ocfs2: do not modify lksb->status in the unlock ast

This can race with other ast notification, which can cause bad status values
to propagate into the unlock ast.

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 12 insertions, 25 deletions

diff --git a/fs/ocfs2/dlm/dlmunlock.c b/fs/ocfs2/dlm/dlmunlock.c
index 4ce3f82fb736..59866e471d96 100644
--- a/fs/ocfs2/dlm/dlmunlock.c
+++ b/fs/ocfs2/dlm/dlmunlock.c
@@ -155,7 +155,7 @@ static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
         else
                 status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions);
 
-        if (status != DLM_NORMAL)
+        if (status != DLM_NORMAL && status != DLM_CANCELGRANT)
                 goto leave;
 
         /* By now this has been masked out of cancel requests. */
@@ -183,8 +183,7 @@ static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
                 spin_lock(&lock->spinlock);
                 /* if the master told us the lock was already granted,
                  * let the ast handle all of these actions */
-                if (status == DLM_NORMAL &&
-                    lksb->status == DLM_CANCELGRANT) {
+                if (status == DLM_CANCELGRANT) {
                         actions &= ~(DLM_UNLOCK_REMOVE_LOCK|
                                      DLM_UNLOCK_REGRANT_LOCK|
                                      DLM_UNLOCK_CLEAR_CONVERT_TYPE);
@@ -349,14 +348,9 @@ static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
                                         vec, veclen, owner, &status);
         if (tmpret >= 0) {
                 // successfully sent and received
-                if (status == DLM_CANCELGRANT)
-                        ret = DLM_NORMAL;
-                else if (status == DLM_FORWARD) {
+                if (status == DLM_FORWARD)
                         mlog(0, "master was in-progress.  retry\n");
-                        ret = DLM_FORWARD;
-                } else
-                        ret = status;
-                lksb->status = status;
+                ret = status;
         } else {
                 mlog_errno(tmpret);
                 if (dlm_is_host_down(tmpret)) {
@@ -372,7 +366,6 @@ static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
                         /* something bad.  this will BUG in ocfs2 */
                         ret = dlm_err_to_dlm_status(tmpret);
                 }
-                lksb->status = ret;
         }
 
         return ret;
@@ -511,11 +504,8 @@ not_found:
                                "cookie=%u:%llu\n",
                                dlm_get_lock_cookie_node(unlock->cookie),
                                dlm_get_lock_cookie_seq(unlock->cookie));
-        else {
-                /* send the lksb->status back to the other node */
-                status = lksb->status;
+        else
                 dlm_lock_put(lock);
-        }
 
 leave:
         if (res)
@@ -537,26 +527,22 @@ static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
 
         if (dlm_lock_on_list(&res->blocked, lock)) {
                 /* cancel this outright */
-                lksb->status = DLM_NORMAL;
                 status = DLM_NORMAL;
                 *actions = (DLM_UNLOCK_CALL_AST |
                             DLM_UNLOCK_REMOVE_LOCK);
         } else if (dlm_lock_on_list(&res->converting, lock)) {
                 /* cancel the request, put back on granted */
-                lksb->status = DLM_NORMAL;
                 status = DLM_NORMAL;
                 *actions = (DLM_UNLOCK_CALL_AST |
                             DLM_UNLOCK_REMOVE_LOCK |
                             DLM_UNLOCK_REGRANT_LOCK |
                             DLM_UNLOCK_CLEAR_CONVERT_TYPE);
         } else if (dlm_lock_on_list(&res->granted, lock)) {
-                /* too late, already granted.  DLM_CANCELGRANT */
-                lksb->status = DLM_CANCELGRANT;
-                status = DLM_NORMAL;
+                /* too late, already granted. */
+                status = DLM_CANCELGRANT;
                 *actions = DLM_UNLOCK_CALL_AST;
         } else {
                 mlog(ML_ERROR, "lock to cancel is not on any list!\n");
-                lksb->status = DLM_IVLOCKID;
                 status = DLM_IVLOCKID;
                 *actions = 0;
         }
@@ -573,13 +559,11 @@ static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
 
         /* unlock request */
         if (!dlm_lock_on_list(&res->granted, lock)) {
-                lksb->status = DLM_DENIED;
                 status = DLM_DENIED;
                 dlm_error(status);
                 *actions = 0;
         } else {
                 /* unlock granted lock */
-                lksb->status = DLM_NORMAL;
                 status = DLM_NORMAL;
                 *actions = (DLM_UNLOCK_FREE_LOCK |
                             DLM_UNLOCK_CALL_AST |
@@ -671,7 +655,7 @@ retry:
         }
 
         if (call_ast) {
-                mlog(0, "calling unlockast(%p, %d)\n", data, lksb->status);
+                mlog(0, "calling unlockast(%p, %d)\n", data, status);
                 if (is_master) {
                         /* it is possible that there is one last bast 
                          * pending.  make sure it is flushed, then
@@ -683,9 +667,12 @@ retry:
                         wait_event(dlm->ast_wq, 
                                    dlm_lock_basts_flushed(dlm, lock));
                 }
-                (*unlockast)(data, lksb->status);
+                (*unlockast)(data, status);
         }
 
+        if (status == DLM_CANCELGRANT)
+                status = DLM_NORMAL;
+
         if (status == DLM_NORMAL) {
                 mlog(0, "kicking the thread\n");
                 dlm_kick_thread(dlm, res);