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authorKevin Wolf <kwolf@redhat.com>2013-03-15 10:35:08 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2013-03-15 16:07:49 +0100
commit74c4510a3cf7c369ee524c6f8fa8a87cf08ba608 (patch)
tree47513b79f00b7aba967176fed0cf2738c4a5ee62 /block
parent0006383e1549b6f9b264575d124c553efca19d62 (diff)
qcow2: Allow lazy refcounts to be enabled on the command line
qcow2 images now accept a boolean lazy_refcounts options. Use it like this: -drive file=test.qcow2,lazy_refcounts=on If the option is specified on the command line, it overrides the default specified by the qcow2 header flags that were set when creating the image. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/qcow2-cluster.c2
-rw-r--r--block/qcow2.c37
-rw-r--r--block/qcow2.h1
3 files changed, 39 insertions, 1 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 56fccf9487..ff9ae18e4a 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -668,7 +668,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
}
/* Update L2 table. */
- if (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS) {
+ if (s->use_lazy_refcounts) {
qcow2_mark_dirty(bs);
}
if (qcow2_need_accurate_refcounts(s)) {
diff --git a/block/qcow2.c b/block/qcow2.c
index f5e4269363..ad43a13cb0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -285,11 +285,26 @@ static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
return ret;
}
+static QemuOptsList qcow2_runtime_opts = {
+ .name = "qcow2",
+ .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head),
+ .desc = {
+ {
+ .name = "lazy_refcounts",
+ .type = QEMU_OPT_BOOL,
+ .help = "Postpone refcount updates",
+ },
+ { /* end of list */ }
+ },
+};
+
static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
{
BDRVQcowState *s = bs->opaque;
int len, i, ret = 0;
QCowHeader header;
+ QemuOpts *opts;
+ Error *local_err = NULL;
uint64_t ext_end;
ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
@@ -495,6 +510,28 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
}
}
+ /* Enable lazy_refcounts according to image and command line options */
+ opts = qemu_opts_create_nofail(&qcow2_runtime_opts);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (error_is_set(&local_err)) {
+ qerror_report_err(local_err);
+ error_free(local_err);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->use_lazy_refcounts = qemu_opt_get_bool(opts, "lazy_refcounts",
+ (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
+
+ qemu_opts_del(opts);
+
+ if (s->use_lazy_refcounts && s->qcow_version < 3) {
+ qerror_report(ERROR_CLASS_GENERIC_ERROR, "Lazy refcounts require "
+ "a qcow2 image with at least qemu 1.1 compatibility level");
+ ret = -EINVAL;
+ goto fail;
+ }
+
#ifdef DEBUG_ALLOC
{
BdrvCheckResult result = {0};
diff --git a/block/qcow2.h b/block/qcow2.h
index 718b52baca..103abdb2c0 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -173,6 +173,7 @@ typedef struct BDRVQcowState {
int flags;
int qcow_version;
+ bool use_lazy_refcounts;
uint64_t incompatible_features;
uint64_t compatible_features;