From 8eb499d3541579ab0a9cad8fc454259b3688999b Mon Sep 17 00:00:00 2001
From: Peter Lesslie <pclesslie@gmail.com>
Date: Tue, 26 Nov 2019 19:36:33 -0600
Subject: [PATCH] Check for fread failure

On failure fread may return either a short read or 0. Need to use
ferror to detect error versus eof.
---
 programs/fileio.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/programs/fileio.c b/programs/fileio.c
index a45dedc46..8fc25d357 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -1769,7 +1769,7 @@ static int FIO_passThrough(const FIO_prefs_t* const prefs,
                            size_t alreadyLoaded)
 {
     size_t const blockSize = MIN(64 KB, bufferSize);
-    size_t readFromInput = 1;
+    size_t readFromInput;
     unsigned storedSkips = 0;
 
     /* assumption : ress->srcBufferLoaded bytes already loaded and stored within buffer */
@@ -1779,10 +1779,15 @@ static int FIO_passThrough(const FIO_prefs_t* const prefs,
             return 1;
     }   }
 
-    while (readFromInput) {
+    do {
         readFromInput = fread(buffer, 1, blockSize, finput);
         storedSkips = FIO_fwriteSparse(prefs, foutput, buffer, readFromInput, storedSkips);
+    } while (readFromInput == blockSize);
+    if (ferror(finput)) {
+        DISPLAYLEVEL(1, "Pass-through read error : %s\n", strerror(errno));
+        return 1;
     }
+    assert(feof(finput));
 
     FIO_fwriteSparseEnd(prefs, foutput, storedSkips);
     return 0;