diff options
| -rw-r--r-- | fs/mount.h | 7 | ||||
| -rw-r--r-- | fs/namespace.c | 42 | ||||
| -rw-r--r-- | fs/pnode.c | 10 | ||||
| -rw-r--r-- | fs/pnode.h | 2 |
4 files changed, 40 insertions, 21 deletions
diff --git a/fs/mount.h b/fs/mount.h index e2501a724688..96862eba2246 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -5,6 +5,12 @@ #include <linux/ns_common.h> #include <linux/fs_pin.h> +extern struct list_head notify_list; + +typedef __u32 __bitwise mntns_flags_t; + +#define MNTNS_PROPAGATING ((__force mntns_flags_t)(1 << 0)) + struct mnt_namespace { struct ns_common ns; struct mount * root; @@ -27,6 +33,7 @@ struct mnt_namespace { struct rb_node mnt_ns_tree_node; /* node in the mnt_ns_tree */ struct list_head mnt_ns_list; /* entry in the sequential list of mounts namespace */ refcount_t passive; /* number references not pinning @mounts */ + mntns_flags_t mntns_flags; } __randomize_layout; struct mnt_pcp { diff --git a/fs/namespace.c b/fs/namespace.c index a7da41e81673..59894e3f3e68 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3536,13 +3536,6 @@ static int do_move_mount(struct path *old_path, if (!may_use_mount(p)) goto out; - /* - * Don't allow moving an attached mount tree to an anonymous - * mount tree. - */ - if (!is_anon_ns(ns) && is_anon_ns(p->mnt_ns)) - goto out; - /* The thing moved must be mounted... */ if (!is_mounted(&old->mnt)) goto out; @@ -3551,15 +3544,31 @@ static int do_move_mount(struct path *old_path, if (!(attached ? check_mnt(old) : is_anon_ns(ns))) goto out; - /* - * Ending up with two files referring to the root of the same - * anonymous mount namespace would cause an error as this would - * mean trying to move the same mount twice into the mount tree - * which would be rejected later. But be explicit about it right - * here. - */ - if (is_anon_ns(ns) && is_anon_ns(p->mnt_ns) && ns == p->mnt_ns) + if (is_anon_ns(ns)) { + /* + * Ending up with two files referring to the root of the + * same anonymous mount namespace would cause an error + * as this would mean trying to move the same mount + * twice into the mount tree which would be rejected + * later. But be explicit about it right here. + */ + if ((is_anon_ns(p->mnt_ns) && ns == p->mnt_ns)) + goto out; + + /* + * If this is an anonymous mount tree ensure that mount + * propagation can detect mounts that were just + * propagated to the target mount tree so we don't + * propagate onto them. + */ + ns->mntns_flags |= MNTNS_PROPAGATING; + } else if (is_anon_ns(p->mnt_ns)) { + /* + * Don't allow moving an attached mount tree to an + * anonymous mount tree. + */ goto out; + } if (old->mnt.mnt_flags & MNT_LOCKED) goto out; @@ -3603,6 +3612,9 @@ static int do_move_mount(struct path *old_path, if (err) goto out; + if (is_anon_ns(ns)) + ns->mntns_flags &= ~MNTNS_PROPAGATING; + /* if the mount is moved, it should no longer be expire * automatically */ list_del_init(&old->mnt_expire); diff --git a/fs/pnode.c b/fs/pnode.c index ef048f008bdd..6dd26ca96cdd 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -150,7 +150,7 @@ static struct mount *propagation_next(struct mount *m, struct mount *origin) { /* are there any slaves of this mount? */ - if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) + if (!IS_MNT_PROPAGATED(m) && !list_empty(&m->mnt_slave_list)) return first_slave(m); while (1) { @@ -174,7 +174,7 @@ static struct mount *skip_propagation_subtree(struct mount *m, * Advance m such that propagation_next will not return * the slaves of m. */ - if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) + if (!IS_MNT_PROPAGATED(m) && !list_empty(&m->mnt_slave_list)) m = last_slave(m); return m; @@ -185,7 +185,7 @@ static struct mount *next_group(struct mount *m, struct mount *origin) while (1) { while (1) { struct mount *next; - if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) + if (!IS_MNT_PROPAGATED(m) && !list_empty(&m->mnt_slave_list)) return first_slave(m); next = next_peer(m); if (m->mnt_group_id == origin->mnt_group_id) { @@ -226,7 +226,7 @@ static int propagate_one(struct mount *m, struct mountpoint *dest_mp) struct mount *child; int type; /* skip ones added by this propagate_mnt() */ - if (IS_MNT_NEW(m)) + if (IS_MNT_PROPAGATED(m)) return 0; /* skip if mountpoint isn't covered by it */ if (!is_subdir(dest_mp->m_dentry, m->mnt.mnt_root)) @@ -380,7 +380,7 @@ bool propagation_would_overmount(const struct mount *from, if (!IS_MNT_SHARED(from)) return false; - if (IS_MNT_NEW(to)) + if (IS_MNT_PROPAGATED(to)) return false; if (to->mnt.mnt_root != mp->m_dentry) diff --git a/fs/pnode.h b/fs/pnode.h index 0b02a6393891..ddafe0d087ca 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -12,7 +12,7 @@ #define IS_MNT_SHARED(m) ((m)->mnt.mnt_flags & MNT_SHARED) #define IS_MNT_SLAVE(m) ((m)->mnt_master) -#define IS_MNT_NEW(m) (!(m)->mnt_ns || is_anon_ns((m)->mnt_ns)) +#define IS_MNT_PROPAGATED(m) (!(m)->mnt_ns || ((m)->mnt_ns->mntns_flags & MNTNS_PROPAGATING)) #define CLEAR_MNT_SHARED(m) ((m)->mnt.mnt_flags &= ~MNT_SHARED) #define IS_MNT_UNBINDABLE(m) ((m)->mnt.mnt_flags & MNT_UNBINDABLE) #define IS_MNT_MARKED(m) ((m)->mnt.mnt_flags & MNT_MARKED) |