77 Commits

Author SHA1 Message Date
Kent Overstreet
bc82d08bae bcachefs: Tracepoint improvements
This improves the transaction restart tracepoints - adding distinct
tracepoints for all the locations and reasons a transaction might have
been restarted, and ensures that there's a tracepoint for every
transaction restart.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:22 -04:00
Kent Overstreet
669f87a5da bcachefs: Switch to __func__for recording where btree_trans was initialized
Symbol decoding, via %ps, isn't supported in userspace - this will also
be faster when we're using trans->fn in the fast path, as with the new
BCH_JSET_ENTRY_log journal messages.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:21 -04:00
Kent Overstreet
c7ce813fe4 bcachefs: Add a tracepoint for the btree cache shrinker
This is to help with diagnosing why the btree node can doesn't seem to
be shrinking - we've had issues in the past with granularity/batch size,
since btree nodes are so big.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:20 -04:00
Kent Overstreet
1aeed4549d bcachefs: Optimize memory accesses in bch2_btree_node_get()
This puts a load behind some branches before where it's used, so that it
can execute in parallel with other loads.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:19 -04:00
Kent Overstreet
54b2db3d58 bcachefs: Fix infinite loop in bch2_btree_cache_scan()
When attempting to free btree nodes, we might not be able to free all
the nodes that were requested. But the code was looping until it had
freed _all_ the nodes requested, when it should have only been
attempting to free nr nodes.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:16 -04:00
Kent Overstreet
aae4eea60c bcachefs: Improve btree_node_mem_ptr optimization
This patch checks b->hash_val before attempting to lock the node in the
btree, which makes it more equivalent to the "lookup in hash table"
path - and potentially avoids an unnecessary transaction restart if
btree_node_mem_ptr(k) no longer points to the node we want.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
67e0dd8f0d bcachefs: btree_path
This splits btree_iter into two components: btree_iter is now the
externally visible componont, and it points to a btree_path which is now
reference counted.

This means we no longer have to clone iterators up front if they might
be mutated - btree_path can be shared by multiple iterators, and cloned
if an iterator would mutate a shared btree_path. This will help us use
iterators more efficiently, as well as slimming down the main long lived
state in btree_trans, and significantly cleans up the logic for iterator
lifetimes.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:11 -04:00
Kent Overstreet
cab8e23373 bcachefs: Add an assertion for removing btree nodes from cache
Chasing a bug that has something to do with the btree node cache.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:11 -04:00
Kent Overstreet
78cf784eaa bcachefs: Further reduce iter->trans usage
This is prep work for splitting btree_path out from btree_iter -
btree_path will not have a pointer to btree_trans.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:11 -04:00
Kent Overstreet
e5af273fce bcachefs: trans->restarted
Start tracking when btree transactions have been restarted - and assert
that we're always calling bch2_trans_begin() immediately after
transaction restart.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:09 -04:00
Kent Overstreet
8b3e9bd65f bcachefs: Always check for transaction restarts
On transaction restart iterators won't be locked anymore - make sure
we're always checking for errors.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:09 -04:00
Kent Overstreet
a32b9573c7 bcachefs: Add an option for btree node mem ptr optimization
bch2_btree_node_ptr_v2 has a field for stashing a pointer to the in
memory btree node; this is safe because we clear this field when reading
in nodes from disk and we never free in memory btree nodes - but, we
have bug reports that indicate something might be faulty with this
optimization, so let's add an option for it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:09 -04:00
Kent Overstreet
6e075b54a3 bcachefs: bch2_btree_iter_relock_intent()
This adds a new helper for btree_cache.c that does what we want where
the iterator is still being traverse - and also eliminates some
unnecessary transaction restarts.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:09 -04:00
Kent Overstreet
f8f86c6aec bcachefs: Improve btree_bad_header() error message
We should always print out the full btree node ptr.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:08 -04:00
Kent Overstreet
5aab663534 bcachefs: Tighten up btree_iter locking assertions
We weren't correctly verifying that we had interior node intent locks -
this patch also fixes bugs uncovered by the new assertions.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:08 -04:00
Kent Overstreet
0a70089062 bcachefs: Kick off btree node writes from write completions
This is a performance improvement by removing the need to wait for the
in flight btree write to complete before kicking one off, which is going
to be needed to avoid a performance regression with the upcoming patch
to update btree ptrs after every btree write.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:08 -04:00
Kent Overstreet
19d5432445 bcachefs: Really don't hold btree locks while btree IOs are in flight
This is something we've attempted to stick to for quite some time, as it
helps guarantee filesystem latency - but there's a few remaining paths
that this patch fixes.

