Re: [Qemu-devel] [PATCH 05/11] migration: add error handling to migrate_fd_put_notify().

[Juan Quintela <quintela@redhat.com>]

(Adding new Yoshiaki email address)

Paolo Bonzini <pbonzini@redhat.com> wrote:
> On 09/23/2011 02:50 PM, Juan Quintela wrote:
>> From: Yoshiaki Tamura<tamura.yoshiaki@lab.ntt.co.jp>
>>
>> Although migrate_fd_put_buffer() sets MIG_STATE_ERROR if it failed,
>> since migrate_fd_put_notify() isn't checking error of underlying
>> QEMUFile, those resources are kept open.  This patch checks it and
>> calls migrate_fd_error() in case of error.
>>
>> Signed-off-by: Yoshiaki Tamura<tamura.yoshiaki@lab.ntt.co.jp>
>> Signed-off-by: Juan Quintela<quintela@redhat.com>
>> ---
>>   migration.c |    6 +++---
>>   1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/migration.c b/migration.c
>> index 9498e20..0b284ff 100644
>> --- a/migration.c
>> +++ b/migration.c
>> @@ -313,6 +313,9 @@ void migrate_fd_put_notify(void *opaque)
>>
>>       qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
>>       qemu_file_put_notify(s->file);
>> +    if (qemu_file_has_error(s->file)) {
>> +        migrate_fd_error(s);
>> +    }
>>   }
>>
>>   ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
>> @@ -329,9 +332,6 @@ ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
>>
>>       if (ret == -EAGAIN) {
>>           qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
>> -    } else if (ret<  0) {
>> -        s->state = MIG_STATE_ERROR;
>> -        notifier_list_notify(&migration_state_notifiers, NULL);
>>       }
>>
>>       return ret;
>
> Why not leave both (or even better, call migrate_fd_error in the else
> branch)?

In the big scheme of things, it don't matter.  migration_fd_put_buffer()
still returns the errno.  it is only called from buffered_put_buffer()
and buffered_flush(), both check the error handling and setup
s->has_error correctly (after this series).

Yoshi, do you remember better?

Later, Juan.