[CRIU] [PATCH] restore: Order file restoring by their type

[Cyrill Gorcunov]

We need the files being restored in order of their
type. In particular when we restore eventpoll file
we expect every file descriptor the epoll watches on
is already created and opened.

Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
 files.c           |   27 +++++++++++++++++++--------
 include/crtools.h |    2 +-
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/files.c b/files.c
index 2fd4ec0..b5e7508 100644
--- a/files.c
+++ b/files.c
@@ -373,9 +373,11 @@ static int collect_fd(int pid, struct fdinfo_entry *e, struct list_head *fds)
 int prepare_fd_pid(int pid, struct rst_info *rst_info)
 {
 	int fdinfo_fd, ret = 0;
+	unsigned int i;
 	u32 type = 0;
 
-	INIT_LIST_HEAD(&rst_info->fds);
+	for (i = 0; i < ARRAY_SIZE(rst_info->fds); i++)
+		INIT_LIST_HEAD(&rst_info->fds[i]);
 
 	fdinfo_fd = open_image_ro(CR_FD_FDINFO, pid);
 	if (fdinfo_fd < 0) {
@@ -391,8 +393,14 @@ int prepare_fd_pid(int pid, struct rst_info *rst_info)
 		ret = read_img_eof(fdinfo_fd, &e);
 		if (ret <= 0)
 			break;
+		if (e.type >= FD_INFO_MAX) {
+			ret = -1;
+			pr_err("Unexpected file type found %d [%#x]\n",
+			       e.fd, e.type);
+			break;
+		}
 
-		ret = collect_fd(pid, &e, &rst_info->fds);
+		ret = collect_fd(pid, &e, &rst_info->fds[e.type]);
 		if (ret < 0)
 			break;
 	}
@@ -648,18 +656,21 @@ static int open_fdinfo(int pid, struct fdinfo_entry *fe, int state)
 int prepare_fds(struct pstree_item *me)
 {
 	u32 type = 0, ret;
-	int state;
+	int state, i;
 	struct fdinfo_list_entry *fle;
 	int nr = 0;
 
 	pr_info("%d: Opening fdinfo-s\n", me->pid);
 
-	for (state = 0; state < FD_STATE_MAX; state++)
-		list_for_each_entry(fle, &me->rst->fds, ps_list) {
-			ret = open_fdinfo(me->pid, &fle->fe, state);
-			if (ret)
-				goto done;
+	for (state = 0; state < FD_STATE_MAX; state++) {
+		for (i = 0; i < (int)ARRAY_SIZE(me->rst->fds); i++) {
+			list_for_each_entry(fle, &me->rst->fds[i], ps_list) {
+				ret = open_fdinfo(me->pid, &fle->fe, state);
+				if (ret)
+					goto done;
+			}
 		}
+	}
 
 	ret = run_unix_connections();
 done:
diff --git a/include/crtools.h b/include/crtools.h
index 291c880..99bd69f 100644
--- a/include/crtools.h
+++ b/include/crtools.h
@@ -193,7 +193,7 @@ struct vma_area {
 #define vma_area_len(vma_area)		vma_entry_len(&((vma_area)->vma))
 
 struct rst_info {
-	struct list_head	fds;
+	struct list_head	fds[FD_INFO_MAX];
 };
 
 struct pstree_item {
-- 
1.7.7.6