[PATCH v2 06/11] qemu: block: Add function to check if storage source allows concurrent access

[Peter Krempa <pkrempa@xxxxxxxxxx>]

Storage source format backing a shared device (e.g. running a cluster
filesystem) needs to support the sharing so that metadata are not
corrupted. Add a central function for checking this.
---
 src/qemu/qemu_block.c | 15 +++++++++++++++
 src/qemu/qemu_block.h |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 8b23df8227..29a341f149 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -390,6 +390,21 @@ qemuBlockGetNodeData(virJSONValuePtr data)
 }


+/**
+ * qemuBlockStorageSourceSupportsConcurrentAccess:
+ * @src: disk storage source
+ *
+ * Returns true if the given storage format supports concurrent access from two
+ * separate processes.
+ */
+bool
+qemuBlockStorageSourceSupportsConcurrentAccess(virStorageSourcePtr src)
+{
+    /* no need to check in backing chain since only RAW storage supports this */
+    return src->format == VIR_STORAGE_FILE_RAW;
+}
+
+
 /**
  * qemuBlockStorageSourceGetURI:
  * @src: disk storage source
diff --git a/src/qemu/qemu_block.h b/src/qemu/qemu_block.h
index b9ee97f488..45485733fc 100644
--- a/src/qemu/qemu_block.h
+++ b/src/qemu/qemu_block.h
@@ -54,6 +54,9 @@ qemuBlockNodeNamesDetect(virQEMUDriverPtr driver,
 virHashTablePtr
 qemuBlockGetNodeData(virJSONValuePtr data);

+bool
+qemuBlockStorageSourceSupportsConcurrentAccess(virStorageSourcePtr src);
+
 virJSONValuePtr
 qemuBlockStorageSourceGetBackendProps(virStorageSourcePtr src);

-- 
2.14.3

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