Add async objs list for
- promote_op
- bch_read_bio
- btree_read_bio
- btree_write_bio
This gets us introspection on in-flight async ops, and because under the
hood it uses fast_lists (percpu slot buffer on top of a radix tree),
it'll be fast enough to enable in production.
This will be very helpful for debugging "something got stuck" issues,
which have been cropping up from time to time (in the CI, especially
with folio writeback).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Debugging infrastructure for async objs: this lets us easily create
fast_lists for various object types so they'll be visible in debugfs.
Add new object types to the BCH_ASYNC_OBJS_TYPES() enum, and drop a
pretty-printer wrapper in async_objs.c.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
