mnt: Preparations for mountpoints dumping

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

crtools.c

@@ -27,6 +27,7 @@
 #include "eventfd.h"
 #include "eventpoll.h"
 #include "inotify.h"
+#include "mount.h"
 
 struct cr_options opts;
 
@@ -75,6 +76,7 @@ struct cr_fd_desc_tmpl fdset_template[CR_FD_MAX] = {
 	FD_ENTRY(REMAP_FPATH,	"remap-fpath",	 show_remap_files),
 	FD_ENTRY(GHOST_FILE,	"ghost-file-%x", show_ghost_file),
 	FD_ENTRY(TCP_STREAM,	"tcp-stream-%x", show_tcp_stream),
+	FD_ENTRY(MOUNTPOINTS,	"mountpoints-%d", show_mountpoints),
 };
 
 static struct cr_fdset *alloc_cr_fdset(int nr)
@@ -183,6 +185,8 @@ static int parse_ns_string(const char *ptr)
 			opts.namespaces_flags |= CLONE_NEWUTS;
 		else if (!strncmp(ptr, "ipc", 3))
 			opts.namespaces_flags |= CLONE_NEWIPC;
+		else if (!strncmp(ptr, "mnt", 3))
+			opts.namespaces_flags |= CLONE_NEWNS;
 		else
 			goto bad_ns;
 		ptr += 4;

include/crtools.h

@@ -40,6 +40,7 @@ enum {
 	CR_FD_IPCNS_SHM,
 	CR_FD_IPCNS_MSG,
 	CR_FD_IPCNS_SEM,
+	CR_FD_MOUNTPOINTS,
 	_CR_FD_NS_TO,
 
 	CR_FD_PSTREE,

include/image.h

@@ -39,6 +39,7 @@
 #define EVENTPOLL_TFD_MAGIC	0x44433746 /* Novorossiysk */
 #define INOTIFY_MAGIC		0x48424431 /* Volgograd */
 #define INOTIFY_WD_MAGIC	0x54562009 /* Svetlogorsk (Rauschen) */
+#define MOUNTPOINTS_MAGIC	0x55563928 /* Petushki */
 
 enum fd_types {
 	FDINFO_UND,

include/mount.h

@@ -6,4 +6,9 @@ struct proc_mountinfo;
 extern int open_mount(unsigned int s_dev);
 extern int collect_mount_info(void);
 
+struct cr_fdset;
+extern int dump_mnt_ns(int pid, struct cr_fdset *);
+struct cr_options;
+extern void show_mountpoints(int fd, struct cr_options *);
+
 #endif /* MOUNT_H__ */

include/syscall-types.h

@@ -40,6 +40,10 @@ struct file_handle;
 #define F_GETFD 1
 #endif
 
+#ifndef CLONE_NEWNS
+#define CLONE_NEWNS	0x00020000
+#endif
+
 #ifndef CLONE_NEWPID
 #define CLONE_NEWPID	0x20000000
 #endif

mount.c

@@ -53,3 +53,14 @@ int collect_mount_info(void)
 
 	return 0;
 }
+
+int dump_mnt_ns(int ns_pid, struct cr_fdset *fdset)
+{
+	return -1;
+}
+
+void show_mountpoints(int fd, struct cr_options *o)
+{
+	pr_img_head(CR_FD_MOUNTPOINTS);
+	pr_img_tail(CR_FD_MOUNTPOINTS);
+}

namespaces.c

@@ -5,6 +5,7 @@
 #include "syscall.h"
 #include "uts_ns.h"
 #include "ipc_ns.h"
+#include "mount.h"
 
 int switch_ns(int pid, int type, char *ns)
 {
@@ -49,6 +50,12 @@ static int do_dump_namespaces(int ns_pid, unsigned int ns_flags)
 		if (ret < 0)
 			goto err;
 	}
+	if (ns_flags & CLONE_NEWNS) {
+		pr_info("Dump MNT namespace (mountpoints)\n");
+		ret = dump_mnt_ns(ns_pid, fdset);
+		if (ret < 0)
+			goto err;
+	}
 err:
 	close_cr_fdset(&fdset);
 	return ret;