[Qemu-devel] Re: [PATCH] fix ioctl return value

[Glauber Costa <glommer@redhat.com>]

On Tue, Jul 21, 2009 at 08:40:36AM -0500, Anthony Liguori wrote:
> Glauber Costa wrote:
>> we expect a number less than 0, not exactly -1.
>> And furthermore, we return errno itself, so no need to use it.
>>
>> This might break guests when this ioctl fails for some reason.
>>
>> Signed-off-by: Glauber Costa <glommer@redhat.com>
>> ---
>>  kvm-all.c |    5 ++---
>>  1 files changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/kvm-all.c b/kvm-all.c
>> index 8567ac9..9a79466 100644
>> --- a/kvm-all.c
>> +++ b/kvm-all.c
>> @@ -319,9 +319,8 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
>>
>>          d.slot = mem->slot;
>>
>> -        if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
>> -            dprintf("ioctl failed %d\n", errno);
>> -            ret = -1;
>> +        if ((ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d)) < 0) {
>> +            dprintf("ioctl failed %d\n", ret);
>>   
>
> While this is fine, I usually prefer:
>
> ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
> if (ret < 0) {
>    dprintf(ioctl failed %d\n", ret);

want me to shoot a new one?