Re: [Qemu-devel] [PATCH 04/11] migration: return real error code

[Anthony Liguori <anthony@codemonkey.ws>]

On 09/23/2011 07:50 AM, Juan Quintela wrote:
> make functions propaget errno, instead of just using -EIO.
>
> Signed-off-by: Juan Quintela<quintela@redhat.com>

qemu_file_has_error() implies a boolean response.  Wouldn't 
qemu_file_get_error() make more sense if you're going to rely on the return value?

Regards,

Anthony Liguori

> ---
>   migration.c |    6 +++++-
>   savevm.c    |   33 +++++++++++++++------------------
>   2 files changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/migration.c b/migration.c
> index ea7bcc8..9498e20 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -363,6 +363,7 @@ void migrate_fd_connect(FdMigrationState *s)
>   void migrate_fd_put_ready(void *opaque)
>   {
>       FdMigrationState *s = opaque;
> +    int ret;
>
>       if (s->state != MIG_STATE_ACTIVE) {
>           DPRINTF("put_ready returning because of non-active state\n");
> @@ -370,7 +371,10 @@ void migrate_fd_put_ready(void *opaque)
>       }
>
>       DPRINTF("iterate\n");
> -    if (qemu_savevm_state_iterate(s->mon, s->file) == 1) {
> +    ret = qemu_savevm_state_iterate(s->mon, s->file);
> +    if (ret<  0) {
> +        migrate_fd_error(s);
> +    } else if (ret == 1) {
>           int old_vm_running = runstate_is_running();
>
>           DPRINTF("done iterating\n");
> diff --git a/savevm.c b/savevm.c
> index 46f2447..c382076 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -1466,6 +1466,7 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
>                               int shared)
>   {
>       SaveStateEntry *se;
> +    int ret;
>
>       QTAILQ_FOREACH(se,&savevm_handlers, entry) {
>           if(se->set_params == NULL) {
> @@ -1497,13 +1498,13 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
>
>           se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
>       }
> -
> -    if (qemu_file_has_error(f)) {
> +    ret = qemu_file_has_error(f);
> +    if (ret != 0) {
>           qemu_savevm_state_cancel(mon, f);
> -        return -EIO;
>       }
>
> -    return 0;
> +    return ret;
> +
>   }
>
>   int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
> @@ -1528,16 +1529,14 @@ int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
>               break;
>           }
>       }
> -
> -    if (ret)
> -        return 1;
> -
> -    if (qemu_file_has_error(f)) {
> +    if (ret != 0) {
> +        return ret;
> +    }
> +    ret = qemu_file_has_error(f);
> +    if (ret != 0) {
>           qemu_savevm_state_cancel(mon, f);
> -        return -EIO;
>       }
> -
> -    return 0;
> +    return ret;
>   }
>
>   int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
> @@ -1580,10 +1579,7 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
>
>       qemu_put_byte(f, QEMU_VM_EOF);
>
> -    if (qemu_file_has_error(f))
> -        return -EIO;
> -
> -    return 0;
> +    return qemu_file_has_error(f);
>   }
>
>   void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
> @@ -1623,8 +1619,9 @@ static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
>       ret = qemu_savevm_state_complete(mon, f);
>
>   out:
> -    if (qemu_file_has_error(f))
> -        ret = -EIO;
> +    if (ret == 0) {
> +        ret = qemu_file_has_error(f);
> +    }
>
>       if (!ret&&  saved_vm_running)
>           vm_start();