Btree nodes are log structured; thus, we need to emit whiteouts when
we're deleting a key that's been written out to disk.
k->needs_whiteout tracks whether a key will need a whiteout when it's
deleted, and this requires some careful handling; e.g. the key we're
deleting may not have been written out to disk, but it may have
overwritten a key that was - thus we need to carry this flag around on
overwrites.
Invariants:
There may be multiple key for the same position in a given node (because
of overwrites), but only one of them will be a live (non deleted) key,
and only one key for a given position will have the needs_whiteout flag
set.
Additionally, we don't want to carry around whiteouts that need to be
written in the main searchable part of a btree node - btree_iter_peek()
will have to skip past them, and this can lead to an O(n^2) issues when
doing sequential deletions (e.g. inode rm/truncate). So there's a
separate region in the btree node buffer for unwritten whiteouts; these
are merge sorted with the rest of the keys we're writing in the btree
node write path.
The unwritten whiteouts was a later optimization that bch2_sort_keys()
didn't take into account; the unwritten whiteouts area means that we
never have deleted keys with needs_whiteout set in the main searchable
part of a btree node.
That means we can simplify and optimize some sort paths, and eliminate
an assertion that syzbot found:
- Unless we're in the btree node write path, it's always ok to drop
whiteouts when sorting
- When sorting for a btree node write, we drop the whiteout if it's not
from the unwritten whiteouts area, or if it's overwritten by a real
key at the same position.
This completely eliminates some tricky logic for propagating the
needs_whiteout flag: syzbot was able to hit the assertion that checked
that there shouldn't be more than one key at the same pos with
needs_whiteout set, likely due to a combination of flipping on
needs_whiteout on all written keys (they need whiteouts if overwritten),
combined with not always dropping unneeded whiteouts, and the tricky
logic in the sort path for preserving needs_whiteout that wasn't really
needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When building for 32-bit platforms, for which size_t is 'unsigned int',
there is a warning from a format string in validate_bset_keys():
fs/bcachefs/btree_io.c: In function 'validate_bset_keys':
fs/bcachefs/btree_io.c:891:34: error: format '%lu' expects argument of type 'long unsigned int', but argument 12 has type 'unsigned int' [-Werror=format=]
891 | "bad k->u64s %u (min %u max %lu)", k->u64s,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/bcachefs/btree_io.c:603:32: note: in definition of macro 'btree_err'
603 | msg, ##__VA_ARGS__); \
| ^~~
fs/bcachefs/btree_io.c:887:21: note: in expansion of macro 'btree_err_on'
887 | if (btree_err_on(!bkeyp_u64s_valid(&b->format, k),
| ^~~~~~~~~~~~
fs/bcachefs/btree_io.c:891:64: note: format string is defined here
891 | "bad k->u64s %u (min %u max %lu)", k->u64s,
| ~~^
| |
| long unsigned int
| %u
cc1: all warnings being treated as errors
BKEY_U64s is size_t so the entire expression is promoted to size_t. Use
the '%zu' specifier so that there is no warning regardless of the width
of size_t.
Fixes: 031ad9e7db ("bcachefs: Check for packed bkeys that are too big")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404130747.wH6Dd23p-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202404131536.HdAMBOVc-lkp@intel.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
When dropping keys now outside a now because we're changing the node
min/max, we need to redo the node's accounting as well.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
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>
validate_bset_keys() never properly validated k->u64s; it checked if it
was 0, but not if it was smaller than keys for the given packed format;
this fixes that small oversight.
This patch was backported, so it's adding quite a few error enums so
that they don't get renumbered and we don't have confusing gaps.
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>
new helpers:
- bch2_csum_to_text()
- bch2_csum_err_msg()
standardize our checksum error messages a bit, and print out the
checksums a bit more nicely.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Seeing weird latency issues in the btree node read path - add one
bch2_btree_node_read_done().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
single_device.merge_torture_flakey is, very rarely, finding a btree node
that doesn't match the key that points to it: this patch improves the
error message to print out more fields from the btree node header, so
that we can see what else does or does not match the key.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There's no need to drop journal pins in our exit paths - the code was
trying to have everything cleaned up on any shutdown, but better to just
tweak the assertions a bit.
This fixes a bug where calling into journal reclaim in the exit path
would cass a null ptr deref.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Control flow integrity is now checking that type signatures match on
indirect function calls. That breaks closures, which embed a work_struct
in a closure in such a way that a closure_fn may also be used as a
workqueue fn by the underlying closure code.
So we have to change closure fns to take a work_struct as their
argument - but that results in a loss of clarity, as closure fns have
different semantics from normal workqueue functions (they run owning a
ref on the closure, which must be released with continue_at() or
closure_return()).
Thus, this patc introduces CLOSURE_CALLBACK() and closure_type() macros
as suggested by Kees, to smooth things over a bit.
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Coly Li <colyli@suse.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch adds a superblock error counter for every distinct fsck
error; this means that when analyzing filesystems out in the wild we'll
be able to see what sorts of inconsistencies are being found and repair,
and hence what bugs to look for.
Errors validating bkeys are not yet considered distinct fsck errors, but
this patch adds a new helper, bkey_fsck_err(), in order to add distinct
error types for them as well.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We now track IO errors per device since filesystem creation.
IO error counts can be viewed in sysfs, or with the 'bcachefs
show-super' command.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Since we can run with unknown btree IDs, we can't directly index btree
IDs into fixed size arrays.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're using more stack than we'd like in a number of functions, and
btree_trans is the biggest object that we stack allocate.
But we have to do a heap allocatation to initialize it anyways, so
there's no real downside to heap allocating the entire thing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
More reorganization, this splits up io.c into
- io_read.c
- io_misc.c - fallocate, fpunch, truncate
- io_write.c
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It's no longer legal to use a zero size array as a flexible array
member - this causes UBSAN to complain.
This patch switches our zero size arrays to normal flexible array
members when possible, and inserts casts in other places (e.g. where we
use the zero size array as a marker partway through an array).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Awhile back, we changed bkey_format generation to ensure that the packed
representation could never represent fields larger than the unpacked
representation.
This was to ensure that bkey_packed_successor() always gave a sensible
result, but in the current code bkey_packed_successor() is only used in
a debug assertion - not for anything important.
This kills the requirement that we've gotten rid of those weird bkey
formats, and instead changes the assertion to check if we're dealing
with an old weird bkey format.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- add a to_text() method for bkey_format
- convert bch2_bkey_format_validate() to modern error message style,
where we pass a printbuf for the error string instead of returning a
static string
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds bch2_run_explicit_recovery_pass(), for rewinding recovery and
explicitly running a specific recovery pass - this is a more general
replacement for how we were running topology repair before.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This introduces major/minor versioning to the superblock version number.
Major version number changes indicate incompatible releases; we can move
forward to a new major version number, but not backwards. Minor version
numbers indicate compatible changes - these add features, but can still
be mounted and used by old versions.
With the recent patches that make it possible to roll out new btrees and
key types without breaking compatibility, we should be able to roll out
most new features without incompatible changes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- endianness fixes
- mark some things static
- fix a few __percpu annotations
- fix silent enum conversions
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
