xfs: add tracepoints for high level iunlink operations

Add tracepoints so we can associate high level operations with low level
updates.  No functional changes.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_inode.c

@@ -2047,6 +2047,7 @@ xfs_iunlink(
 	int			error;
 
 	ASSERT(VFS_I(ip)->i_mode != 0);
+	trace_xfs_iunlink(ip);
 
 	/* Get the agi buffer first.  It ensures lock ordering on the list. */
 	error = xfs_read_agi(mp, tp, agno, &agibp);
@@ -2193,6 +2194,8 @@ xfs_iunlink_remove(
 	short			bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
 	int			error;
 
+	trace_xfs_iunlink_remove(ip);
+
 	/* Get the agi buffer first.  It ensures lock ordering on the list. */
 	error = xfs_read_agi(mp, tp, agno, &agibp);
 	if (error)

fs/xfs/xfs_trace.h

@@ -3423,6 +3423,31 @@ TRACE_EVENT(xfs_iunlink_update_dinode,
 		  __entry->new_ptr)
 );
 
+DECLARE_EVENT_CLASS(xfs_ag_inode_class,
+	TP_PROTO(struct xfs_inode *ip),
+	TP_ARGS(ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agino_t, agino)
+	),
+	TP_fast_assign(
+		__entry->dev = VFS_I(ip)->i_sb->s_dev;
+		__entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+		__entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+	),
+	TP_printk("dev %d:%d agno %u agino %u",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->agno, __entry->agino)
+)
+
+#define DEFINE_AGINODE_EVENT(name) \
+DEFINE_EVENT(xfs_ag_inode_class, name, \
+	TP_PROTO(struct xfs_inode *ip), \
+	TP_ARGS(ip))
+DEFINE_AGINODE_EVENT(xfs_iunlink);
+DEFINE_AGINODE_EVENT(xfs_iunlink_remove);
+
 #endif /* _TRACE_XFS_H */
 
 #undef TRACE_INCLUDE_PATH