On Tue, 17 Nov 2015 12:08:31 +0300
"Denis V. Lunev" <d...@openvz.org> wrote:
> basically all bdrv_* operations must be called under aio_context_acquire
> except ones with bdrv_all prefix.
>
> Signed-off-by: Denis V. Lunev <d...@openvz.org>
> Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
> Reviewed-by: Fam Zheng <f...@redhat.com>
> CC: Juan Quintela <quint...@redhat.com>
> CC: Kevin Wolf <kw...@redhat.com>
> ---
> migration/savevm.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/migration/savevm.c b/migration/savevm.c
> index a845e69..09e6a43 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1917,6 +1917,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
> struct tm tm;
> const char *name = qdict_get_try_str(qdict, "name");
> Error *local_err = NULL;
> + AioContext *aio_context;
>
> if (!bdrv_all_can_snapshot(&bs)) {
> monitor_printf(mon, "Device '%s' is writable but does not "
> @@ -1938,6 +1939,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
> monitor_printf(mon, "No block device can accept snapshots\n");
> return;
> }
> + aio_context = bdrv_get_aio_context(bs);
>
> saved_vm_running = runstate_is_running();
>
> @@ -1948,6 +1950,8 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
> }
> vm_stop(RUN_STATE_SAVE_VM);
>
> + aio_context_acquire(aio_context);
> +
> memset(sn, 0, sizeof(*sn));
>
> /* fill auxiliary fields */
> @@ -1992,6 +1996,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
> }
>
> the_end:
> + aio_context_release(aio_context);
> if (saved_vm_running) {
> vm_start();
> }
> @@ -2030,6 +2035,7 @@ int load_vmstate(const char *name)
> QEMUSnapshotInfo sn;
> QEMUFile *f;
> int ret;
> + AioContext *aio_context;
>
> if (!bdrv_all_can_snapshot(&bs)) {
> error_report("Device '%s' is writable but does not support
> snapshots.",
> @@ -2048,9 +2054,12 @@ int load_vmstate(const char *name)
> error_report("No block device supports snapshots");
> return -ENOTSUP;
> }
> + aio_context = bdrv_get_aio_context(bs);
>
bs is used for error reporting earlier in this function.
bs_vm_state is the one to be used here.
> /* Don't even try to load empty VM states */
> + aio_context_acquire(aio_context);
> ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
> + aio_context_release(aio_context);
> if (ret < 0) {
> return ret;
> } else if (sn.vm_state_size == 0) {
> @@ -2078,9 +2087,12 @@ int load_vmstate(const char *name)
>
> qemu_system_reset(VMRESET_SILENT);
> migration_incoming_state_new(f);
> - ret = qemu_loadvm_state(f);
>
> + aio_context_acquire(aio_context);
> + ret = qemu_loadvm_state(f);
> qemu_fclose(f);
> + aio_context_release(aio_context);
> +
> migration_incoming_state_destroy();
> if (ret < 0) {
> error_report("Error %d while loading VM state", ret);
> @@ -2111,14 +2123,19 @@ void hmp_info_snapshots(Monitor *mon, const QDict
> *qdict)
> int nb_sns, i;
> int total;
> int *available_snapshots;
> + AioContext *aio_context;
>
> bs = bdrv_all_find_vmstate_bs();
> if (!bs) {
> monitor_printf(mon, "No available block device supports
> snapshots\n");
> return;
> }
> + aio_context = bdrv_get_aio_context(bs);
>
> + aio_context_acquire(aio_context);
> nb_sns = bdrv_snapshot_list(bs, &sn_tab);
> + aio_context_release(aio_context);
> +
> if (nb_sns < 0) {
> monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
> return;
