Add a line for capacity

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Limit these messages to once every 2 minutes to avoid spamming logs;
with multiple devices the output can be quite significant.

Also, up the default timeout to 30 seconds from 10 seconds.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

chasing down a device removal deadlock with erasure coding

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

When we're called via
trans commit -> btree split -> allocator

We may have already arbitrarily many btree_paths, for the transaction
commit we're trying to do; when this happens, the
btree_trans_too_many_iters() call causes us to livelock.

Since the allocator calls btree_iter_dontneed to release paths as it
iterates, this shouldn't cause any problems.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Rewrite fsck/gc for the new accounting scheme.

This adds a second set of in-memory accounting counters for gc to use;
like with other parts of gc we run all trigger in TRIGGER_GC mode, then
compare what we calculated to existing in-memory accounting at the end.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Add a pretty printer so the btree reserve cache can be seen in sysfs; as
it pins open_buckets we need it for tracking down open_buckets issues.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fixes warnings from bch2_print_allocator_stuck()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

There's no reason for discards to be single threaded across all devices;
this will improve performance on multi device setups.

Additionally, making them per-device simplifies the refcounting on
bch_dev->io_ref; we now hold it for the duration that the discard path
is running, which fixes a race between the discard path and device
removal.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

We now have a small bitmap in the member info section of the superblock
for "regions that have btree nodes", so that if we ever have to scan for
btree nodes in repair we don't have to scan the whole device(s).

This tweaks the allocator to prefer allocating from regions that are
already marked in this bitmap.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>