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

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

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
This commit is contained in:
Dave Chinner 2010-01-11 11:47:46 +00:00 committed by Alex Elder
parent aed3bb90ab
commit 0fa800fbd5
4 changed files with 65 additions and 23 deletions
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27
fs/xfs/linux-2.6/xfs_trace.h
View File

@ -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), \

2
fs/xfs/xfs_ag.h
View File

@ -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 */

34
fs/xfs/xfs_mount.c
View File

@ -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();
}

25
fs/xfs/xfs_mount.h
View File

@ -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