[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 1/3] block: add missed aio_context_acquire aroun
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH 1/3] block: add missed aio_context_acquire around bdrv_set_aio_context |
Date: |
Fri, 6 Nov 2015 13:35:45 +0000 |
User-agent: |
Mutt/1.5.23 (2015-06-09) |
On Wed, Nov 04, 2015 at 08:27:22PM +0300, Denis V. Lunev wrote:
> It is required for bdrv_drain.
What bug does this patch fix?
Existing blk_set_aio_context() callers acquire the AioContext or are
sure it's already acquired by their caller, so I don't see where the bug
is.
No function in block/block-backend.c acquires AioContext internally.
The same reasoning I mentioned in another email thread about consistent
locking strategy applies here. Either all blk_*() functions should take
the AioContext internally (which I disagree with) or none of them should
take it.
> Signed-off-by: Denis V. Lunev <address@hidden>
> CC: Stefan Hajnoczi <address@hidden>
> ---
> block/block-backend.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 19fdaae..07fcfc7 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -1065,7 +1065,10 @@ static AioContext
> *blk_aiocb_get_aio_context(BlockAIOCB *acb)
> void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
> {
> if (blk->bs) {
> + AioContext *ctx = blk_get_aio_context(blk);
> + aio_context_acquire(ctx);
> bdrv_set_aio_context(blk->bs, new_context);
> + aio_context_release(ctx);
> }
> }
>
> --
> 2.5.0
>
>
signature.asc
Description: PGP signature
[Qemu-devel] [PATCH 2/3] blockdev: acquire AioContext in hmp_commit(), Denis V. Lunev, 2015/11/04