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[Qemu-devel] [PATCH v2 02/11] block: add helper function to determine if
From: |
Jeff Cody |
Subject: |
[Qemu-devel] [PATCH v2 02/11] block: add helper function to determine if a BDS is in a chain |
Date: |
Tue, 27 May 2014 10:28:32 -0400 |
This is a small helper function, to determine if 'base' is in the
chain of BlockDriverState 'top'. It returns true if it is in the chain,
and false otherwise.
If either argument is NULL, it will also return false.
Reviewed-by: Benoit Canet <address@hidden>
Signed-off-by: Jeff Cody <address@hidden>
---
block.c | 11 +++++++++++
include/block/block.h | 1 +
2 files changed, 12 insertions(+)
diff --git a/block.c b/block.c
index 415f0d2..cf4b296 100644
--- a/block.c
+++ b/block.c
@@ -3811,6 +3811,17 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
return NULL;
}
+/* If 'base' is in the same chain as 'top', return true. Otherwise,
+ * return false. If either argument is NULL, return false. */
+bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
+{
+ while (top && top != base) {
+ top = top->backing_hd;
+ }
+
+ return top != NULL;
+}
+
BlockDriverState *bdrv_next(BlockDriverState *bs)
{
if (!bs) {
diff --git a/include/block/block.h b/include/block/block.h
index faee3aa..4dc68be 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -404,6 +404,7 @@ BlockDeviceInfoList *bdrv_named_nodes_list(void);
BlockDriverState *bdrv_lookup_bs(const char *device,
const char *node_name,
Error **errp);
+bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
BlockDriverState *bdrv_next(BlockDriverState *bs);
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs),
void *opaque);
--
1.8.3.1
- [Qemu-devel] [PATCH v2 00/11] Modify block jobs to use node-names, Jeff Cody, 2014/05/27
- [Qemu-devel] [PATCH v2 01/11] block: Auto-generate node_names for each BDS entry, Jeff Cody, 2014/05/27
- [Qemu-devel] [PATCH v2 02/11] block: add helper function to determine if a BDS is in a chain,
Jeff Cody <=
- [Qemu-devel] [PATCH v2 03/11] block: Add overlay BDS pointer into the BlockDriverState struct, Jeff Cody, 2014/05/27
- [Qemu-devel] [PATCH v2 04/11] block: add helper function to find the active layer of any BDS, Jeff Cody, 2014/05/27
- [Qemu-devel] [PATCH v2 05/11] block: simplify bdrv_find_base(), Jeff Cody, 2014/05/27
- [Qemu-devel] [PATCH v2 06/11] block: make 'top' argument to block-commit optional, Jeff Cody, 2014/05/27