refactor: replace boxed_debug_trace with trait BoxTrace

alioth/src/errors.rs

@@ -15,6 +15,8 @@
 use std::error::Error;
 use std::fmt;
 
+use snafu::{ErrorCompat, IntoError, ResultExt};
+
 pub use macros::{DebugTrace, trace_error};
 
 pub trait DebugTrace: Error {
@@ -27,8 +29,22 @@ impl Error for Box<dyn DebugTrace + Send + Sync + 'static> {
     }
 }
 
-pub fn boxed_debug_trace<E: DebugTrace + Send + Sync + 'static>(
-    e: E,
-) -> Box<dyn DebugTrace + Send + Sync + 'static> {
-    Box::new(e)
+pub trait BoxTrace<'a, T> {
+    fn box_trace<C, E>(self, context: C) -> Result<T, E>
+    where
+        C: IntoError<E, Source = Box<dyn DebugTrace + Send + Sync + 'a>>,
+        E: Error + ErrorCompat;
+}
+
+impl<'a, T, E1> BoxTrace<'a, T> for Result<T, E1>
+where
+    E1: DebugTrace + Send + Sync + 'a,
+{
+    fn box_trace<C, E>(self, context: C) -> Result<T, E>
+    where
+        C: IntoError<E, Source = Box<dyn DebugTrace + Send + Sync + 'a>>,
+        E: Error + ErrorCompat,
+    {
+        self.map_err(|e| Box::new(e) as _).context(context)
+    }
 }

alioth/src/vfio/container.rs

@@ -20,7 +20,7 @@ use std::sync::Arc;
 use parking_lot::Mutex;
 use snafu::ResultExt;
 
-use crate::errors::boxed_debug_trace;
+use crate::errors::BoxTrace;
 use crate::mem::mapped::ArcMemPages;
 use crate::mem::{self, LayoutChanged};
 use crate::vfio::bindings::{
@@ -110,15 +110,13 @@ pub struct UpdateContainerMapping {
 impl LayoutChanged for UpdateContainerMapping {
     fn ram_added(&self, gpa: u64, pages: &ArcMemPages) -> mem::Result<()> {
         let ret = self.container.map(pages.addr(), gpa, pages.size());
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         Ok(())
     }
 
     fn ram_removed(&self, gpa: u64, pages: &ArcMemPages) -> mem::Result<()> {
         let ret = self.container.unmap(gpa, pages.size());
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         Ok(())
     }
 }

alioth/src/vfio/iommu.rs

@@ -20,7 +20,7 @@ use std::sync::Arc;
 
 use snafu::ResultExt;
 
-use crate::errors::boxed_debug_trace;
+use crate::errors::BoxTrace;
 use crate::mem::mapped::ArcMemPages;
 use crate::mem::{self, LayoutChanged};
 use crate::vfio::bindings::{
@@ -128,15 +128,13 @@ pub struct UpdateIommuIoas {
 impl LayoutChanged for UpdateIommuIoas {
     fn ram_added(&self, gpa: u64, pages: &ArcMemPages) -> mem::Result<()> {
         let ret = self.ioas.map(pages.addr(), gpa, pages.size());
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         Ok(())
     }
 
     fn ram_removed(&self, gpa: u64, pages: &ArcMemPages) -> mem::Result<()> {
         let ret = self.ioas.unmap(gpa, pages.size());
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         Ok(())
     }
 }

alioth/src/vfio/pci.rs

@@ -25,10 +25,9 @@ use std::sync::atomic::AtomicU64;
 use libc::{PROT_READ, PROT_WRITE};
 use macros::Layout;
 use parking_lot::{Mutex, RwLock};
-use snafu::ResultExt;
 use zerocopy::{FromBytes, Immutable, IntoBytes, transmute};
 
-use crate::errors::boxed_debug_trace;
+use crate::errors::BoxTrace;
 use crate::hv::{IrqFd, MsiSender};
 use crate::mem::emulated::{Action, Mmio, MmioBus};
 use crate::mem::mapped::ArcMemPages;
@@ -341,7 +340,7 @@ where
 
     fn reset(&self) -> pci::Result<()> {
         let ret = VfioPciDev::reset(self);
-        ret.map_err(boxed_debug_trace).context(pci::error::Reset)?;
+        ret.box_trace(pci::error::Reset)?;
         Ok(())
     }
 }
@@ -696,8 +695,7 @@ where
             let offset = offset - self.table_range.start;
             if self.table.write_val(offset as u64, size, val)? {
                 self.enable_irqfd(offset / size_of::<MsixTableEntry>())
-                    .map_err(boxed_debug_trace)
-                    .context(mem::error::Mmio)?;
+                    .box_trace(mem::error::Mmio)?;
             }
         } else if self.pba_range.contains(&offset) {
             log::error!(
@@ -825,9 +823,7 @@ where
         }
         drop(cap);
         if need_update {
-            self.update_msi()
-                .map_err(boxed_debug_trace)
-                .context(mem::error::Mmio)?;
+            self.update_msi().box_trace(mem::error::Mmio)?;
         }
         Ok(Action::None)
     }

alioth/src/virtio/vhost/vhost.rs

@@ -22,7 +22,7 @@ use std::sync::Arc;
 
 use snafu::{ResultExt, Snafu};
 
-use crate::errors::{DebugTrace, boxed_debug_trace, trace_error};
+use crate::errors::{BoxTrace, DebugTrace, trace_error};
 use crate::mem::mapped::Ram;
 use crate::mem::{self, LayoutUpdated};
 
@@ -158,8 +158,7 @@ impl LayoutUpdated for UpdateVsockMem {
             table.regions[index].size = user_mem.size();
         }
         let ret = self.dev.set_mem_table(&table);
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         log::trace!(
             "vhost-{}: updated mem table to {:x?}",
             self.dev.fd.as_raw_fd(),

alioth/src/virtio/vu.rs

@@ -27,7 +27,7 @@ use parking_lot::Mutex;
 use snafu::{ResultExt, Snafu};
 use zerocopy::{FromBytes, FromZeros, Immutable, IntoBytes};
 
-use crate::errors::{DebugTrace, boxed_debug_trace, trace_error};
+use crate::errors::{BoxTrace, DebugTrace, trace_error};
 use crate::mem::LayoutChanged;
 use crate::mem::mapped::ArcMemPages;
 use crate::{ffi, mem};
@@ -542,8 +542,7 @@ impl LayoutChanged for UpdateVuMem {
             },
         };
         let ret = self.dev.add_mem_region(&region, fd.as_raw_fd());
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         log::trace!(
             "vu-{}: added memory region {:x?}",
             self.dev.conn.lock().as_raw_fd(),
@@ -566,8 +565,7 @@ impl LayoutChanged for UpdateVuMem {
             },
         };
         let ret = self.dev.remove_mem_region(&region);
-        ret.map_err(boxed_debug_trace)
-            .context(mem::error::ChangeLayout)?;
+        ret.box_trace(mem::error::ChangeLayout)?;
         log::trace!(
             "vu-{}: removed memory region {:x?}",
             self.dev.conn.lock().as_raw_fd(),