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[Qemu-devel] [PATCH 15/20] qcow2: Add qcow2_alloc_clusters_at()
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 15/20] qcow2: Add qcow2_alloc_clusters_at() |
Date: |
Mon, 12 Mar 2012 16:19:46 +0100 |
This function allows to allocate clusters at a given offset in the image
file. This is useful if you want to allocate the second part of an area
that must be contiguous.
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
---
block/qcow2-refcount.c | 28 ++++++++++++++++++++++++++++
block/qcow2.h | 2 ++
2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 2db2ede..f39928a 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -582,6 +582,34 @@ int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t
size)
return offset;
}
+int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
+ int nb_clusters)
+{
+ BDRVQcowState *s = bs->opaque;
+ uint64_t cluster_index;
+ int i, refcount, ret;
+
+ /* Check how many clusters there are free */
+ cluster_index = offset >> s->cluster_bits;
+ for(i = 0; i < nb_clusters; i++) {
+ refcount = get_refcount(bs, cluster_index++);
+
+ if (refcount < 0) {
+ return refcount;
+ } else if (refcount != 0) {
+ break;
+ }
+ }
+
+ /* And then allocate them */
+ ret = update_refcount(bs, offset, i << s->cluster_bits, 1);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return i;
+}
+
/* only used to allocate compressed sectors. We try to allocate
contiguous sectors. size must be <= cluster_size */
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
diff --git a/block/qcow2.h b/block/qcow2.h
index fc35838..5129e3e 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -193,6 +193,8 @@ int qcow2_refcount_init(BlockDriverState *bs);
void qcow2_refcount_close(BlockDriverState *bs);
int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
+int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
+ int nb_clusters);
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
void qcow2_free_clusters(BlockDriverState *bs,
int64_t offset, int64_t size);
--
1.7.6.5
- [Qemu-devel] [PATCH 10/20] qapi: complete implementation of unions, (continued)
- [Qemu-devel] [PATCH 10/20] qapi: complete implementation of unions, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 04/20] block: handle -EBUSY in bdrv_commit_all(), Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 20/20] test-coroutine: add performance test for nesting, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 07/20] make check: Add qemu-iotests subset, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 14/20] qcow2: Factor out count_cow_clusters, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 09/20] use QSIMPLEQ_FOREACH_SAFE when freeing list elements, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 12/20] add mode field to blockdev-snapshot-sync transaction item, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 19/20] coroutine: adding configure option for sigaltstack coroutine backend, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 13/20] qmp: convert blockdev-snapshot-sync to a wrapper around transactions, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 11/20] rename blockdev-group-snapshot-sync, Kevin Wolf, 2012/03/12
- [Qemu-devel] [PATCH 15/20] qcow2: Add qcow2_alloc_clusters_at(),
Kevin Wolf <=
- Re: [Qemu-devel] [PULL 00/20] Block patches, Anthony Liguori, 2012/03/12