diff --git a/src/main/java/com/google/devtools/build/lib/vfs/AbstractFileSystem.java b/src/main/java/com/google/devtools/build/lib/vfs/AbstractFileSystem.java
index 8a4e53d..1ff1435 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/AbstractFileSystem.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/AbstractFileSystem.java
@@ -14,8 +14,13 @@
 //
 package com.google.devtools.build.lib.vfs;
 
+import static java.nio.file.StandardOpenOption.CREATE;
 import static java.nio.file.StandardOpenOption.READ;
+import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
+import static java.nio.file.StandardOpenOption.WRITE;
 
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
@@ -27,8 +32,11 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
 import java.nio.file.Files;
-import java.util.EnumSet;
+import java.nio.file.OpenOption;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
 
 /** This class implements the FileSystem interface using direct calls to the UNIX filesystem. */
 @ThreadSafe
@@ -83,21 +91,42 @@
     }
   }
 
+  private static final ImmutableSet<StandardOpenOption> READABLE_BYTE_CHANNEL_OPEN_OPTIONS =
+      Sets.immutableEnumSet(READ);
+  private static final ImmutableSet<ProfilerTask> READABLE_BYTE_CHANNEL_PROFILER_TASKS =
+      Sets.immutableEnumSet(ProfilerTask.VFS_OPEN, ProfilerTask.VFS_READ);
+  private static final ImmutableSet<StandardOpenOption> READ_WRITE_BYTE_CHANNEL_OPEN_OPTIONS =
+      Sets.immutableEnumSet(READ, WRITE, CREATE, TRUNCATE_EXISTING);
+  private static final ImmutableSet<ProfilerTask> READ_WRITE_BYTE_CHANNEL_PROFILER_TASKS =
+      Sets.immutableEnumSet(ProfilerTask.VFS_OPEN, ProfilerTask.VFS_READ, ProfilerTask.VFS_WRITE);
+
   @Override
   protected ReadableByteChannel createReadableByteChannel(PathFragment path) throws IOException {
-    final String name = path.toString();
-    if (profiler.isActive()
-        && (profiler.isProfiling(ProfilerTask.VFS_READ)
-            || profiler.isProfiling(ProfilerTask.VFS_OPEN))) {
-      long startTime = Profiler.nanoTimeMaybe();
-      try {
-        // Currently, we do not proxy ReadableByteChannel for profiling.
-        return Files.newByteChannel(java.nio.file.Paths.get(name), EnumSet.of(READ));
-      } finally {
-        profiler.logSimpleTask(startTime, ProfilerTask.VFS_OPEN, name);
-      }
-    } else {
-      return Files.newByteChannel(java.nio.file.Paths.get(name));
+    return createSeekableByteChannelInternal(
+        path, READABLE_BYTE_CHANNEL_OPEN_OPTIONS, READABLE_BYTE_CHANNEL_PROFILER_TASKS);
+  }
+
+  @Override
+  protected SeekableByteChannel createReadWriteByteChannel(PathFragment path) throws IOException {
+    return createSeekableByteChannelInternal(
+        path, READ_WRITE_BYTE_CHANNEL_OPEN_OPTIONS, READ_WRITE_BYTE_CHANNEL_PROFILER_TASKS);
+  }
+
+  private static SeekableByteChannel createSeekableByteChannelInternal(
+      PathFragment path,
+      ImmutableSet<? extends OpenOption> options,
+      ImmutableSet<ProfilerTask> profilerTasks)
+      throws IOException {
+    String name = path.getPathString();
+    if (!profiler.isActive() || profilerTasks.stream().noneMatch(profiler::isProfiling)) {
+      return Files.newByteChannel(Paths.get(name), options);
+    }
+    long startTime = Profiler.nanoTimeMaybe();
+    try {
+      // Currently, we do not proxy SeekableByteChannel for profiling.
+      return Files.newByteChannel(Paths.get(name), options);
+    } finally {
+      profiler.logSimpleTask(startTime, ProfilerTask.VFS_OPEN, name);
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/BUILD b/src/main/java/com/google/devtools/build/lib/vfs/BUILD
index bcd1791..2f1c648 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/vfs/BUILD
@@ -59,6 +59,7 @@
         "//third_party:caffeine",
         "//third_party:guava",
         "//third_party:jsr305",
+        "//third_party/protobuf:protobuf_java",
     ],
 )
 
