From f1155542d2e8ce5192a4001b1156b9d3bff4a398 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Fri, 7 Nov 2014 17:17:53 +0100
Subject: [PATCH 06/41] dump: add API to write vmcore

Message-id: <1415380693-16593-7-git-send-email-lersek@redhat.com>
Patchwork-id: 62192
O-Subject: [RHEL-7.1 qemu-kvm PATCH 06/26] dump: add API to write vmcore
Bugzilla: 1157798
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
RH-Acked-by: dgibson <dgibson@redhat.com>

From: qiaonuohan <qiaonuohan@cn.fujitsu.com>

Function is used to write vmcore in flatten format. In flatten format, data is
written block by block, and in front of each block, a struct
MakedumpfileDataHeader is stored there to indicate the offset and size of the
data block.

struct MakedumpfileDataHeader {
    int64_t offset;
    int64_t buf_size;
};

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
(cherry picked from commit 5d31babe5c7d854d6b8470bc9fa67a698926e65d)
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 dump.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/dump.c b/dump.c
index 6c902e5..710893f 100644
--- a/dump.c
+++ b/dump.c
@@ -734,6 +734,27 @@ static int write_end_flat_header(int fd)
     return 0;
 }
 
+static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
+{
+    size_t written_size;
+    MakedumpfileDataHeader mdh;
+
+    mdh.offset = cpu_to_be64(offset);
+    mdh.buf_size = cpu_to_be64(size);
+
+    written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
+    if (written_size != sizeof(mdh)) {
+        return -1;
+    }
+
+    written_size = qemu_write_full(fd, buf, size);
+    if (written_size != size) {
+        return -1;
+    }
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
-- 
1.8.3.1