Paolo Bonzini <pbonz...@redhat.com> writes:
> Il 15/03/2013 16:14, Stefan Hajnoczi ha scritto:
>> From: Kevin Wolf <kw...@redhat.com>
>>
>> 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 <kw...@redhat.com>
>> Reviewed-by: Eric Blake <ebl...@redhat.com>
>> Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
>> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
>> ---
>> 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);
>
> This breaks migration with qcow2 images:
I already processed the pull unfortunately. I'm going to be offline for
most of the weekend but if there's a patch in the next hour to revert or
fix I can apply it.
Regards,
Anthony Liguori
>
> Program received signal SIGSEGV, Segmentation fault.
> qdict_next_entry (first_bucket=0, qdict=0x0) at
> /home/pbonzini/work/upstream/qemu/qobject/qdict.c:371
> 371 if (!QLIST_EMPTY(&qdict->table[i])) {
> (gdb) up
> #1 qdict_first (qdict=qdict@entry=0x0) at
> /home/pbonzini/work/upstream/qemu/qobject/qdict.c:384
> 384 return qdict_next_entry(qdict, 0);
> (gdb)
> #2 0x00007fb8edf75ae6 in qemu_opts_absorb_qdict
> (opts=opts@entry=0x7fb8f0651740, qdict=qdict@entry=0x0,
> errp=errp@entry=0x7fb8edc36e80)
> at /home/pbonzini/work/upstream/qemu/util/qemu-option.c:1078
> 1078 entry = qdict_first(qdict);
> (gdb)
> #3 0x00007fb8edd15074 in qcow2_open (bs=0x7fb8f041b800, options=0x0,
> flags=<optimized out>) at /home/pbonzini/work/upstream/qemu/block/qcow2.c:515
> 515 qemu_opts_absorb_qdict(opts, options, &local_err);
> (gdb)
> #4 0x00007fb8edd00352 in bdrv_invalidate_cache (bs=0x7fb8f041b800) at
> /home/pbonzini/work/upstream/qemu/block.c:4192
> 4192 bs->drv->bdrv_invalidate_cache(bs);
>
> Paolo
>
>> + 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;
>>
