From 697c5dc405035b4b1aecb6a44ae11252e934d3e5 Mon Sep 17 00:00:00 2001
From: Marc Hartmayer <mhartmay@linux.ibm.com>
Date: Fri, 19 Nov 2021 11:42:14 +0100
Subject: [PATCH] zdump: write_dump: use `FILE *`
MIME-Version: 1.0
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Use the more common `FILE *` for writing to the output.

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zdump/output.c   | 15 +++++----------
 zdump/output.h   |  4 +++-
 zdump/zgetdump.c | 19 +++++++++++++------
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/zdump/output.c b/zdump/output.c
index d2b54436..0112c100 100644
--- a/zdump/output.c
+++ b/zdump/output.c
@@ -14,15 +14,12 @@
 #include "dfo.h"
 #include "output.h"
 
-int write_dump(int fd)
+int write_dump(FILE *stream)
 {
 	const u64 output_size = dfo_size();
 	char buf[8UL * PAGE_SIZE];
 	u64 written = 0;
 
-	if (fd < 0)
-		ERR_EXIT("fd must be a valid file descriptor");
-
 	if (!dfi_feat_copy())
 		ERR_EXIT("Copying not possible for %s dumps", dfi_name());
 	STDERR("Format Info:\n");
@@ -31,15 +28,13 @@ int write_dump(int fd)
 	STDERR("\n");
 	zg_progress_init("Copying dump", output_size);
 	while (written != output_size) {
-		ssize_t rc;
+		size_t rc;
 		u64 cnt;
 
 		cnt = dfo_read(buf, sizeof(buf));
-		rc = write(fd, buf, cnt);
-		if (rc == -1)
-			ERR_EXIT_ERRNO("Error: Write failed");
-		if (rc != (ssize_t) cnt)
-			ERR_EXIT("Error: Could not write full block");
+		rc = fwrite(buf, cnt, 1, stream);
+		if (rc != 1 && ferror(stream))
+			ERR_EXIT("Error: Write failed");
 		written += cnt;
 		zg_progress(written);
 	};
diff --git a/zdump/output.h b/zdump/output.h
index 054fe7be..a0eed0a7 100644
--- a/zdump/output.h
+++ b/zdump/output.h
@@ -8,6 +8,8 @@
 #ifndef OUTPUT_H
 #define OUTPUT_H
 
-int write_dump(int fd);
+#include <stdio.h>
+
+int write_dump(FILE *stream);
 
 #endif /* OUTPUT_H */
diff --git a/zdump/zgetdump.c b/zdump/zgetdump.c
index 259ef0e9..6096afee 100644
--- a/zdump/zgetdump.c
+++ b/zdump/zgetdump.c
@@ -156,8 +156,9 @@ static int do_mount(void)
 	return rc;
 }
 
-static int open_file_for_writing(const char *output)
+static FILE *open_file_for_writing(const char *output)
 {
+	FILE *stream;
 	int fd;
 
 	if (output) {
@@ -172,7 +173,12 @@ static int open_file_for_writing(const char *output)
 			ERR_EXIT_ERRNO("Could not dup() stdout");
 	}
 
-	return fd;
+	stream = fdopen(fd, "w");
+	if (!stream)
+		ERR_EXIT_ERRNO("Could not fdopen()");
+	fd = -1;
+
+	return stream;
 }
 
 /*
@@ -180,15 +186,16 @@ static int open_file_for_writing(const char *output)
  */
 static int do_copy(const char *output)
 {
-	int rc, fd;
+	FILE *stream;
+	int rc;
 
 	if (dfi_init() != 0)
 		ERR_EXIT("Dump cannot be processed (is not complete)");
 	dfo_init();
 	kdump_select_check();
-	fd = open_file_for_writing(output);
-	rc = write_dump(fd);
-	close(fd);
+	stream = open_file_for_writing(output);
+	rc = write_dump(stream);
+	fclose(stream);
 	dfi_exit();
 	return rc;
 }