Gate FUSE behind a runsc flag

This change gates all FUSE commands (by gating /dev/fuse) behind a runsc
flag. In order to use FUSE commands, use the --fuse flag with the --vfs2
flag. Check if FUSE is enabled by running dmesg in the sandbox.

2 files changed, 29 insertions, 1 deletions

diff --git a/test/runner/defs.bzl b/test/runner/defs.bzl
index 921e499be..600cb5192 100644
--- a/test/runner/defs.bzl
+++ b/test/runner/defs.bzl
@@ -61,7 +61,8 @@ def _syscall_test(
         file_access = "exclusive",
         overlay = False,
         add_uds_tree = False,
-        vfs2 = False):
+        vfs2 = False,
+        fuse = False):
     # Prepend "runsc" to non-native platform names.
     full_platform = platform if platform == "native" else "runsc_" + platform
 
@@ -73,6 +74,8 @@ def _syscall_test(
         name += "_overlay"
     if vfs2:
         name += "_vfs2"
+        if fuse:
+            name += "_fuse"
     if network != "none":
         name += "_" + network + "net"
 
@@ -107,6 +110,7 @@ def _syscall_test(
         "--overlay=" + str(overlay),
         "--add-uds-tree=" + str(add_uds_tree),
         "--vfs2=" + str(vfs2),
+        "--fuse=" + str(fuse),
     ]
 
     # Call the rule above.
@@ -129,6 +133,7 @@ def syscall_test(
         add_uds_tree = False,
         add_hostinet = False,
         vfs2 = False,
+        fuse = False,
         tags = None):
     """syscall_test is a macro that will create targets for all platforms.
 
@@ -188,6 +193,19 @@ def syscall_test(
         vfs2 = True,
     )
 
+    if vfs2 and fuse:
+        _syscall_test(
+            test = test,
+            shard_count = shard_count,
+            size = size,
+            platform = default_platform,
+            use_tmpfs = use_tmpfs,
+            add_uds_tree = add_uds_tree,
+            tags = platforms[default_platform] + vfs2_tags,
+            vfs2 = True,
+            fuse = True,
+        )
+
     # TODO(gvisor.dev/issue/1487): Enable VFS2 overlay tests.
     if add_overlay:
         _syscall_test(
diff --git a/test/runner/runner.go b/test/runner/runner.go
index 5456e46a6..2296f3a46 100644
--- a/test/runner/runner.go
+++ b/test/runner/runner.go
@@ -47,6 +47,7 @@ var (
 	fileAccess = flag.String("file-access", "exclusive", "mounts root in exclusive or shared mode")
 	overlay    = flag.Bool("overlay", false, "wrap filesystem mounts with writable tmpfs overlay")
 	vfs2       = flag.Bool("vfs2", false, "enable VFS2")
+	fuse       = flag.Bool("fuse", false, "enable FUSE")
 	parallel   = flag.Bool("parallel", false, "run tests in parallel")
 	runscPath  = flag.String("runsc", "", "path to runsc binary")
 
@@ -149,6 +150,9 @@ func runRunsc(tc gtest.TestCase, spec *specs.Spec) error {
 	}
 	if *vfs2 {
 		args = append(args, "-vfs2")
+		if *fuse {
+			args = append(args, "-fuse")
+		}
 	}
 	if *debug {
 		args = append(args, "-debug", "-log-packets=true")
@@ -358,6 +362,12 @@ func runTestCaseRunsc(testBin string, tc gtest.TestCase, t *testing.T) {
 	vfsVar := "GVISOR_VFS"
 	if *vfs2 {
 		env = append(env, vfsVar+"=VFS2")
+		fuseVar := "FUSE_ENABLED"
+		if *fuse {
+			env = append(env, fuseVar+"=TRUE")
+		} else {
+			env = append(env, fuseVar+"=FALSE")
+		}
 	} else {
 		env = append(env, vfsVar+"=VFS1")
 	}