1 files changed, 144 insertions, 140 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 1f2f70a1b824..0fe8d80ce5e8 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -12,48 +12,68 @@
 #include <trace/events/dlm.h>
 
 #include "dlm_internal.h"
+#include "lvb_table.h"
 #include "memory.h"
 #include "lock.h"
 #include "user.h"
 #include "ast.h"
 
-void dlm_release_callback(struct kref *ref)
+static void dlm_run_callback(uint32_t ls_id, uint32_t lkb_id, int8_t mode,
+			     uint32_t flags, uint8_t sb_flags, int sb_status,
+			     struct dlm_lksb *lksb,
+			     void (*astfn)(void *astparam),
+			     void (*bastfn)(void *astparam, int mode),
+			     void *astparam, const char *res_name,
+			     size_t res_length)
 {
-	struct dlm_callback *cb = container_of(ref, struct dlm_callback, ref);
+	if (flags & DLM_CB_BAST) {
+		trace_dlm_bast(ls_id, lkb_id, mode, res_name, res_length);
+		bastfn(astparam, mode);
+	} else if (flags & DLM_CB_CAST) {
+		trace_dlm_ast(ls_id, lkb_id, sb_flags, sb_status, res_name,
+			      res_length);
+		lksb->sb_status = sb_status;
+		lksb->sb_flags = sb_flags;
+		astfn(astparam);
+	}
+}
 
+static void dlm_do_callback(struct dlm_callback *cb)
+{
+	dlm_run_callback(cb->ls_id, cb->lkb_id, cb->mode, cb->flags,
+			 cb->sb_flags, cb->sb_status, cb->lkb_lksb,
+			 cb->astfn, cb->bastfn, cb->astparam,
+			 cb->res_name, cb->res_length);
 	dlm_free_cb(cb);
 }
 
-void dlm_callback_set_last_ptr(struct dlm_callback **from,
-			       struct dlm_callback *to)
+static void dlm_callback_work(struct work_struct *work)
 {
-	if (*from)
-		kref_put(&(*from)->ref, dlm_release_callback);
-
-	if (to)
-		kref_get(&to->ref);
+	struct dlm_callback *cb = container_of(work, struct dlm_callback, work);
 
-	*from = to;
+	dlm_do_callback(cb);
 }
 
-int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
-			     int status, uint32_t sbflags)
+bool dlm_may_skip_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
+			   int status, uint32_t sbflags, int *copy_lvb)
 {
-	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
-	int rv = DLM_ENQUEUE_CALLBACK_SUCCESS;
-	struct dlm_callback *cb;
+	struct dlm_rsb *rsb = lkb->lkb_resource;
+	struct dlm_ls *ls = rsb->res_ls;
 	int prev_mode;
 
+	if (copy_lvb)
+		*copy_lvb = 0;
+
 	if (flags & DLM_CB_BAST) {
 		/* 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);
-				goto out;
+					  lkb->lkb_last_cast_cb_mode);
+				return true;
 			}
 		}
 
@@ -63,152 +83,130 @@ 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)) {
 				log_debug(ls, "skip %x add bast mode %d for bast mode %d",
 					  lkb->lkb_id, mode, prev_mode);
-				goto out;
+				return true;
 			}
 		}
-	}
-
-	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);
-	kref_init(&cb->ref);
-	if (!test_and_set_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags))
-		rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
+		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)) {
+			prev_mode = lkb->lkb_last_cast_cb_mode;
 
-	list_add_tail(&cb->list, &lkb->lkb_callbacks);
+			if (!status && lkb->lkb_lksb->sb_lvbptr &&
+			    dlm_lvb_operations[prev_mode + 1][mode + 1]) {
+				if (copy_lvb)
+					*copy_lvb = 1;
+			}
+		}
 
-	if (flags & DLM_CB_CAST)
-		dlm_callback_set_last_ptr(&lkb->lkb_last_cast, cb);
+		lkb->lkb_last_cast_cb_mode = mode;
+		lkb->lkb_last_cast_time = ktime_get();
+	}
 
-	dlm_callback_set_last_ptr(&lkb->lkb_last_cb, cb);
+	lkb->lkb_last_cb_mode = mode;
+	lkb->lkb_last_cb_flags = flags;
 
