On 04/05/2017 02:28 PM, Jeff Cody wrote:
> Introduce try function for setting read_only flags. Will return < 0 on
> error, with appropriate Error value set. Does not alter any flags.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block.c | 14 +++++++++++++-
> include/block/block.h | 1 +
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/block.c b/block.c
> index 8bfe7f4..ad958b9 100644
> --- a/block.c
> +++ b/block.c
> @@ -197,7 +197,7 @@ bool bdrv_is_read_only(BlockDriverState *bs)
> return bs->read_only;
> }
>
> -int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
> +int bdrv_try_set_read_only(BlockDriverState *bs, bool read_only, Error
> **errp)
> {
> /* Do not set read_only if copy_on_read is enabled */
> if (bs->copy_on_read && read_only) {
> @@ -213,6 +213,18 @@ int bdrv_set_read_only(BlockDriverState *bs, bool
> read_only, Error **errp)
> return -EPERM;
> }
>
> + return 0;
> +}
> +
> +int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
> +{
> + int ret = 0;
> +
> + ret = bdrv_try_set_read_only(bs, read_only, errp);
> + if (ret < 0) {
> + return ret;
> + }
> +
> bs->read_only = read_only;
> return 0;
> }
> diff --git a/include/block/block.h b/include/block/block.h
> index beb563a..0049b57 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -426,6 +426,7 @@ int bdrv_is_allocated_above(BlockDriverState *top,
> BlockDriverState *base,
> int64_t sector_num, int nb_sectors, int *pnum);
>
> bool bdrv_is_read_only(BlockDriverState *bs);
> +int bdrv_try_set_read_only(BlockDriverState *bs, bool read_only, Error
> **errp);
> int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp);
> bool bdrv_is_sg(BlockDriverState *bs);
> bool bdrv_is_inserted(BlockDriverState *bs);
>
Maybe I'm just green, but I find it weird that the function is named
try_x when we aren't actually trying to do anything, we're checking to
see if we can.
