Kent Overstreet [Sun, 14 Apr 2024 03:59:28 +0000 (23:59 -0400)]
bcachefs: Interior known are required to have known key types
For forwards compatibilyt, we allow bkeys of unknown type in leaf nodes;
we can simply ignore metadata we don't understand. Pointers to btree
nodes must always be of known types, howwever.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 13 Apr 2024 22:39:03 +0000 (18:39 -0400)]
bcachefs: Disable merges from interior update path
There's been a bug in the btree write buffer where it wasn't triggering
btree node merges - and leaving behind a bunch of nearly empty btree
nodes.
Then during journal replay, when updates to the backpointers btree
aren't using the btree write buffer (because we require synchronization
with journal replay), we end up doing those merges all at once.
Then if it's the interior update path running them, we deadlock because
those run with the highest watermark.
There's no real need for the interior update path to be doing btree node
merges; other code paths can handle that at lower watermarks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 13 Apr 2024 01:07:05 +0000 (21:07 -0400)]
bcachefs: Fix deadlock in journal replay
btree_key_can_insert_cached() should be checking the watermark -
BCH_TRANS_COMMIT_journal_replay really means nonblocking mode when
watermark < reclaim, it was being used incorrectly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Thu, 11 Apr 2024 21:47:42 +0000 (17:47 -0400)]
bcachefs: Fix UAFs of btree_insert_entry array
The btree paths array is now dynamically resizable - and as well the
btree_insert_entries array, as it needs to be the same size.
The merge path (and interior update path) allocates new btree paths,
thus can trigger a resize; thus we need to not retain direct pointers
after invoking merge; similarly when running btree node triggers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Thu, 11 Apr 2024 05:01:11 +0000 (01:01 -0400)]
bcachefs: Don't use bch2_btree_node_lock_write_nofail() in btree split path
It turns out - btree splits happen with the rest of the transaction
still locked, to avoid unnecessary restarts, which means using nofail
doesn't work here - we can deadlock.
Fortunately, we now have the ability to return errors here.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Wed, 10 Apr 2024 04:10:18 +0000 (00:10 -0400)]
bcachefs: Kill read lock dropping in bch2_btree_node_lock_write_nofail()
dropping read locks in bch2_btree_node_lock_write_nofail() dates from
before we had the cycle detector; we can now tell the cycle detector
directly when taking a lock may not fail because we can't handle
transaction restarts.
This is needed for adding should_be_locked asserts.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Tue, 9 Apr 2024 02:32:08 +0000 (22:32 -0400)]
bcachefs: fix eytzinger0_find_gt()
- fix return types: promoting from unsigned to ssize_t does not do what
we want here, and was pointless since the rest of the eytzinger code
is u32
- nr, not size
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Hongbo Li [Tue, 26 Mar 2024 04:04:56 +0000 (12:04 +0800)]
bcachefs: fix the count of nr_freed_pcpu after changing bc->freed_nonpcpu list
When allocating bkey_cached from bc->freed_pcpu list, it missed
decreasing the count of nr_freed_pcpu which would cause the mismatch
between the value of nr_freed_pcpu and the list items. This problem
also exists in moving new bkey_cached to bc->freed_pcpu list.
If these happened, the bug info may appear in
bch2_fs_btree_key_cache_exit by the follow code:
Fixes: c65c13f0eac6 ("bcachefs: Run btree key cache shrinker less aggressively") Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sun, 7 Apr 2024 01:45:46 +0000 (21:45 -0400)]
bcachefs: Fix gap buffer bug in bch2_journal_key_insert_take()
Multiple bug fixes for journal iters:
- When the journal keys gap buffer is resized, we have to adjust the
iterators for moving the gap to the end
- We don't want to rewind iterators to point to the key we just
inserted if it's not for the correct btree/level
Also, add some new assertions.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Commit eb386617be4bdf ("bcachefs: Errcode tracepoint, documentation")
adds initial bcachefs documentation (private error codes) but without
any table of contents tree for the filesystem docs, hence Sphinx warns:
Documentation/filesystems/bcachefs/errorcodes.rst: WARNING: document isn't included in any toctree
Kent Overstreet [Sat, 6 Apr 2024 03:27:27 +0000 (23:27 -0400)]
bcachefs: JOURNAL_SPACE_LOW
"bcachefs; Fix deadlock in bch2_btree_update_start()" was a significant
performance regression (nearly 50%) on multithreaded random writes with
fio.
