remove FUSE workaround

src/uucore/src/lib/features/pipes.rs

@@ -75,13 +75,6 @@ pub fn drain_pipe(pipe: &PipeReader, dest: &impl AsFd, len: usize) -> PipeRes {
     Ok(Ok(()))
 }
 
-/// check that source is FUSE
-/// we fallback to read() at FUSE <https://github.com/uutils/coreutils/issues/9609>
-#[inline]
-pub fn might_fuse(source: &impl AsFd) -> bool {
-    rustix::fs::fstatfs(source).map_or(true, |stats| stats.f_type == 0x6573_5546) // FUSE magic number, too many platform specific clippy warning with const
-}
-
 /// force-splice source to dest even both of them are not pipe via broker pipe
 ///
 /// throughput is better than direct splice for the case one of in/output is pipe by unknown reason
@@ -125,59 +118,37 @@ pub fn send_n_bytes(input: impl AsFd, target: impl AsFd, n: u64) -> std::io::Res
     }
     let mut n = n;
     let mut bytes_written: u64 = 0;
-    let succeed_or_fuse = loop {
-        if n == 0 {
-            // avoid unnecessary syscall
-            return Ok(bytes_written);
-        }
-        match splice(&input, &target, n as usize) {
-            Ok(0) => break true,
-            Ok(s) => {
-                n -= s as u64;
-                bytes_written += s as u64;
+    if let Some((broker_r, broker_w)) = PIPE_CACHE
+        .get_or_init(|| {
+            // use std::io::pipe to avoid unnecessary fcntl
+            let pair = std::io::pipe().ok()?;
+            if pipe_size > KERNEL_DEFAULT_PIPE_SIZE {
+                let _ = fcntl_setpipe_size(&pair.0, pipe_size);
             }
-            _ => break false, // input or output is not pipe
-        }
-    };
-    let succeed_or_fuse = succeed_or_fuse
-        || if let Some((broker_r, broker_w)) = PIPE_CACHE
-            .get_or_init(|| {
-                // use std::io::pipe to avoid unnecessary fcntl
-                let pair = std::io::pipe().ok()?;
-                if pipe_size > KERNEL_DEFAULT_PIPE_SIZE {
-                    let _ = fcntl_setpipe_size(&pair.0, pipe_size);
-                }
-                Some(pair)
-            })
-            .as_ref()
-        {
-            // todo: create fn splice_bounded_broker
-            loop {
-                if n == 0 {
-                    return Ok(bytes_written);
-                }
-                match splice(&input, &broker_w, n as usize) {
-                    Ok(0) => break true,
-                    Ok(s) => {
-                        n -= s as u64;
-                        bytes_written += s as u64;
-                        if drain_pipe(broker_r, &target, s)?.is_err() {
-                            break false;
-                        }
+            Some(pair)
+        })
+        .as_ref()
+    {
+        // todo: create fn splice_bounded_broker
+        loop {
+            if n == 0 {
+                return Ok(bytes_written);
+            }
+            match splice(&input, &broker_w, n as usize) {
+                Ok(0) => return Ok(bytes_written),
+                Ok(s) => {
+                    n -= s as u64;
+                    bytes_written += s as u64;
+                    if drain_pipe(broker_r, &target, s)?.is_err() {
+                        break;
                     }
-                    _ => break false,
                 }
+                _ => break,
             }
-        } else {
-            false
-        };
-    // do not always fallback to write for fuse, or 2 Ctrl+D is required to exit on tty
-    // todo: move fuse patch to callers
-    if !succeed_or_fuse || might_fuse(&input) {
-        // remove buffering from this fallback by RawReader, or order of output would be wrong with multiple input
-        bytes_written += std::io::copy(&mut RawReader(input).take(n), &mut RawWriter(target))?;
-    }
-
+        }
+    };
+    // fallback. remove buffering from this fallback by RawReader, or order of output would be wrong with multiple input
+    bytes_written += std::io::copy(&mut RawReader(input).take(n), &mut RawWriter(target))?;
     Ok(bytes_written)
 }