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authorChristian Brauner <brauner@kernel.org>2025-02-21 14:13:00 +0100
committerChristian Brauner <brauner@kernel.org>2025-03-04 09:29:19 +0100
commit3b0cdba4da55188b8ae49430f2730fade56b43ae (patch)
treec3437c79475f073d4d166c83398a4d99632bf763 /fs/namespace.c
parent822c11592522dc00e1f447dbe95350071001d9f1 (diff)
fs: record sequence number of origin mount namespace
Store the sequence number of the mount namespace the anonymous mount namespace has been created from. This information will be used in follow-up patches. Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-1-dbcfcb98c676@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index a3ed3f2980cb..d5c85b6ecb98 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2853,15 +2853,30 @@ out:
static struct file *open_detached_copy(struct path *path, bool recursive)
{
- struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
- struct mnt_namespace *ns = alloc_mnt_ns(user_ns, true);
+ struct mnt_namespace *ns, *mnt_ns = current->nsproxy->mnt_ns, *src_mnt_ns;
+ struct user_namespace *user_ns = mnt_ns->user_ns;
struct mount *mnt, *p;
struct file *file;
+ ns = alloc_mnt_ns(user_ns, true);
if (IS_ERR(ns))
return ERR_CAST(ns);
namespace_lock();
+
+ /*
+ * Record the sequence number of the source mount namespace.
+ * This needs to hold namespace_sem to ensure that the mount
+ * doesn't get attached.
+ */
+ if (is_mounted(path->mnt)) {
+ src_mnt_ns = real_mount(path->mnt)->mnt_ns;
+ if (is_anon_ns(src_mnt_ns))
+ ns->seq_origin = src_mnt_ns->seq_origin;
+ else
+ ns->seq_origin = src_mnt_ns->seq;
+ }
+
mnt = __do_loopback(path, recursive);
if (IS_ERR(mnt)) {
namespace_unlock();