[CRIU] [PATCH v5 4/8] criu: page-{pipe, xfer}: add helper function for dumping holes

[Mike Rapoport]

Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
---
 criu/include/page-pipe.h |  1 +
 criu/page-pipe.c         |  2 ++
 criu/page-xfer.c         | 54 +++++++++++++++++++++++-------------------------
 3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/criu/include/page-pipe.h b/criu/include/page-pipe.h
index a018af0..f11071c 100644
--- a/criu/include/page-pipe.h
+++ b/criu/include/page-pipe.h
@@ -83,6 +83,7 @@ struct page_pipe_buf {
 struct page_pipe_iovs {
 	unsigned int nr_iovs;	/* number of iovs */
 	unsigned int free_iov;	/* number of iovs in use */
+	unsigned int busy_iov;	/* first iov that not yet dumped */
 	struct iovec *iovs;	/* iovs */
 };
 
diff --git a/criu/page-pipe.c b/criu/page-pipe.c
index 9bc7eaf..d002c3a 100644
--- a/criu/page-pipe.c
+++ b/criu/page-pipe.c
@@ -149,10 +149,12 @@ struct page_pipe *create_page_pipe(unsigned int nr_segs,
 	pp->pages.nr_iovs = nr_segs;
 	pp->pages.iovs = iovs;
 	pp->pages.free_iov = 0;
+	pp->pages.busy_iov = 0;
 
 	pp->holes.nr_iovs = 0;
 	pp->holes.free_iov = 0;
 	pp->holes.iovs = NULL;
+	pp->holes.busy_iov = 0;
 
 	pp->chunk_mode = chunk_mode;
 
diff --git a/criu/page-xfer.c b/criu/page-xfer.c
index 4bb8ea0..32b50f7 100644
--- a/criu/page-xfer.c
+++ b/criu/page-xfer.c
@@ -320,17 +320,35 @@ int open_page_xfer(struct page_xfer *xfer, int fd_type, long id)
 		return open_page_local_xfer(xfer, fd_type, id);
 }
 
+static int dump_hole(struct page_xfer *xfer, struct page_pipe_iovs *iov,
+		     void *limit, unsigned long off)
+{
+	while (iov->busy_iov < iov->free_iov) {
+		struct iovec *hole = &iov->iovs[iov->busy_iov];
+
+		if (limit && hole->iov_base >= limit)
+			break;
+
+		BUG_ON(hole->iov_base < (void *)off);
+		hole->iov_base -= off;
+		pr_debug("\th %p [%u]\n", hole->iov_base,
+			 (unsigned int)(hole->iov_len / PAGE_SIZE));
+		if (xfer->write_hole(xfer, hole))
+			return -1;
+
+		iov->busy_iov++;
+	}
+
+	return 0;
+}
+
 int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
 		unsigned long off)
 {
 	struct page_pipe_buf *ppb;
-	struct iovec *hole = NULL;
 
 	pr_debug("Transfering pages:\n");
 
-	if (pp->holes.free_iov)
-		hole = &pp->holes.iovs[0];
-
 	list_for_each_entry(ppb, &pp->bufs, l) {
 		int i;
 
@@ -339,18 +357,8 @@ int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
 		for (i = 0; i < ppb->nr_segs; i++) {
 			struct iovec *iov = &ppb->iov[i];
 
-			while (hole && (hole->iov_base < iov->iov_base)) {
-				BUG_ON(hole->iov_base < (void *)off);
-				hole->iov_base -= off;
-				pr_debug("\th %p [%u]\n", hole->iov_base,
-						(unsigned int)(hole->iov_len / PAGE_SIZE));
-				if (xfer->write_hole(xfer, hole))
-					return -1;
-
-				hole++;
-				if (hole >= &pp->holes.iovs[pp->holes.free_iov])
-					hole = NULL;
-			}
+			if (dump_hole(xfer, &pp->holes, iov->iov_base, off))
+				return -1;
 
 			BUG_ON(iov->iov_base < (void *)off);
 			iov->iov_base -= off;
@@ -364,18 +372,8 @@ int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
 		}
 	}
 
-	while (hole) {
-		BUG_ON(hole->iov_base < (void *)off);
-		hole->iov_base -= off;
-		pr_debug("\th* %p [%u]\n", hole->iov_base,
-				(unsigned int)(hole->iov_len / PAGE_SIZE));
-		if (xfer->write_hole(xfer, hole))
-			return -1;
-
-		hole++;
-		if (hole >= &pp->holes.iovs[pp->holes.free_iov])
-			hole = NULL;
-	}
+	if (dump_hole(xfer, &pp->holes, NULL, off))
+		return -1;
 
 	return 0;
 }
-- 
1.9.1