[Xen-devel] Re: [PATCH -v3 2/3] xen-blkback: repleace check kthread_should_stop() to remove_requested in xen_blkif_schedule() loop.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Thu, Aug 04, 2011 at 03:24:44PM +0800, Joe Jin wrote:
> 
> When backend state change to XenbusStateClosed, remove_requested will be set,
> so repleace check kthread_should_stop() to remove_requested in 
> xen_blkif_schedule() loop.
> 
> Signed-off-by: Joe Jin <joe.jin@xxxxxxxxxx>
> Cc: Daniel Stodden <daniel.stodden@xxxxxxxxxx>
> Cc: Jens Axboe <jaxboe@xxxxxxxxxxxx>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Cc: Annie Li <annie.li@xxxxxxxxxx>
> Cc: Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>
> --
>  drivers/block/xen-blkback/blkback.c |   10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c 
> b/drivers/block/xen-blkback/blkback.c
> index 2330a9a..3d64b52 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -274,7 +274,7 @@ int xen_blkif_schedule(void *arg)
>  
>       xen_blkif_get(blkif);
>  
> -     while (!kthread_should_stop()) {
> +     while (!blkif->remove_requested) {
>               if (try_to_freeze())
>                       continue;
>               if (unlikely(vbd->size != vbd_sz(vbd)))
> @@ -282,11 +282,11 @@ int xen_blkif_schedule(void *arg)
>  
>               wait_event_interruptible(
>                       blkif->wq,
> -                     blkif->waiting_reqs || kthread_should_stop());
> +                     blkif->waiting_reqs || blkif->remove_requested);
>               wait_event_interruptible(
>                       blkbk->pending_free_wq,
>                       !list_empty(&blkbk->pending_free) ||
> -                     kthread_should_stop());
> +                     blkif->remove_requested);
>  
>               blkif->waiting_reqs = 0;
>               smp_mb(); /* clear flag *before* checking for work */
> @@ -301,8 +301,8 @@ int xen_blkif_schedule(void *arg)
>       if (log_stats)
>               print_stats(blkif);
>  
> -     blkif->xenblkd = NULL;
>       xen_blkif_put(blkif);
> +     xen_blkback_close(blkif);

<sigh> I can't believe I didn't catch this earlier, but this a
big NO NO. Each patch _MUST_ be compile on its own. If I commit
patch 1 and this patch, the compile (actually linker) process
stops b/c xen_blkback_close is not defined:

drivers/built-in.o: In function `xen_blkif_schedule':
/home/konrad/ssd/linux/drivers/block/xen-blkback/blkback.c:305: undefined 
reference to `xen_blkback_close'
make[2]: *** [.tmp_vmlinux1] Error 1

You can move the xen_blkback_close() to the third patch
instead of having it here.

I will be nice and do it for you.

>  
>       return 0;
>  }
> @@ -476,7 +476,7 @@ __do_block_io_op(struct xen_blkif *blkif)
>               if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))
>                       break;
>  
> -             if (kthread_should_stop()) {
> +             if (blkif->remove_requested) {
>                       more_to_do = 1;
>                       break;
>               }

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel