[CRIU] [PATCH 3/6] mnt: add --enable-external-sharing flag

[Tycho Andersen]

With this flag, external shared bind mounts are attempted to be resolved
automatically.

Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
---
 crtools.c            | 6 ++++++
 include/cr_options.h | 1 +
 mount.c              | 3 +++
 3 files changed, 10 insertions(+)

diff --git a/crtools.c b/crtools.c
index a6ee2d7..fe77f39 100644
--- a/crtools.c
+++ b/crtools.c
@@ -204,6 +204,7 @@ int main(int argc, char *argv[], char *envp[])
 		{ "inherit-fd",		required_argument,	0, 1062	},
 		{ "feature",		required_argument,	0, 1063	},
 		{ "skip-mnt",		required_argument,	0, 1064},
+		{ "enable-external-sharing", no_argument, 	0, 1065 },
 		{ },
 	};
 
@@ -421,6 +422,9 @@ int main(int argc, char *argv[], char *envp[])
 			if (!add_skip_mount(optarg))
 				return 1;
 			break;
+		case 1065:
+			opts.enable_external_sharing = true;
+			break;
 		case 'M':
 			{
 				char *aux;
@@ -649,6 +653,8 @@ usage:
 "                        add external mount mapping\n"
 "  -M|--ext-mount-map auto\n"
 "                        attempt to autodetect external mount mapings\n"
+"  --enable-external-sharing\n"
+"                        allow autoresolving mounts with external sharing\n"
 "  --manage-cgroups      dump or restore cgroups the process is in\n"
 "  --cgroup-root [controller:]/newroot\n"
 "                        change the root cgroup the controller will be\n"
diff --git a/include/cr_options.h b/include/cr_options.h
index f1cfc84..29be2c8 100644
--- a/include/cr_options.h
+++ b/include/cr_options.h
@@ -63,6 +63,7 @@ struct cr_options {
 	char			*new_global_cg_root;
 	struct list_head	new_cgroup_roots;
 	bool			autodetect_ext_mounts;
+	bool			enable_external_sharing;
 	bool			aufs;		/* auto-deteced, not via cli */
 };
 
diff --git a/mount.c b/mount.c
index 49a07dd..8835a81 100644
--- a/mount.c
+++ b/mount.c
@@ -688,6 +688,9 @@ static int resolve_external_mounts(struct mount_info *info)
 			if (mounts_equal(pm, m, true))
 				match = true;
 
+			if (opts.enable_external_sharing && pm->shared_id == m->shared_id)
+				match = true;
+
 			if (!match)
 				continue;
 
-- 
2.1.4