chore: fix clippy lints from nightly-2025-03-16 (#11273)

I like to run nightly clippy every so often to make our future rust
upgrades easier. Some notable changes:

* Prefer `next_back()` over `last()`. Generic iterators will implement
`last()` to run forward through the iterator until the end.

* Prefer `io::Error::other()`.

* Use implicit returns

One case where I haven't dealt with the issues is the now
[more-sensitive "large enum variant"
lint](rust-lang/rust-clippy#13833). I chose not
to take any decisions around it here, and simply marked them as allow
for now.

Author: conradludgate

compute_tools/src/catalog.rs

@@ -98,13 +98,15 @@ pub async fn get_database_schema(
         .kill_on_drop(true)
         .spawn()?;
 
-    let stdout = cmd.stdout.take().ok_or_else(|| {
-        std::io::Error::new(std::io::ErrorKind::Other, "Failed to capture stdout.")
-    })?;
+    let stdout = cmd
+        .stdout
+        .take()
+        .ok_or_else(|| std::io::Error::other("Failed to capture stdout."))?;
 
-    let stderr = cmd.stderr.take().ok_or_else(|| {
-        std::io::Error::new(std::io::ErrorKind::Other, "Failed to capture stderr.")
-    })?;
+    let stderr = cmd
+        .stderr
+        .take()
+        .ok_or_else(|| std::io::Error::other("Failed to capture stderr."))?;
 
     let mut stdout_reader = FramedRead::new(stdout, BytesCodec::new());
     let stderr_reader = BufReader::new(stderr);
@@ -128,8 +130,7 @@ pub async fn get_database_schema(
                 }
             });
 
-            return Err(SchemaDumpError::IO(std::io::Error::new(
-                std::io::ErrorKind::Other,
+            return Err(SchemaDumpError::IO(std::io::Error::other(
                 "failed to start pg_dump",
             )));
         }

control_plane/storcon_cli/src/main.rs

@@ -941,7 +941,7 @@ async fn main() -> anyhow::Result<()> {
             let mut node_to_fill_descs = Vec::new();
 
             for desc in node_descs {
-                let to_drain = nodes.iter().any(|id| *id == desc.id);
+                let to_drain = nodes.contains(&desc.id);
                 if to_drain {
                     node_to_drain_descs.push(desc);
                 } else {

libs/postgres_backend/src/lib.rs

@@ -5,7 +5,6 @@
 #![deny(unsafe_code)]
 #![deny(clippy::undocumented_unsafe_blocks)]
 use std::future::Future;
-use std::io::ErrorKind;
 use std::net::SocketAddr;
 use std::os::fd::{AsRawFd, RawFd};
 use std::pin::Pin;
@@ -227,7 +226,7 @@ impl<IO: AsyncRead + AsyncWrite + Unpin> MaybeWriteOnly<IO> {
         match self {
             MaybeWriteOnly::Full(framed) => framed.read_startup_message().await,
             MaybeWriteOnly::WriteOnly(_) => {
-                Err(io::Error::new(ErrorKind::Other, "reading from write only half").into())
+                Err(io::Error::other("reading from write only half").into())
             }
             MaybeWriteOnly::Broken => panic!("IO on invalid MaybeWriteOnly"),
         }
@@ -237,7 +236,7 @@ impl<IO: AsyncRead + AsyncWrite + Unpin> MaybeWriteOnly<IO> {
         match self {
             MaybeWriteOnly::Full(framed) => framed.read_message().await,
             MaybeWriteOnly::WriteOnly(_) => {
-                Err(io::Error::new(ErrorKind::Other, "reading from write only half").into())
+                Err(io::Error::other("reading from write only half").into())
             }
             MaybeWriteOnly::Broken => panic!("IO on invalid MaybeWriteOnly"),
         }
@@ -975,7 +974,7 @@ impl<IO: AsyncRead + AsyncWrite + Unpin> AsyncWrite for CopyDataWriter<'_, IO> {
             .write_message_noflush(&BeMessage::CopyData(buf))
             // write_message only writes to the buffer, so it can fail iff the
             // message is invaid, but CopyData can't be invalid.
-            .map_err(|_| io::Error::new(ErrorKind::Other, "failed to serialize CopyData"))?;
+            .map_err(|_| io::Error::other("failed to serialize CopyData"))?;
 
         Poll::Ready(Ok(buf.len()))
     }

libs/postgres_backend/tests/simple_select.rs

@@ -85,8 +85,8 @@ static KEY: Lazy<rustls::pki_types::PrivateKeyDer<'static>> = Lazy::new(|| {
 
 static CERT: Lazy<rustls::pki_types::CertificateDer<'static>> = Lazy::new(|| {
     let mut cursor = Cursor::new(include_bytes!("cert.pem"));
-    let cert = rustls_pemfile::certs(&mut cursor).next().unwrap().unwrap();
-    cert
+
+    rustls_pemfile::certs(&mut cursor).next().unwrap().unwrap()
 });
 
