page-read: Sanitize opening routines

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

cr-dedup.c

@@ -65,7 +65,7 @@ static int cr_dedup_one_pagemap(int pid)
 	struct page_read * prp;
 	struct iovec iov;
 
-	ret = open_page_rw(pid, &pr);
+	ret = open_page_read(pid, &pr, O_RDWR);
 	if (ret) {
 		ret = -1;
 		goto exit;

cr-restore.c

@@ -338,15 +338,11 @@ static int restore_priv_vma_content(pid_t pid)
 	struct page_read pr;
 
 	vma = list_first_entry(vmas, struct vma_area, list);
-	if (!opts.auto_dedup) {
-		ret = open_page_read(pid, &pr);
-		if (ret)
-			return -1;
-	} else {
-		ret = open_page_rw(pid, &pr);
-		if (ret)
-			return -1;
-	}
+
+	ret = open_page_read(pid, &pr,
+			opts.auto_dedup ? O_RDWR : O_RSTR);
+	if (ret)
+		return -1;
 
 	/*
 	 * Read page contents.

include/page-read.h

@@ -66,9 +66,8 @@ struct page_read {
 	unsigned id; /* for logging */
 };
 
-extern int open_page_read(int pid, struct page_read *);
+extern int open_page_read(int pid, struct page_read *, int flags);
 extern int open_page_read_at(int dfd, int pid, struct page_read *pr, int flags);
-extern int open_page_rw(int pid, struct page_read *);
 extern void pagemap2iovec(PagemapEntry *pe, struct iovec *iov);
 extern int seek_pagemap_page(struct page_read *pr, unsigned long vaddr, bool warn);
 

page-read.c

@@ -246,12 +246,7 @@ int open_page_read_at(int dfd, int pid, struct page_read *pr, int flags)
 	return 0;
 }
 
-int open_page_read(int pid, struct page_read *pr)
+int open_page_read(int pid, struct page_read *pr, int flags)
 {
-	return open_page_read_at(get_service_fd(IMG_FD_OFF), pid, pr, O_RSTR);
-}
-
-int open_page_rw(int pid, struct page_read *pr)
-{
-	return open_page_read_at(get_service_fd(IMG_FD_OFF), pid, pr, O_RDWR);
+	return open_page_read_at(get_service_fd(IMG_FD_OFF), pid, pr, flags);
 }