diff options
Diffstat (limited to 'fs/namespace.c')
-rw-r--r-- | fs/namespace.c | 52 |
1 files changed, 43 insertions, 9 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index e5e1c7d..cfc6d44 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1048,15 +1048,12 @@ static int show_mountinfo(struct seq_file *m, void *v) if (err) goto out; seq_putc(m, ' '); - seq_path_root(m, &mnt_path, &root, " \t\n\\"); - if (root.mnt != p->root.mnt || root.dentry != p->root.dentry) { - /* - * Mountpoint is outside root, discard that one. Ugly, - * but less so than trying to do that in iterator in a - * race-free way (due to renames). - */ - return SEQ_SKIP; - } + + /* mountpoints outside of chroot jail will give SEQ_SKIP on this */ + err = seq_path_root(m, &mnt_path, &root, " \t\n\\"); + if (err) + goto out; + seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw"); show_mnt_opts(m, mnt); @@ -2483,11 +2480,43 @@ struct mnt_namespace *create_mnt_ns(struct vfsmount *mnt) __mnt_make_longterm(mnt); new_ns->root = mnt; list_add(&new_ns->list, &new_ns->root->mnt_list); + } else { + mntput(mnt); } return new_ns; } EXPORT_SYMBOL(create_mnt_ns); +struct dentry *mount_subtree(struct vfsmount *mnt, const char *name) +{ + struct mnt_namespace *ns; + struct super_block *s; + struct path path; + int err; + + ns = create_mnt_ns(mnt); + if (IS_ERR(ns)) + return ERR_CAST(ns); + + err = vfs_path_lookup(mnt->mnt_root, mnt, + name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path); + + put_mnt_ns(ns); + + if (err) + return ERR_PTR(err); + + /* trade a vfsmount reference for active sb one */ + s = path.mnt->mnt_sb; + atomic_inc(&s->s_active); + mntput(path.mnt); + /* lock the sucker */ + down_write(&s->s_umount); + /* ... and return the root of (sub)tree on it */ + return path.dentry; +} +EXPORT_SYMBOL(mount_subtree); + SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, char __user *, type, unsigned long, flags, void __user *, data) { @@ -2744,3 +2773,8 @@ void kern_unmount(struct vfsmount *mnt) } } EXPORT_SYMBOL(kern_unmount); + +bool our_mnt(struct vfsmount *mnt) +{ + return check_mnt(mnt); +} |