fix NFS4 handling of mountpoint stat
RFC says we need to follow the chain of mounts if there's more
than one stacked on that point.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index a8587e9..bbf72d8 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2121,9 +2121,15 @@
* and this is the root of a cross-mounted filesystem.
*/
if (ignore_crossmnt == 0 &&
- exp->ex_path.mnt->mnt_root->d_inode == dentry->d_inode) {
- err = vfs_getattr(exp->ex_path.mnt->mnt_parent,
- exp->ex_path.mnt->mnt_mountpoint, &stat);
+ dentry == exp->ex_path.mnt->mnt_root) {
+ struct path path = exp->ex_path;
+ path_get(&path);
+ while (follow_up(&path)) {
+ if (path.dentry != path.mnt->mnt_root)
+ break;
+ }
+ err = vfs_getattr(path.mnt, path.dentry, &stat);
+ path_put(&path);
if (err)
goto out_nfserr;
}