From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: Re: [PATCH 1/3] autofs4 - fix device ioctl mount lookup Date: Wed, 4 Sep 2013 02:03:02 +0100 Message-ID: <20130904010301.GE13318@ZenIV.linux.org.uk> References: <20130904005456.5025.94309.stgit@perseus.fritz.box> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , linux-fsdevel , rui.xiang@huawei.com, autofs mailing list , Kernel Mailing List To: Ian Kent Return-path: Content-Disposition: inline In-Reply-To: <20130904005456.5025.94309.stgit@perseus.fritz.box> Sender: autofs-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Sep 04, 2013 at 08:54:57AM +0800, Ian Kent wrote: > +static int kern_path_top(const char *pathname, > + unsigned int flags, struct path *path) > +{ > + struct dentry *dentry; > + struct qstr name; > + const char *tmp; > + unsigned int len; > + int err; > + > + len = strlen(pathname); > + if (len <= 1) > + return -EINVAL; > + > + tmp = pathname + len - 1; > + len = 0; > + if (*tmp == '/') > + tmp--; > + do { > + if (*tmp == '/') > + break; > + len++; > + } while (--tmp >= pathname); > + tmp++; > + > + err = kern_path(pathname, flags | LOOKUP_PARENT, path); > + if (err) > + return err; > + > + name.name = tmp; > + name.len = len; > + name.hash = full_name_hash(tmp, len); > + > + dentry = d_lookup(path->dentry, &name); > + if (!dentry) { > + path_put(path); > + return -ENOENT; > + } > + dput(path->dentry); > + path->dentry = dentry; > + > + while (follow_down_one(path)) > + ; > + > + return 0; > +} Ewwww... NAK in that form. Just what will happen if the last component given to that sucker will be . or .., for starters? Or a symlink, with '/' added to it to force following the damn thing?