dlm: remove callback reference counting

Get rid of the unnecessary refcounting on callback structs.
Copy interesting callback info into the lkb struct rather
than maintaining pointers to callback structs from the lkb.
This goes back to the way things were done prior to
commit 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks").

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 17 insertions, 39 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index e9da812352b4..03879c94fadb 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -18,25 +18,6 @@
 #include "user.h"
 #include "ast.h"
 
-void dlm_release_callback(struct kref *ref)
-{
-	struct dlm_callback *cb = container_of(ref, struct dlm_callback, ref);
-
-	dlm_free_cb(cb);
-}
-
-void dlm_callback_set_last_ptr(struct dlm_callback **from,
-			       struct dlm_callback *to)
-{
-	if (*from)
-		kref_put(&(*from)->ref, dlm_release_callback);
-
-	if (to)
-		kref_get(&to->ref);
-
-	*from = to;
-}
-
 static void dlm_callback_work(struct work_struct *work)
 {
 	struct dlm_callback *cb = container_of(work, struct dlm_callback, work);
@@ -53,7 +34,7 @@ static void dlm_callback_work(struct work_struct *work)
 		cb->astfn(cb->astparam);
 	}
 
-	kref_put(&cb->ref, dlm_release_callback);
+	dlm_free_cb(cb);
 }
 
 int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
@@ -70,11 +51,11 @@ int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
 		/* if cb is a bast, it should be skipped if the blocking mode is
 		 * compatible with the last granted mode
 		 */
-		if (lkb->lkb_last_cast) {
-			if (dlm_modes_compat(mode, lkb->lkb_last_cast->mode)) {
+		if (lkb->lkb_last_cast_cb_mode != -1) {
+			if (dlm_modes_compat(mode, lkb->lkb_last_cast_cb_mode)) {
 				log_debug(ls, "skip %x bast mode %d for cast mode %d",
 					  lkb->lkb_id, mode,
-					  lkb->lkb_last_cast->mode);
+					  lkb->lkb_last_cast_cb_mode);
 				goto out;
 			}
 		}
@@ -85,8 +66,9 @@ int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
 		 * is a bast for the same mode or a more restrictive mode.
 		 * (the addional > PR check is needed for PR/CW inversion)
 		 */
-		if (lkb->lkb_last_cb && lkb->lkb_last_cb->flags & DLM_CB_BAST) {
-			prev_mode = lkb->lkb_last_cb->mode;
+		if (lkb->lkb_last_cb_mode != -1 &&
+		    lkb->lkb_last_cb_flags & DLM_CB_BAST) {
+			prev_mode = lkb->lkb_last_cb_mode;
 
 			if ((prev_mode == mode) ||
 			    (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
@@ -95,19 +77,25 @@ int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
 				goto out;
 			}
 		}
+
+		lkb->lkb_last_bast_time = ktime_get();
+		lkb->lkb_last_bast_cb_mode = mode;
 	} else if (flags & DLM_CB_CAST) {
 		if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
-			if (lkb->lkb_last_cast)
-				prev_mode = lkb->lkb_last_cb->mode;
-			else
-				prev_mode = -1;
+			prev_mode = lkb->lkb_last_cast_cb_mode;
 
 			if (!status && lkb->lkb_lksb->sb_lvbptr &&
 			    dlm_lvb_operations[prev_mode + 1][mode + 1])
 				copy_lvb = 1;
 		}
+
+		lkb->lkb_last_cast_cb_mode = mode;
+		lkb->lkb_last_cast_time = ktime_get();
 	}
 
+	lkb->lkb_last_cb_mode = mode;
+	lkb->lkb_last_cb_flags = flags;
+
 	*cb = dlm_allocate_cb();
 	if (!*cb) {
 		rv = DLM_ENQUEUE_CALLBACK_FAILURE;
@@ -126,17 +114,7 @@ int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
 	(*cb)->sb_flags = (sbflags & 0x000000FF);
 	(*cb)->copy_lvb = copy_lvb;
 	(*cb)->lkb_lksb = lkb->lkb_lksb;
-	kref_init(&(*cb)->ref);
-
-	if (flags & DLM_CB_BAST) {
-		lkb->lkb_last_bast_time = ktime_get();
-		lkb->lkb_last_bast_mode = mode;
-	} else if (flags & DLM_CB_CAST) {
-		dlm_callback_set_last_ptr(&lkb->lkb_last_cast, *cb);
-		lkb->lkb_last_cast_time = ktime_get();
-	}
 
-	dlm_callback_set_last_ptr(&lkb->lkb_last_cb, *cb);
 	rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
 
 out: