TP_ARGS(c),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16 )
+               __field(dev_t,          dev                     )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev            = c->dev;
        ),
 
-       TP_printk("%pU", __entry->uuid)
+       TP_printk("%d,%d", MAJOR(__entry->dev), MINOR(__entry->dev))
 );
 
 DECLARE_EVENT_CLASS(bio,
                btree_key_cache_dirty, btree_key_cache_total),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16              )
+               __field(dev_t,          dev                     )
                __field(u64,            min_nr                  )
                __field(u64,            prereserved             )
                __field(u64,            prereserved_total       )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev                    = c->dev;
                __entry->min_nr                 = min_nr;
                __entry->prereserved            = prereserved;
                __entry->prereserved_total      = prereserved_total;
                __entry->btree_key_cache_total  = btree_key_cache_total;
        ),
 
-       TP_printk("%pU min %llu prereserved %llu/%llu btree cache %llu/%llu key cache %llu/%llu",
-                 __entry->uuid,
+       TP_printk("%d,%d min %llu prereserved %llu/%llu btree cache %llu/%llu key cache %llu/%llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
                  __entry->min_nr,
                  __entry->prereserved,
                  __entry->prereserved_total,
        TP_ARGS(c, nr_flushed),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16 )
-               __field(u64,            nr_flushed )
+               __field(dev_t,          dev                     )
+               __field(u64,            nr_flushed              )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
-               __entry->nr_flushed = nr_flushed;
+               __entry->dev            = c->dev;
+               __entry->nr_flushed     = nr_flushed;
        ),
 
-       TP_printk("%pU flushed %llu", __entry->uuid, __entry->nr_flushed)
+       TP_printk("%d%d flushed %llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->nr_flushed)
 );
 
 /* bset.c: */
        TP_ARGS(c, b),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,           16      )
+               __field(dev_t,          dev                     )
                __field(u8,             level                   )
                __field(u8,             id                      )
                __field(u64,            inode                   )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev            = c->dev;
                __entry->level          = b->c.level;
                __entry->id             = b->c.btree_id;
                __entry->inode          = b->key.k.p.inode;
                __entry->offset         = b->key.k.p.offset;
        ),
 
-       TP_printk("%pU  %u id %u %llu:%llu",
-                 __entry->uuid, __entry->level, __entry->id,
+       TP_printk("%d,%d  %u id %u %llu:%llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->level, __entry->id,
                  __entry->inode, __entry->offset)
 );
 
        TP_ARGS(c, b)
 );
 
-DECLARE_EVENT_CLASS(btree_node_cannibalize_lock,
-       TP_PROTO(struct bch_fs *c),
-       TP_ARGS(c),
-
-       TP_STRUCT__entry(
-               __array(char,                   uuid,   16      )
-       ),
-
-       TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
-       ),
-
-       TP_printk("%pU", __entry->uuid)
-);
-
-DEFINE_EVENT(btree_node_cannibalize_lock, btree_node_cannibalize_lock_fail,
+DEFINE_EVENT(bch_fs, btree_node_cannibalize_lock_fail,
        TP_PROTO(struct bch_fs *c),
        TP_ARGS(c)
 );
 
-DEFINE_EVENT(btree_node_cannibalize_lock, btree_node_cannibalize_lock,
+DEFINE_EVENT(bch_fs, btree_node_cannibalize_lock,
        TP_PROTO(struct bch_fs *c),
        TP_ARGS(c)
 );
 
-DEFINE_EVENT(btree_node_cannibalize_lock, btree_node_cannibalize,
+DEFINE_EVENT(bch_fs, btree_node_cannibalize,
        TP_PROTO(struct bch_fs *c),
        TP_ARGS(c)
 );
        TP_ARGS(c, required, cl),
 
        TP_STRUCT__entry(
-               __array(char,                   uuid,   16      )
+               __field(dev_t,          dev                     )
                __field(size_t,                 required        )
                __field(struct closure *,       cl              )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev            = c->dev;
                __entry->required = required;
                __entry->cl = cl;
        ),
 
-       TP_printk("%pU required %zu by %p", __entry->uuid,
+       TP_printk("%d,%d required %zu by %p",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
                  __entry->required, __entry->cl)
 );
 
        TP_ARGS(c, sectors_moved, keys_moved),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16      )
+               __field(dev_t,          dev                     )
                __field(u64,            sectors_moved   )
                __field(u64,            keys_moved      )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev                    = c->dev;
                __entry->sectors_moved = sectors_moved;
                __entry->keys_moved = keys_moved;
        ),
 
-       TP_printk("%pU sectors_moved %llu keys_moved %llu",
-               __entry->uuid, __entry->sectors_moved, __entry->keys_moved)
+       TP_printk("%d,%d sectors_moved %llu keys_moved %llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->sectors_moved, __entry->keys_moved)
 );
 
 TRACE_EVENT(copygc,
                buckets_moved, buckets_not_moved),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16              )
+               __field(dev_t,          dev                     )
                __field(u64,            sectors_moved           )
                __field(u64,            sectors_not_moved       )
                __field(u64,            buckets_moved           )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev                    = c->dev;
                __entry->sectors_moved          = sectors_moved;
                __entry->sectors_not_moved      = sectors_not_moved;
                __entry->buckets_moved          = buckets_moved;
                __entry->buckets_not_moved = buckets_moved;
        ),
 
-       TP_printk("%pU sectors moved %llu remain %llu buckets moved %llu remain %llu",
-               __entry->uuid,
-               __entry->sectors_moved, __entry->sectors_not_moved,
-               __entry->buckets_moved, __entry->buckets_not_moved)
+       TP_printk("%d,%d sectors moved %llu remain %llu buckets moved %llu remain %llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->sectors_moved, __entry->sectors_not_moved,
+                 __entry->buckets_moved, __entry->buckets_not_moved)
 );
 
 TRACE_EVENT(copygc_wait,
        TP_ARGS(c, wait_amount, until),
 
        TP_STRUCT__entry(
-               __array(char,           uuid,   16              )
+               __field(dev_t,          dev                     )
                __field(u64,            wait_amount             )
                __field(u64,            until                   )
        ),
 
        TP_fast_assign(
-               memcpy(__entry->uuid, c->sb.user_uuid.b, 16);
+               __entry->dev            = c->dev;
                __entry->wait_amount    = wait_amount;
                __entry->until          = until;
        ),
 
-       TP_printk("%pU waiting for %llu sectors until %llu",
-               __entry->uuid, __entry->wait_amount, __entry->until)
+       TP_printk("%d,%u waiting for %llu sectors until %llu",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->wait_amount, __entry->until)
 );
 
 TRACE_EVENT(trans_get_iter,