Commit 393da918 authored by Liu Bo's avatar Liu Bo Committed by David Sterba

Btrfs: add tracepoint for em's EEXIST case

This is adding a tracepoint 'btrfs_handle_em_exist' to help debug the
subtle bugs around merge_extent_mapping.
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5d23515b
......@@ -551,6 +551,9 @@ int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
ret = 0;
existing = search_extent_mapping(em_tree, start, len);
trace_btrfs_handle_em_exist(existing, em, start, len);
/*
* existing will always be non-NULL, since there must be
* extent causing the -EEXIST.
......
......@@ -248,6 +248,41 @@ TRACE_EVENT_CONDITION(btrfs_get_extent,
__entry->refs, __entry->compress_type)
);
TRACE_EVENT(btrfs_handle_em_exist,
TP_PROTO(const struct extent_map *existing, const struct extent_map *map, u64 start, u64 len),
TP_ARGS(existing, map, start, len),
TP_STRUCT__entry(
__field( u64, e_start )
__field( u64, e_len )
__field( u64, map_start )
__field( u64, map_len )
__field( u64, start )
__field( u64, len )
),
TP_fast_assign(
__entry->e_start = existing->start;
__entry->e_len = existing->len;
__entry->map_start = map->start;
__entry->map_len = map->len;
__entry->start = start;
__entry->len = len;
),
TP_printk("start=%llu len=%llu "
"existing(start=%llu len=%llu) "
"em(start=%llu len=%llu)",
(unsigned long long)__entry->start,
(unsigned long long)__entry->len,
(unsigned long long)__entry->e_start,
(unsigned long long)__entry->e_len,
(unsigned long long)__entry->map_start,
(unsigned long long)__entry->map_len)
);
/* file extent item */
DECLARE_EVENT_CLASS(btrfs__file_extent_item_regular,
......
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