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/FileSystem.java b/src/main/java/com/google/devtools/build/lib/vfs/FileSystem.java
index 283e87b..67a225b 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/FileSystem.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/FileSystem.java
@@ -28,6 +28,7 @@
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
 import java.nio.file.FileAlreadyExistsException;
 import java.util.Collection;
 import java.util.Iterator;
@@ -720,6 +721,16 @@
   }
 
   /**
+   * Returns a {@link SeekableByteChannel} for writing to a file at provided path.
+   *
+   * <p>Truncates the target file, therefore it cannot be used to read already existing files.
+   * Please use {@link #createReadableByteChannel} to get a {@linkplain ReadableByteChannel channel}
+   * for reads instead.
+   */
+  protected abstract SeekableByteChannel createReadWriteByteChannel(PathFragment path)
+      throws IOException;
+
+  /**
    * Creates an OutputStream accessing the file denoted by path.
    *
    * @throws IOException if there was an error opening the file for writing
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/Path.java b/src/main/java/com/google/devtools/build/lib/vfs/Path.java
index 71d21c6..bfc4161 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/Path.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/Path.java
@@ -32,6 +32,7 @@
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
 import java.util.ArrayList;
 import java.util.Collection;
 import javax.annotation.Nullable;
@@ -790,10 +791,21 @@
   }
 
   /**
+   * Opens the file denoted by this path, following symbolic links, for reading and writing and
+   * returns a file channel for it.
+   *
+   * <p>Truncates the file, therefore it cannot be used to read already existing files. Please use
+   * {@link #createReadableByteChannel} to get a {@linkplain ReadableByteChannel channel} for reads
+   * instead.
+   */
+  public SeekableByteChannel createReadWriteByteChannel() throws IOException {
+    return fileSystem.createReadWriteByteChannel(asFragment());
+  }
+
+  /**
    * Returns a java.io.File representation of this path.
    *
-   * <p>Caveat: the result may be useless if this path's getFileSystem() is not
-   * the UNIX filesystem.
+   * <p>Caveat: the result may be useless if this path's getFileSystem() is not the UNIX filesystem.
    */
   public File getPathFile() {
     return new File(getPathString());
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/PathTransformingDelegateFileSystem.java b/src/main/java/com/google/devtools/build/lib/vfs/PathTransformingDelegateFileSystem.java
index 3070239..063ecc6 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/PathTransformingDelegateFileSystem.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/PathTransformingDelegateFileSystem.java
@@ -19,6 +19,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
 import java.util.Collection;
 
 /**
@@ -178,6 +179,11 @@
   }
 
   @Override
+  protected SeekableByteChannel createReadWriteByteChannel(PathFragment path) throws IOException {
+    return delegateFs.createReadWriteByteChannel(toDelegatePath(path));
+  }
+
+  @Override
   protected OutputStream getOutputStream(PathFragment path, boolean append) throws IOException {
     return delegateFs.getOutputStream(toDelegatePath(path), append);
   }
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystem.java b/src/main/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystem.java
index 097f7fa..39eb14f 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystem.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystem.java
@@ -35,6 +35,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -611,6 +612,12 @@
   }
 
   @Override
+  protected synchronized SeekableByteChannel createReadWriteByteChannel(PathFragment path) {
+    // It's feasible to implement, but so far it is not needed.
+    throw new UnsupportedOperationException("Not implemented");
+  }
+
+  @Override
   protected synchronized byte[] getFastDigest(PathFragment path) throws IOException {
     return statFile(path).getFastDigest();
   }
diff --git a/src/test/java/com/google/devtools/build/lib/vfs/BUILD b/src/test/java/com/google/devtools/build/lib/vfs/BUILD
index 49defcd..662b976 100644
--- a/src/test/java/com/google/devtools/build/lib/vfs/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/vfs/BUILD
@@ -66,10 +66,8 @@
         "//src/test/java/com/google/devtools/build/lib/testutil:TestThread",
         "//src/test/java/com/google/devtools/build/lib/testutil:TestUtils",
         "//src/test/java/com/google/devtools/build/lib/vfs/util",
-        "//third_party:caffeine",
         "//third_party:guava",
         "//third_party:guava-testlib",
-        "//third_party:jsr305",
         "//third_party:junit4",
         "//third_party:mockito",
         "//third_party:truth",
@@ -90,6 +88,7 @@
         "//third_party:guava",
         "//third_party:junit4",
         "//third_party:truth",
+        "@com_google_testparameterinjector//:testparameterinjector",
     ],
 )
 
