1 files changed, 77 insertions, 137 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index decedc4ee1..59711486d8 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -18,31 +18,32 @@
 #include "user.h"
 #include "ast.h"
 
-void dlm_release_callback(struct kref *ref)
+static void dlm_callback_work(struct work_struct *work)
 {
-	struct dlm_callback *cb = container_of(ref, struct dlm_callback, ref);
+	struct dlm_callback *cb = container_of(work, struct dlm_callback, work);
+
+	if (cb->flags & DLM_CB_BAST) {
+		trace_dlm_bast(cb->ls_id, cb->lkb_id, cb->mode, cb->res_name,
+			       cb->res_length);
+		cb->bastfn(cb->astparam, cb->mode);
+	} else if (cb->flags & DLM_CB_CAST) {
+		trace_dlm_ast(cb->ls_id, cb->lkb_id, cb->sb_status,
+			      cb->sb_flags, cb->res_name, cb->res_length);
+		cb->lkb_lksb->sb_status = cb->sb_status;
+		cb->lkb_lksb->sb_flags = cb->sb_flags;
+		cb->astfn(cb->astparam);
+	}
 
 	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;
-}
-
-int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
-			     int status, uint32_t sbflags)
+int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
+			   int status, uint32_t sbflags,
+			   struct dlm_callback **cb)
 {
-	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+	struct dlm_rsb *rsb = lkb->lkb_resource;
 	int rv = DLM_ENQUEUE_CALLBACK_SUCCESS;
-	struct dlm_callback *cb;
+	struct dlm_ls *ls = rsb->res_ls;
 	int copy_lvb = 0;
 	int prev_mode;
 
@@ -50,11 +51,11 @@ int dlm_enqueue_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;
 			}
 		}
@@ -65,8 +66,9 @@ int dlm_enqueue_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)) {
@@ -75,65 +77,55 @@ int dlm_enqueue_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();
 	}
 
-	cb = dlm_allocate_cb();
-	if (!cb) {
+	lkb->lkb_last_cb_mode = mode;
+	lkb->lkb_last_cb_flags = flags;
+
+	*cb = dlm_allocate_cb();
+	if (!*cb) {
 		rv = DLM_ENQUEUE_CALLBACK_FAILURE;
 		goto out;
 	}
 
-	cb->flags = flags;
-	cb->mode = mode;
-	cb->sb_status = status;
-	cb->sb_flags = (sbflags & 0x000000FF);
-	cb->copy_lvb = copy_lvb;
-	kref_init(&cb->ref);
-	if (!test_and_set_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags))
-		rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
-
-	list_add_tail(&cb->list, &lkb->lkb_callbacks);
+	/* for tracing */
+	(*cb)->lkb_id = lkb->lkb_id;
+	(*cb)->ls_id = ls->ls_global_id;
+	memcpy((*cb)->res_name, rsb->res_name, rsb->res_length);
+	(*cb)->res_length = rsb->res_length;
 
-	if (flags & DLM_CB_CAST)
-		dlm_callback_set_last_ptr(&lkb->lkb_last_cast, cb);
+	(*cb)->flags = flags;
+	(*cb)->mode = mode;
+	(*cb)->sb_status = status;
+	(*cb)->sb_flags = (sbflags & 0x000000FF);
+	(*cb)->copy_lvb = copy_lvb;
+	(*cb)->lkb_lksb = lkb->lkb_lksb;
 
-	dlm_callback_set_last_ptr(&lkb->lkb_last_cb, cb);
+	rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
 
- out:
+out:
 	return rv;
 }
 
-int dlm_dequeue_lkb_callback(struct dlm_lkb *lkb, struct dlm_callback **cb)
-{
-	/* oldest undelivered cb is callbacks first entry */
-	*cb = list_first_entry_or_null(&lkb->lkb_callbacks,
-				       struct dlm_callback, list);
-	if (!*cb)
-		return DLM_DEQUEUE_CALLBACK_EMPTY;
-
-	/* remove it from callbacks so shift others down */
-	list_del(&(*cb)->list);
-	if (list_empty(&lkb->lkb_callbacks))
-		return DLM_DEQUEUE_CALLBACK_LAST;
-
-	return DLM_DEQUEUE_CALLBACK_SUCCESS;
-}
-
 void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
-		uint32_t sbflags)
+		  uint32_t sbflags)
 {
 	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+	struct dlm_callback *cb;
 	int rv;
 
 	if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
@@ -141,88 +133,36 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
 		return;
 	}
 
