On Thu, Jul 20, 2023 at 09:28:52PM +0200, Michał Mirosław wrote:

This is a massaged version of patch by Muhammad Usama Anjum [1] to illustrate my review comments and hopefully push the implementation efforts closer to conclusion. The changes are:

[...]

+static void pagemap_scan_backout_range(struct pagemap_scan_private *p,

• 		       unsigned long addr, unsigned long end)
  

+{

• struct page_region *cur_buf = &p->cur_buf;
• if (cur_buf->start != addr) {

• cur_buf->end = addr;
  

• } else {

• cur_buf->start = cur_buf->end = 0;
  

• }
• p->end_addr = 0;

Just noticed that this is missing:

p->found_pages -= (end - addr) / PAGE_SIZE;

+}

[...]

Best Regards Michał Mirosław