Re: [Qemu-devel] [v2 Patch 1/9]block: Framework for reopening image files safely

[Stefan Hajnoczi]

On Mon, Jul 30, 2012 at 10:34 PM, Supriya Kannery
<address@hidden> wrote:
> +void bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
> +{
> +    BlockDriver *drv = bs->drv;
> +    int ret = 0;
> +    BDRVReopenState *reopen_state = NULL;
> +
> +    /* Quiesce IO for the given block device */
> +    bdrv_drain_all();
> +    ret = bdrv_flush(bs);
> +    if (ret != 0) {
> +        error_set(errp, QERR_IO_ERROR);
> +        return;
> +    }
> +
> +    /* Use driver specific reopen() if available */
> +    if (drv->bdrv_reopen_prepare) {
> +        ret = bdrv_reopen_prepare(bs, &reopen_state, bdrv_flags);
> +         if (ret < 0) {

Indentation is off.

> +            bdrv_reopen_abort(bs, reopen_state);
> +            error_set(errp, QERR_OPEN_FILE_FAILED, bs->filename);
> +            return;
> +        }
> +
> +        bdrv_reopen_commit(bs, reopen_state);
> +        bs->open_flags = bdrv_flags;
> +    } else {
> +        error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
> +                  drv->format_name, bs->device_name,
> +                  "reopening of file");
> +        return;
> +    }

This would be slightly simpler if written as:

if (drv->bdrv_reopen_prepare == NULL) {
    ...error return...
}

...success case...

Stefan