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[Qemu-devel] [PATCH 07/13] qcow2: Allow lazy refcounts to be enabled on
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 07/13] qcow2: Allow lazy refcounts to be enabled on the command line |
Date: |
Tue, 12 Mar 2013 15:41:13 +0100 |
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 <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
---
block/qcow2-cluster.c | 2 +-
block/qcow2.c | 37 +++++++++++++++++++++++++++++++++++++
block/qcow2.h | 1 +
3 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 56fccf9..ff9ae18 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 f5e4269..ad43a13 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 718b52b..103abdb 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;
--
1.8.1.4
- [Qemu-devel] [PATCH 04/13] block: Add options QDict to bdrv_open_common(), (continued)
- [Qemu-devel] [PATCH 04/13] block: Add options QDict to bdrv_open_common(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 01/13] block: Add options QDict to .bdrv_open(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 02/13] block: Add options QDict to bdrv_open() prototype, Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 08/13] qcow2: flush refcount cache correctly in alloc_refcount_block(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 06/13] block: Support driver specific options in drive_init(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 03/13] Add qdict_clone_shallow(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 05/13] qemu-option: Add qemu_opts_absorb_qdict(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 09/13] qcow2: flush refcount cache correctly in qcow2_write_snapshots(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 11/13] qcow2: flush in qcow2_update_snapshot_refcount(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 10/13] qcow2: set L2 cache dependency in qcow2_alloc_bytes(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 07/13] qcow2: Allow lazy refcounts to be enabled on the command line,
Kevin Wolf <=
- [Qemu-devel] [PATCH 12/13] qcow2: drop flush in update_cluster_refcount(), Kevin Wolf, 2013/03/12
- [Qemu-devel] [PATCH 13/13] qcow2: drop unnecessary flush in qcow2_update_snapshot_refcount(), Kevin Wolf, 2013/03/12