@@ -147,5 +146,6 @@
         "//third_party:guava",
         "//third_party:junit4",
         "//third_party:truth",
+        "@com_google_testparameterinjector//:testparameterinjector",
     ],
 )
diff --git a/src/test/java/com/google/devtools/build/lib/vfs/FileSystemTest.java b/src/test/java/com/google/devtools/build/lib/vfs/FileSystemTest.java
index b4f6f60..09fc304 100644
--- a/src/test/java/com/google/devtools/build/lib/vfs/FileSystemTest.java
+++ b/src/test/java/com/google/devtools/build/lib/vfs/FileSystemTest.java
@@ -14,7 +14,9 @@
 //
 package com.google.devtools.build.lib.vfs;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.truth.Truth.assertThat;
+import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.fail;
@@ -26,6 +28,9 @@
 import com.google.devtools.build.lib.unix.FileStatus;
 import com.google.devtools.build.lib.unix.NativePosixFiles;
 import com.google.devtools.build.lib.util.Fingerprint;
+import com.google.testing.junit.testparameterinjector.TestParameter;
+import com.google.testing.junit.testparameterinjector.TestParameter.TestParameterValuesProvider;
+import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -33,9 +38,10 @@
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.channels.WritableByteChannel;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.FileAlreadyExistsException;
-import java.util.Collection;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.regex.Matcher;
@@ -44,17 +50,13 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.junit.runners.Parameterized;
-import org.junit.runners.Parameterized.Parameter;
-import org.junit.runners.Parameterized.Parameters;
 
 /**
  * This class handles the generic tests that any filesystem must pass.
  *
- * <p>Each filesystem-test should inherit from this class, thereby obtaining
- * all the tests.
+ * <p>Each filesystem-test should inherit from this class, thereby obtaining all the tests.
  */
-@RunWith(Parameterized.class)
+@RunWith(TestParameterInjector.class)
 public abstract class FileSystemTest {
 
   private long savedTime;
@@ -69,18 +71,15 @@
   protected Path xNonEmptyDirectoryFoo;
   protected Path xEmptyDirectory;
 
-  @Parameters(name = "{index}: digestHashFunction={0}")
-  public static Collection<DigestHashFunction[]> hashFunctions() {
-    // TODO(b/112537387): Remove the array-ification and return Collection<DigestHashFunction>. This
-    // is possible in Junit4.12, but 4.11 requires the array. Bazel 0.18 will have Junit4.12, so
-    // this can change then.
-    return DigestHashFunction.getPossibleHashFunctions()
-        .stream()
-        .map(dhf -> new DigestHashFunction[] {dhf})
-        .collect(ImmutableList.toImmutableList());
-  }
+  @TestParameter(valuesProvider = DigestHashFunctionsProvider.class)
+  public DigestHashFunction digestHashFunction;
 
-  @Parameter public DigestHashFunction digestHashFunction;
+  private static final class DigestHashFunctionsProvider implements TestParameterValuesProvider {
+    @Override
+    public ImmutableList<?> provideValues() {
+      return DigestHashFunction.getPossibleHashFunctions().asList();
+    }
+  }
 
   @Before
   public final void createDirectories() throws Exception  {
@@ -1321,6 +1320,74 @@
     }
   }
 
