We don't reopen the actual file, but instead invoke the close and open routines.
We specifically ignore the backing file since it's contents are read-only and
therefore immutable.
Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
block/qcow2.c | 19 +++++++++++++++++++
block/qcow2.h | 2 ++
2 files changed, 21 insertions(+), 0 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index e4126b7..b5171e0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -241,6 +241,7 @@ static int qcow2_open(BlockDriverState *bs, int flags)
s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
s->cluster_size
+ 512);
s->cluster_cache_offset = -1;
+ s->flags = flags;
ret = qcow2_refcount_init(bs);
if (ret != 0) {
@@ -641,6 +642,22 @@ static void qcow2_close(BlockDriverState *bs)
qcow2_refcount_close(bs);
}
+static void qcow2_invalidate_cache(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ int flags = s->flags;
+
+ /*
+ * Backing files are read-only which makes all of their metadata immutable,
+ * that means we don't have to worry about reopening them here.
+ */
+
+ qcow2_close(bs);
+
+ memset(s, 0, sizeof(BDRVQcowState));
+ qcow2_open(bs, flags);
+}
+
/*
* Updates the variable length parts of the qcow2 header, i.e. the backing file
* name and all extensions. qcow2 was not designed to allow such changes, so if
@@ -1278,6 +1295,8 @@ static BlockDriver bdrv_qcow2 = {
.bdrv_change_backing_file = qcow2_change_backing_file,
+ .bdrv_invalidate_cache = qcow2_invalidate_cache,
+
.create_options = qcow2_create_options,
.bdrv_check = qcow2_check,
};
diff --git a/block/qcow2.h b/block/qcow2.h
index 0734b23..6312cd9 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -127,6 +127,8 @@ typedef struct BDRVQcowState {
QCowSnapshot *snapshots;
Error *migration_blocker;
+
+ int flags;
} BDRVQcowState;
/* XXX: use std qcow open function ? */
--
1.7.4.1
