Exemplos de open_page_xfer em C++ (Cpp)

Exemplo n.º 1

Arquivo: shmem.c Projeto: nicescale/criu

static int dump_one_shmem(struct shmem_info_dump *si)
{
	struct iovec *iovs;
	struct page_pipe *pp;
	struct page_xfer xfer;
	int err, ret = -1, fd;
	unsigned char *map = NULL;
	void *addr = NULL;
	unsigned long pfn, nrpages;

	pr_info("Dumping shared memory %ld\n", si->shmid);

	nrpages = (si->size + PAGE_SIZE - 1) / PAGE_SIZE;
	map = xmalloc(nrpages * sizeof(*map));
	if (!map)
		goto err;

	fd = open_proc(si->pid, "map_files/%lx-%lx", si->start, si->end);
	if (fd < 0)
		goto err;

	addr = mmap(NULL, si->size, PROT_READ, MAP_SHARED, fd, 0);
	close(fd);
	if (addr == MAP_FAILED) {
		pr_err("Can't map shmem 0x%lx (0x%lx-0x%lx)\n",
				si->shmid, si->start, si->end);
		goto err;
	}

	/*
	 * We can't use pagemap here, because this vma is
	 * not mapped to us at all, but mincore reports the
	 * pagecache status of a file, which is correct in
	 * this case.
	 */

	err = mincore(addr, si->size, map);
	if (err)
		goto err_unmap;

	iovs = xmalloc(((nrpages + 1) / 2) * sizeof(struct iovec));
	if (!iovs)
		goto err_unmap;

	pp = create_page_pipe((nrpages + 1) / 2, iovs, true);
	if (!pp)
		goto err_iovs;

	err = open_page_xfer(&xfer, CR_FD_SHMEM_PAGEMAP, si->shmid);
	if (err)
		goto err_pp;

	for (pfn = 0; pfn < nrpages; pfn++) {
		if (!(map[pfn] & PAGE_RSS))
			continue;
again:
		ret = page_pipe_add_page(pp, (unsigned long)addr + pfn * PAGE_SIZE);
		if (ret == -EAGAIN) {
			ret = dump_pages(pp, &xfer, addr);
			if (ret)
				goto err_xfer;
			page_pipe_reinit(pp);
			goto again;
		} else if (ret)
			goto err_xfer;
	}

	ret = dump_pages(pp, &xfer, addr);

err_xfer:
	xfer.close(&xfer);
err_pp:
	destroy_page_pipe(pp);
err_iovs:
	xfree(iovs);
err_unmap:
	munmap(addr,  si->size);
err:
	xfree(map);
	return ret;
}

Exemplo n.º 2

Arquivo: shmem.c Projeto: avagin/crtools

static int dump_one_shmem(struct shmem_info_dump *si)
{
	struct iovec *iovs;
	struct page_pipe *pp;
	struct page_pipe_buf *ppb;
	struct page_xfer xfer;
	int err, ret = -1, fd;
	unsigned char *map = NULL;
	void *addr = NULL;
	unsigned long pfn, nrpages;

	pr_info("Dumping shared memory %ld\n", si->shmid);

	nrpages = (si->size + PAGE_SIZE - 1) / PAGE_SIZE;
	map = xmalloc(nrpages * sizeof(*map));
	if (!map)
		goto err;

	fd = open_proc(si->pid, "map_files/%lx-%lx", si->start, si->end);
	if (fd < 0)
		goto err;

	addr = mmap(NULL, si->size, PROT_READ, MAP_SHARED, fd, 0);
	close(fd);
	if (addr == MAP_FAILED) {
		pr_err("Can't map shmem 0x%lx (0x%lx-0x%lx)\n",
				si->shmid, si->start, si->end);
		goto err;
	}

	/*
	 * We can't use pagemap here, because this vma is
	 * not mapped to us at all, but mincore reports the
	 * pagecache status of a file, which is correct in
	 * this case.
	 */

	err = mincore(addr, si->size, map);
	if (err)
		goto err_unmap;

	iovs = xmalloc(((nrpages + 1) / 2) * sizeof(struct iovec));
	if (!iovs)
		goto err_unmap;

	pp = create_page_pipe((nrpages + 1) / 2, iovs);
	if (!pp)
		goto err_iovs;

	for (pfn = 0; pfn < nrpages; pfn++) {
		if (!(map[pfn] & PAGE_RSS))
			continue;

		if (page_pipe_add_page(pp, (unsigned long)addr + pfn * PAGE_SIZE))
			goto err_pp;
	}

	list_for_each_entry(ppb, &pp->bufs, l)
		if (vmsplice(ppb->p[1], ppb->iov, ppb->nr_segs,
					SPLICE_F_GIFT | SPLICE_F_NONBLOCK) !=
				ppb->pages_in * PAGE_SIZE) {
			pr_perror("Can't get shmem into page-pipe");
			goto err_pp;
		}

	err = open_page_xfer(&xfer, CR_FD_SHMEM_PAGEMAP, si->shmid);
	if (err)
		goto err_pp;

	ret = page_xfer_dump_pages(&xfer, pp, (unsigned long)addr);

	xfer.close(&xfer);
err_pp:
	destroy_page_pipe(pp);
err_iovs:
	xfree(iovs);
err_unmap:
	munmap(addr,  si->size);
err:
	xfree(map);
	return ret;
}