From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279Ab3L0Eci (ORCPT ); Thu, 26 Dec 2013 23:32:38 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:52361 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754230Ab3L0EcY (ORCPT ); Thu, 26 Dec 2013 23:32:24 -0500 X-Sasl-enc: +oq40Ak/rVXg2wOV2Fd7jf2Tq64frZVAiXOuGVLXTzp2 1388118739 Subject: [PATCH] autofs - fix symlinks aren't checked for expiry To: Andrew Morton From: Ian Kent Cc: linux-fsdevel , autofs mailing list , Kernel Mailing List Date: Fri, 27 Dec 2013 12:32:16 +0800 Message-ID: <20131227043216.3519.3477.stgit@perseus.fritz.box> In-Reply-To: <20131227042828.3519.11223.stgit@perseus.fritz.box> References: <20131227042828.3519.11223.stgit@perseus.fritz.box> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Kent The autofs4 module doesn't consider symlinks for expire as it did in the older autofs v3 module (so it's actually a long stnding regression). The user space daemon has focused on the use of bind mounts instead of symlinks for a long time now and that's why this has not been noticed. But with the future addition of amd map parsing to automount(8), not to mention amd itself (of am-utils), symlink expiry will be needed. The direct and offset mount types can't be symlinks and the tree mounts of version 4 were always real mounts so only indirect mounts need expire symlinks. Since the current users of the autofs4 module haven't reproted this as a problem to date this patch probably isn't a candidate for backport to stable. Signed-off-by: Ian Kent --- fs/autofs4/expire.c | 14 ++++++++++++++ fs/autofs4/symlink.c | 4 ++++ 2 files changed, 18 insertions(+) diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 3d9d3f5..394e90b 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -402,6 +402,20 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, goto next; } + if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) { + DPRINTK("checking symlink %p %.*s", + dentry, (int)dentry->d_name.len, dentry->d_name.name); + /* + * A symlink can't be "busy" in the usual sense so + * just check last used for expire timeout. + */ + if (autofs4_can_expire(dentry, timeout, do_now)) { + expired = dentry; + goto found; + } + goto next; + } + if (simple_empty(dentry)) goto next; diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c index f27c094..1e8ea19 100644 --- a/fs/autofs4/symlink.c +++ b/fs/autofs4/symlink.c @@ -14,6 +14,10 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) { + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino && !autofs4_oz_mode(sbi)) + ino->last_used = jiffies; nd_set_link(nd, dentry->d_inode->i_private); return NULL; }