In order to allow users to iterate through children mount namespaces via
listmount we need a way for them to know what the ns id for the mount.
Add a new field to statmount called mnt_ns_id which will carry the ns id
for the given mount entry.
Co-developed-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
fs/namespace.c | 11 +++++++++++
include/uapi/linux/mount.h | 4 +++-
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index babdebdb0a9c..3c6711fec3cd 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4977,6 +4977,14 @@ static int statmount_fs_type(struct kstatmount *s, struct seq_file *seq)
return 0;
}
+static void statmount_mnt_ns_id(struct kstatmount *s)
+{
+ struct mnt_namespace *ns = current->nsproxy->mnt_ns;
+
+ s->sm.mask |= STATMOUNT_MNT_NS_ID;
+ s->sm.mnt_ns_id = ns->seq;
+}
+
static int statmount_string(struct kstatmount *s, u64 flag)
{
int ret;
@@ -5073,6 +5081,9 @@ static int do_statmount(struct kstatmount *s)
if (!err && s->mask & STATMOUNT_MNT_POINT)
err = statmount_string(s, STATMOUNT_MNT_POINT);
+ if (!err && s->mask & STATMOUNT_MNT_NS_ID)
+ statmount_mnt_ns_id(s);
+
if (err)
return err;
diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h
index 88d78de1519f..a07508aee518 100644
--- a/include/uapi/linux/mount.h
+++ b/include/uapi/linux/mount.h
@@ -172,7 +172,8 @@ struct statmount {
__u64 propagate_from; /* Propagation from in current namespace */
__u32 mnt_root; /* [str] Root of mount relative to root of fs */
__u32 mnt_point; /* [str] Mountpoint relative to current root */
- __u64 __spare2[50];
+ __u64 mnt_ns_id; /* ID of the mount namespace */
+ __u64 __spare2[49];
char str[]; /* Variable size part containing strings */
};
@@ -202,6 +203,7 @@ struct mnt_id_req {
#define STATMOUNT_MNT_ROOT 0x00000008U /* Want/got mnt_root */
#define STATMOUNT_MNT_POINT 0x00000010U /* Want/got mnt_point */
#define STATMOUNT_FS_TYPE 0x00000020U /* Want/got fs_type */
+#define STATMOUNT_MNT_NS_ID 0x00000040U /* Want/got mnt_ns_id */
/*
* Special @mnt_id values that can be passed to listmount
--
2.43.0
