Re: [Qemu-devel] [PATCH v3 04/19] block: move aio initialization into a helper function

[Jeff Cody <jcody@redhat.com>]

On 09/20/2012 09:14 AM, Kevin Wolf wrote:
> Am 18.09.2012 20:53, schrieb Jeff Cody:
>> Move AIO initialization for raw-posix block driver into a helper function.
>>
>> In addition to just code motion, the aio_ctx pointer is checked for NULL,
>> prior to calling laio_init(), to make sure laio_init() is only run once.
>>
>> Signed-off-by: Jeff Cody <jcody@redhat.com>
>> ---
>>  block/raw-posix.c | 55 +++++++++++++++++++++++++++++++++++--------------------
>>  1 file changed, 35 insertions(+), 20 deletions(-)
>>
>> diff --git a/block/raw-posix.c b/block/raw-posix.c
>> index 6be20b1..ee55f79 100644
>> --- a/block/raw-posix.c
>> +++ b/block/raw-posix.c
>> @@ -185,6 +185,40 @@ static int raw_normalize_devicepath(const char **filename)
>>  }
>>  #endif
>>  
>> +static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
>> +{
>> +#ifdef CONFIG_LINUX_AIO
>> +    int ret = -1;
>> +    assert(aio_ctx != NULL);
>> +    assert(use_aio != NULL);
>> +    /*
>> +     * Currently Linux do AIO only for files opened with O_DIRECT
>> +     * specified so check NOCACHE flag too
>> +     */
>> +    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
>> +                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
>> +
>> +        /* if non-NULL, laio_init() has already been run */
>> +        if (*aio_ctx == NULL) {
>> +            *aio_ctx = laio_init();
>> +            if (!*aio_ctx) {
>> +                goto error;
>> +            }
>> +        }
>> +        *use_aio = 1;
>> +    } else {
>> +        *use_aio = 0;
>> +    }
>> +
>> +    ret = 0;
>> +
>> +error:
>> +    return ret;
>> +#else
>> +    return 0;
>> +#endif
>> +}
>> +
>>  static int raw_open_common(BlockDriverState *bs, const char *filename,
>>                             int bdrv_flags, int open_flags)
>>  {
>> @@ -239,26 +273,7 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
>>          goto out_free_buf;
>>      }
>>  
>> -#ifdef CONFIG_LINUX_AIO
>> -    /*
>> -     * Currently Linux do AIO only for files opened with O_DIRECT
>> -     * specified so check NOCACHE flag too
>> -     */
>> -    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
>> -                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
>> -
>> -        s->aio_ctx = laio_init();
>> -        if (!s->aio_ctx) {
>> -            goto out_free_buf;
>> -        }
>> -        s->use_aio = 1;
>> -    } else
>> -#endif
>> -    {
>> -#ifdef CONFIG_LINUX_AIO
>> -        s->use_aio = 0;
>> -#endif
>> -    }
>> +    raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags);
> 
> This should check the return value to handle laio_init() failure properly.
> 
> Kevin
> 

Thanks, fixed for v4.