criu: pagemap: use pid instead if id where appropriate

Some pagemap methods mix up using PIDs and pagemap internal ids. Using the
'pid' name in places that actually refer to PIDs makes the code clearer.

travis-ci: success for criu: pagemap: minor improvements
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/include/pagemap.h

@@ -85,8 +85,8 @@ struct page_read {
  *  0 -- no images
  *  1 -- opened
  */
-extern int open_page_read(int id, struct page_read *, int pr_flags);
-extern int open_page_read_at(int dfd, int id, struct page_read *pr,
+extern int open_page_read(int pid, struct page_read *, int pr_flags);
+extern int open_page_read_at(int dfd, int pid, struct page_read *pr,
 		int pr_flags);
 extern void pagemap2iovec(PagemapEntry *pe, struct iovec *iov);
 extern void iovec2pagemap(struct iovec *iov, PagemapEntry *pe);

criu/pagemap.c

@@ -408,7 +408,7 @@ free_pagemaps:
 	return -1;
 }
 
-int open_page_read_at(int dfd, int id, struct page_read *pr, int pr_flags)
+int open_page_read_at(int dfd, int pid, struct page_read *pr, int pr_flags)
 {
 	int flags, i_typ;
 	static unsigned ids = 1;
@@ -440,7 +440,7 @@ int open_page_read_at(int dfd, int id, struct page_read *pr, int pr_flags)
 	pr->bunch.iov_base = NULL;
 	pr->pmes = NULL;
 
-	pr->pmi = open_image_at(dfd, i_typ, O_RSTR, (long)id);
+	pr->pmi = open_image_at(dfd, i_typ, O_RSTR, (long)pid);
 	if (!pr->pmi)
 		return -1;
 
@@ -449,7 +449,7 @@ int open_page_read_at(int dfd, int id, struct page_read *pr, int pr_flags)
 		return 0;
 	}
 
-	if (try_open_parent(dfd, id, pr, pr_flags)) {
+	if (try_open_parent(dfd, pid, pr, pr_flags)) {
 		close_image(pr->pmi);
 		return -1;
 	}
@@ -478,7 +478,7 @@ int open_page_read_at(int dfd, int id, struct page_read *pr, int pr_flags)
 	return 1;
 }
 
-int open_page_read(int id, struct page_read *pr, int pr_flags)
+int open_page_read(int pid, struct page_read *pr, int pr_flags)
 {
-	return open_page_read_at(get_service_fd(IMG_FD_OFF), id, pr, pr_flags);
+	return open_page_read_at(get_service_fd(IMG_FD_OFF), pid, pr, pr_flags);
 }