On Wed, 4 Nov 2015 20:19:35 +0300
"Denis V. Lunev" <d...@openvz.org> wrote:
> to switch to snapshot on all loaded block drivers.
>
> The patch also ensures proper locking.
>
> Signed-off-by: Denis V. Lunev <d...@openvz.org>
> CC: Juan Quintela <quint...@redhat.com>
> CC: Stefan Hajnoczi <stefa...@redhat.com>
> CC: Kevin Wolf <kw...@redhat.com>
> ---
Reviewed-by: Greg Kurz <gk...@linux.vnet.ibm.com>
> block/snapshot.c | 20 ++++++++++++++++++++
> include/block/snapshot.h | 1 +
> migration/savevm.c | 15 +++++----------
> 3 files changed, 26 insertions(+), 10 deletions(-)
>
> diff --git a/block/snapshot.c b/block/snapshot.c
> index 1b4b846..639074f 100644
> --- a/block/snapshot.c
> +++ b/block/snapshot.c
> @@ -406,3 +406,23 @@ int bdrv_all_delete_snapshot(const char *name,
> BlockDriverState **first_bad_bs,
> *first_bad_bs = bs;
> return ret;
> }
> +
> +
> +int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
> +{
> + int err = 0;
Cosmetic comment again :)
What about s/err/ret to be consistent with other functions in block/snapshot.c ?
> + BlockDriverState *bs = NULL;
> +
> + while ((bs = bdrv_next(bs)) && err == 0) {
> + AioContext *ctx = bdrv_get_aio_context(bs);
> +
> + aio_context_acquire(ctx);
> + if (bdrv_can_snapshot(bs)) {
> + err = bdrv_snapshot_goto(bs, name);
> + }
> + aio_context_release(ctx);
> + }
> +
> + *first_bad_bs = bs;
> + return err;
> +}
> diff --git a/include/block/snapshot.h b/include/block/snapshot.h
> index 9c9750a..9c54b7c 100644
> --- a/include/block/snapshot.h
> +++ b/include/block/snapshot.h
> @@ -85,5 +85,6 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState
> *bs,
> bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
> int bdrv_all_delete_snapshot(const char *name, BlockDriverState
> **first_bsd_bs,
> Error **err);
> +int bdrv_all_goto_snapshot(const char *name, BlockDriverState
> **first_bsd_bs);
>
> #endif
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 5a4a8c2..101dff5 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1425,16 +1425,11 @@ int load_vmstate(const char *name)
> /* Flush all IO requests so they don't interfere with the new state. */
> bdrv_drain_all();
>
> - bs = NULL;
> - while ((bs = bdrv_next(bs))) {
> - if (bdrv_can_snapshot(bs)) {
> - ret = bdrv_snapshot_goto(bs, name);
> - if (ret < 0) {
> - error_report("Error %d while activating snapshot '%s' on
> '%s'",
> - ret, name, bdrv_get_device_name(bs));
> - return ret;
> - }
> - }
> + ret = bdrv_all_goto_snapshot(name, &bs);
> + if (ret < 0) {
> + error_report("Error %d while activating snapshot '%s' on '%s'",
> + ret, name, bdrv_get_device_name(bs));
> + return ret;
> }
>
> /* restore the VM state */