- out:
-	return rv;
+	return false;
 }
 
-int dlm_dequeue_lkb_callback(struct dlm_lkb *lkb, struct dlm_callback **cb)
+int dlm_get_cb(struct dlm_lkb *lkb, uint32_t flags, int mode,
+	       int status, uint32_t sbflags,
+	       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;
+	struct dlm_rsb *rsb = lkb->lkb_resource;
+	struct dlm_ls *ls = rsb->res_ls;
+
+	*cb = dlm_allocate_cb();
+	if (WARN_ON_ONCE(!*cb))
+		return -ENOMEM;
+
+	/* 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;
+
+	(*cb)->flags = flags;
+	(*cb)->mode = mode;
+	(*cb)->sb_status = status;
+	(*cb)->sb_flags = (sbflags & 0x000000FF);
+	(*cb)->lkb_lksb = lkb->lkb_lksb;
+
+	return 0;
 }
 
-void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
-		uint32_t sbflags)
+static int dlm_get_queue_cb(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;
 	int rv;
 
-	if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
-		dlm_user_add_ast(lkb, flags, mode, status, sbflags);
-		return;
-	}
+	rv = dlm_get_cb(lkb, flags, mode, status, sbflags, cb);
+	if (rv)
+		return rv;
 
-	spin_lock(&lkb->lkb_cb_lock);
-	rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
-	switch (rv) {
-	case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
-		kref_get(&lkb->lkb_ref);
+	(*cb)->astfn = lkb->lkb_astfn;
+	(*cb)->bastfn = lkb->lkb_bastfn;
+	(*cb)->astparam = lkb->lkb_astparam;
+	INIT_WORK(&(*cb)->work, dlm_callback_work);
 
-		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);
-		break;
-	case DLM_ENQUEUE_CALLBACK_SUCCESS:
-		break;
-	default:
-		WARN_ON_ONCE(1);
-		break;
-	}
-	spin_unlock(&lkb->lkb_cb_lock);
+	return 0;
 }
 
-void dlm_callback_work(struct work_struct *work)
+void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
+		uint32_t sbflags)
 {
-	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_rsb *rsb = lkb->lkb_resource;
+	struct dlm_ls *ls = rsb->res_ls;
 	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;
+	if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
+		dlm_user_add_ast(lkb, flags, mode, status, sbflags);
+		return;
 	}
-	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);
+	if (dlm_may_skip_callback(lkb, flags, mode, status, sbflags, NULL))
+		return;
 
-		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_lock_bh(&ls->ls_cb_lock);
+	if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
+		rv = dlm_get_queue_cb(lkb, flags, mode, status, sbflags, &cb);
+		if (!rv)
+			list_add(&cb->list, &ls->ls_cb_delay);
+	} else {
+		if (test_bit(LSFL_SOFTIRQ, &ls->ls_flags)) {
+			dlm_run_callback(ls->ls_global_id, lkb->lkb_id, mode, flags,
+					 sbflags, status, lkb->lkb_lksb,
+					 lkb->lkb_astfn, lkb->lkb_bastfn,
+					 lkb->lkb_astparam, rsb->res_name,
+					 rsb->res_length);
+		} else {
+			rv = dlm_get_queue_cb(lkb, flags, mode, status, sbflags, &cb);
+			if (!rv)
+				queue_work(ls->ls_callback_wq, &cb->work);
 		}
-		spin_unlock(&lkb->lkb_cb_lock);
 	}
-
-out:
-	/* undo kref_get from dlm_add_callback, may cause lkb to be freed */
-	dlm_put_lkb(lkb);
+	spin_unlock_bh(&ls->ls_cb_lock);
 }
 
 int dlm_callback_start(struct dlm_ls *ls)
 {
-	ls->ls_callback_wq = alloc_workqueue("dlm_callback",
-					     WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
+	if (!test_bit(LSFL_FS, &ls->ls_flags) ||
+	    test_bit(LSFL_SOFTIRQ, &ls->ls_flags))
+		return 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;
@@ -224,31 +222,37 @@ 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);
-		set_bit(LSFL_CB_DELAY, &ls->ls_flags);
-		spin_unlock(&ls->ls_cb_lock);
+	if (!test_bit(LSFL_FS, &ls->ls_flags))
+		return;
+
+	spin_lock_bh(&ls->ls_cb_lock);
+	set_bit(LSFL_CB_DELAY, &ls->ls_flags);
+	spin_unlock_bh(&ls->ls_cb_lock);
 
+	if (ls->ls_callback_wq)
 		flush_workqueue(ls->ls_callback_wq);
-	}
 }
 
 #define MAX_CB_QUEUE 25
 
 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;
 
-	if (!ls->ls_callback_wq)
+	if (!test_bit(LSFL_FS, &ls->ls_flags))
 		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);
+		if (test_bit(LSFL_SOFTIRQ, &ls->ls_flags))
+			dlm_do_callback(cb);
+		else
+			queue_work(ls->ls_callback_wq, &cb->work);
+
 		count++;
 		if (count == MAX_CB_QUEUE)
 			break;
@@ -256,7 +260,7 @@ 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) {