fs: added feature to delegate /tmp to uhyve

Author: jounathaen

Cargo.toml

@@ -71,6 +71,7 @@ smp = []
 strace = []
 tcp = ["net", "smoltcp", "smoltcp/socket-tcp"]
 trace = ["smoltcp?/log", "smoltcp?/verbose"]
+uhyve-tmp = []
 udp = ["net", "smoltcp", "smoltcp/socket-udp"]
 vga = []
 virtio = ["dep:virtio"]

src/fs/mod.rs

@@ -340,11 +340,13 @@ pub(crate) fn init() {
 	const UTC_BUILT_TIME: &str = build_time::build_time_utc!();
 
 	FILESYSTEM.set(Filesystem::new()).unwrap();
-	FILESYSTEM
-		.get()
-		.unwrap()
-		.mkdir("/tmp", AccessPermission::from_bits(0o777).unwrap())
-		.expect("Unable to create /tmp");
+	if !(crate::env::is_uhyve() && cfg!(feature = "uhyve-tmp")) {
+		FILESYSTEM
+			.get()
+			.unwrap()
+			.mkdir("/tmp", AccessPermission::from_bits(0o777).unwrap())
+			.expect("Unable to create /tmp");
+	}
 	FILESYSTEM
 		.get()
 		.unwrap()

src/fs/uhyve.rs

@@ -276,5 +276,18 @@ pub(crate) fn init() {
 				)
 				.expect("Mount failed. Duplicate mount_point?");
 		}
+
+		#[cfg(feature = "uhyve-tmp")]
+		{
+		info!("Mounting /tmp as uhyve filesystem");
+		fs::FILESYSTEM
+			.get()
+			.unwrap()
+			.mount(
+				"/tmp",
+				Box::new(UhyveDirectory::new(Some("/tmp".to_string()))),
+			)
+			.unwrap();
+		}
 	}
 }