Re: [Qemu-devel] [PATCH v2] block: Use bdrv functions to replace file operation in cow.c

[Stefan Hajnoczi]

On Mon, Nov 07, 2011 at 02:52:17PM +0800, Li Zhi Hui wrote:
> @@ -260,10 +261,15 @@ static int cow_create(const char *filename, 
> QEMUOptionParameter *options)
>          options++;
>      }
> 
> -    cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
> -              0644);
> -    if (cow_fd < 0)
> -        return -errno;
> +    ret = bdrv_create_file(filename, options);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    ret = bdrv_file_open(&cow_bs, filename, BDRV_O_RDWR);
> +    if (ret < 0) {
> +        return ret;
> +    }
>      memset(&cow_header, 0, sizeof(cow_header));
>      cow_header.magic = cpu_to_be32(COW_MAGIC);
>      cow_header.version = cpu_to_be32(COW_VERSION);
> @@ -271,16 +277,16 @@ static int cow_create(const char *filename, 
> QEMUOptionParameter *options)
>          /* Note: if no file, we put a dummy mtime */
>          cow_header.mtime = cpu_to_be32(0);
> 
> -        fd = open(image_filename, O_RDONLY | O_BINARY);
> -        if (fd < 0) {
> -            close(cow_fd);
> +        ret = bdrv_file_open(&image_bs, image_filename, BDRV_O_RDWR);
> +        if (ret < 0) {
> +            bdrv_close(cow_bs);

This should be bdrv_delete() instead of bdrv_close() because
bdrv_file_open() does bdrv_new() to allocate the BlockDriverState - it
needs to be freed.

The same applies to the other hunks in this patch.

Stefan