page-xfer: Simplify one page-pipe dumping

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/page-xfer.h

@@ -14,5 +14,8 @@ struct page_xfer {
 
 int open_page_xfer(struct page_xfer *xfer, int fd_type, long id);
 int open_page_server_xfer(struct page_xfer *, int fd_type, long id);
+struct page_pipe;
+int page_xfer_dump_pages(struct page_xfer *, struct page_pipe *,
+		unsigned long off);
 int connect_to_page_server(void);
 #endif

page-xfer.c

@@ -5,6 +5,7 @@
 
 #include "crtools.h"
 #include "page-xfer.h"
+#include "page-pipe.h"
 
 #include "protobuf.h"
 #include "protobuf/pagemap.pb-c.h"
@@ -278,6 +279,32 @@ static void close_page_xfer(struct page_xfer *xfer)
 	close(xfer->fd);
 }
 
+int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
+		unsigned long off)
+{
+	struct page_pipe_buf *ppb;
+
+	list_for_each_entry(ppb, &pp->bufs, l) {
+		int i;
+
+		pr_debug("Dump shmem pages %d/%d\n", ppb->pages_in, ppb->nr_segs);
+
+		for (i = 0; i < ppb->nr_segs; i++) {
+			struct iovec *iov = &ppb->iov[i];
+
+			BUG_ON(iov->iov_base < (void *)off);
+			iov->iov_base -= off;
+			pr_debug("\t%p [%u]\n", iov->iov_base,
+					(unsigned int)(iov->iov_len / PAGE_SIZE));
+
+			if (xfer->write_pagemap(xfer, iov, ppb->p[0]))
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
 int open_page_xfer(struct page_xfer *xfer, int fd_type, long id)
 {
 	if (opts.use_page_server)

parasite-syscall.c

@@ -610,25 +610,8 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, int vpid,
 	if (ret < 0)
 		goto out_pp;
 
-	ret = -1;
-	list_for_each_entry(ppb, &pp->bufs, l) {
-		int i;
-
-		pr_debug("Dump pages %d/%d\n", ppb->pages_in, ppb->nr_segs);
-
-		for (i = 0; i < ppb->nr_segs; i++) {
-			struct iovec *iov = &ppb->iov[i];
-
-			pr_debug("\t%p [%u]\n", iov->iov_base,
-					(unsigned int)(iov->iov_len / PAGE_SIZE));
+	ret = page_xfer_dump_pages(&xfer, pp, 0);
 
-			if (xfer.write_pagemap(&xfer, iov, ppb->p[0]))
-				goto out_xfer;
-		}
-	}
-
-	ret = 0;
-out_xfer:
 	xfer.close(&xfer);
 out_pp:
 	destroy_page_pipe(pp);

shmem.c

@@ -362,27 +362,8 @@ static int dump_one_shmem(struct shmem_info_dump *si)
 	if (err)
 		goto err_pp;
 
-	list_for_each_entry(ppb, &pp->bufs, l) {
-		int i;
-
-		pr_debug("Dump shmem pages %d/%d\n", ppb->pages_in, ppb->nr_segs);
-
-		for (i = 0; i < ppb->nr_segs; i++) {
-			struct iovec *iov = &ppb->iov[i];
-
-			BUG_ON(iov->iov_base < addr);
-			iov->iov_base -= (unsigned long)addr;
-			pr_debug("\t%p [%u]\n", iov->iov_base,
-					(unsigned int)(iov->iov_len / PAGE_SIZE));
-
-			if (xfer.write_pagemap(&xfer, iov, ppb->p[0]))
-				goto out_xfer;
-		}
-	}
-
-	ret = 0;
+	ret = page_xfer_dump_pages(&xfer, pp, (unsigned long)addr);
 
-out_xfer:
 	xfer.close(&xfer);
 err_pp:
 	destroy_page_pipe(pp);