diff options
| -rw-r--r-- | fs/namei.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/fs/namei.c b/fs/namei.c index 9cfb7096e307..6529c2506491 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1134,6 +1134,26 @@ int follow_up(struct path *path) } EXPORT_SYMBOL(follow_up); +static bool choose_mountpoint_rcu(struct mount *m, const struct path *root, + struct path *path, unsigned *seqp) +{ + while (mnt_has_parent(m)) { + struct dentry *mountpoint = m->mnt_mountpoint; + + m = m->mnt_parent; + if (unlikely(root->dentry == mountpoint && + root->mnt == &m->mnt)) + break; + if (mountpoint != m->mnt.mnt_root) { + path->mnt = &m->mnt; + path->dentry = mountpoint; + *seqp = read_seqcount_begin(&mountpoint->d_seq); + return true; + } + } + return false; +} + /* * Perform an automount * - return -EISDIR to tell follow_managed() to stop and return the path we @@ -1696,23 +1716,11 @@ static struct dentry *follow_dotdot_rcu(struct nameidata *nd, if (path_equal(&nd->path, &nd->root)) goto in_root; if (unlikely(nd->path.dentry == nd->path.mnt->mnt_root)) { - struct path path = nd->path; + struct path path; unsigned seq; - - while (1) { - struct mount *mnt = real_mount(path.mnt); - struct mount *mparent = mnt->mnt_parent; - struct dentry *mountpoint = mnt->mnt_mountpoint; - seq = read_seqcount_begin(&mountpoint->d_seq); - if (&mparent->mnt == path.mnt) - goto in_root; - path.dentry = mountpoint; - path.mnt = &mparent->mnt; - if (path_equal(&path, &nd->root)) - goto in_root; - if (path.dentry != path.mnt->mnt_root) - break; - } + if (!choose_mountpoint_rcu(real_mount(nd->path.mnt), + &nd->root, &path, &seq)) + goto in_root; if (unlikely(nd->flags & LOOKUP_NO_XDEV)) return ERR_PTR(-ECHILD); nd->path = path; |