From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Kent Subject: [RFC PATCH 08/11] autofs4 - eliminate d_unhashed in path walk checks Date: Thu, 24 Sep 2009 16:22:12 +0800 Message-ID: <20090924082212.22151.76953.stgit@zeus.themaw.net> References: <20090924082036.22151.85151.stgit@zeus.themaw.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Al Viro , Christoph Hellwig , Andreas Dilger , Yehuda Saheh , Jim Garlick To: Sage Weil , linux-fsdevel , Kernel Mailing List Return-path: Received: from outbound.icp-qv1-irony-out4.iinet.net.au ([203.59.1.150]:1113 "EHLO outbound.icp-qv1-irony-out4.iinet.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752622AbZIXIb1 (ORCPT ); Thu, 24 Sep 2009 04:31:27 -0400 In-Reply-To: <20090924082036.22151.85151.stgit@zeus.themaw.net> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: We unhash the dentry (in a subsequent patch) in ->d_revalidate() in order to send mount requests to ->lookup(). But then we can not rely on d_unhased() to give reliable results because it may be called at any time by any code path. The d_unhashed() function is used by __simple_empty() in the path walking callbacks but autofs mount point dentrys should have no directories at all so a list_empty() on d_subdirs should be (and is) sufficient. Signed-off-by: Ian Kent --- fs/autofs4/root.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 81700f4..b6530f3 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -133,7 +133,7 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) * it. */ spin_lock(&dcache_lock); - if (!d_mountpoint(dentry) && __simple_empty(dentry)) { + if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { spin_unlock(&dcache_lock); return -ENOENT; } @@ -257,7 +257,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) * mount it again. */ if (ino->flags & AUTOFS_INF_PENDING || - (!d_mountpoint(dentry) && __simple_empty(dentry))) { + (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { spin_unlock(&dcache_lock); spin_unlock(&sbi->fs_lock); @@ -340,8 +340,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) /* Check for a non-mountpoint directory with no contents */ spin_lock(&dcache_lock); if (S_ISDIR(dentry->d_inode->i_mode) && - !d_mountpoint(dentry) && - __simple_empty(dentry)) { + !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { DPRINTK("dentry=%p %.*s, emptydir", dentry, dentry->d_name.len, dentry->d_name.name); spin_unlock(&dcache_lock);