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Diffstat (limited to 'fs/nfsd/vfs.c')
-rw-r--r--fs/nfsd/vfs.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 9aaf6ca77569..2be32955d7f2 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -94,6 +94,12 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
err = follow_down(&path);
if (err < 0)
goto out;
+ if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
+ nfsd_mountpoint(dentry, exp) == 2) {
+ /* This is only a mountpoint in some other namespace */
+ path_put(&path);
+ goto out;
+ }
exp2 = rqst_exp_get_by_name(rqstp, &path);
if (IS_ERR(exp2)) {
@@ -167,16 +173,26 @@ static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, st
/*
* For nfsd purposes, we treat V4ROOT exports as though there was an
* export at *every* directory.
+ * We return:
+ * '1' if this dentry *must* be an export point,
+ * '2' if it might be, if there is really a mount here, and
+ * '0' if there is no chance of an export point here.
*/
int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
{
- if (d_mountpoint(dentry))
+ if (!d_inode(dentry))
+ return 0;
+ if (exp->ex_flags & NFSEXP_V4ROOT)
return 1;
if (nfsd4_is_junction(dentry))
return 1;
- if (!(exp->ex_flags & NFSEXP_V4ROOT))
- return 0;
- return d_inode(dentry) != NULL;
+ if (d_mountpoint(dentry))
+ /*
+ * Might only be a mountpoint in a different namespace,
+ * but we need to check.
+ */
+ return 2;
+ return 0;
}
__be32