[CRIU] [PATCH RFC 3/3] files: Allow postponed fdinfo callbacks

[Kirill Tkhai]

Unix sockets need postponed .post_open() to close some task sockets
after all other sockets have executed their .post_open() method.

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 criu/files.c         |   15 ++++++++++++++-
 criu/include/files.h |    2 ++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/criu/files.c b/criu/files.c
index 51556c9..286f553 100644
--- a/criu/files.c
+++ b/criu/files.c
@@ -1096,11 +1096,24 @@ static int open_fdinfos(int pid, struct list_head *list, int state)
 {
 	int ret = 0;
 	struct fdinfo_list_entry *fle;
+	LIST_HEAD(postpone);
 
 	list_for_each_entry(fle, list, ps_list) {
 		ret = open_fdinfo(pid, fle, state);
-		if (ret)
+		if (ret == FDO_ERROR)
 			break;
+		if (ret == FDO_REPEAT)
+			list_add(&fle->postpone, &postpone);
+	}
+
+	list_for_each_entry(fle, &postpone, postpone) {
+		ret = open_fdinfo(pid, fle, state);
+		if (ret == FDO_ERROR)
+			break;
+		if (ret == FDO_REPEAT) {
+			pr_err("Twice postponed fle\n");
+			break;
+		}
 	}
 
 	return ret;
diff --git a/criu/include/files.h b/criu/include/files.h
index 19ee26a..136ca7c 100644
--- a/criu/include/files.h
+++ b/criu/include/files.h
@@ -69,6 +69,7 @@ struct fdinfo_list_entry {
 	struct file_desc	*desc;		/* Associated file descriptor */
 	struct list_head	ps_list;	/* To chain  per-task files */
 	struct list_head	used_list;	/* To chain per-task used fds */
+	struct list_head	postpone;	/* To chain during open_fdinfos() */
 	int			pid;
 	futex_t			real_pid;
 	FdinfoEntry		*fe;
@@ -82,6 +83,7 @@ static inline int fdinfo_rst_prio(struct fdinfo_list_entry *fd_a, struct fdinfo_
 }
 
 #define FDO_ERROR	-1
+#define FDO_REPEAT	-2
 
 struct file_desc_ops {
 	/* fd_types from images/fdinfo.proto */