This adds a new watermark, higher priority than BCH_WATERMARK_reclaim,
for interior btree updates. We've seen a deadlock where journal replay
triggers a ton of btree node merges, and these use up all available open
buckets and then interior updates get stuck.
One cause of this is that we're currently lacking btree node merging on
write buffer btrees - that needs to be fixed as well.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The disk space accounting rewrite is splitting out accounting for each
replicas set - those are moving to btree keys, instead of percpu
counters.
This breaks bch2_trans_fs_usage_apply() up, splitting out the part we
will still need.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Prep work for disk space accounting rewrite: we're going to want to use
a single callback for both of our current triggers, so we need to change
them to have the same type signature first.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Prep work for disk space accounting rewrite: we're going to want to use
a single callback for both of our current triggers, so we need to change
them to have the same type signature first.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_update_cached_sectors_list() is closer to how the new disk space
accounting works, called from trans_mark().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Upcoming rebalance_work btree will require extent triggers to be
BTREE_TRIGGER_WANTS_OLD_AND_NEW - so to reduce potential confusion,
let's just make all triggers BTREE_TRIGGER_WANTS_OLD_AND_NEW.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't mark device superblocks or allocate journal on a device that
isn't online.
That means we may need to do this on every mount, because we may have
formatted a new filesystem and then done the first mount
(bch2_fs_initialize()) in degraded mode.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
fsck_err() may sleep - it takes a mutex and may allocate memory, so
bucket_lock() needs to be a sleepable lock.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bucket_lock() previously open coded a spinlock, because we need to cram
a spinlock into a single byte.
But it turns out not all archs support xchg() on a single byte; since we
need struct bucket to be small, this means we have to play fun games
with casts and ifdefs for endianness.
This fixes building on 32 bit arm, and likely other architectures.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: linux-bcachefs@vger.kernel.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In general it's a good idea to avoid using bare unreachable() because it
introduces undefined behavior in compiled code. In this case it even
confuses GCC into emitting an empty unused
bch2_dev_buckets_reserved.part.0() function.
Use BUG() instead, which is nice and defined. While in theory it should
never trigger, if something were to go awry and the BCH_WATERMARK_NR
case were to actually hit, the failure mode is much more robust.
Fixes the following warnings:
vmlinux.o: warning: objtool: bch2_bucket_alloc_trans() falls through to next function bch2_reset_alloc_cursors()
vmlinux.o: warning: objtool: bch2_dev_buckets_reserved.part.0() is missing an ELF size annotation
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Split out a new file for bch_sb_field_members - we'll likely want to
move more code here in the future.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add another watermark for journal reclaim - this is needed for the next
patches, that unify BCH_WATERMARK with JOURNAL_WATERMARK.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We were copying the size of a struct bch_fs_usage_online to a struct
bch_fs_usage, which is 8 bytes smaller.
This adds some new helpers so we can do this correctly, and get rid of
some magic +1s too.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Rework stripe creation path - new algorithm for deciding when to create
new stripes or reuse existing stripes.
We add a new allocation watermark, RESERVE_stripe, above RESERVE_none.
Then we always try to create a new stripe by doing RESERVE_stripe
allocations; if this fails, we reuse an existing stripe and allocate
buckets for it with the reserve watermark for the given write
(RESERVE_none or RESERVE_movinggc).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
btree & level are passed to trans_mark - for backpointers -
bch2_mark_key() should take them as well.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch adds backpointers: we now have a reverse index from device
and offset on that device (specifically, offset within a bucket) back to
btree nodes and (non cached) data extents.
The first 40 backpointers within a bucket are stored in the alloc key;
after that backpointers spill over to the next backpointers btree. This
is to help avoid performance regressions from additional btree updates
on large streaming workloads.
This patch adds all the code for creating, checking and repairing
backpointers. The next patch in the series is going to use backpointers
for copygc - finally getting rid of the need to scan all extents to do
copygc.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new method of doing btree updates - a straight write buffer,
implemented as a flat fixed size array.
This is only useful when we don't need to read from the btree in order
to do the update, and when reading is infrequent - perfect for the LRU
btree.
This will make LRU btree updates fast enough that we'll be able to use
it for persistently indexing buckets by fragmentation, which will be a
massive boost to copygc performance.
Changes:
- A new btree_insert_type enum, for btree_insert_entries. Specifies
btree, btree key cache, or btree write buffer.
- bch2_trans_update_buffered(): updates via the btree write buffer
don't need a btree path, so we need a new update path.
- Transaction commit path changes:
The update to the btree write buffer both mutates global, and can
fail if there isn't currently room. Therefore we do all write buffer
updates in the transaction all at once, and also if it fails we have
to revert filesystem usage counter changes.
If there isn't room we flush the write buffer in the transaction
commit error path and retry.
