From: Josef Bacik <josef@toxicpanda.com>
Date: Wed, 14 Jul 2021 14:47:18 -0400
Subject: btrfs: include delalloc related info in dump space info tracepoint
Git-commit: 8197766d806f02d69d2f54563e0b4672bddcc535
Patch-mainline: v5.15-rc1
References: bsc#1202528

In order to debug delalloc flushing issues I added delalloc_bytes and
ordered_bytes to this tracepoint to see if they were non-zero when we
were going ENOSPC. This was valuable for me and showed me cases where we
weren't waiting on ordered extents properly. In order to add this to the
tracepoint we need to take away the const modifier for fs_info, as
percpu_sum_counter_positive() will change the counter when it adds up
the percpu buckets.  This is needed to make sure we're getting accurate
information at these tracepoints, as the wrong information could send us
down the wrong path when debugging problems.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 include/trace/events/btrfs.h |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -536,7 +536,7 @@ DEFINE_EVENT(btrfs__writepage, __extent_
 
 
 DECLARE_EVENT_CLASS(btrfs_dump_space_info,
-	TP_PROTO(const struct btrfs_fs_info *fs_info,
+	TP_PROTO(struct btrfs_fs_info *fs_info,
 		 const struct btrfs_space_info *sinfo),
 
 	TP_ARGS(fs_info, sinfo),
@@ -556,6 +556,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_inf
 		__field(	u64,	delayed_refs_reserved	)
 		__field(	u64,	delayed_reserved	)
 		__field(	u64,	free_chunk_space	)
+		__field(	u64,	delalloc_bytes		)
+		__field(	u64,	ordered_bytes		)
 	),
 
 	TP_fast_assign_btrfs(fs_info,
@@ -573,6 +575,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_inf
 		__entry->delayed_refs_reserved	=	fs_info->delayed_refs_rsv.reserved;
 		__entry->delayed_reserved	=	fs_info->delayed_block_rsv.reserved;
 		__entry->free_chunk_space	=	atomic64_read(&fs_info->free_chunk_space);
+		__entry->delalloc_bytes		=	percpu_counter_sum_positive(&fs_info->delalloc_bytes);
+		__entry->ordered_bytes		=	percpu_counter_sum_positive(&fs_info->ordered_bytes);
 	),
 
 	TP_printk_btrfs("flags=%s total_bytes=%llu bytes_used=%llu "
@@ -580,7 +584,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_inf
 			"bytes_may_use=%llu bytes_readonly=%llu "
 			"reclaim_size=%llu clamp=%d global_reserved=%llu "
 			"trans_reserved=%llu delayed_refs_reserved=%llu "
-			"delayed_reserved=%llu chunk_free_space=%llu",
+			"delayed_reserved=%llu chunk_free_space=%llu "
+			"delalloc_bytes=%llu ordered_bytes=%llu",
 			__print_flags(__entry->flags, "|", BTRFS_GROUP_FLAGS),
 			__entry->total_bytes, __entry->bytes_used,
 			__entry->bytes_pinned, __entry->bytes_reserved,
@@ -588,11 +593,12 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_inf
 			__entry->reclaim_size, __entry->clamp,
 			__entry->global_reserved, __entry->trans_reserved,
 			__entry->delayed_refs_reserved,
-			__entry->delayed_reserved, __entry->free_chunk_space)
+			__entry->delayed_reserved, __entry->free_chunk_space,
+			__entry->delalloc_bytes, __entry->ordered_bytes)
 );
 
 DEFINE_EVENT(btrfs_dump_space_info, btrfs_done_preemptive_reclaim,
-	TP_PROTO(const struct btrfs_fs_info *fs_info,
+	TP_PROTO(struct btrfs_fs_info *fs_info,
 		 const struct btrfs_space_info *sinfo),
 	TP_ARGS(fs_info, sinfo)
 );