[CRIU] [PATCH] proc_parse: Borrow vmi iif there is file referenced

[Pavel Emelyanov]

On 03/06/2014 06:02 PM, Cyrill Gorcunov wrote:
> On Thu, Mar 06, 2014 at 04:51:38PM +0400, Pavel Emelyanov wrote:
>>
>> Hm... Can we do it like this
>>
>> if (prev->vm_file_fd < 0)
>> 	return 0;
>>
>> Since for anonymous mappings dev:ino would be 0:0 (matching) and we don't
>> even need to try messing the map_files -- it will be absent for sure.
> 
> Like this?
> 

Not exactly (I withdraw the previous comment).

> @@ -172,6 +172,13 @@ static int vma_get_mapfile(struct vma_area *vma, DIR *mfd,
>  	if (prev_vfi->vma && vfi_equal(vfi, prev_vfi)) {
>  		struct vma_area *prev = prev_vfi->vma;
>  
> +		/*
> +		 * If vfi is equal (!) and negative @vm_file_fd --
> +		 * we have nothing to borrow for sure.
> +		 */
> +		if (prev->vm_file_fd < 0)

The vma->vm_file_id = -1; should be here. Otherwise it's 0 and the rest
of criu code thinks it's a file descriptor 0 :)

> +			return 0;
> +
>  		pr_debug("vma %"PRIx64" borrows vfi from previous %"PRIx64"\n",
>  				vma->e->start, prev->e->start);
>  		vma->vm_file_fd = prev->vm_file_fd;