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

[Feiran Zheng <famcool@gmail.com>]

Sorry for the confusing, I'll clean up it.

On Tue, Mar 29, 2011 at 2:16 AM, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> On Mon, 28 Mar 2011, Feiran Zheng wrote:
>> On Mon, Mar 28, 2011 at 9:42 PM, Stefano Stabellini
>> <stefano.stabellini@eu.citrix.com> 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 <famcool@gmail.com>
>> >> ---
>> >>  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.
>
> I am not sure I understand what you mean here because in case of error
> we don't call qemu_aio_complete at all in the err_no_map code path.



-- 
Best regards!
Fam Zheng