These utility functions are for managing btree node state within a
btree_trans - rename them for consistency, and drop some unneeded
arguments.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Add a field to struct bset for the sector offset within the btree node
where it was written.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This closes a significant hole (and last known hole) in our ability to
verify metadata. Previously, since btree nodes are log structured, we
couldn't detect lost btree writes that weren't the first write to a
given node. Additionally, this seems to have lead to some significant
metadata corruption on multi device filesystems with metadata
replication: since a write may have made it to one device and not
another, if we read that btree node back from the replica that did have
that write and started appending after that point, the other replica
would have a gap in the bset entries and reading from that replica
wouldn't find the rest of the bsets.
But, since updates to interior btree nodes are now journalled, we can
close this hole by updating pointers to btree nodes after every write
with the currently written number of sectors, without negatively
affecting performance. This means we will always detect lost or corrupt
metadata - it also means that our btree is now a curious hybrid of COW
and non COW btrees, with all the benefits of both (excluding
complexity).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
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>
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>
btree_trans should always be passed when we have one - iter->trans is
disfavoured. This mainly updates old code in btree_update_interior.c,
some of which predates btree_trans.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Waiting on a btree node write with btree locks held can deadlock, if the
write errors: the write error path has to do do a btree update to drop
the pointer to the replica that errored.
The interior update path has to wait on in flight btree writes before
freeing nodes on disk. Previously, this was done in
bch2_btree_interior_update_will_free_node(), and could deadlock; now, we
just stash a pointer to the node and do it in
btree_update_nodes_written(), just prior to the transactional part of
the update.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't use btree_update_wq becuase btree updates may be waiting on
btree writes to complete.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
After unclean shutdown, btree writes may have completed on one device
and not others - and this inconsistency could lead us to writing new
bsets with a gap in our btree node in one of our replicas.
Fortunately, this is only an issue with bsets that are newer than the
most recent journal flush, and we already have a mechanism for detecting
and blacklisting those. We just need to make sure to start new btree
writes after the most recent _non_ blacklisted bset.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Also, clean up workqueue usage - we shouldn't be using system
workqueues, pretty much everything we do needs to be on our own
WQ_MEM_RECLAIM workqueues.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
There's a new module parameter, verify_all_btree_replicas, that enables
reading from every btree replica when reading in btree nodes and
comparing them against each other. We've been seeing some strange btree
corruption - this will hopefully aid in tracking it down and catching it
more often.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Fix a possible out of bounds write in __bch2_btree_node_write when
the data buffer padding is cleared up to the block size. The out of
bounds write is possible if the data buffers size is not a multiple
of the block size.
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This splits out btree topology repair into a separate pass, and makes
some improvements:
- When we have to pick which of two overlapping nodes to drop keys
from, we use the btree node header sequence number to preserve the
newer node
- the gc code has been changed so that it doesn't bail out if we're
continuing/ignoring on fsck error - this way the dump tool can skip
running the repair pass but still walk all reachable metadata
- add a new superblock flag indicating when a filesystem is known to
have btree topology issues, and the topology repair pass should be
run
- changing the start/end of a node might mean keys in that node have to
be deleted: this patch handles that better by splitting it out into a
separate function and running it explicitly in the topology repair
code, previously those keys were only being dropped when the btree
node was read in.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch adds self healing functionality for btree nodes - if we
notice a problem when reading a btree node, we just rewrite it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We don't want to be submitting IO with btree locks held, and btree
writes usually aren't latency sensitive.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
Useful number for performance tuning.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This just drops the offending key - in the bug report where this was
seen, it was clearly a single bit memory error, and fsck will fix the
missing key.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
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>
Bkey noops were introduced to deal with trimming inline data extents in
place in the btree: if the u64s field of a bkey was 0, that u64 was a
noop and we'd start looking for the next bkey immediately after it.
But extent handling has been lifted above the btree - we no longer
modify existing extents in place in the btree, and the compatibilty code
for old style extent btree nodes is gone, so we can completely drop this
code.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The superblock version fields need to be accurate to know whether a
filesystem is supported, thus we should be verifying them.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We keep running into occasional bugs with btree transaction iterators
overflowing - this will make those bugs more visible.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch standardizes all the enums that have associated string tables
(probably more enums should have string tables).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
KEY_TYPE_discard used to be used for extent whiteouts, but when handling
over overlapping extents was lifted above the core btree code it became
unused. This patch updates various code to reflect that.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bcachefs has been aggressively migrating filesystems and btree nodes to
the new format for quite some time - this shouldn't affect anyone
anymore, and lets us delete a _lot_ of code. Also, it frees up
KEY_TYPE_discard for a new whiteout key type for snapshots.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If a ptr gen doesn't match the bucket gen, the bucket likely doesn't
contain the data we want - but it's still possible the data we want
might have been overwritten, and for btree node pointers we can verify
whether or not the node is the one we wanted with the node's sequence
number, so it's better to keep the pointer and try reading from it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new data job type to scan for btree nodes in the old extent
format, and rewrite them.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is so that when we discover btree topology issues, we can just
update the pointer to a btree node and signal btree read path that the
min/max keys in the node header should be updated from the node pointer.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There was a race: btree node writes drop their reference on journal pins
before clearing the btree_node_write_in_flight flag.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is because we had a bug where we were writing out journal entries
with garbage last_seq, and not catching it.
Also, completely ignore jset->last_seq when JSET_NO_FLUSH is true,
because of aforementioned bug, but change the write path to set last_seq
to 0 when JSET_NO_FLUSH is true.
Minor other cleanups and comments.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
Metadata corruption bugs are hard to debug if we can't see exactly what
went wrong - try to allocate a bigger buffer so we can print out
everything we have.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If we have an error in the btree interior update path that prevents us
from journalling the update, we can't issue the corresponding btree node
write - we didn't get a journal sequence number that would cause it to
be ignored in recovery.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
it's useful to know whether an error was for a read or a write - this
also standardizes error messages a bit more.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
tracking down a bug where we see a btree node pointer in the wrong node
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_varint_decode can do reads up to 7 bytes past the end ptr, for the
sake of performance - these extra bytes are always masked off.
This won't be a problem in practice if we make sure to burn 8 bytes in
any buffer that has bkeys in it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
This only did anything in two places, and those can just be replaced
wiht bkey_cmp_left_packed()).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
Previously, we would start doing btree updates before writing the first
journal entry; if this was after an unclean shutdown, this could cause
those btree updates to not be blacklisted.
Also, move some code to headers for userspace debug tools.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
printbufs know how big the buffer is that was allocated, so we can get
rid of the random PAGE_SIZEs all over the place.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We define our own BLK_STS_REMOVED, so we need our own to_str helper too.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
