ceph: fix listxattr handling for vxattrs

Only include vxattrs in the result if they are not hidden and exist
(as determined by the exists_cb callback).

Note that the buffer size we return when 0 is passed in always includes
vxattrs that *might* exist, forming an upper bound.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Sam Lang <sam.lang@inktank.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 87b85f3403d4..ec09ea5c4f07 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -657,23 +657,30 @@ list_xattr:
         vir_namelen = ceph_vxattrs_name_size(vxattrs);
 
         /* adding 1 byte per each variable due to the null termination */
-        namelen = vir_namelen + ci->i_xattrs.names_size + ci->i_xattrs.count;
+        namelen = ci->i_xattrs.names_size + ci->i_xattrs.count;
         err = -ERANGE;
-        if (size && namelen > size)
+        if (size && vir_namelen + namelen > size)
                 goto out;
 
-        err = namelen;
+        err = namelen + vir_namelen;
         if (size == 0)
                 goto out;
 
         names = __copy_xattr_names(ci, names);
 
         /* virtual xattr names, too */
-        if (vxattrs)
+        err = namelen;
+        if (vxattrs) {
                 for (i = 0; vxattrs[i].name; i++) {
-                        len = sprintf(names, "%s", vxattrs[i].name);
-                        names += len + 1;
+                        if (!vxattrs[i].hidden &&
+                            !(vxattrs[i].exists_cb &&
+                              !vxattrs[i].exists_cb(ci))) {
+                                len = sprintf(names, "%s", vxattrs[i].name);
+                                names += len + 1;
+                                err += len + 1;
+                        }
                 }
+        }
 
 out:
         spin_unlock(&ci->i_ceph_lock);