dlm: change to single hashtable lock

Prepare to replace our own hash table with rhashtable by replacing
the per-bucket locks in our own hash table with a single lock.

Signed-off-by: Alexander Aring <[email protected]>
Signed-off-by: David Teigland <[email protected]>

Author: Alexander Aring

fs/dlm/debug_fs.c

@@ -452,20 +452,20 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
 
 	tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
-	spin_lock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock_bh(&ls->ls_rsbtbl_lock);
 	if (!RB_EMPTY_ROOT(tree)) {
 		for (node = rb_first(tree); node; node = rb_next(node)) {
 			r = rb_entry(node, struct dlm_rsb, res_hashnode);
 			if (!entry--) {
 				dlm_hold_rsb(r);
 				ri->rsb = r;
 				ri->bucket = bucket;
-				spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+				spin_unlock_bh(&ls->ls_rsbtbl_lock);
 				return ri;
 			}
 		}
 	}
-	spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock_bh(&ls->ls_rsbtbl_lock);
 
 	/*
 	 * move to the first rsb in the next non-empty bucket
@@ -484,18 +484,18 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
 		}
 		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
-		spin_lock_bh(&ls->ls_rsbtbl[bucket].lock);
+		spin_lock_bh(&ls->ls_rsbtbl_lock);
 		if (!RB_EMPTY_ROOT(tree)) {
 			node = rb_first(tree);
 			r = rb_entry(node, struct dlm_rsb, res_hashnode);
 			dlm_hold_rsb(r);
 			ri->rsb = r;
 			ri->bucket = bucket;
-			spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+			spin_unlock_bh(&ls->ls_rsbtbl_lock);
 			*pos = n;
 			return ri;
 		}
-		spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+		spin_unlock_bh(&ls->ls_rsbtbl_lock);
 	}
 }
 
@@ -516,20 +516,20 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
 	 * move to the next rsb in the same bucket
 	 */
 
-	spin_lock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock_bh(&ls->ls_rsbtbl_lock);
 	rp = ri->rsb;
 	next = rb_next(&rp->res_hashnode);
 
 	if (next) {
 		r = rb_entry(next, struct dlm_rsb, res_hashnode);
 		dlm_hold_rsb(r);
 		ri->rsb = r;
-		spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+		spin_unlock_bh(&ls->ls_rsbtbl_lock);
 		dlm_put_rsb(rp);
 		++*pos;
 		return ri;
 	}
-	spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock_bh(&ls->ls_rsbtbl_lock);
 	dlm_put_rsb(rp);
 
 	/*
@@ -550,18 +550,18 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
 		}
 		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
-		spin_lock_bh(&ls->ls_rsbtbl[bucket].lock);
+		spin_lock_bh(&ls->ls_rsbtbl_lock);
 		if (!RB_EMPTY_ROOT(tree)) {
 			next = rb_first(tree);
 			r = rb_entry(next, struct dlm_rsb, res_hashnode);
 			dlm_hold_rsb(r);
 			ri->rsb = r;
 			ri->bucket = bucket;
-			spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+			spin_unlock_bh(&ls->ls_rsbtbl_lock);
 			*pos = n;
 			return ri;
 		}
-		spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+		spin_unlock_bh(&ls->ls_rsbtbl_lock);
 	}
 }
 

fs/dlm/dir.c

@@ -204,12 +204,12 @@ static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, const char *name,
 	hash = jhash(name, len, 0);
 	bucket = hash & (ls->ls_rsbtbl_size - 1);
 
-	spin_lock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock_bh(&ls->ls_rsbtbl_lock);
 	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, &r);
 	if (rv)
 		rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].toss,
 					 name, len, &r);
-	spin_unlock_bh(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock_bh(&ls->ls_rsbtbl_lock);
 
 	if (!rv)
 		return r;

fs/dlm/dlm_internal.h

@@ -105,7 +105,6 @@ do { \
 struct dlm_rsbtable {
 	struct rb_root		keep;
 	struct rb_root		toss;
-	spinlock_t		lock;
 	unsigned long		flags;
 };
 
@@ -593,6 +592,7 @@ struct dlm_ls {
 	spinlock_t		ls_lkbidr_spin;
 
 	struct dlm_rsbtable	*ls_rsbtbl;
+	spinlock_t		ls_rsbtbl_lock;
 	uint32_t		ls_rsbtbl_size;
 
 	spinlock_t		ls_waiters_lock;