Commit 79b3c12a authored by Denis V. Lunev's avatar Denis V. Lunev Committed by Juan Quintela
Browse files

migration: normalize locking in migration/savevm.c 



basically all bdrv_* operations must be called under aio_context_acquire
except ones with bdrv_all prefix.

Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 7cb14481

migration/savevm.c

+18 −1
Original line number Diff line number Diff line
@@ -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_vm_state);



    /* 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;