Commit 6fc7871f authored by Al Viro's avatar Al Viro
Browse files

vfs: spread struct mount - get_dominating_id / do_make_slave



next pile of horrors, similar to mnt_parent one; this time it's
mnt_master.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 6b41d536
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+1 −1
Original line number Diff line number Diff line
@@ -1053,7 +1053,7 @@ static int show_mountinfo(struct seq_file *m, void *v)
		seq_printf(m, " shared:%i", mnt->mnt_group_id);
	if (IS_MNT_SLAVE(mnt)) {
		int master = mnt->mnt_master->mnt_group_id;
		int dom = get_dominating_id(mnt, &p->root);
		int dom = get_dominating_id(r, &p->root);
		seq_printf(m, " master:%i", master);
		if (dom && dom != master)
			seq_printf(m, " propagate_from:%i", dom);
+29 −29
Original line number Diff line number Diff line
@@ -28,19 +28,19 @@ static inline struct vfsmount *next_slave(struct vfsmount *p)
	return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);
}

static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
static struct mount *get_peer_under_root(struct mount *mnt,
					 struct mnt_namespace *ns,
					 const struct path *root)
{
	struct mount *m = real_mount(mnt);
	struct mount *m = mnt;

	do {
		/* Check the namespace first for optimization */
		if (m->mnt.mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))
			return &m->mnt;
			return m;

		m = real_mount(next_peer(&m->mnt));
	} while (&m->mnt != mnt);
	} while (m != mnt);

	return NULL;
}
@@ -51,22 +51,22 @@ static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
 *
 * Caller must hold namespace_sem
 */
int get_dominating_id(struct vfsmount *mnt, const struct path *root)
int get_dominating_id(struct mount *mnt, const struct path *root)
{
	struct vfsmount *m;
	struct mount *m;

	for (m = mnt->mnt_master; m != NULL; m = m->mnt_master) {
		struct vfsmount *d = get_peer_under_root(m, mnt->mnt_ns, root);
	for (m = real_mount(mnt->mnt.mnt_master); m != NULL; m = real_mount(m->mnt.mnt_master)) {
		struct mount *d = get_peer_under_root(m, mnt->mnt.mnt_ns, root);
		if (d)
			return d->mnt_group_id;
			return d->mnt.mnt_group_id;
	}

	return 0;
}

static int do_make_slave(struct vfsmount *mnt)
static int do_make_slave(struct mount *mnt)
{
	struct vfsmount *peer_mnt = mnt, *master = mnt->mnt_master;
	struct mount *peer_mnt = mnt, *master = real_mount(mnt->mnt.mnt_master);
	struct vfsmount *slave_mnt;

	/*
@@ -74,31 +74,31 @@ static int do_make_slave(struct vfsmount *mnt)
	 * same root dentry. If none is available then
	 * slave it to anything that is available.
	 */
	while ((peer_mnt = next_peer(peer_mnt)) != mnt &&
	       peer_mnt->mnt_root != mnt->mnt_root) ;
	while ((peer_mnt = real_mount(next_peer(&peer_mnt->mnt))) != mnt &&
	       peer_mnt->mnt.mnt_root != mnt->mnt.mnt_root) ;

	if (peer_mnt == mnt) {
		peer_mnt = next_peer(mnt);
		peer_mnt = real_mount(next_peer(&mnt->mnt));
		if (peer_mnt == mnt)
			peer_mnt = NULL;
	}
	if (IS_MNT_SHARED(mnt) && list_empty(&mnt->mnt_share))
		mnt_release_group_id(real_mount(mnt));
	if (IS_MNT_SHARED(&mnt->mnt) && list_empty(&mnt->mnt.mnt_share))
		mnt_release_group_id(mnt);

	list_del_init(&mnt->mnt_share);
	mnt->mnt_group_id = 0;
	list_del_init(&mnt->mnt.mnt_share);
	mnt->mnt.mnt_group_id = 0;

	if (peer_mnt)
		master = peer_mnt;

	if (master) {
		list_for_each_entry(slave_mnt, &mnt->mnt_slave_list, mnt_slave)
			slave_mnt->mnt_master = master;
		list_move(&mnt->mnt_slave, &master->mnt_slave_list);
		list_splice(&mnt->mnt_slave_list, master->mnt_slave_list.prev);
		INIT_LIST_HEAD(&mnt->mnt_slave_list);
		list_for_each_entry(slave_mnt, &mnt->mnt.mnt_slave_list, mnt_slave)
			slave_mnt->mnt_master = &master->mnt;
		list_move(&mnt->mnt.mnt_slave, &master->mnt.mnt_slave_list);
		list_splice(&mnt->mnt.mnt_slave_list, master->mnt.mnt_slave_list.prev);
		INIT_LIST_HEAD(&mnt->mnt.mnt_slave_list);
	} else {
		struct list_head *p = &mnt->mnt_slave_list;
		struct list_head *p = &mnt->mnt.mnt_slave_list;
		while (!list_empty(p)) {
                        slave_mnt = list_first_entry(p,
					struct vfsmount, mnt_slave);
@@ -106,8 +106,8 @@ static int do_make_slave(struct vfsmount *mnt)
			slave_mnt->mnt_master = NULL;
		}
	}
	mnt->mnt_master = master;
	CLEAR_MNT_SHARED(mnt);
	mnt->mnt.mnt_master = &master->mnt;
	CLEAR_MNT_SHARED(&mnt->mnt);
	return 0;
}

@@ -120,7 +120,7 @@ void change_mnt_propagation(struct mount *mnt, int type)
		set_mnt_shared(mnt);
		return;
	}
	do_make_slave(&mnt->mnt);
	do_make_slave(mnt);
	if (type != MS_SLAVE) {
		list_del_init(&mnt->mnt.mnt_slave);
		mnt->mnt.mnt_master = NULL;
+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ int propagate_mnt(struct vfsmount *, struct dentry *, struct vfsmount *,
int propagate_umount(struct list_head *);
int propagate_mount_busy(struct mount *, int);
void mnt_release_group_id(struct mount *);
int get_dominating_id(struct vfsmount *mnt, const struct path *root);
int get_dominating_id(struct mount *mnt, const struct path *root);
unsigned int mnt_get_count(struct mount *mnt);
void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
			struct mount *);