[PATCH 09/43] xfs: trace in-memory freecounters

[Christoph Hellwig <hch@xxxxxx>]

Add two tracepoints when the freecounter dips into the reserved pool
and when it is entirely out of space.

This requires moving enum xfs_free_counter to xfs_types.h to avoid
build failures in various sources files include xfs_trace.h, but
that's probably the right place for it anyway.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/xfs/libxfs/xfs_types.h | 17 +++++++++++++++++
 fs/xfs/xfs_mount.c        |  2 ++
 fs/xfs/xfs_mount.h        | 13 -------------
 fs/xfs/xfs_trace.h        | 36 ++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index ca2401c1facd..76f3c31573ec 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -233,6 +233,23 @@ enum xfs_group_type {
 	{ XG_TYPE_AG,	"ag" }, \
 	{ XG_TYPE_RTG,	"rtg" }
 
+enum xfs_free_counter {
+	/*
+	 * Number of free blocks on the data device.
+	 */
+	XC_FREE_BLOCKS,
+
+	/*
+	 * Number of free RT extents on the RT device.
+	 */
+	XC_FREE_RTEXTENTS,
+	XC_FREE_NR,
+};
+
+#define XFS_FREECOUNTER_STR \
+	{ XC_FREE_BLOCKS,		"blocks" }, \
+	{ XC_FREE_RTEXTENTS,		"rtextents" }
+
 /*
  * Type verifier functions
  */
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 65123f4ffc2a..1cce5ad0e7a4 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1347,6 +1347,7 @@ xfs_dec_freecounter(
 		}
 
 		mp->m_resblks[ctr].avail = lcounter;
+		trace_xfs_freecounter_reserved(mp, ctr, delta, _RET_IP_);
 		spin_unlock(&mp->m_sb_lock);
 	}
 
@@ -1354,6 +1355,7 @@ xfs_dec_freecounter(
 	return 0;
 
 fdblocks_enospc:
+	trace_xfs_freecounter_enospc(mp, ctr, delta, _RET_IP_);
 	spin_unlock(&mp->m_sb_lock);
 	return -ENOSPC;
 }
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 2d0e34e517b1..d4a57e2fdcc5 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -105,19 +105,6 @@ struct xfs_groups {
 	uint64_t		blkmask;
 };
 
-enum xfs_free_counter {
-	/*
-	 * Number of free blocks on the data device.
-	 */
-	XC_FREE_BLOCKS,
-
-	/*
-	 * Number of free RT extents on the RT device.
-	 */
-	XC_FREE_RTEXTENTS,
-	XC_FREE_NR,
-};
-
 /*
  * The struct xfsmount layout is optimised to separate read-mostly variables
  * from variables that are frequently modified. We put the read-mostly variables
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 7fdcb519cf2f..740e0a8c3eca 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -5668,6 +5668,42 @@ TRACE_EVENT(xfs_growfs_check_rtgeom,
 );
 #endif /* CONFIG_XFS_RT */
 
+TRACE_DEFINE_ENUM(XC_FREE_BLOCKS);
+TRACE_DEFINE_ENUM(XC_FREE_RTEXTENTS);
+
+DECLARE_EVENT_CLASS(xfs_freeblocks_class,
+	TP_PROTO(struct xfs_mount *mp, enum xfs_free_counter ctr,
+		 uint64_t delta, unsigned long caller_ip),
+	TP_ARGS(mp, ctr, delta, caller_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(enum xfs_free_counter, ctr)
+		__field(uint64_t, delta)
+		__field(uint64_t, avail)
+		__field(unsigned long, caller_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = mp->m_super->s_dev;
+		__entry->ctr = ctr;
+		__entry->delta = delta;
+		__entry->avail = mp->m_resblks[ctr].avail;
+		__entry->caller_ip = caller_ip;
+	),
+	TP_printk("dev %d:%d ctr %s delta %llu avail %llu caller %pS",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __print_symbolic(__entry->ctr, XFS_FREECOUNTER_STR),
+		  __entry->delta,
+		  __entry->avail,
+		  (char *)__entry->caller_ip)
+)
+#define DEFINE_FREEBLOCKS_RESV_EVENT(name) \
+DEFINE_EVENT(xfs_freeblocks_class, name, \
+	TP_PROTO(struct xfs_mount *mp, enum xfs_free_counter ctr, \
+		 uint64_t delta, unsigned long caller_ip), \
+	TP_ARGS(mp, ctr, delta, caller_ip))
+DEFINE_FREEBLOCKS_RESV_EVENT(xfs_freecounter_reserved);
+DEFINE_FREEBLOCKS_RESV_EVENT(xfs_freecounter_enospc);
+
 #endif /* _TRACE_XFS_H */
 
 #undef TRACE_INCLUDE_PATH
-- 
2.45.2