---

yaml
---
r: 181786
b: refs/heads/master
c: aed3bb9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1c1c6ebcf5284aee4910f3b906ac90c20e510c82
+refs/heads/master: aed3bb90abaf0b42e8c8747e192f7bb97f445279

trunk/fs/xfs/xfs_ag.h

@@ -196,8 +196,8 @@ typedef struct xfs_perag_busy {
 #define XFS_PAGB_NUM_SLOTS	128
 #endif
 
-typedef struct xfs_perag
-{
+typedef struct xfs_perag {
+	atomic_t	pag_ref;	/* perag reference count */
 	char		pagf_init;	/* this agf's entry is initialized */
 	char		pagi_init;	/* this agi's entry is initialized */
 	char		pagf_metadata;	/* the agf is preferred to be metadata */

trunk/fs/xfs/xfs_mount.c

@@ -215,6 +215,7 @@ xfs_free_perag(
 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
 		spin_lock(&mp->m_perag_lock);
 		pag = radix_tree_delete(&mp->m_perag_tree, agno);
+		ASSERT(atomic_read(&pag->pag_ref) == 0);
 		spin_unlock(&mp->m_perag_lock);
 		ASSERT(pag);
 		kmem_free(pag->pagb_list);

trunk/fs/xfs/xfs_mount.h

@@ -384,7 +384,7 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
 }
 
 /*
- * perag get/put wrappers for eventual ref counting
+ * perag get/put wrappers for ref counting
  */
 static inline struct xfs_perag *
 xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
@@ -393,14 +393,21 @@ xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
 
 	spin_lock(&mp->m_perag_lock);
 	pag = radix_tree_lookup(&mp->m_perag_tree, agno);
+	if (pag) {
+		ASSERT(atomic_read(&pag->pag_ref) >= 0);
+		/* catch leaks in the positive direction during testing */
+		ASSERT(atomic_read(&pag->pag_ref) < 1000);
+		atomic_inc(&pag->pag_ref);
+	}
 	spin_unlock(&mp->m_perag_lock);
 	return pag;
 }
 
 static inline void
 xfs_perag_put(struct xfs_perag *pag)
 {
-	/* nothing to see here, move along */
+	ASSERT(atomic_read(&pag->pag_ref) > 0);
+	atomic_dec(&pag->pag_ref);
 }
 
 /*