The reason is that the journal watermark checks multiple things,
including the state of the btree write buffer, and on multithreaded
update heavy workloads we're bottleneked on write buffer flushing - we
don't want kicknig off btree updates to depend on the state of the write
buffer.
This isn't strictly correct; the interior btree update path does do
write buffer updates, but it's a tiny fraction of total accounting
updates and we're more concerned with space in the journal itself.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 6 Apr 2024 02:30:30 +0000 (22:30 -0400)]
bcachefs: Disable errors=panic for BCH_IOCTL_FSCK_OFFLINE
BCH_IOCTL_FSCK_OFFLINE allows the userspace fsck tool to use the kernel
implementation of fsck - primarily when the kernel version is a better
version match.
It should look and act exactly like the normal userspace fsck that the
user expected to be invoking, so errors should never result in a kernel
panic.
We may want to consider further restricting errors=panic - it's only
intended for debugging in controlled test environments, it should have
no purpose it normal usage.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 6 Apr 2024 02:23:29 +0000 (22:23 -0400)]
bcachefs: Fix BCH_IOCTL_FSCK_OFFLINE for encrypted filesystems
To open an encrypted filesystem, we use request_key() to get the
encryption key from the user's keyring - but request_key() needs to
happen in the context of the process that invoked the ioctl.
This easily fixed by using bch2_fs_open() in nostart mode.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Dan Carpenter [Fri, 5 Apr 2024 15:01:02 +0000 (18:01 +0300)]
bcachefs: fix ! vs ~ typo in __clear_bit_le64()
The ! was obviously intended to be ~. As it is, this function does
the equivalent to: "addr[bit / 64] = 0;".
Fixes: 27fcec6c27ca ("bcachefs: Clear recovery_passes_required as they complete without errors") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 30 Mar 2024 22:43:00 +0000 (18:43 -0400)]
bcachefs: Check for extents that point to same space
In backpointer repair, if we get a missing backpointer - but there's
already a backpointer that points to an existing extent - we've got
multiple extents that point to the same space and need to decide which
to keep.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sun, 17 Mar 2024 02:45:30 +0000 (22:45 -0400)]
bcachefs: Topology repair now uses nodes found by scanning to fill holes
With the new btree node scan code, we can now recover from corrupt btree
roots - simply create a new fake root at depth 1, and then insert all
the leaves we found.
If the root wasn't corrupt but there's corruption elsewhere in the
btree, we can fill in holes as needed with the newest version of a given
node(s) from the scan; we also check if a given btree node is older than
what we found from the scan.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Fri, 22 Mar 2024 23:26:33 +0000 (19:26 -0400)]
bcachefs: Etyzinger cleanups
Pull out eytzinger.c and kill eytzinger_cmp_fn. We now provide
eytzinger0_sort and eytzinger0_sort_r, which use the standard cmp_func_t
and cmp_r_func_t callbacks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Tue, 2 Apr 2024 22:30:14 +0000 (18:30 -0400)]
bcachefs: Check for bad needs_discard before doing discard
In the discard worker, we were failing to validate the bucket state -
meaning a corrupt needs_discard btree could cause us to discard a bucket
that we shouldn't.
If check_alloc_info hasn't run yet we just want to bail out, otherwise
it's a filesystem inconsistent error.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Guenter Roeck [Sun, 25 Feb 2024 16:29:25 +0000 (08:29 -0800)]
mean_and_variance: Drop always failing tests
mean_and_variance_test_2 and mean_and_variance_test_4 always fail.
The input parameters to those tests are identical to the input parameters
to tests 1 and 3, yet the expected result for tests 2 and 4 is different
for the mean and stddev tests. That will always fail.
Kent Overstreet [Mon, 1 Apr 2024 23:20:36 +0000 (19:20 -0400)]
bcachefs: BCH_WATERMARK_interior_updates
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>
This adds opts.recovery_pass_limit, and redoes -o norecovery to make use
of it; this fixes some issues with -o norecovery so it can be safely
used for data recovery.
Norecovery means "don't do journal replay"; it's an important data
recovery tool when we're getting stuck in journal replay.
