From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758636AbcINGOr (ORCPT ); Wed, 14 Sep 2016 02:14:47 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:41418 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbcINGOo (ORCPT ); Wed, 14 Sep 2016 02:14:44 -0400 X-Sasl-enc: XUsLBjzlybmt+ThQb/An25jSjEcX5zsLVmh83u/jNg7C 1473833682 Subject: [PATCH 2/4] fs - add have_local_submounts() From: Ian Kent To: Andrew Morton Cc: autofs mailing list , Kernel Mailing List , Al Viro , linux-fsdevel , Omar Sandoval , "Eric W. Biederman" Date: Wed, 14 Sep 2016 14:14:40 +0800 Message-ID: <20160914061440.24714.82139.stgit@pluto.themaw.net> In-Reply-To: <20160914061434.24714.490.stgit@pluto.themaw.net> References: <20160914061434.24714.490.stgit@pluto.themaw.net> User-Agent: StGit/0.17.1-dirty 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 The have_submounts() function checks if a dentry is a mountpoint in any namespace but autofs needs to know if the dentry is a mountpoint within the current namespace. Add have_local_submounts() to to do this. Signed-off-by: Ian Kent Cc: Al Viro Cc: Eric W. Biederman Cc: Omar Sandoval --- fs/dcache.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/dcache.h | 1 + 2 files changed, 35 insertions(+) diff --git a/fs/dcache.c b/fs/dcache.c index 5c7cc95..218166b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1307,6 +1307,40 @@ int have_submounts(struct dentry *parent) EXPORT_SYMBOL(have_submounts); /* + * Search for at least 1 mount point in the dentry's subdirs. + * We descend to the next level whenever the d_subdirs + * list is non-empty and continue searching. + */ + +static enum d_walk_ret check_local_mount(void *data, struct dentry *dentry) +{ + int *ret = data; + if (is_local_mountpoint(dentry)) { + *ret = 1; + return D_WALK_QUIT; + } + return D_WALK_CONTINUE; +} + +/** + * have_local_submounts - check for mounts over a dentry + * in the current namespace + * @parent: dentry to check. + * + * Return true if the parent or its subdirectories contain + * a mount point + */ +int have_local_submounts(struct dentry *parent) +{ + int ret = 0; + + d_walk(parent, &ret, check_local_mount, NULL); + + return ret; +} +EXPORT_SYMBOL(have_local_submounts); + +/* * Called by mount code to set a mountpoint and check if the mountpoint is * reachable (e.g. NFS can unhash a directory dentry and then the complete * subtree can become unreachable). diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 5ff3e9a..796b358 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -255,6 +255,7 @@ extern void d_prune_aliases(struct inode *); /* test whether we have any submounts in a subdir tree */ extern int have_submounts(struct dentry *); +extern int have_local_submounts(struct dentry *); /* * This adds the entry to the hash queues.