[CRIU] [PATCH 03/10] uffdd: Move loop into collect_uffd_pages

[Pavel Emelyanov]

It just makes the code look cleaner and allows further
improvements.

Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
---
 criu/uffd.c | 80 ++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 40 insertions(+), 40 deletions(-)

diff --git a/criu/uffd.c b/criu/uffd.c
index 4ee37fa..5c34007 100644
--- a/criu/uffd.c
+++ b/criu/uffd.c
@@ -497,53 +497,55 @@ static int collect_uffd_pages(struct page_read *pr, struct lazy_pages_info *lpi)
 
 	BUG_ON(!item);
 
+	ps = page_size();
 	vmas = &rsti(item)->vmas;
 
-	rc = pr->get_pagemap(pr, &iov);
-	if (rc <= 0)
-		return 0;
+	while (1) {
+		rc = pr->get_pagemap(pr, &iov);
+		if (rc <= 0)
+			break;
 
-	ps = page_size();
-	nr_pages = iov.iov_len / ps;
-	base = (unsigned long) iov.iov_base;
-	pr_debug("iov.iov_base 0x%lx (%ld pages)\n", base, nr_pages);
+		nr_pages = iov.iov_len / ps;
+		base = (unsigned long) iov.iov_base;
+		pr_debug("iov.iov_base 0x%lx (%ld pages)\n", base, nr_pages);
 
-	for (i = 0; i < nr_pages; i++) {
-		bool uffd_page = false;
-		base = (unsigned long) iov.iov_base + (i * ps);
-		/*
-		 * Only pages which are MAP_ANONYMOUS and MAP_PRIVATE
-		 * are relevant for userfaultfd handling.
-		 * Loop over all VMAs to see if the flags matching.
-		 */
-		list_for_each_entry(vma, &vmas->h, list) {
+		for (i = 0; i < nr_pages; i++) {
+			bool uffd_page = false;
+			base = (unsigned long) iov.iov_base + (i * ps);
 			/*
-			 * This loop assumes that base can actually be found
-			 * in the VMA list.
+			 * Only pages which are MAP_ANONYMOUS and MAP_PRIVATE
+			 * are relevant for userfaultfd handling.
+			 * Loop over all VMAs to see if the flags matching.
 			 */
-			if (base >= vma->e->start && base < vma->e->end) {
-				if (vma_entry_can_be_lazy(vma->e)) {
-					if(!pagemap_in_parent(pr->pe))
-						uffd_page = true;
-					break;
+			list_for_each_entry(vma, &vmas->h, list) {
+				/*
+				 * This loop assumes that base can actually be found
+				 * in the VMA list.
+				 */
+				if (base >= vma->e->start && base < vma->e->end) {
+					if (vma_entry_can_be_lazy(vma->e)) {
+						if(!pagemap_in_parent(pr->pe))
+							uffd_page = true;
+						break;
+					}
 				}
 			}
-		}
 
-		/* This is not a page we are looking for. Move along */
-		if (!uffd_page)
-			continue;
+			/* This is not a page we are looking for. Move along */
+			if (!uffd_page)
+				continue;
 
-		pr_debug("Adding 0x%lx to our list\n", base);
+			pr_debug("Adding 0x%lx to our list\n", base);
 
-		uffd_pages = xzalloc(sizeof(struct uffd_pages_struct));
-		if (!uffd_pages)
-			return -1;
-		uffd_pages->addr = base;
-		list_add(&uffd_pages->list, &lpi->pages);
+			uffd_pages = xzalloc(sizeof(struct uffd_pages_struct));
+			if (!uffd_pages)
+				return -1;
+			uffd_pages->addr = base;
+			list_add(&uffd_pages->list, &lpi->pages);
+		}
 	}
 
-	return 1;
+	return 0;
 }
 
 static int handle_remaining_pages(struct lazy_pages_info *lpi, void *dest)
@@ -660,12 +662,10 @@ static int find_vmas(struct lazy_pages_info *lpi)
 	 * a page has already been transferred or if it needs to be
 	 * pushed into the process using userfaultfd.
 	 */
-	do {
-		ret = collect_uffd_pages(&lpi->pr, lpi);
-		if (ret == -1) {
-			goto out;
-		}
-	} while (ret);
+	ret = collect_uffd_pages(&lpi->pr, lpi);
+	if (ret == -1) {
+		goto out;
+	}
 
 	/* Count detected pages */
 	list_for_each_entry(uffd_pages, &lpi->pages, list)
-- 
2.5.0