ocfs2: Reset xattr value size after xa_cleanup_value_truncate().

In ocfs2_prepare_xattr_entry, if we fail to grow an existing value,
xa_cleanup_value_truncate() will leave the old entry in place.  Thus, we
reset its value size.  However, if we were allocating a new value, we
must not reset the value size or we will BUG().  This resolves
oss.oracle.com bug 1247.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 10 insertions, 7 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index a1cf195935cf..e87130f44cb7 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -2135,15 +2135,18 @@ alloc_value:
                 orig_clusters = ocfs2_xa_value_clusters(loc);
                 rc = ocfs2_xa_value_truncate(loc, xi->xi_value_len, ctxt);
                 if (rc < 0) {
-                        /*
-                         * If we tried to grow an existing external value,
-                         * ocfs2_xa_cleanuP-value_truncate() is going to
-                         * let it stand.  We have to restore its original
-                         * value size.
-                         */
-                        loc->xl_entry->xe_value_size = orig_value_size;
                         ocfs2_xa_cleanup_value_truncate(loc, "growing",
                                                         orig_clusters);
+                        /*
+                         * If we were growing an existing value,
+                         * ocfs2_xa_cleanup_value_truncate() won't remove
+                         * the entry. We need to restore the original value
+                         * size.
+                         */
+                        if (loc->xl_entry) {
+                                BUG_ON(!orig_value_size);
+                                loc->xl_entry->xe_value_size = orig_value_size;
+                        }
                         mlog_errno(rc);
                 }
         }