This runs on extents that haven't yet been validated, so we don't want
to assert that we have a valid entry type.
Reported-by: syzbot+4f29c3f12f864d8a8d17@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We had a bug report where the data update path was creating an extent
that failed to validate because it had too many pointers; almost all of
them were cached.
To fix this, we have:
- want_cached_ptr(), a new helper that checks if we even want a cached
pointer (is on appropriate target, device is readable).
- bch2_extent_set_ptr_cached() now only sets a pointer cached if we want
it.
- bch2_extent_normalize_by_opts() now ensures that we only have a single
cached pointer that we want.
While working on this, it was noticed that this doesn't work well with
reflinked data and per-file options. Another patch series is coming that
plumbs through additional io path options through bch_extent_rebalance,
with improved option handling.
Reported-by: Reed Riley <reed@riley.engineer>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_bkey_drop_ptrs() had a some complicated machinery for avoiding
O(n^2) when dropping multiple pointers - but when n is only going to be
~4, it's not worth it.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was caught as a very rare nonce inconsistency, on systems with
encryption and replication (and tiering, or some form of rebalance
operation running):
[Wed Jul 17 13:30:03 2024] about to insert invalid key in data update path
[Wed Jul 17 13:30:03 2024] old: u64s 10 type extent 671283510:6392:U32_MAX len 16 ver 106595503: durability: 2 crc: c_size 8 size 16 offset 0 nonce 0 csum chacha20_poly1305_80 compress zstd ptr: 3:355968:104 gen 7 ptr: 4:513244:48 gen 6 rebalance: target hdd compression zstd
[Wed Jul 17 13:30:03 2024] k: u64s 10 type extent 671283510:6400:U32_MAX len 16 ver 106595508: durability: 2 crc: c_size 8 size 16 offset 0 nonce 0 csum chacha20_poly1305_80 compress zstd ptr: 3:355968:112 gen 7 ptr: 4:513244:56 gen 6 rebalance: target hdd compression zstd
[Wed Jul 17 13:30:03 2024] new: u64s 14 type extent 671283510:6392:U32_MAX len 8 ver 106595508: durability: 2 crc: c_size 8 size 16 offset 0 nonce 0 csum chacha20_poly1305_80 compress zstd ptr: 3:355968:112 gen 7 cached ptr: 4:513244:56 gen 6 cached rebalance: target hdd compression zstd crc: c_size 8 size 16 offset 8 nonce 0 csum chacha20_poly1305_80 compress zstd ptr: 1:10860085:32 gen 0 ptr: 0:17285918:408 gen 0
[Wed Jul 17 13:30:03 2024] bcachefs (cca5bc65-fe77-409d-a9fa-465a6e7f4eae): fatal error - emergency read only
bch2_extents_match() was reporting true for extents that did not
actually point to the same data.
bch2_extent_match() iterates over pairs of pointers, looking for
pointers that point to the same location on disk (with matching
generation numbers). However one or both extents may have been trimmed
(or merged) and they might not have the same disk offset: it corrects
for this by subtracting the key offset and the checksum entry offset.
However, this failed when an extent was immediately partially
overwritten, and the new overwrite was allocated the next adjacent disk
space.
Normally, with compression off, this would never cause a bug, since the
new extent would have to be immediately after the old extent for the
pointer offsets to match, and the rebalance index update path is not
looking for an extent outside the range of the extent it moved.
However with compression enabled, extents take up less space on disk
than they do in the btree index space - and spuriously matching after
partial overwrite is possible.
To fix this, add a secondary check, that strictly checks that the
regions pointed to on disk overlap.
https://github.com/koverstreet/bcachefs/issues/717
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
rebalance_work was keying off of the presence of rebelance_opts in the
extent - but that was incorrect, we keep those around after rebalance
for indirect extents since the inode's options are not directly
available
Fixes: 20ac515a9c ("bcachefs: bch_acct_rebalance_work")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We don't have sufficient information to debug:
https://github.com/koverstreet/bcachefs/issues/726
- print out durability of extent ptrs, when non default
- print the number of replicas we need in data_update_to_text()
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>
This repurposes the promote path, which already knows how to call
data_update() after a read: we now automatically rewrite bad data when
we get a read error and then successfully retry from a different
replica.
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>
If a btree root or interior btree node goes bad, we're going to lose a
lot of data, unless we can recover the nodes that it pointed to by
scanning.
Fortunately btree node headers are fully self describing, and
additionally the magic number is xored with the filesytem UUID, so we
can do so safely.
This implements the scanning - next patch will rework topology repair to
make use of the found nodes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The "apply this compression method in the background" paths now use the
compression option if background_compression is not set; this means that
setting or changing the compression option will cause existing data to
be compressed accordingly in the background.
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>
This fixes a bug where rebalance would loop repeatedly on the same
extents.
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Durability of an erasure coded pointer doesn't add the device
durability; durability is the same for any extent in that stripe so the
calculation only comes from the stripe.
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>
This adds a new btree, rebalance_work, to eliminate scanning required
for finding extents that need work done on them in the background - i.e.
for the background_target and background_compression options.
rebalance_work is a bitset btree, where a KEY_TYPE_set corresponds to an
extent in the extents or reflink btree at the same pos.
A new extent field is added, bch_extent_rebalance, which indicates that
this extent has work that needs to be done in the background - and which
options to use. This allows per-inode options to be propagated to
indirect extents - at least in some circumstances. In this patch,
changing IO options on a file will not propagate the new options to
indirect extents pointed to by that file.
Updating (setting/clearing) the rebalance_work btree is done by the
extent trigger, which looks at the bch_extent_rebalance field.
Scanning is still requrired after changing IO path options - either just
for a given inode, or for the whole filesystem. We indicate that
scanning is required by adding a KEY_TYPE_cookie key to the
rebalance_work btree: the cookie counter is so that we can detect that
scanning is still required when an option has been flipped mid-way
through an existing scan.
Future possible work:
- Propagate options to indirect extents when being changed
- Add other IO path options - nr_replicas, ec, to rebalance_work so
they can be applied in the background when they change
- Add a counter, for bcachefs fs usage output, showing the pending
amount of rebalance work: we'll probably want to do this after the
disk space accounting rewrite (moving it to a new btree)
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes the device removal tests, which have been failing at random
due to the fact that when we're running the .key_invalid checks in the
write path the key may actually no longer exist - we might be racing
with the keys being deleted.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
As part of the forward compatibility patch series, we need to allow for
new key types without complaining loudly when running an old version.
This patch changes the flags parameter of bkey_invalid to an enum, and
adds a new flag to indicate we're being called from the transaction
commit path.
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>
This adds the extent entry for extents that rebalance needs to do
something with.
We're adding this ahead of the main rebalance_work patchset, because
adding new extent entries can't be done in a forwards-compatible way.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new helper for getting a pointer's durability irrespective
of the device state, and uses it in the the data update path.
This fixes a bug where we do a data update but request 0 replicas to be
allocated, because the replica being rewritten is on a device marked as
failed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new field to bkey_ops for the minimum size of the value,
which standardizes that check and also enforces the new rule (previously
done somewhat ad-hoc) that we can extend value types by adding new
fields on to the end.
To make that work we do _not_ initialize min_val_size with sizeof,
instead we initialize it to the size of the first version of those
values.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch deletes a .key_invalid check for btree pointers that only
applies to _very_ old on disk format versions, and potentially
complicates the upgrade process.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
