[CRIU] [PATCH] files: print a error message if proc of sysfs files are not supported

[Andrey Vagin]

A remap schem doesn't work for proc and sysfs.

Reported-by: Dilip Daya <dilip.daya at hp.com>
Signed-off-by: Andrey Vagin <avagin at openvz.org>
---
 files-reg.c     | 26 ++++++++++++++++++++++++++
 include/magic.h |  2 ++
 2 files changed, 28 insertions(+)

diff --git a/files-reg.c b/files-reg.c
index b52fe36..b94b7fc 100644
--- a/files-reg.c
+++ b/files-reg.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <linux/magic.h>
 
 #include "crtools.h"
 #include "file-ids.h"
@@ -280,11 +281,33 @@ struct file_remap *lookup_ghost_remap(u32 dev, u32 ino)
 	return NULL;
 }
 
+static int check_is_remap_supp(int fd)
+{
+	struct statfs fst;
+
+	if (fstatfs(fd, &fst) == -1) {
+		pr_perror("Can't obtain statfs on fd %d\n", fd);
+		return -1;
+	}
+
+	switch (fst.f_type) {
+	case PROC_SUPER_MAGIC:
+	case SYSFS_MAGIC:
+		pr_err("Can't dump unlinked files on the fs [0x%lx]\n", fst.f_type);
+		return -1;
+	}
+
+	return 0;
+}
+
 static int dump_ghost_remap(char *path, const struct stat *st, int lfd, u32 id)
 {
 	struct ghost_file *gf;
 	RemapFilePathEntry rpe = REMAP_FILE_PATH_ENTRY__INIT;
 
+	if (check_is_remap_supp(lfd))
+		return -1;
+
 	pr_info("Dumping ghost file for fd %d id %#x\n", lfd, id);
 
 	if (st->st_size > MAX_GHOST_FILE_SIZE) {
@@ -323,6 +346,9 @@ static int create_link_remap(char *path, int len, int lfd, u32 *idp)
 	RegFileEntry rfe = REG_FILE_ENTRY__INIT;
 	FownEntry fwn = FOWN_ENTRY__INIT;
 
+	if (check_is_remap_supp(lfd))
+		return -1;
+
 	if (!opts.link_remap_ok) {
 		pr_err("Can't create link remap for %s. "
 				"Use " LREMAP_PARAM " option.\n", path);
diff --git a/include/magic.h b/include/magic.h
index 66a4b1c..fd08ca0 100644
--- a/include/magic.h
+++ b/include/magic.h
@@ -70,7 +70,9 @@
 
 #define IFADDR_MAGIC		RAW_IMAGE_MAGIC
 #define ROUTE_MAGIC		RAW_IMAGE_MAGIC
+#ifndef TMPFS_MAGIC
 #define TMPFS_MAGIC		RAW_IMAGE_MAGIC
+#endif
 
 #define PAGES_OLD_MAGIC		PAGEMAP_MAGIC
 #define SHM_PAGES_OLD_MAGIC	PAGEMAP_MAGIC
-- 
1.8.2