+  @Test
+  public void testCreateReadWriteByteChannelWrite(@TestParameter boolean overwrite)
+      throws Exception {
+    String text = "hello";
+    Path file = overwrite ? xFile : xNothing;
+    try (SeekableByteChannel channel = file.createReadWriteByteChannel()) {
+      writeToChannelAsLatin1(channel, text);
+      assertThat(channel.position()).isEqualTo(text.length());
+    }
+
+    assertThat(FileSystemUtils.readContent(file, ISO_8859_1)).isEqualTo("hello");
+  }
+
+  @Test
+  public void testCreateReadWriteByteChannelWriteAfterSeek() throws Exception {
+    try (SeekableByteChannel channel = xNothing.createReadWriteByteChannel()) {
+      writeToChannelAsLatin1(channel, "01234567890");
+      channel.position(5);
+      writeToChannelAsLatin1(channel, "hello!");
+      assertThat(channel.position()).isEqualTo(5 + "hello!".length());
+    }
+
+    assertThat(FileSystemUtils.readContent(xNothing, ISO_8859_1)).isEqualTo("01234hello!");
+  }
+
+  @Test
+  public void testCreateReadWriteByteChannelRead(@TestParameter({"0", "5", "12"}) int seekPosition)
+      throws Exception {
+    String text = "hello there!";
+    try (SeekableByteChannel channel = xNothing.createReadWriteByteChannel()) {
+      writeToChannelAsLatin1(channel, text);
+      channel.position(seekPosition);
+
+      String read = readAllAsString(channel, text.length() - seekPosition);
+      assertThat(channel.position()).isEqualTo(text.length());
+      assertThat(read).isEqualTo(text.substring(seekPosition));
+    }
+  }
+
+  private static void writeToChannelAsLatin1(WritableByteChannel channel, String text)
+      throws IOException {
+    byte[] bytes = text.getBytes(ISO_8859_1);
+    ByteBuffer buffer = ByteBuffer.wrap(bytes);
+    int toWrite = bytes.length;
+    while (toWrite > 0) {
+      toWrite -= channel.write(buffer);
+    }
+    assertThat(toWrite).isEqualTo(0);
+    assertThat(buffer.remaining()).isEqualTo(0);
+  }
+
+  private static String readAllAsString(ReadableByteChannel channel, int expectedSize)
+      throws IOException {
+    checkArgument(expectedSize >= 0, "negative expected size: %s", expectedSize);
+    // +1 to make sure we can observe EOF -- Channel::read will always return 0 for a full buffer.
+    ByteBuffer buffer = ByteBuffer.allocate(expectedSize + 1);
+    int totalRead = 0;
+    for (; ; ) {
+      int read = channel.read(buffer);
+      if (read == -1) {
+        assertThat(totalRead).isEqualTo(expectedSize);
+        return new String(buffer.array(), 0, expectedSize, ISO_8859_1);
+      }
+      totalRead += read;
+      assertThat(buffer.position()).isEqualTo(totalRead);
+    }
+  }
+
   private static int readFromChannel(ReadableByteChannel channel, ByteBuffer buffer, int expected)
       throws IOException {
     int numRead = 0;
diff --git a/src/test/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystemTest.java b/src/test/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystemTest.java
index e1654a0..827e3f2 100644
--- a/src/test/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystemTest.java
+++ b/src/test/java/com/google/devtools/build/lib/vfs/inmemoryfs/InMemoryFileSystemTest.java
@@ -26,6 +26,7 @@
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.SymlinkAwareFileSystemTest;
+import com.google.testing.junit.testparameterinjector.TestParameter;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
@@ -64,8 +65,8 @@
   }
 
   /**
-   * Tests concurrent creation of a substantial tree hierarchy including
-   * files, directories, symlinks, file contents, and permissions.
+   * Tests concurrent creation of a substantial tree hierarchy including files, directories,
+   * symlinks, file contents, and permissions.
    */
   @Test
   public void testConcurrentTreeConstruction() throws Exception {
@@ -410,4 +411,19 @@
 
     assertThat(symlink.getxattr("some.xattr")).isNull();
   }
+
+  // createSeekableByteChannel is not supported by InMemoryFileSystem.
+  @Test
+  @Override
+  public void testCreateReadWriteByteChannelWrite(@TestParameter boolean overwrite) {}
+
+  // createSeekableByteChannel is not supported by InMemoryFileSystem.
+  @Test
+  @Override
+  public void testCreateReadWriteByteChannelWriteAfterSeek() {}
+
+  // createSeekableByteChannel is not supported by InMemoryFileSystem.
+  @Test
+  @Override
+  public void testCreateReadWriteByteChannelRead(@TestParameter({"0"}) int seekPosition) {}
 }