[CRIU] [PATCH 2/2] mm: handle new processes which created between snapshots

[Pavel Emelyanov]

On 06/24/2013 07:59 PM, Andrey Vagin wrote:
> These processes don't have image files in a parent snapshot and crtools
> should not fail in this case.
> 
> https://bugzilla.openvz.org/show_bug.cgi?id=2636
> 
> Signed-off-by: Andrey Vagin <avagin at openvz.org>
> ---
>  mem.c       | 10 +++++++---
>  page-read.c |  2 +-
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/mem.c b/mem.c
> index d6c807c..3316c4e 100644
> --- a/mem.c
> +++ b/mem.c
> @@ -86,7 +86,7 @@ static struct mem_snap_ctx *mem_snap_init(struct parasite_ctl *ctl)
>  
>  	pm_fd = open_image_at(p_fd, CR_FD_PAGEMAP, O_RSTR, ctl->pid.virt);
>  	if (pm_fd < 0)
> -		return ERR_PTR(pm_fd);
> +		return ERR_PTR(-errno);

Check for ENOENT here and return NULL if so.

>  
>  	ctx = xmalloc(sizeof(*ctx));
>  	if (!ctx)
> @@ -325,8 +325,12 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
>  	 */
>  
>  	snap = mem_snap_init(ctl);
> -	if (IS_ERR(snap))
> -		goto out;
> +	if (IS_ERR(snap)) {
> +		if (PTR_ERR(snap) == -ENOENT)
> +			snap = NULL;
> +		else
> +			goto out;
> +	}
>  
>  	map = xmalloc(vma_area_list->longest * sizeof(*map));
>  	if (!map)
> diff --git a/page-read.c b/page-read.c
> index 7de69d2..0f9a9cc 100644
> --- a/page-read.c
> +++ b/page-read.c
> @@ -162,7 +162,7 @@ static int try_open_parent(int dfd, int pid, struct page_read *pr)
>  	if (!parent)
>  		goto err_cl;
>  
> -	if (open_page_read_at(pfd, pid, parent))
> +	if (open_page_read_at(pfd, pid, parent) && errno != ENOENT)
>  		goto err_free;
>  
>  	close(pfd);
>