images: regfile -- Save file @mode into image

We will need it for NFS. While we're saving it
into image, the test for mode change must be
done in account with NFS. So put fixme there.

CC: Pavel Emelyanov <xemul@virtuozzo.com>
CC: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/files-reg.c

@@ -1166,6 +1166,8 @@ ext:
 	rfe.flags	= p->flags;
 	rfe.pos		= p->pos;
 	rfe.fown	= (FownEntry *)&p->fown;
+	rfe.has_mode	= true;
+	rfe.mode	= p->stat.st_mode;
 
 	if (S_ISREG(p->stat.st_mode) && should_check_size(rfe.flags)) {
 		rfe.has_size = true;
@@ -1471,7 +1473,8 @@ ext:
 		return -1;
 	}
 
-	if (rfi->rfe->has_size && !rfi->size_checked) {
+	if ((rfi->rfe->has_size || rfi->rfe->has_mode) &&
+	    !rfi->size_mode_checked) {
 		struct stat st;
 
 		if (fstat(tmp, &st) < 0) {
@@ -1479,19 +1482,28 @@ ext:
 			return -1;
 		}
 
-		if (st.st_size != rfi->rfe->size) {
+		if (rfi->rfe->has_size && (st.st_size != rfi->rfe->size)) {
 			pr_err("File %s has bad size %"PRIu64" (expect %"PRIu64")\n",
 					rfi->path, st.st_size,
 					rfi->rfe->size);
 			return -1;
 		}
 
+		if (rfi->rfe->has_mode && (st.st_mode != rfi->rfe->mode)) {
+			if (st.st_mode != rfi->rfe->mode) {
+				pr_err("File %s has bad mode 0%o (expect 0%o)\n",
+				       rfi->path, (int)st.st_mode,
+				       rfi->rfe->mode);
+				return -1;
+			}
+		}
+
 		/*
 		 * This is only visible in the current process, so
 		 * change w/o locks. Other tasks sharing the same
 		 * file will get one via unix sockets.
 		 */
-		rfi->size_checked = true;
+		rfi->size_mode_checked = true;
 	}
 
 	if (rfi->remap) {
@@ -1696,7 +1708,7 @@ static int collect_one_regfile(void *o, ProtobufCMessage *base, struct cr_img *i
 	else
 		rfi->path = rfi->rfe->name + 1;
 	rfi->remap = NULL;
-	rfi->size_checked = false;
+	rfi->size_mode_checked = false;
 
 	pr_info("Collected [%s] ID %#x\n", rfi->path, rfi->rfe->id);
 	return file_desc_add(&rfi->d, rfi->rfe->id, &reg_desc_ops);

criu/include/files-reg.h

@@ -22,7 +22,7 @@ struct reg_file_info {
 	struct file_desc	d;
 	RegFileEntry		*rfe;
 	struct file_remap	*remap;
-	bool			size_checked;
+	bool			size_mode_checked;
 	bool			is_dir;
 	char			*path;
 };

images/regfile.proto

@@ -10,4 +10,5 @@ message reg_file_entry {
 	optional sint32		mnt_id	= 7 [default = -1];
 	optional uint64		size	= 8;
 	optional bool		ext	= 9;
+	optional uint32         mode    = 10;
 }