- A new persistent option, for specifying the number of entries in the
write buffer.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- Marking a non-static function as inline doesn't actually work and is
now causing problems - drop that
- Introduce BCACHEFS_LOG_PREFIX for when we want to prefix log messages
with bcachefs (filesystem name)
- Userspace doesn't have real percpu variables (maybe we can get this
fixed someday), put an #ifdef around bch2_disk_reservation_add()
fastpath
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Long ago, bkey_unpack_key() was added to bset.h instead of bkey.h
because bkey.h didn't include btree_types.h, which it needs for the
compiled unpack function.
This patch finally moves it to the proper location.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- add bch2_dev_usage_read_fast(), which doesn't return by value -
bch_dev_usage is big enough that we don't want the silent memcpy
- tweak the allocation path to only call bch2_dev_usage_read() once per
bucket allocated
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
__dev_available() now calculates available buckets correctly. Previously
it would almost always return 0 when we have cached data.
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, dev_buckets_available() only counted buckets that are
eligible to be allocated right now - i.e. buckets that don't have cached
data, or need discard, or need gc gens, etc.
But most users of this function want to know how many buckets are
eligible to be allocated from without moving data around - copygc,
allocator striping, which means we should be including cached data
buckets etc.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
For backpointers, we'll need the full key location - that means btree_id
and btree level. This patch plumbs it through.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Previously, we were missing accounting for buckets in need_gc_gens and
need_discard states. This matters because buckets in those states need
other btree operations done before they can be used, so they can't be
conuted when checking current number of free buckets against the
allocation watermark.
Also, we weren't directly counting free buckets at all. Now, data type 0
== BCH_DATA_free, and free buckets are counted; this means we can get
rid of the separate (poorly defined) count of unavailable buckets.
This is a new on disk format version, with upgrade and fsck required for
the accounting changes.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
mark_stripe_bucket() was busted; it was using @new unitialized.
Also, clean up all the gc mark functions, and convert them to the same
style.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This switches struct bucket to using a lock, instead of cmpxchg. And now
that the protected members no longer need to fit into a u64, we can
expand the sector counts to 32 bits.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
All code using the in-memory bucket array, excluding GC, has now been
converted to use the alloc btree directly - so we can finally delete it.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is one of the last steps in getting rid of the main in-memory
bucket array.
This changes bch2_dev_usage_update() to take bkey_alloc_unpacked instead
of bucket_mark, and for the places where we are in fact working with
bucket_mark and don't have bkey_alloc_unpacked, we add a wrapper that
takes bucket_mark and converts to bkey_alloc_unpacked.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we have new persistent data structures for the allocator, this
patch converts the allocator to use them.
Now, foreground bucket allocation uses the freespace btree to find
buckets to allocate, instead of popping buckets off the freelist.
The background allocator threads are no longer needed and are deleted,
as well as the allocator freelists. Now we only need background tasks
for invalidating buckets containing cached data (when we are low on
empty buckets), and for issuing discards.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds two new btrees for the upcoming allocator rewrite: an extents
btree of free buckets, and a btree for buckets awaiting discards.
We also add a new trigger for alloc keys to keep the new btrees up to
date, and a compatibility path to initialize them on existing
filesystems.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This introduces a new alloc key which doesn't use varints. Soon we'll be
adding backpointers and storing them in alloc keys, which means our
pack/unpack workflow for alloc keys won't really work - we'll need to be
mutating alloc keys in place.
Instead of bch2_alloc_unpack(), we now have bch2_alloc_to_v4() that
converts older types of alloc keys to v4 if needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This replaces the switch statements in bch2_mark_key(),
bch2_trans_mark_key() with new bkey methods - prep work for the next
patch, which fixes BTREE_TRIGGER_WANTS_OLD_AND_NEW.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Upcoming patches are doing more work on the triggers code, this patch
just moves code around.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
We're now coming up with triggers that modify the update being done. A
bkey_s_c is const - bkey_i is the correct type to be using here.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Like the previous patches, this converts bch2_gc_gens() to use the alloc
btree directly, and private arrays of generation numbers for its own
recalculation of oldest_gen.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Previously, bucket fragmentation was considered to be bucket size -
total amount of live data, both dirty and cached.
This meant that if a bucket was full but only a small amount of data in
it was dirty - the rest cached, we'd get stuck: copygc wouldn't move the
dirty data out of the bucket and the allocator wouldn't be able to
invalidate and drop the cached data.
This changes fragmentation to exclude cached data, so that copygc will
evacuate these buckets and copygc/the allocator will always be able to
make forward progress.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Implement a hash table, using cuckoo hashing, for empty buckets that are
waiting on a journal commit before they can be reused.
This replaces the journal_seq field of bucket_mark, and is part of
eventually getting rid of the in memory bucket array.
We may need to make bch2_bucket_needs_journal_commit() lockless, pending
profiling and testing.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