This is also necessary for an upcoming patch to update btree pointers
after every btree write - since the btree write completion path will now
be doing btree operations.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:08 -04:00
Kent Overstreet
c205321b12 bcachefs: Drop all btree locks when submitting btree node reads
As a rule we don't want to be holding btree locks while submitting IO -
this will improve overall filesystem latency.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:05 -04:00
Kent Overstreet
531a0095c9 bcachefs: Improve btree iterator tracepoints
This patch adds some new tracepoints to the btree iterator code, and
adds new fields to the existing tracepoints - primarily for the iterator
position.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:05 -04:00
Kent Overstreet
e68031fb46 bcachefs: Mark newly allocated btree nodes as accessed
This was a major oversight - this means under memory pressure we can end
up reading in a btree node, then having it evicted before we get to use
it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:02 -04:00
Kent Overstreet
ceda1b9a17 bcachefs: Evict btree nodes we're deleting
There was a bug that led to duplicate btree node pointers being inserted
at the wrong level. The new topology repair code can fix that, except
that the btree cache code gets confused when we read in a btree node
from the pointer that was at the wrong level. This patch evicts nodes
that we're deleting to, which nicely solves the problem.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:02 -04:00
Kent Overstreet
65c0601a32 bcachefs: Use mmap() instead of vmalloc_exec() in userspace
Calling mmap() directly is much better than malloc() then mprotect(), we
end up with much less address space fragmentation.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:02 -04:00
Kent Overstreet
537c32f521 bcachefs: Don't BUG_ON() btree topology error
This replaces an assertion in the btree merge path with a
bch2_inconsistent_error() - fsck will fix it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
6adaac0b95 bcachefs: Update bch2_btree_verify()
bch2_btree_verify() verifies that the btree node on disk matches what we
have in memory. This patch changes it to verify every replica, and also
fixes it for interior btree nodes - there's a mem_ptr field which is
used as a scratch space and needs to be zeroed out for comparing with
what's on disk.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:01 -04:00
Kent Overstreet
2177147b39 bcachefs: Improve bset compaction
The previous patch that fixed btree nodes being written too aggressively
now meant that we weren't sorting btree node bsets optimally - this
patch fixes that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:59 -04:00
Kent Overstreet
54ca47e114 bcachefs: Kill bch2_btree_node_get_sibling()
This patch reworks the btree node merge path to use a second btree
iterator to get the sibling node - which means
bch2_btree_iter_get_sibling() can be deleted. Also, it uses
bch2_btree_iter_traverse_all() if necessary - which means it should be
more reliable. We don't currently even try to make it work when
trans->nounlock is set - after a BTREE_INSERT_NOUNLOCK transaction
commit, hopefully this will be a worthwhile tradeoff.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:58 -04:00
Kent Overstreet
e751c01a8e bcachefs: Start using bpos.snapshot field
This patch starts treating the bpos.snapshot field like part of the key
in the btree code:

* bpos_successor() and bpos_predecessor() now include the snapshot field
* Keys in btrees that will be using snapshots (extents, inodes, dirents
  and xattrs) now always have their snapshot field set to U32_MAX

The btree iterator code gets a new flag, BTREE_ITER_ALL_SNAPSHOTS, that
determines whether we're iterating over keys in all snapshots or not -
internally, this controlls whether bkey_(successor|predecessor)
increment/decrement the snapshot field, or only the higher bits of the
key.

We add a new member to struct btree_iter, iter->snapshot: when
BTREE_ITER_ALL_SNAPSHOTS is not set, iter->pos.snapshot should always
equal iter->snapshot, which will be 0 for btrees that don't use
snapshots, and alsways U32_MAX for btrees that will use snapshots
(until we enable snapshot creation).

This patch also introduces a new metadata version number, and compat
code for reading from/writing to older versions - this isn't a forced
upgrade (yet).

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:57 -04:00
Kent Overstreet
4cf91b0270 bcachefs: Split out bpos_cmp() and bkey_cmp()
With snapshots, we're going to need to differentiate between comparisons
that should and shouldn't include the snapshot field. bpos_cmp is now
the comparison function that does include the snapshot field, used by
core btree code.

