From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valerie Aurora Subject: [PATCH 28/34] union-mount: Process negative dentries in __union_lookup() Date: Thu, 16 Sep 2010 15:12:19 -0700 Message-ID: <1284675145-4391-29-git-send-email-vaurora@redhat.com> References: <1284675145-4391-1-git-send-email-vaurora@redhat.com> Cc: Miklos Szeredi , Christoph Hellwig , Andreas Gruenbacher , Nick Piggin , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Valerie Aurora To: Alexander Viro Return-path: In-Reply-To: <1284675145-4391-1-git-send-email-vaurora@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Whiteouts end a union lookup. So do opaque directories, unless specific fallthru entry exists for this name. Signed-off-by: Valerie Aurora --- fs/namei.c | 23 ++++++++++++++++++++++- 1 files changed, 22 insertions(+), 1 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 8373463..f6ad8b3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -781,11 +781,32 @@ static int __lookup_union(struct nameidata *nd, struct qstr *name, err = PTR_ERR(lower.dentry); goto out_err; } - /* XXX - do nothing, lookup rule processing in later patches */ + + /* + * A negative dentry can mean several things. A plain + * negative dentry is ignored and lookup continues to + * the next layer. But a whiteout or a non-fallthru + * in an opaque dir covers everything below it. + */ + if (!lower.dentry->d_inode) { + if (d_is_whiteout(lower.dentry)) + goto out_lookup_done; + if (IS_OPAQUE(nd->path.dentry->d_inode) && + !d_is_fallthru(lower.dentry)) + goto out_lookup_done; + path_put(&lower); + continue; + } + + /* XXX - do nothing, more in later patches */ path_put(&lower); } return 0; +out_lookup_done: + path_put(&lower); + return 0; + out_err: d_free_unions(topmost->dentry); path_put(&lower); -- 1.6.3.3