We can't assume that btrees only contain keys of a given type - even if
they only have a single key type listed in the allowed key types for
that btree; this is a forwards compatibility issue.
Reported-by: syzbot+a27c3aaa3640dd3e1dfb@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes an assertion pop where we try to navigate to the target of
the backpointer, and the path level isn't what we expect.
Reported-by: syzbot+b17df21b4d370f2dc330@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The header files bbpos.h is included twice in backpointers.c,
so one inclusion of each can be removed.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=10783
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In backpointers fsck, we do a seqential scan of one btree, and check
references to another: extents <-> backpointers
Checking references generates random lookups, so we want to pin that
btree in memory (or only a range, if it doesn't fit in ram).
Previously, this was done with a simple check in the shrinker - "if
btree node is in range being pinned, don't free it" - but this generated
OOMs, as our shrinker wasn't well behaved if there was less memory
available than expected.
Instead, we now have two different shrinkers and lru lists; the second
shrinker being for pinned nodes, with seeks set much higher than normal
- so they can still be freed if necessary, but we'll prefer not to.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bkey_fsck_err() was added as an interface that looks like fsck_err(),
but previously all it did was ensure that the appropriate error counter
was incremented in the superblock.
This is a cleanup and bugfix patch that converts it to a wrapper around
fsck_err(). This is needed to fix an issue with the upgrade path to
disk_accounting_v3, where the "silent fix" error list now includes
bkey_fsck errors; fsck_err() handles this in a unified way, and since we
need to change printing of bkey fsck errors from the caller to the inner
bkey_fsck_err() calls, this ends up being a pretty big change.
Als,, rename .invalid() methods to .validate(), for clarity, while we're
changing the function signature anyways (to drop the printbuf argument).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
for_each_btree_node() now works similarly to for_each_btree_key(), where
the loop body is passed as an argument to be passed to lockrestart_do().
This now calls trans_begin() on every loop iteration - which fixes an
SRCU warning in backpointers fsck.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
fsck_err() now optionally takes a btree_trans; if the current thread has
one, it is required that it be passed.
The next patch will use this to unlock when waiting for user input.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new helper for checking references to write buffer btrees, where
we need a flush before we definitively know we have an inconsistency.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're about to start using bch_validate_flags for superblock section
validation - it's no longer bkey specific.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Combine iter/update/trigger/str_hash flags into a single enum, and
x-macroize them for a to_text() function later.
These flags are all for a specific iter/key/update context, so it makes
sense to group them together - iter/update/trigger flags were already
given distinct bits, this cleans up and unifies that handling.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
Remove some duplication, and inconsistency between check_fix_ptrs and
the main ptr marking paths
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Backpointers that point to invalid devices are caught by fsck, not
.key_invalid; so .key_invalid needs to check for them instead of hitting
asserts.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we've got the errors_silent mechanism, we don't have to check
if the reconstruct_alloc option is set all over the place.
Also - users no longer have to explicitly select fsck and fix_errors.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Various phases of fsck involve checking references from one btree to
another: this means doing a sequential scan of one btree, and then
mostly random access into the second.
This is particularly painful for checking extents <-> backpointers; we
can prefetch btree node access on the sequential scan, but not on the
random access portion, and this is particularly painful on spinning
rust, where we'd like to keep the pipeline fairly full of btree node
reads so that the elevator can reduce seeking.
This patch implements prefetching and pinning of the portion of the
btree that we'll be doing random access to. We already calculate how
much of the random access btree will fit in memory so it's a fairly
straightforward change.
This will put more pressure on system memory usage, so we introduce a
new option, fsck_memory_usage_percent, which is the percentage of total
system ram that fsck is allowed to pin.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This converts -EIOs related to btree node errors to private error codes,
which will help with some ongoing debugging by giving us better error
messages.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.
And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.
Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
backpointers fsck now always runs in rw mode - the btree is being
modified while it runs, by e.g. copygc, rebalance, the discard worker,
the invalidate worker.
We could find a missing backpointer, flush the btree write buffer, and
then on the next iteration find a new key at the exact same position -
which will most likely need another write buffer flush.
Hence, we have to check for an exact match on last_flushed, not just the
pos.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It appears that BTREE_ITER_ALL_LEVELS is racy with concurrent interior
node btree updates; unfortunate but not terribly surprising it's a
difficult problem - that was the original reason for gc_lock.
BTREE_ITER_ALL_LEVELS will probably be deleted in a subsequent patch,
this changes backpointers fsck to instead walk keys at one level of the
btree at a time.
This fixes the tiering_drop_alloc test, which stopped working with the
patch to not flush the journal after journal replay.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_btree_iter_peek_node() can return a NULL ptr (when the tree is
shorter than the search depth); handle this with an early return.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: https://lore.kernel.org/linux-bcachefs/5fc3c28b-c232-4ec7-b0ac-4ef220ddf976@moroto.mountain/T/
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- backpointer_not_found() checks backpointers_no_use_write_buffer, no
need to do it inbackpointer_get_key().
- always use backpointer_get_node() for pointers to nodes:
backpointer_get_key() was sometimes returning the key from the root
node unlocked.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The bucket_offset field of bch_backpointer is a 40-bit bitfield, but the
bch2_backpointer_swab() helper uses swab32. This leads to inconsistency
when an on-disk fs is accessed from an opposite endian machine.
As it turns out, we already have an internal swab40() helper that is
used from the bch_alloc_v4 swab callback. Lift it into the backpointers
header file and use it consistently in both places.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
