[Qemu-devel] Re: [PATCH]hw/xen_disk: ioreq not finished on error

[Feiran Zheng]

On Mon, Mar 28, 2011 at 9:42 PM, Stefano Stabellini
<address@hidden> wrote:
> On Sun, 27 Mar 2011, Feiran Zheng wrote:
>> Bug fix: routines 'ioreq_runio_qemu_sync' and 'ioreq_runio_qemu_aio'
>> won't call 'ioreq_unmap' or 'ioreq_finish' on errors, leaving ioreq in
>> the blkdev->inflight list and a leak.
>>
>> Signed-off-by: Feiran Zheng <address@hidden>
>> ---
>>  hw/xen_disk.c |   22 +++++++++++++++++-----
>>  1 files changed, 17 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/xen_disk.c b/hw/xen_disk.c
>> index 445bf03..7940fab 100644
>> --- a/hw/xen_disk.c
>> +++ b/hw/xen_disk.c
>> @@ -309,8 +309,10 @@ static int ioreq_runio_qemu_sync(struct ioreq *ioreq)
>>      int i, rc, len = 0;
>>      off_t pos;
>>
>> -    if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1)
>> -     goto err;
>> +    if (ioreq->req.nr_segments) {
>> +     if (ioreq_map(ioreq) == -1)
>> +         goto err_no_map;
>> +    }
>>      if (ioreq->presync)
>>       bdrv_flush(blkdev->bs);
>>
>
> this change is just to make the code clearer and easier to read, right?

I think so.

>
>
>> @@ -364,6 +366,9 @@ static int ioreq_runio_qemu_sync(struct ioreq *ioreq)
>>      return 0;
>>
>>  err:
>> +    ioreq_unmap(ioreq);
>> +err_no_map:
>> +    ioreq_finish(ioreq);
>>      ioreq->status = BLKIF_RSP_ERROR;
>>      return -1;
>>  }
>> @@ -392,8 +397,10 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
>>  {
>>      struct XenBlkDev *blkdev = ioreq->blkdev;
>>
>> -    if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1)
>> -     goto err;
>> +    if (ioreq->req.nr_segments) {
>> +     if (ioreq_map(ioreq) == -1)
>> +         goto err_no_map;
>> +    }
>>
>>      ioreq->aio_inflight++;
>>      if (ioreq->presync)
>> @@ -425,9 +432,14 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
>>      qemu_aio_complete(ioreq, 0);
>>
>>      return 0;
>> +
>> +err_no_map:
>> +    ioreq_finish(ioreq);
>> +    ioreq->status = BLKIF_RSP_ERROR;
>> +    return -1;
>>
>
> why aren't you calling ioreq_unmap before ioreq_finish, like in the
> previous case?
>
>
>
It seems not a must but if call qemu_aio_complete, the error info can
be printed, I thought it may be helpful.


-- 
Best regards!
Fam Zheng