Commit 0fa800fb authored by Dave Chinner's avatar Dave Chinner Committed by Alex Elder
Browse files

xfs: Add trace points for per-ag refcount debugging. 



Uninline xfs_perag_{get,put} so that tracepoints can be inserted
into them to speed debugging of reference count problems.

Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent aed3bb90

fs/xfs/linux-2.6/xfs_trace.h

+27 −0
Original line number Diff line number Diff line
@@ -78,6 +78,33 @@ DECLARE_EVENT_CLASS(xfs_attr_list_class, 
	)

)



#define DEFINE_PERAG_REF_EVENT(name) \

TRACE_EVENT(name, \

	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, int refcount, \

		 unsigned long caller_ip), \

	TP_ARGS(mp, agno, refcount, caller_ip), \

	TP_STRUCT__entry( \

		__field(dev_t, dev) \

		__field(xfs_agnumber_t, agno) \

		__field(int, refcount) \

		__field(unsigned long, caller_ip) \

	), \

	TP_fast_assign( \

		__entry->dev = mp->m_super->s_dev; \

		__entry->agno = agno; \

		__entry->refcount = refcount; \

		__entry->caller_ip = caller_ip; \

	), \

	TP_printk("dev %d:%d agno %u refcount %d caller %pf", \

		  MAJOR(__entry->dev), MINOR(__entry->dev), \

		  __entry->agno, \

		  __entry->refcount, \

		  (char *)__entry->caller_ip) \

);



DEFINE_PERAG_REF_EVENT(xfs_perag_get)

DEFINE_PERAG_REF_EVENT(xfs_perag_put)



#define DEFINE_ATTR_LIST_EVENT(name) \

DEFINE_EVENT(xfs_attr_list_class, name, \

	TP_PROTO(struct xfs_attr_list_context *ctx), \

fs/xfs/xfs_ag.h

+2 −0
Original line number Diff line number Diff line
@@ -197,6 +197,8 @@ typedef struct xfs_perag_busy { 
#endif



typedef struct xfs_perag {

	struct xfs_mount *pag_mount;	/* owner filesystem */

	xfs_agnumber_t	pag_agno;	/* AG this structure belongs to */

	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 */

fs/xfs/xfs_mount.c

+34 −0
Original line number Diff line number Diff line
@@ -200,6 +200,38 @@ xfs_uuid_unmount( 
}





/*

 * Reference counting access wrappers to the perag structures.

 */

struct xfs_perag *

xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)

{

	struct xfs_perag	*pag;

	int			ref = 0;



	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);

		ref = atomic_inc_return(&pag->pag_ref);

	}

	spin_unlock(&mp->m_perag_lock);

	trace_xfs_perag_get(mp, agno, ref, _RET_IP_);

	return pag;

}



void

xfs_perag_put(struct xfs_perag *pag)

{

	int	ref;



	ASSERT(atomic_read(&pag->pag_ref) > 0);

	ref = atomic_dec_return(&pag->pag_ref);

	trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);

}



/*

 * Free up the resources associated with a mount structure.  Assume that

 * the structure was initially zeroed, so we can tell which fields got
@@ -433,6 +465,8 @@ xfs_initialize_perag( 
			kmem_free(pag);

			return -EEXIST;

		}

		pag->pag_agno = index;

		pag->pag_mount = mp;

		spin_unlock(&mp->m_perag_lock);

		radix_tree_preload_end();

	}

fs/xfs/xfs_mount.h

+2 −23
Original line number Diff line number Diff line
@@ -386,29 +386,8 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d) 
/*

 * perag get/put wrappers for ref counting

 */

static inline struct xfs_perag *

xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)

{

	struct xfs_perag	*pag;



	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)

{

	ASSERT(atomic_read(&pag->pag_ref) > 0);

	atomic_dec(&pag->pag_ref);

}

struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);

void	xfs_perag_put(struct xfs_perag *pag);



/*

 * Per-cpu superblock locking functions