[CRIU] [PATCH 27/32] tools: cpt2 -- Add "write" routines for virtual memory areas

[Cyrill Gorcunov]

On Mon, Apr 01, 2013 at 02:25:40PM +0400, Pavel Emelyanov wrote:
> > +	list_for_each_entry(vma, &mm->vma_list, list) {
> > +
> > +		if (!vma_is(vma, VMA_AREA_REGULAR))
> > +			continue;
> > +
> > +		if (vma_is(vma, VMA_AREA_SYSVIPC))
> > +			continue;
> 
> Why?

sysvipc was not addressed neither it was yet tested
(while crtools is ready to restore this zone i desided
 to not include it until anything else tested).

> 
> > +
> 
> > +		if (vma_is_shared(vma))
> 
> This define is in patch #19 and ...
> 
> > +			e.flags = MAP_SHARED;
> > +		else
> > +			e.flags = MAP_PRIVATE;
> > +
> > +		if (vma_is(vma, VMA_ANON_SHARED | VMA_ANON_PRIVATE))
> 
> ... looks exactly like this one. Such tricks do not improve code readability.

Thanks, will update!

> 
> > +			e.flags |= MAP_ANONYMOUS;
> > +
> 
> > +
> > +#define write_socket_map(ctx, vma, pid)		0
> 
> WTF???

not covered yet, but to not fail I zapped it.

> > +	for (; start < end; start += u.h.cpt_next) {
> > +		if (read_obj_cpt(ctx->fd, OBJ_ANY, &u.h, start)) {
> > +			pr_err("Can't read page header at %li\n", (long)start);
> > +			goto err;
> > +		}
> > +
> > +		/*
> > +		 * Skip any non regular pages.
> > +		 */
> > +		switch (u.h.cpt_object) {
> > +		case CPT_OBJ_PAGES:
> > +			break;
> > +		case CPT_OBJ_REMAPPAGES:
> > +		case CPT_OBJ_COPYPAGES:
> > +		case CPT_OBJ_LAZYPAGES:
> > +		case CPT_OBJ_ITERPAGES:
> > +		case CPT_OBJ_ITERYOUNGPAGES:
> > +			continue;
> 
> Bail out with error.

ok

> > +		for (i = 0; i < nr_pages; i++) {
> > +			if (__read(ctx->fd, page, sizeof(page))) {
> > +				pr_err("Can't read page at %li\n",
> > +				       (long)start);
> > +					goto err;
> > +				}
> > +			if (__write(page_fd, page, sizeof(page))) {
> > +				pr_err("Can't write page at %li\n",
> > +				       (long)start);
> > +				goto err;
> > +			}
> 
> Plz, use sendfile for this.

I don't think it worth, we will be teaching crtools to work with
cpt pages directly so this is for simplicity.