-	spin_lock(&lkb->lkb_cb_lock);
-	rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
+	rv = dlm_queue_lkb_callback(lkb, flags, mode, status, sbflags,
+				    &cb);
 	switch (rv) {
 	case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
-		kref_get(&lkb->lkb_ref);
-
-		spin_lock(&ls->ls_cb_lock);
-		if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
-			list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
-		} else {
-			queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
-		}
-		spin_unlock(&ls->ls_cb_lock);
-		break;
-	case DLM_ENQUEUE_CALLBACK_FAILURE:
-		WARN_ON_ONCE(1);
+		cb->astfn = lkb->lkb_astfn;
+		cb->bastfn = lkb->lkb_bastfn;
+		cb->astparam = lkb->lkb_astparam;
+		INIT_WORK(&cb->work, dlm_callback_work);
+
+		spin_lock_bh(&ls->ls_cb_lock);
+		if (test_bit(LSFL_CB_DELAY, &ls->ls_flags))
+			list_add(&cb->list, &ls->ls_cb_delay);
+		else
+			queue_work(ls->ls_callback_wq, &cb->work);
+		spin_unlock_bh(&ls->ls_cb_lock);
 		break;
 	case DLM_ENQUEUE_CALLBACK_SUCCESS:
 		break;
+	case DLM_ENQUEUE_CALLBACK_FAILURE:
+		fallthrough;
 	default:
 		WARN_ON_ONCE(1);
 		break;
 	}
-	spin_unlock(&lkb->lkb_cb_lock);
-}
-
-void dlm_callback_work(struct work_struct *work)
-{
-	struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
-	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
-	void (*castfn) (void *astparam);
-	void (*bastfn) (void *astparam, int mode);
-	struct dlm_callback *cb;
-	int rv;
-
-	spin_lock(&lkb->lkb_cb_lock);
-	rv = dlm_dequeue_lkb_callback(lkb, &cb);
-	if (WARN_ON_ONCE(rv == DLM_DEQUEUE_CALLBACK_EMPTY)) {
-		clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
-		spin_unlock(&lkb->lkb_cb_lock);
-		goto out;
-	}
-	spin_unlock(&lkb->lkb_cb_lock);
-
-	for (;;) {
-		castfn = lkb->lkb_astfn;
-		bastfn = lkb->lkb_bastfn;
-
-		if (cb->flags & DLM_CB_BAST) {
-			trace_dlm_bast(ls, lkb, cb->mode);
-			lkb->lkb_last_bast_time = ktime_get();
-			lkb->lkb_last_bast_mode = cb->mode;
-			bastfn(lkb->lkb_astparam, cb->mode);
-		} else if (cb->flags & DLM_CB_CAST) {
-			lkb->lkb_lksb->sb_status = cb->sb_status;
-			lkb->lkb_lksb->sb_flags = cb->sb_flags;
-			trace_dlm_ast(ls, lkb);
-			lkb->lkb_last_cast_time = ktime_get();
-			castfn(lkb->lkb_astparam);
-		}
-
-		kref_put(&cb->ref, dlm_release_callback);
-
-		spin_lock(&lkb->lkb_cb_lock);
-		rv = dlm_dequeue_lkb_callback(lkb, &cb);
-		if (rv == DLM_DEQUEUE_CALLBACK_EMPTY) {
-			clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
-			spin_unlock(&lkb->lkb_cb_lock);
-			break;
-		}
-		spin_unlock(&lkb->lkb_cb_lock);
-	}
-
-out:
-	/* undo kref_get from dlm_add_callback, may cause lkb to be freed */
-	dlm_put_lkb(lkb);
 }
 
 int dlm_callback_start(struct dlm_ls *ls)
 {
-	ls->ls_callback_wq = alloc_workqueue("dlm_callback",
-					     WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
+	ls->ls_callback_wq = alloc_ordered_workqueue("dlm_callback",
+						     WQ_HIGHPRI | WQ_MEM_RECLAIM);
 	if (!ls->ls_callback_wq) {
 		log_print("can't start dlm_callback workqueue");
 		return -ENOMEM;
@@ -239,9 +179,9 @@ void dlm_callback_stop(struct dlm_ls *ls)
 void dlm_callback_suspend(struct dlm_ls *ls)
 {
 	if (ls->ls_callback_wq) {
-		spin_lock(&ls->ls_cb_lock);
+		spin_lock_bh(&ls->ls_cb_lock);
 		set_bit(LSFL_CB_DELAY, &ls->ls_flags);
-		spin_unlock(&ls->ls_cb_lock);
+		spin_unlock_bh(&ls->ls_cb_lock);
 
 		flush_workqueue(ls->ls_callback_wq);
 	}
@@ -251,7 +191,7 @@ void dlm_callback_suspend(struct dlm_ls *ls)
 
 void dlm_callback_resume(struct dlm_ls *ls)
 {
-	struct dlm_lkb *lkb, *safe;
+	struct dlm_callback *cb, *safe;
 	int count = 0, sum = 0;
 	bool empty;
 
@@ -259,10 +199,10 @@ void dlm_callback_resume(struct dlm_ls *ls)
 		return;
 
 more:
-	spin_lock(&ls->ls_cb_lock);
-	list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
-		list_del_init(&lkb->lkb_cb_list);
-		queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
+	spin_lock_bh(&ls->ls_cb_lock);
+	list_for_each_entry_safe(cb, safe, &ls->ls_cb_delay, list) {
+		list_del(&cb->list);
+		queue_work(ls->ls_callback_wq, &cb->work);
 		count++;
 		if (count == MAX_CB_QUEUE)
 			break;
@@ -270,7 +210,7 @@ more:
 	empty = list_empty(&ls->ls_cb_delay);
 	if (empty)
 		clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
-	spin_unlock(&ls->ls_cb_lock);
+	spin_unlock_bh(&ls->ls_cb_lock);
 
 	sum += count;
 	if (!empty) {