExt(long wantExt) {
+		fuse_conn_info.want_ext(segment, wantExt);
+	}
+
+	@Override
+	public boolean setFeatureFlag(long flag) {
+		return FuseFunctions.fuse_set_feature_flag(segment, flag);
+	}
+
+	@Override
+	public void unsetFeatureFlag(long flag) {
+		FuseFunctions.fuse_unset_feature_flag(segment, flag);
+	}
+
+	@Override
+	public boolean getFeatureFlag(long flag) {
+		return FuseFunctions.fuse_get_feature_flag(segment, flag);
+	}
+
+}

jfuse-linux-aarch64/src/main/java/org/cryptomator/jfuse/linux/aarch64/FuseFunctions.java

@@ -5,28 +5,43 @@
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.SymbolLookup;
 import java.lang.invoke.MethodHandle;
+import java.util.Optional;
 
 import static java.lang.foreign.ValueLayout.ADDRESS;
 import static java.lang.foreign.ValueLayout.JAVA_INT;
+import static java.lang.foreign.ValueLayout.JAVA_LONG;
 
 /**
  * These method references can not be jextract'ed, partly due to jextract not being able to understand {@code #define},
  * partly due to slight differences in the FUSE API, which applies a versioning scheme via dlvsym, that Panama's default
- * {@link java.lang.foreign.SymbolLookup} doesn't support.
+ * {@link SymbolLookup} doesn't support.
  */
 class FuseFunctions {
 
 	// see https://github.com/libfuse/libfuse/blob/fuse-3.12.0/include/fuse_lowlevel.h#L1892-L1923
 	private static final FunctionDescriptor FUSE_PARSE_CMDLINE = FunctionDescriptor.of(JAVA_INT, ADDRESS, ADDRESS);
+	//https://github.com/libfuse/libfuse/blob/fuse-3.17.4/lib/fuse_lowlevel.c#L2035
+	private static final FunctionDescriptor FUSE_SET_FEATURE_FLAG = FunctionDescriptor.of(JAVA_INT, ADDRESS, JAVA_LONG);
+	private static final FunctionDescriptor FUSE_UNSET_FEATURE_FLAG = FunctionDescriptor.ofVoid(ADDRESS, JAVA_LONG);
+	private static final FunctionDescriptor FUSE_GET_FEATURE_FLAG = FunctionDescriptor.of(JAVA_INT, ADDRESS, JAVA_LONG);
 
 	private final MethodHandle fuse_parse_cmdline;
+	private final Optional<MethodHandle> fuse_set_feature_flag;
+	private final Optional<MethodHandle> fuse_unset_feature_flag;
+	private final Optional<MethodHandle> fuse_get_feature_flag;
 
 	private FuseFunctions() {
 		var lookup = SymbolLookup.loaderLookup();
 		var linker = Linker.nativeLinker();
 		this.fuse_parse_cmdline = lookup.find("fuse_parse_cmdline")
 				.map(symbol -> linker.downcallHandle(symbol, FUSE_PARSE_CMDLINE))
 				.orElseThrow(() -> new UnsatisfiedLinkError("unresolved symbol fuse_parse_cmdline"));
+		this.fuse_set_feature_flag = lookup.find("fuse_set_feature_flag")
+				.map(symbol -> linker.downcallHandle(symbol, FUSE_SET_FEATURE_FLAG));
+		this.fuse_unset_feature_flag = lookup.find("fuse_unset_feature_flag")
+				.map(symbol -> linker.downcallHandle(symbol, FUSE_UNSET_FEATURE_FLAG));
+		this.fuse_get_feature_flag = lookup.find("fuse_get_feature_flag")
+				.map(symbol -> linker.downcallHandle(symbol, FUSE_GET_FEATURE_FLAG));
 	}
 
 	private static class Holder {
@@ -41,4 +56,31 @@ public static int fuse_parse_cmdline(MemorySegment args, MemorySegment opts) {
 		}
 	}
 
+	public static boolean fuse_set_feature_flag(MemorySegment fuse_conn_info, long flag) throws UnsupportedOperationException {
+		var method = Holder.INSTANCE.fuse_set_feature_flag.orElseThrow(() -> new UnsupportedOperationException("The loaded fuse library does not implement fuse_set_feature_flag"));
+		try {
+			return ((int) method.invokeExact(fuse_conn_info, flag)) != 0;
+		} catch (Throwable e) {
+			throw new AssertionError("should not reach here", e);
+		}
+	}
+
+	public static void fuse_unset_feature_flag(MemorySegment fuse_conn_info, long flag) throws UnsupportedOperationException {
+		var method = Holder.INSTANCE.fuse_unset_feature_flag.orElseThrow(() -> new UnsupportedOperationException("The loaded fuse library does not implement fuse_unset_feature_flag"));
+		try {
+			method.invokeExact(fuse_conn_info, flag);
+		} catch (Throwable e) {
+			throw new AssertionError("should not reach here", e);
+		}
+	}
+
+	public static boolean fuse_get_feature_flag(MemorySegment fuse_conn_info, long flag) throws UnsupportedOperationException {
+		var method = Holder.INSTANCE.fuse_get_feature_flag.orElseThrow(() -> new UnsupportedOperationException("The loaded fuse library does not implement fuse_get_feature_flag"));
+		try {
+			return ((int) method.invokeExact(fuse_conn_info, flag)) != 0;
+		} catch (Throwable e) {
+			throw new AssertionError("should not reach here", e);
+		}
+	}
+
 }

jfuse-linux-aarch64/src/main/java/org/cryptomator/jfuse/linux/aarch64/FuseImpl.java

@@ -109,7 +109,12 @@ protected void bind(FuseOperations.Operation operation) {
 	@VisibleForTesting
 	MemorySegment init(MemorySegment conn, MemorySegment cfg) {
 		var connInfo = new FuseConnInfoImpl(conn);
-		connInfo.setWant(connInfo.want() | FuseConnInfo.FUSE_CAP_READDIRPLUS);
+		if (fuse_h.fuse_version() >= 317) {
+			connInfo = new FuseConnInfoImpl317(conn);
+			connInfo.setFeatureFlag(FuseConnInfo.FUSE_CAP_READDIRPLUS);
+		} else {
+			connInfo.setWant(connInfo.want() | FuseConnInfo.FUSE_CAP_READDIRPLUS);
+		}
 		var config = new FuseConfigImpl(cfg);
 		fuseOperations.init(connInfo, config);
 		return MemorySegment.NULL;

jfuse-linux-aarch64/src/test/java/org/cryptomator/jfuse/linux/aarch64/FuseConnInfoImpl317Test.java

@@ -0,0 +1,72 @@
+package org.cryptomator.jfuse.linux.aarch64;
+
+import org.cryptomator.jfuse.api.FuseConnInfo;
+import org.cryptomator.jfuse.linux.aarch64.extr.fuse3.fuse_conn_info;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Named;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+public class FuseConnInfoImpl317Test {
+
+	@DisplayName("test long getters")
+	@ParameterizedTest(name = "{1}")
+	@MethodSource
+	void testGetters(SetInMemorySegment setter, GetInConnInfo getter) {
+		try (var arena = Arena.ofConfined()) {
+			var segment = fuse_conn_info.allocate(arena);
+			var connInfo = new FuseConnInfoImpl317(segment);
+
+			setter.accept(segment, 42L);
+
+			Assertions.assertEquals(42L, getter.apply(connInfo));
+		}
+	}
+
+	public static Stream<Arguments> testGetters() {
+		return Stream.of(
+				Arguments.arguments((SetInMemorySegment) fuse_conn_info::want_ext, Named.of("wantExt()", (GetInConnInfo) FuseConnInfo::wantExt)),
+				Arguments.arguments((SetInMemorySegment) fuse_conn_info::capable_ext, Named.of("capableExt()", (GetInConnInfo) FuseConnInfo::capableExt))
+		);
+	}
+
+	interface SetInMemorySegment extends BiConsumer<MemorySegment, Long> {
+	}
+
+	interface GetInConnInfo extends Function<FuseConnInfo, Long> {
+	}
+
+	@DisplayName("test setters")
+	@ParameterizedTest(name = "{0}")
+	@MethodSource
+	void testSetters(SetInConnInfo setter, GetInMemorySegment getter) {
+		try (var arena = Arena.ofConfined()) {
+			var segment = fuse_conn_info.allocate(arena);
+			var connInfo = new FuseConnInfoImpl317(segment);
+
+			setter.accept(connInfo, 42L);
+
+			Assertions.assertEquals(42L, getter.apply(segment));
+		}
+	}
+
+	public static Stream<Arguments> testSetters() {
+		return Stream.of(
+				Arguments.arguments(Named.of("setWantExt()", (SetInConnInfo) FuseConnInfo::setWantExt), (GetInMemorySegment) fuse_conn_info::want_ext)
+		);
+	}
+
+	interface SetInConnInfo extends BiConsumer<FuseConnInfo, Long> {
+	}
+
+	interface GetInMemorySegment extends Function<MemorySegment, Long> {
+	}
+}