When using it this way we need to make sure we don't free journal keys
after startup, so we continue to overlay them: thus it needs to imply
retain_recovery_info, as well as nochanges.
recovery_pass_limit is an explicit option for telling recovery to exit
after a specific recovery pass; this is a much cleaner way of
implementing -o norecovery, as well as being a useful debug feature in
its own right.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 30 Mar 2024 22:57:53 +0000 (18:57 -0400)]
bcachefs: Ensure bch_sb_field_ext always exists
This makes bch_sb_field_ext more consistent with the rest of -o
nochanges - we don't want to be varying other codepaths based on -o
nochanges, since it's used for testing in dry run mode; also fixes some
potential null ptr derefs.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 23 Mar 2024 23:31:15 +0000 (19:31 -0400)]
bcachefs: Resume logged ops after fsck
Finishing logged ops requires the filesystem to be in a reasonably
consistent state - and other fsck passes don't require it to have
completed, so just run it last.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sun, 24 Mar 2024 00:07:46 +0000 (20:07 -0400)]
bcachefs: Split out recovery_passes.c
We've grown a fair amount of code for managing recovery passes; tracking
which ones we're running, which ones need to be run, and flagging in the
superblock which ones need to be run on the next recovery.
So it's worth splitting out into its own file, this code is pretty
different from the code in recovery.c.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 23 Mar 2024 23:29:19 +0000 (19:29 -0400)]
bcachefs: Improved topology repair checks
Consolidate bch2_gc_check_topology() and btree_node_interior_verify(),
and replace them with an improved version,
bch2_btree_node_check_topology().
This checks that children of an interior node correctly span the full
range of the parent node with no overlaps.
Also, ensure that topology repairs at runtime are always a fatal error;
in particular, this adds a check in btree_iter_down() - if we don't find
a key while walking down the btree that's indicative of a topology error
and should be flagged as such, not a null ptr deref.
Some checks in btree_update_interior.c remaining BUG_ONS(), because we
already checked the node for topology errors when starting the update,
and the assertions indicate that we _just_ corrupted the btree node -
i.e. the problem can't be that existing on disk corruption, they
indicate an actual algorithmic bug.
In the future, we'll be annotating the fsck errors list with which
recovery pass corrects them; the open coded "run explicit recovery pass
or fatal error" in bch2_btree_node_check_topology() will in the future
be done for every fsck_err() call.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Hongbo Li [Mon, 25 Mar 2024 02:50:48 +0000 (10:50 +0800)]
bcachefs: fix trans->mem realloc in __bch2_trans_kmalloc
The old code doesn't consider the mem alloced from mempool when call
krealloc on trans->mem. Also in bch2_trans_put, using mempool_free to
free trans->mem by condition "trans->mem_bytes == BTREE_TRANS_MEM_MAX"
is inaccurate when trans->mem was allocated by krealloc function.
Instead, we use used_mempool stuff to record the situation, and realloc
or free the trans->mem in elegant way.
Also, after krealloc failed in __bch2_trans_kmalloc, the old data
should be copied to the new buffer when alloc from mempool_alloc.
Fixes: 31403dca5bb1 ("bcachefs: optimize __bch2_trans_get(), kill DEBUG_TRANSACTIONS") Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Sat, 23 Mar 2024 23:29:55 +0000 (19:29 -0400)]
bcachefs: Don't do extent merging before journal replay is finished
We don't normally do extent updates this early in recovery, but some of
the repair paths have to and when we do, we don't want to do anything
that requires the snapshots table.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Fri, 22 Mar 2024 20:29:23 +0000 (16:29 -0400)]
bcachefs: Add checks for invalid snapshot IDs
Previously, we assumed that keys were consistent with the snapshots
btree - but that's not correct as fsck may not have been run or may not
be complete.
This adds checks and error handling when using the in-memory snapshots
table (that mirrors the snapshots btree).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Fri, 22 Mar 2024 00:16:23 +0000 (20:16 -0400)]
bcachefs: Move snapshot table size to struct snapshot_table
We need to add bounds checking for snapshot table accesses - it turns
out there are cases where we do need to use the snapshots table before
fsck checks have completed (and indeed, fsck may not have been run).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Fri, 22 Mar 2024 08:01:27 +0000 (04:01 -0400)]
bcachefs: Fix journal pins in btree write buffer
btree write buffer flush has two phases
- in natural key order, which is more efficient but may fail
- then in journal order
The journal order flush was assuming that keys were still correctly
ordered by journal sequence number - but due to coalescing by the
previous phase, we need an additional sort.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>