 // test that basic select with ssl works

libs/pq_proto/src/framed.rs

@@ -35,7 +35,7 @@ impl ConnectionError {
     pub fn into_io_error(self) -> io::Error {
         match self {
             ConnectionError::Io(io) => io,
-            ConnectionError::Protocol(pe) => io::Error::new(io::ErrorKind::Other, pe.to_string()),
+            ConnectionError::Protocol(pe) => io::Error::other(pe.to_string()),
         }
     }
 }

libs/pq_proto/src/lib.rs

@@ -257,7 +257,7 @@ pub enum ProtocolError {
 impl ProtocolError {
     /// Proxy stream.rs uses only io::Error; provide it.
     pub fn into_io_error(self) -> io::Error {
-        io::Error::new(io::ErrorKind::Other, self.to_string())
+        io::Error::other(self.to_string())
     }
 }
 

libs/proxy/postgres-protocol2/src/authentication/sasl.rs

@@ -212,7 +212,7 @@ impl ScramSha256 {
                     password,
                     channel_binding,
                 } => (nonce, password, channel_binding),
-                _ => return Err(io::Error::new(io::ErrorKind::Other, "invalid SCRAM state")),
+                _ => return Err(io::Error::other("invalid SCRAM state")),
             };
 
         let message =
@@ -291,7 +291,7 @@ impl ScramSha256 {
                 server_key,
                 auth_message,
             } => (server_key, auth_message),
-            _ => return Err(io::Error::new(io::ErrorKind::Other, "invalid SCRAM state")),
+            _ => return Err(io::Error::other("invalid SCRAM state")),
         };
 
         let message =
@@ -301,10 +301,7 @@ impl ScramSha256 {
 
         let verifier = match parsed {
             ServerFinalMessage::Error(e) => {
-                return Err(io::Error::new(
-                    io::ErrorKind::Other,
-                    format!("SCRAM error: {}", e),
-                ));
+                return Err(io::Error::other(format!("SCRAM error: {}", e)));
             }
             ServerFinalMessage::Verifier(verifier) => verifier,
         };

libs/remote_storage/src/azure_blob.rs

@@ -801,8 +801,7 @@ where
             // that support needs to be hacked in.
             //
             // including {self:?} into the message would be useful, but unsure how to unproject.
-            _ => std::task::Poll::Ready(Err(std::io::Error::new(
-                std::io::ErrorKind::Other,
+            _ => std::task::Poll::Ready(Err(std::io::Error::other(
                 "cloned or initial values cannot be read",
             ))),
         }
@@ -855,7 +854,7 @@ where
         };
         Err(azure_core::error::Error::new(
             azure_core::error::ErrorKind::Io,
-            std::io::Error::new(std::io::ErrorKind::Other, msg),
+            std::io::Error::other(msg),
         ))
     }
 

libs/utils/src/crashsafe.rs

@@ -81,12 +81,9 @@ pub fn path_with_suffix_extension(
 }
 
 pub fn fsync_file_and_parent(file_path: &Utf8Path) -> io::Result<()> {
-    let parent = file_path.parent().ok_or_else(|| {
-        io::Error::new(
-            io::ErrorKind::Other,
-            format!("File {file_path:?} has no parent"),
-        )
-    })?;
+    let parent = file_path
+        .parent()
+        .ok_or_else(|| io::Error::other(format!("File {file_path:?} has no parent")))?;
 
     fsync(file_path)?;
     fsync(parent)?;

pageserver/src/http/routes.rs

@@ -3381,11 +3381,11 @@ async fn put_tenant_timeline_import_basebackup(
 
         let broker_client = state.broker_client.clone();
 
-        let mut body = StreamReader::new(request.into_body().map(|res| {
-            res.map_err(|error| {
-                std::io::Error::new(std::io::ErrorKind::Other, anyhow::anyhow!(error))
-            })
-        }));
+        let mut body = StreamReader::new(
+            request
+                .into_body()
+                .map(|res| res.map_err(|error| std::io::Error::other(anyhow::anyhow!(error)))),
+        );
 
         tenant.wait_to_become_active(ACTIVE_TENANT_TIMEOUT).await?;
 
@@ -3459,7 +3459,7 @@ async fn put_tenant_timeline_import_wal(
 
         let mut body = StreamReader::new(request.into_body().map(|res| {
             res.map_err(|error| {
-                std::io::Error::new(std::io::ErrorKind::Other, anyhow::anyhow!(error))
+                std::io::Error::other( anyhow::anyhow!(error))
             })
         }));