diff --git a/src/client/sysint/sys-osd-dir.sm b/src/client/sysint/sys-osd-dir.sm
index cdc60cf..1805bd9 100644
--- a/src/client/sysint/sys-osd-dir.sm
+++ b/src/client/sysint/sys-osd-dir.sm
@@ -36,7 +36,8 @@ extern job_context_id pint_client_sm_context;
 enum {
     OSD_DIROPS_RETRY = 191,
     OSD_PVFS_REMOVE = 192,
-    OSD_PVFS_LOCK_FAILED = 193
+    OSD_PVFS_LOCK_FAILED = 193,
+    OSD_PVFS_ATOMIC_FAILED = 194
 };
 
 /* OSD directory completion function prototypes */
@@ -114,6 +115,7 @@ nested machine pvfs2_client_osd_dirops_attr1_sm
     {
         jump pvfs2_osd_msgpairarray_sm;
         success => osd_dirops_attr1_cleanup;
+        OSD_PVFS_ATOMIC_FAILED => osd_dirops_attr1_init;
         default => osd_dirops_attr1_failure;
     }
 
@@ -528,26 +530,66 @@ static int osd_dirops_attr1_comp_fn(void *v_p,
                                     struct PVFS_server_resp *resp_p,
                                     int index)
 {
-    PVFS_error status = 0;
+    int ret = 0;
     PINT_smcb *smcb = v_p;
     PINT_client_sm *sm_p = PINT_sm_frame(smcb, PINT_FRAME_CURRENT);
 
+    struct osd_command *command = &sm_p->msgpair.osd_command;
     gossip_debug(GOSSIP_CLIENT_DEBUG, "osd_dirops_attr1_comp_fn\n");
 
-    status = osd_errno_from_status(sm_p->msgpair.osd_command.status);
-    if (status != 0) {
+    ret = osd_errno_from_status(sm_p->msgpair.osd_command.status);
+    if (ret != 0) {
         gossip_debug(GOSSIP_CLIENT_DEBUG,
                      "osd_command_set_gen_cas failed %d\n", index);
-        return status;
+        goto out;
+    }
+
+    ret = osd_command_attr_resolve(command);
+    if (ret) {
+        osd_error_xerrno(ret, "%s: osd_command_attr_resolve failed", __func__);
+        goto out;
+    }
+
+    if (smcb->op == PVFS_SYS_CREATE || smcb->op == PVFS_SYS_MKDIR) {
+        /* insert dirent operation */
+        if (command->attr[2].val == NULL) {
+            /* successful insert operation */
+            ret = 0;
+            goto out;
+        } else {
+            /*
+             * insert operation failed. either the name is already being
+             * used or we have a hash collision.
+             */
+            gossip_debug(GOSSIP_CLIENT_DEBUG, "Atomic CAS: insert failed\n");
+            ret = OSD_PVFS_ATOMIC_FAILED;
+            goto out;
+        }
+    } else {
+        /* remove dirent operation */
+        assert(command->attr[0].val && command->attr[2].val);
+
+        if (get_ntohll(command->attr[0].val) ==
+            get_ntohll(command->attr[2].val)) {
+            /* successful remove operation */
+            ret = 0;
+            goto out;
+        } else {
+            /* remove operation failed */
+            gossip_debug(GOSSIP_CLIENT_DEBUG, "Atomic CAS: remove failed\n");
+            ret = OSD_PVFS_ATOMIC_FAILED;
+            goto out;
+        }
     }
 
+out:
     /* free data alloced for the create, if this was an insert */
     if (sm_p->msgpair.osd_command.attr->len) {
         free(sm_p->msgpair.osd_command.attr->val);
     }
     osd_command_attr_free(&sm_p->msgpair.osd_command);
  
-    return status;
+    return ret;
 }
 
 static PINT_sm_action osd_dirops_attr1_cleanup(