Re: [Qemu-block] [PATCH] block-backend: Set werror/rerror defaults in blk_new()

[Eric Blake]

On 9/28/18 4:18 AM, Kevin Wolf wrote:
> Currently, the default values for werror and rerror have to be set
> explicitly with blk_set_on_error() by the callers of blk_new(). The only
> caller actually doing this is blockdev_init(), which is called for
> BlockBackends created using -drive.
>
> In particular, anonymous BlockBackends created with
> -device ...,drive=<node-name> didn't get the correct default set and
> instead defaulted to the integer value 0 (= BLOCKDEV_ON_ERROR_REPORT).
> This is the intended default for rerror anyway, but the default for
> werror should be BLOCKDEV_ON_ERROR_ENOSPC.
>
> Set the defaults in blk_new() instead so that they apply no matter what
> way the BlockBackend was created.
>
> Cc: address@hidden
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>   block/block-backend.c | 3 +++
>   1 file changed, 3 insertions(+)

Reviewed-by: Eric Blake <address@hidden>

> diff --git a/block/block-backend.c b/block/block-backend.c
> index 7b1ec5071b..dc0cd57724 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -325,6 +325,9 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm)
>       blk->shared_perm = shared_perm;
>       blk_set_enable_write_cache(blk, true);
>   
> +    blk->on_read_error = BLOCKDEV_ON_ERROR_REPORT;
> +    blk->on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
> +
>       block_acct_init(&blk->stats);
>   
>       notifier_list_init(&blk->remove_bs_notifiers);

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