[CRIU] Re: [PATCH 3/5] restorer: do page-size reads in a while loop

[Pavel Emelyanov]

On 08/21/2012 07:20 PM, Adrian Reber wrote:
> When reading pages-*.img over a network socket using read() and size
> PAGE_SIZE it might not always be possible to read the complete
> PAGE_SIZE in one read(). Therefore read in while loop until PAGE_SIZE
> has actually been read.
> 
> Signed-off-by: Adrian Reber <adrian at lisas.de>
> ---
>  restorer.c |   14 +++++++++-----
>  1 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/restorer.c b/restorer.c
> index 95a7922..48011cb 100644
> --- a/restorer.c
> +++ b/restorer.c
> @@ -343,6 +343,7 @@ long __export_restore_task(struct task_restore_core_args *args)
>  	 * Read page contents.
>  	 */
>  	while (1) {
> +		long i = 0;
>  		ret = sys_read(args->fd_pages, &va, sizeof(va));
>  		if (!ret)
>  			break;
> @@ -353,11 +354,14 @@ long __export_restore_task(struct task_restore_core_args *args)
>  			goto core_restore_end;
>  		}
>  
> -		ret = sys_read(args->fd_pages, (void *)va, PAGE_SIZE);
> -		if (ret != PAGE_SIZE) {
> -			write_num_n(__LINE__);
> -			write_num_n(ret);
> -			goto core_restore_end;
> +		while (i != PAGE_SIZE) {
> +			ret = sys_read(args->fd_pages, (void *)va, PAGE_SIZE - i);
> +			if (ret < 0) {

Shouldn't this be "<=" to catch closed socket case.

> +				write_num_n(__LINE__);
> +				write_num_n(ret);
> +				goto core_restore_end;
> +			}
> +			i += ret;
>  		}
>  	}
>