Gripe when using non-raw block device

bin/propolis-server/src/lib/initializer.rs

@@ -6,6 +6,7 @@ use std::convert::TryInto;
 use std::fs::File;
 use std::io::{Error, ErrorKind};
 use std::num::NonZeroUsize;
+use std::os::unix::fs::FileTypeExt;
 use std::sync::Arc;
 use std::time::{SystemTime, UNIX_EPOCH};
 
@@ -327,6 +328,16 @@ impl<'a> MachineInitializer<'a> {
                 info!(self.log, "Creating file disk backend";
                       "path" => &spec.path);
 
+                // Check if raw device is being used and gripe if it isn't
+                let meta = std::fs::metadata(&spec.path)?;
+                if meta.file_type().is_block_device() {
+                    slog::warn!(
+                        self.log,
+                        "Block backend using standard device rather than raw";
+                        "path" => &spec.path
+                    );
+                }
+
                 let nworkers = NonZeroUsize::new(8).unwrap();
                 let be = propolis::block::FileBackend::create(
                     &spec.path,

bin/propolis-standalone/src/config.rs

@@ -4,6 +4,7 @@
 
 use std::collections::BTreeMap;
 use std::num::NonZeroUsize;
+use std::os::unix::fs::FileTypeExt;
 use std::str::FromStr;
 use std::sync::Arc;
 
@@ -58,6 +59,14 @@ pub fn block_backend(
         "file" => {
             let parsed: FileConfig = opt_deser(&be.options).unwrap();
 
+            // Check if raw device is being used and gripe if it isn't
+            let meta = std::fs::metadata(&parsed.path)
+                .expect("file device path is valid");
+            if meta.file_type().is_block_device() {
+                slog::warn!(log, "Block backend using standard device rather than raw";
+                    "path" => &parsed.path);
+            }
+
             let be = block::FileBackend::create(
                 &parsed.path,
                 opts,