Fix some style issues

kernel/src/device/registry/block.rs

@@ -138,13 +138,17 @@ impl FileIo for OpenBlockFile {
 
     fn ioctl(&self, raw_ioctl: RawIoctl) -> Result<i32> {
         use ioctl_defs::*;
+
         dispatch_ioctl!(match raw_ioctl {
             cmd @ BlkGetSize64 => {
                 let size = (self.0.metadata().nr_sectors * SECTOR_SIZE) as u64;
                 cmd.write(&size)?;
                 Ok(0)
             }
-            _ => return_errno_with_message!(Errno::ENOTTY, "unsupported ioctl on block device"),
+            _ => return_errno_with_message!(
+                Errno::ENOTTY,
+                "the ioctl command is not supported by block devices"
+            ),
         })
     }
 }

kernel/src/syscall/prlimit64.rs

@@ -33,12 +33,12 @@ pub fn sys_prlimit64(
     old_rlim_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let userspace = ctx.user_space();
+    let user_space = ctx.user_space();
 
     let new_raw = if new_rlim_addr == 0 {
         None
     } else {
-        Some(userspace.read_val(new_rlim_addr)?)
+        Some(user_space.read_val(new_rlim_addr)?)
     };
 
     let old_raw = if pid == 0 || pid == ctx.process.pid() {
@@ -53,7 +53,7 @@ pub fn sys_prlimit64(
     };
 
     if old_rlim_addr != 0 {
-        userspace.write_val(old_rlim_addr, &old_raw)?;
+        user_space.write_val(old_rlim_addr, &old_raw)?;
     }
 
     Ok(SyscallReturn::Return(0))

kernel/src/syscall/sched_affinity.rs

@@ -67,7 +67,7 @@ const SIZE_OF_PART: usize = size_of::<Part>();
 const CPUS_IN_PART: usize = SIZE_OF_PART * 8;
 
 fn read_cpu_set_from(
-    uspace: CurrentUserSpace,
+    user_space: CurrentUserSpace,
     cpuset_size: usize,
     cpu_set_ptr: Vaddr,
 ) -> Result<CpuSet> {
@@ -81,7 +81,7 @@ fn read_cpu_set_from(
 
     let nr_parts_to_read = cmp::min(cpuset_size / SIZE_OF_PART, num_cpus.div_ceil(CPUS_IN_PART));
     for part_id in 0..nr_parts_to_read {
-        let user_part: Part = uspace.read_val(cpu_set_ptr + part_id * SIZE_OF_PART)?;
+        let user_part: Part = user_space.read_val(cpu_set_ptr + part_id * SIZE_OF_PART)?;
         for bit_id in 0..CPUS_IN_PART {
             if user_part & (1 << bit_id) != 0 {
                 // If the CPU ID is invalid, just ignore it.
@@ -102,7 +102,7 @@ fn read_cpu_set_from(
 
 // Returns the number of bytes written.
 fn write_cpu_set_to(
-    uspace: CurrentUserSpace,
+    user_space: CurrentUserSpace,
     cpu_set: &CpuSet,
     cpuset_size: usize,
     cpu_set_ptr: Vaddr,
@@ -119,7 +119,7 @@ fn write_cpu_set_to(
     for cpu_id in cpu_set.iter() {
         let id = cpu_id.as_usize();
         while part_idx < cmp::min(id / CPUS_IN_PART, nr_parts_to_write) {
-            uspace.write_val(cpu_set_ptr + part_idx * SIZE_OF_PART, &user_part)?;
+            user_space.write_val(cpu_set_ptr + part_idx * SIZE_OF_PART, &user_part)?;
             user_part = 0;
             part_idx += 1;
         }
@@ -130,7 +130,7 @@ fn write_cpu_set_to(
     }
 
     while part_idx < nr_parts_to_write {
-        uspace.write_val(cpu_set_ptr + part_idx * SIZE_OF_PART, &user_part)?;
+        user_space.write_val(cpu_set_ptr + part_idx * SIZE_OF_PART, &user_part)?;
         user_part = 0;
         part_idx += 1;
     }