Re: [PATCH 07/11] block: Fix AioContext locking in bdrv_open_inherit()

[Eric Blake]

On Wed, May 31, 2023 at 01:02:27PM +0200, Kevin Wolf wrote:
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Commit message is sparse, and doesn't mention....

> ---
>  block.c | 25 ++++++++++++++++++++++++-
>  1 file changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/block.c b/block.c
> index a0793b6435..954b9923d9 100644
> --- a/block.c
> +++ b/block.c
> @@ -3794,6 +3794,7 @@ static BlockDriverState 
> *bdrv_append_temp_snapshot(BlockDriverState *bs,
>      int64_t total_size;
>      QemuOpts *opts = NULL;
>      BlockDriverState *bs_snapshot = NULL;
> +    AioContext *ctx = bdrv_get_aio_context(bs);
>      int ret;
>  
>      GLOBAL_STATE_CODE();
> @@ -3802,7 +3803,10 @@ static BlockDriverState 
> *bdrv_append_temp_snapshot(BlockDriverState *bs,
>         instead of opening 'filename' directly */
>  
>      /* Get the required size from the image */
> +    aio_context_acquire(ctx);
>      total_size = bdrv_getlength(bs);
> +    aio_context_release(ctx);
> +
>      if (total_size < 0) {
>          error_setg_errno(errp, -total_size, "Could not get image size");
>          goto out;
> @@ -3836,7 +3840,10 @@ static BlockDriverState 
> *bdrv_append_temp_snapshot(BlockDriverState *bs,
>          goto out;
>      }
>  
> +    aio_context_acquire(ctx);
>      ret = bdrv_append(bs_snapshot, bs, errp);
> +    aio_context_release(ctx);
> +
>      if (ret < 0) {
>          bs_snapshot = NULL;
>          goto out;

...the changes to bdrv_append_temp_snapshot above.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org