Upper level filesystem code generally does _not_ want to compare against
the snapshot field - that code wants keys to compare as equal even when
one of them is in an ancestor snapshot.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:57 -04:00
Kent Overstreet
a9d79c6e8b bcachefs: Use pcpu mode of six locks for interior nodes
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:57 -04:00
Kent Overstreet
f020bfcdb0 bcachefs: Use bch2_bpos_to_text() more consistently
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
41f8b09edc bcachefs: Rename BTREE_ID enums for consistency with other enums
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
c043a3303c bcachefs: Fix bch2_btree_cache_scan()
It was counting nodes on the freed list that it skips - because we want
to leave a few so that btree splits don't touch the allocator - as nodes
that it touched, meaning that if it was called with <= 3 nodes to
reclaim, and those nodes were on the freed list, it would never do any
work.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
18a7b97239 bcachefs: Fix for bch2_btree_node_get_noiter() returning -ENOMEM
bch2_btree_node_get_noiter() isn't used from the btree iterator code,
which retries with the btree node cache cannibalize lock held on
-ENOMEM, so we should do it ourself if necessary.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:53 -04:00
Kent Overstreet
a0b73c1c53 bcachefs: Add (partial) support for fixing btree topology
When we walk the btrees during recovery, part of that is checking that
btree topology is correct: for every interior btree node, its child
nodes should exactly span the range the parent node covers.

Previously, we had checks for this, but not repair code. Now that we
have the ability to do btree updates during initial GC, this patch adds
that repair code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:52 -04:00
Kent Overstreet
edfbba58e3 bcachefs: Add btree node prefetching to bch2_btree_and_journal_walk()
bch2_btree_and_journal_walk() walks the btree overlaying keys from the
journal; it was introduced so that we could read in the alloc btree
prior to journal replay being done, when journalling of updates to
interior btree nodes was introduced.

But it didn't have btree node prefetching, which introduced a severe
regression with mount times, particularly on spinning rust. This patch
implements btree node prefetching for the btree + journal walk,
hopefully fixing that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:51 -04:00
Kent Overstreet
b929bbef6f bcachefs: Add cannibalize lock to btree_cache_to_text()
More debugging info is always a good thing.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:51 -04:00
Kent Overstreet
07a1006ae8 bcachefs: Reduce/kill BKEY_PADDED use
With various newer key types - stripe keys, inline data extents - the
old approach of calculating the maximum size of the value is becoming
more and more error prone. Better to switch to bkey_on_stack, which can
dynamically allocate if necessary to handle any size bkey.

In particular we also want to get rid of BKEY_EXTENT_VAL_U64s_MAX.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:50 -04:00
Kent Overstreet
d8ebed7d24 bcachefs: Add btree cache stats to sysfs
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:47 -04:00
Kent Overstreet
d8b4600464 bcachefs: Check for errors from register_shrinker()
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:47 -04:00
Kent Overstreet
e648448ca5 bcachefs: Fix missing memalloc_nofs_restore()
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:46 -04:00
Kent Overstreet
6a747c4683 bcachefs: Add accounting for dirty btree nodes/keys
This lets us improve journal reclaim, so that it now tries to make sure
no more than 3/4s of the btree node cache and btree key cache are dirty
- ensuring the shrinkers can free memory.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:46 -04:00
Kent Overstreet
29364f3453 bcachefs: Drop sysfs interface to debug parameters
It's not used much anymore, the module paramter interface is better.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:45 -04:00
Kent Overstreet
a301dc38ef bcachefs: Improve tracing for transaction restarts
We have a bug where we can get stuck with a process spinning in
transaction restarts - need more information.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:45 -04:00
Kent Overstreet
645d72aa36 bcachefs: Fix btree updates when mixing cached and non cached iterators
There was a bug where bch2_trans_update() would incorrectly delete a
pending update where the new update did not actually overwrite the
existing update, because we were incorrectly using BTREE_ITER_TYPE when
sorting pending btree updates.

This affects the pending patch to use cached iterators for inode
updates.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:45 -04:00
Kent Overstreet
97c0e19502 bcachefs: Fix another lockdep splat
vfree() can allocate memory, so we need to call memalloc_nofs_save().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:44 -04:00
Kent Overstreet
5d0b7f906a bcachefs: Fix a lockdep splat
We can't allocate memory with GFP_FS while holding the btree cache lock,
and vfree() can allocate memory.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:44 -04:00
Kent Overstreet
4580baec7f bcachefs: Remove some uses of PAGE_SIZE in the btree code
For portability to userspace, we should try to avoid working in kernel
pages.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:43 -04:00
Kent Overstreet
760992aac8 bcachefs: Ensure we wake up threads locking node when reusing it
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:43 -04:00
Kent Overstreet
47a5649a0a bcachefs: Fix incorrect gfp check
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:41 -04:00
Kent Overstreet
bd2bb273a0 bcachefs: Don't deadlock when btree node reuse changes lock ordering
Btree node lock ordering is based on the logical key. However, 'struct
btree' may be reused for a different btree node under memory pressure.
This patch uses the new six lock callback to check if a btree node is no
longer the node we wanted to lock before blocking.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:41 -04:00