files: Collect fdinfo-s on per-pstree_item list

Later we'll be able to restore them without re-reading the fdinfo file again.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-restore.c

@@ -296,7 +296,7 @@ static int prepare_shared(void)
 		if (ret < 0)
 			break;
 
-		ret = prepare_fd_pid(pi->pid);
+		ret = prepare_fd_pid(pi->pid, pi->rst);
 		if (ret < 0)
 			break;
 	}

files.c

@@ -327,7 +327,7 @@ int collect_reg_files(void)
 	return collect_remaps();
 }
 
-static int collect_fd(int pid, struct fdinfo_entry *e)
+static int collect_fd(int pid, struct fdinfo_entry *e, struct list_head *fds)
 {
 	int i;
 	struct fdinfo_list_entry *l, *le = &fdinfo_list[nr_fdinfo_list];
@@ -357,14 +357,17 @@ static int collect_fd(int pid, struct fdinfo_entry *e)
 			break;
 
 	list_add_tail(&le->desc_list, &l->desc_list);
+	list_add_tail(&le->ps_list, fds);
 	return 0;
 }
 
-int prepare_fd_pid(int pid)
+int prepare_fd_pid(int pid, struct rst_info *rst_info)
 {
 	int fdinfo_fd, ret = 0;
 	u32 type = 0;
 
+	INIT_LIST_HEAD(&rst_info->fds);
+
 	fdinfo_fd = open_image_ro(CR_FD_FDINFO, pid);
 	if (fdinfo_fd < 0) {
 		if (errno == ENOENT)
@@ -380,7 +383,7 @@ int prepare_fd_pid(int pid)
 		if (ret <= 0)
 			break;
 
-		ret = collect_fd(pid, &e);
+		ret = collect_fd(pid, &e, &rst_info->fds);
 		if (ret < 0)
 			break;
 	}

include/crtools.h

@@ -182,6 +182,7 @@ struct vma_area {
 #define vma_area_len(vma_area)		vma_entry_len(&((vma_area)->vma))
 
 struct rst_info {
+	struct list_head	fds;
 };
 
 struct pstree_item {

include/files.h

@@ -29,6 +29,7 @@ enum fdinfo_states {
 
 struct fdinfo_list_entry {
 	struct list_head	desc_list;
+	struct list_head	ps_list;
 	int			pid;
 	futex_t			real_pid;
 	struct fdinfo_entry	fe;
@@ -59,7 +60,8 @@ extern int restore_fown(int fd, fown_t *fown);
 void show_saved_files(void);
 extern int collect_reg_files(void);
 extern int prepare_fds(int pid);
-extern int prepare_fd_pid(int pid);
+struct rst_info;
+extern int prepare_fd_pid(int pid, struct rst_info *);
 extern int prepare_shared_fdinfo(void);
 extern int get_filemap_fd(int pid, struct vma_entry *vma_entry);
 extern int prepare_fs(int pid);