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Commit 643822b4 authored by Al Viro's avatar Al Viro
Browse files

vfs: spread struct mount - is_path_reachable 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 676da58d

fs/namespace.c

+7 −7
Original line number Diff line number Diff line
@@ -2559,21 +2559,21 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, 
 *

 * namespace_sem or vfsmount_lock is held

 */

bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry,

bool is_path_reachable(struct mount *mnt, struct dentry *dentry,

			 const struct path *root)

{

	while (mnt != root->mnt && mnt_has_parent(real_mount(mnt))) {

		dentry = mnt->mnt_mountpoint;

		mnt = mnt->mnt_parent;

	while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {

		dentry = mnt->mnt.mnt_mountpoint;

		mnt = real_mount(mnt->mnt.mnt_parent);

	}

	return mnt == root->mnt && is_subdir(dentry, root->dentry);

	return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);

}



int path_is_under(struct path *path1, struct path *path2)

{

	int res;

	br_read_lock(vfsmount_lock);

	res = is_path_reachable(path1->mnt, path1->dentry, path2);

	res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);

	br_read_unlock(vfsmount_lock);

	return res;

}
@@ -2659,7 +2659,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, 
	if (!mnt_has_parent(new_mnt))

		goto out4; /* not attached */

	/* make sure we can reach put_old from new_root */

	if (!is_path_reachable(old.mnt, old.dentry, &new))

	if (!is_path_reachable(real_mount(old.mnt), old.dentry, &new))

		goto out4;

	br_write_lock(vfsmount_lock);

	detach_mnt(new_mnt, &parent_path);

fs/pnode.c

+5 −5
Original line number Diff line number Diff line
@@ -32,15 +32,15 @@ static struct vfsmount *get_peer_under_root(struct vfsmount *mnt, 
					    struct mnt_namespace *ns,

					    const struct path *root)

{

	struct vfsmount *m = mnt;

	struct mount *m = real_mount(mnt);



	do {

		/* Check the namespace first for optimization */

		if (m->mnt_ns == ns && is_path_reachable(m, m->mnt_root, root))

			return m;

		if (m->mnt.mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))

			return &m->mnt;



		m = next_peer(m);

	} while (m != mnt);

		m = real_mount(next_peer(&m->mnt));

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



	return NULL;

}

fs/pnode.h

+1 −1
Original line number Diff line number Diff line
@@ -42,6 +42,6 @@ void mnt_set_mountpoint(struct vfsmount *, struct dentry *, 
void release_mounts(struct list_head *);

void umount_tree(struct mount *, int, struct list_head *);

struct mount *copy_tree(struct mount *, struct dentry *, int);

bool is_path_reachable(struct vfsmount *, struct dentry *,

bool is_path_reachable(struct mount *, struct dentry *,

			 const struct path *root);

#endif /* _LINUX_PNODE_H */