From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Goldstein Subject: [PATCH v4 14/15] ovl: update documentation w.r.t. constant inode numbers Date: Mon, 1 May 2017 16:42:05 +0300 Message-ID: <1493646126-10101-15-git-send-email-amir73il@gmail.com> References: <1493646126-10101-1-git-send-email-amir73il@gmail.com> Return-path: Received: from mail-wr0-f195.google.com ([209.85.128.195]:34146 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424497AbdEANmX (ORCPT ); Mon, 1 May 2017 09:42:23 -0400 In-Reply-To: <1493646126-10101-1-git-send-email-amir73il@gmail.com> Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Miklos Szeredi Cc: Vivek Goyal , Al Viro , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Signed-off-by: Amir Goldstein --- Documentation/filesystems/overlayfs.txt | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt index 634d03e..c9e884b 100644 --- a/Documentation/filesystems/overlayfs.txt +++ b/Documentation/filesystems/overlayfs.txt @@ -21,12 +21,19 @@ from accessing the corresponding object from the original filesystem. This is most obvious from the 'st_dev' field returned by stat(2). While directories will report an st_dev from the overlay-filesystem, -all non-directory objects will report an st_dev from the lower or +non-directory objects may report an st_dev from the lower filesystem or upper filesystem that is providing the object. Similarly st_ino will only be unique when combined with st_dev, and both of these can change over the lifetime of a non-directory object. Many applications and tools ignore these values and will not be affected. +In the special case of all overlay layers on the same underlying +filesystem, all objects will report an st_dev from the overlay +filesystem and st_ino from the underlying filesystem. This will +make the overlay mount more compliant with filesystem scanners and +overlay objects will be distinguishable from the corresponding +objects in the original filesystem. + Upper and Lower --------------- -- 2.7.4