[PATCH 22/32] union-mount: stop lookup when directory has S_OPAQUE flag set

From: Jan Blunck
Date: Mon May 18 2009 - 12:13:40 EST


Honor the S_OPAQUE flag in the union path lookup.

Signed-off-by: Jan Blunck <jblunck@xxxxxxx>
Signed-off-by: Valerie Aurora (Henson) <vaurora@xxxxxxxxxx>
---
fs/namei.c | 17 ++++++++++++++---
1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 2bb8a22..83cc5ea 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -521,6 +521,9 @@ static int __cache_lookup_build_union(struct nameidata *nd, struct qstr *name,
path_put(&last);
last.dentry = dentry;
last.mnt = mntget(nd->path.mnt);
+
+ if (IS_OPAQUE(last.dentry->d_inode))
+ break;
}

if (last.dentry != path->dentry)
@@ -560,7 +563,8 @@ static int cache_lookup_union(struct nameidata *nd, struct qstr *name,

/* only directories can be part of a union stack */
if (!path->dentry->d_inode ||
- !S_ISDIR(path->dentry->d_inode->i_mode))
+ !S_ISDIR(path->dentry->d_inode->i_mode) ||
+ IS_OPAQUE(path->dentry->d_inode))
goto out;

/* Build the union stack for this part */
@@ -802,6 +806,9 @@ static int __real_lookup_build_union(struct nameidata *nd, struct qstr *name,
path_put(&last);
last.dentry = next.dentry;
last.mnt = mntget(next.mnt);
+
+ if (IS_OPAQUE(last.dentry->d_inode))
+ break;
}

if (last.dentry != path->dentry)
@@ -823,7 +830,8 @@ static int real_lookup_union(struct nameidata *nd, struct qstr *name,

/* only directories can be part of a union stack */
if (!path->dentry->d_inode ||
- !S_ISDIR(path->dentry->d_inode->i_mode))
+ !S_ISDIR(path->dentry->d_inode->i_mode) ||
+ IS_OPAQUE(path->dentry->d_inode))
goto out;

/* Build the union stack for this part */
@@ -1108,7 +1116,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
{
int err;

- if (IS_MNT_UNION(nd->path.mnt))
+ if (IS_MNT_UNION(nd->path.mnt) && !IS_OPAQUE(nd->path.dentry->d_inode))
goto need_union_lookup;

path->dentry = __d_lookup(nd->path.dentry, name);
@@ -1643,6 +1651,9 @@ static int __hash_lookup_build_union(struct nameidata *nd, struct qstr *name,
path_put(&last);
last.dentry = next.dentry;
last.mnt = mntget(next.mnt);
+
+ if (IS_OPAQUE(last.dentry->d_inode))
+ break;
}

if (last.dentry != path->dentry)
--
1.6.1.3

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