nfsd: filter readdir results in V4ROOT case

As with lookup, we treat every boject as a mountpoint and pretend it
doesn't exist if it isn't exported.

The preexisting code here is confusing, but I haven't yet figured out
how to make it clearer.

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

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index cab978031100..a8587e90fd5a 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2196,11 +2196,14 @@ nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
          * we will not follow the cross mount and will fill the attribtutes
          * directly from the mountpoint dentry.
          */
-        if (d_mountpoint(dentry) && !attributes_need_mount(cd->rd_bmval))
-                ignore_crossmnt = 1;
-        else if (d_mountpoint(dentry)) {
+        if (nfsd_mountpoint(dentry, exp)) {
                 int err;
 
+                if (!(exp->ex_flags & NFSEXP_V4ROOT)
+                                && !attributes_need_mount(cd->rd_bmval)) {
+                        ignore_crossmnt = 1;
+                        goto out_encode;
+                }
                 /*
                  * Why the heck aren't we just using nfsd_lookup??
                  * Different "."/".." handling?  Something else?
@@ -2216,6 +2219,7 @@ nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
                         goto out_put;
 
         }
+out_encode:
         nfserr = nfsd4_encode_fattr(NULL, exp, dentry, p, buflen, cd->rd_bmval,
                                         cd->rd_rqstp, ignore_crossmnt);
 out_put: