From: J. Bruce Fields <bfields@citi.umich.edu>
Date: Mon, 26 Oct 2009 01:33:15 +0000 (-0400)
Subject: nfsd: filter lookup results in V4ROOT case
X-Git-Tag: v2.6.33-rc8~37^2~12
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=82ead7fe41da960ed80652d13d5a1072f85f5aca;hp=3b6cee7bc4b2f7858e9202293104acda8826bb68

nfsd: filter lookup results in V4ROOT case

We treat every object as a mountpoint and pretend it doesn't exist if
it isn't exported.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 7e2fdd5..eaf2f0d 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -166,6 +166,19 @@ static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, st
 	return 0;
 }
 
+/*
+ * For nfsd purposes, we treat V4ROOT exports as though there was an
+ * export at *every* directory.
+ */
+static int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
+{
+	if (d_mountpoint(dentry))
+		return 1;
+	if (!(exp->ex_flags & NFSEXP_V4ROOT))
+		return 0;
+	return dentry->d_inode != NULL;
+}
+
 __be32
 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		   const char *name, unsigned int len,
@@ -211,7 +224,7 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		/*
 		 * check if we have crossed a mount point ...
 		 */
-		if (d_mountpoint(dentry)) {
+		if (nfsd_mountpoint(dentry, exp)) {
 			if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
 				dput(dentry);
 				goto out_nfserr;