From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K. V" Subject: Re: [PATCH -V14 04/11] vfs: Allow handle based open on symlinks Date: Wed, 07 Jul 2010 21:54:52 +0530 Message-ID: <87d3uzfeej.fsf@linux.vnet.ibm.com> References: <1276621981-2774-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1276621981-2774-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20100707152303.GS11732@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: hch@infradead.org, viro@zeniv.linux.org.uk, adilger@sun.com, corbet@lwn.net, serue@us.ibm.com, neilb@suse.de, hooanon05@yahoo.co.jp, bfields@fieldses.org, linux-fsdevel@vger.kernel.org, sfrench@us.ibm.com, philippe.deniel@CEA.FR, linux-kernel@vger.kernel.org To: Nick Piggin Return-path: In-Reply-To: <20100707152303.GS11732@laptop> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, 8 Jul 2010 01:23:03 +1000, Nick Piggin wrote: > On Tue, Jun 15, 2010 at 10:42:54PM +0530, Aneesh Kumar K.V wrote: > > The patch update may_open to allow handle based open on symlinks. > > The file handle based API use file descritor returned from open_by_handle_at > > to do different file system operations. To find the link target name we > > need to get a file descriptor on symlinks. > > This is a pretty big change, isn't it? Yes > Have you looked through vfs to > ensure this is actually OK? I was just looking at remount,ro code, for > example, and it seems to assume only writable open files on ISREG > files. I verified that write and read returns an error on that descriptor. I will look at rest of code to ensure the it doesn't break assumptions in the rest of VFS. > > Is this restricted to RDONLY? Really, it should be O_NONE... > > we need the interface so that we can do fstat(lstat) and readlink using the handle. If we are against the idea of allowing an fd on symlink, how about adding stat_by_handle and readlink_by_handle syscall ? That way we can drop "vfs: Support null pathname in readlink" patch -aneesh