[pbs-devel] [PATCH vma-to-pbs] improve error message for unexpected end of VMA file

[Filip Schauer]

When a VMA file ends unexpectedly while reading the header, change the
error message from "failed to fill whole buffer" to "Unexpected end of
VMA file" for more clarity.

Signed-off-by: Filip Schauer <f.schauer at proxmox.com>
---
 src/vma.rs | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/vma.rs b/src/vma.rs
index 63ee3b5..978e4c7 100644
--- a/src/vma.rs
+++ b/src/vma.rs
@@ -1,4 +1,5 @@
 use std::collections::HashSet;
+use std::io;
 use std::io::Read;
 use std::mem::size_of;
 use std::str;
@@ -126,7 +127,13 @@ impl<T: Read> VmaReader<T> {
 
     fn read_header(vma_file: &mut T) -> Result<VmaHeader, Error> {
         let mut buffer = vec![0; VMA_HEADER_SIZE_NO_BLOB_BUFFER];
-        vma_file.read_exact(&mut buffer)?;
+        vma_file.read_exact(&mut buffer).map_err(|e| {
+            if e.kind() == io::ErrorKind::UnexpectedEof {
+                io::Error::new(io::ErrorKind::UnexpectedEof, "Unexpected end of VMA file")
+            } else {
+                e
+            }
+        })?;
 
         let bincode_options = bincode::DefaultOptions::new()
             .with_fixint_encoding()
@@ -298,9 +305,9 @@ impl<T: Read> VmaReader<T> {
         loop {
             match self.restore_extent(&callback) {
                 Ok(()) => {}
-                Err(e) => match e.downcast_ref::<std::io::Error>() {
+                Err(e) => match e.downcast_ref::<io::Error>() {
                     Some(ioerr) => {
-                        if ioerr.kind() == std::io::ErrorKind::UnexpectedEof {
+                        if ioerr.kind() == io::ErrorKind::UnexpectedEof {
                             break; // Break out of the loop since the end of the file was reached.
                         } else {
                             return Err(format_err!(e)).context("Failed to read VMA file");
-- 
2.39.5