From baf5602ed92628067990abfa7a873f51586a4dc1 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 14 Mar 2016 11:40:23 +0100
Subject: [PATCH] block: Add bdrv_parse_cache_mode()

It's like bdrv_parse_cache_flags(), except that writethrough mode isn't
included in the flags, but returned as a separate bool.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block.c               | 17 +++++++++++++++++
 include/block/block.h |  1 +
 2 files changed, 18 insertions(+)

diff --git a/block.c b/block.c
index af3584389d..14d2ebc35a 100644
--- a/block.c
+++ b/block.c
@@ -667,6 +667,23 @@ int bdrv_parse_cache_flags(const char *mode, int *flags)
     return 0;
 }
 
+int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
+{
+    int ret = bdrv_parse_cache_flags(mode, flags);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (*flags & BDRV_O_CACHE_WB) {
+        *flags &= ~BDRV_O_CACHE_WB;
+        *writethrough = false;
+    } else {
+        *writethrough = true;
+    }
+
+    return 0;
+}
+
 /*
  * Returns the options and flags that a temporary snapshot should get, based on
  * the originally requested flags (the originally requested image will have
diff --git a/include/block/block.h b/include/block/block.h
index b4b4650fd3..4fd6c050f0 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -208,6 +208,7 @@ void bdrv_replace_in_backing_chain(BlockDriverState *old,
                                    BlockDriverState *new);
 
 int bdrv_parse_cache_flags(const char *mode, int *flags);
+int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
 int bdrv_parse_discard_flags(const char *mode, int *flags);
 BdrvChild *bdrv_open_child(const char *filename,
                            QDict *options, const char *bdref_key,