Commit Graph

56 Commits

Author SHA1 Message Date
Kent Overstreet
cb52d23e77 bcachefs: Rename BTREE_INSERT flags
BTREE_INSERT flags are actually transaction commit flags - rename them
for clarity.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:37 -05:00
Kent Overstreet
7b474c77da bcachefs: Fix promotes
The recent work to fix data moves w.r.t. durability broke promotes,
because the caused us to bail out when the extent minus pointers being
dropped still has enough pointers to satisfy the current number of
replicas.

Disable this check when we're adding cached replicas.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-26 19:31:11 -05:00
Kent Overstreet
bedd6fe4d3 bcachefs: Fix nocow locks deadlock
On trylock failure we were waiting for outstanding reads to complete -
but nocow locks need to be held until the whole move is finished.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-11 20:43:11 -05:00
Kent Overstreet
131898b0cb bcachefs: Fix bch2_extent_drop_ptrs() call
Also, make bch2_extent_drop_ptrs() safer, so it works with extents and
non-extents iterators.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-04 16:04:55 -05:00
Kent Overstreet
7d9f8468ff bcachefs: Data update path won't accidentaly grow replicas
Previously, there was a bug where if an extent had greater durability
than required (because we needed to move a durability=1 pointer and
ended up putting it on a durability 2 device), we would submit a write
for replicas=2 - the durability of the pointer being rewritten - instead
of the number of replicas required to bring it back up to the
data_replicas option.

This, plus the allocation path sometimes allocating on a greater
durability device than requested, meant that extents could continue
having more and more replicas added as they were being rewritten.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-25 21:48:42 -05:00
Kent Overstreet
701ff57eb3 bcachefs: Check for nonce offset inconsistency in data_update path
We've rarely been seeing a nonce offset inconsistency that doesn't show
up in tests: this adds some extra verification code to the data update
path that prints out more relevant info when it occurs.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-13 21:45:03 -05:00
Kent Overstreet
be9e782df3 bcachefs: Don't downgrade locks on transaction restart
We should only be downgrading locks on success - otherwise, our
transaction restarts won't be getting the correct locks and we'll
livelock.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-01 21:11:08 -04:00
Kent Overstreet
fb3f57bb11 bcachefs: rebalance_work
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>
2023-11-01 21:11:05 -04:00
Kent Overstreet
96a363a7e6 bcachefs: move: move_stats refactoring
data_progress_list is gone - it was redundant with moving_context_list

The upcoming rebalance rewrite is going to have it using two different
move_stats objects with the same moving_context, depending on whether
it's scanning or using the rebalance_work btree - this patch plumbs
stats around a bit differently so that will work.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-31 12:18:38 -04:00
Kent Overstreet
d5eade9345 bcachefs: move: convert to bbpos
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-31 12:18:37 -04:00
Kent Overstreet
633169035a bcachefs: moving_context now owns a btree_trans
btree_trans and moving_context are used together, and having the
moving_context owns the transaction object reduces some plumbing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-31 12:18:37 -04:00
Kent Overstreet
6bd68ec266 bcachefs: Heap allocate btree_trans
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>
2023-10-22 17:10:13 -04:00
Kent Overstreet
96dea3d599 bcachefs: Fix W=12 build errors
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:13 -04:00
Kent Overstreet
1809b8cba7 bcachefs: Break up io.c
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>
2023-10-22 17:10:12 -04:00
Kent Overstreet
93ee2c4b21 bcachefs: Don't open code closure_nr_remaining()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:10 -04:00
Kent Overstreet
986e9842fb bcachefs: Compression levels
This allows including a compression level when specifying a compression
type, e.g.
  compression=zstd:15

Values from 1 through 15 indicate compression levels, 0 or unspecified
indicates the default.

For LZ4, values 3-15 specify that the HC algorithm should be used.

Note that for compatibility, extents themselves only include the
compression type, not the compression level. This means that specifying
the same compression algorithm but different compression levels for the
compression and background_compression options will have no effect.

XXX: perhaps we could add a warning for this

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:07 -04:00
Kent Overstreet
f33c58fc46 bcachefs: Kill BTREE_INSERT_USE_RESERVE
Now that we have journal watermarks and alloc watermarks unified,
BTREE_INSERT_USE_RESERVE is redundant and can be deleted.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:05 -04:00
Kent Overstreet
e53a961c6b bcachefs: Rename enum alloc_reserve -> bch_watermark
This is prep work for consolidating with JOURNAL_WATERMARK.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:04 -04:00
Kent Overstreet
91ecd41b7f bcachefs: bch2_extent_ptr_desired_durability()
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>
2023-10-22 17:10:04 -04:00
Kent Overstreet
ad520141b1 bcachefs: Fix corruption with writeable snapshots
When partially overwriting an extent in an older snapshot, the existing
extent has to be split.

If the existing extent was overwritten in a different (sibling)
snapshot, we have to ensure that the split won't be visible in the
sibling snapshot.

data_update.c already has code for this,
bch2_insert_snapshot_writeouts() - we just need to move it into
btree_update_leaf.c and change bch2_trans_update_extent() to use it as
well.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:03 -04:00
Kent Overstreet
c26463ce99 bcachefs: Fix move_extent_fail counter
fail counters need to be events, not numbers of sectors - or the
calculations the tests use for determining if we've had too many
slowpath events don't work.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:02 -04:00
Kent Overstreet
bcb79a51cb bcachefs: bch2_bkey_get_iter() helpers
Introduce new helpers for a common pattern:

  bch2_trans_iter_init();
  bch2_btree_iter_peek_slot();

 - bch2_bkey_get_iter_type() returns -ENOENT if it doesn't find a key of
   the correct type
 - bch2_bkey_get_val_typed() copies the val out of the btree to a
   (typically stack allocated) variable; it handles the case where the
   value in the btree is smaller than the current version of the type,
   zeroing out the remainder.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:00 -04:00
Kent Overstreet
5a21764db1 bcachefs: Improve move path tracepoints
Move path tracepoints now include the key being moved. Also, add new
tracepoints for the start of move_extent, and evacuate_bucket.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:00 -04:00
Kent Overstreet
bb6c4b92fd bcachefs: Improve trace_move_extent_fail()
This greatly expands the move_extent_fail tracepoint - now it includes
all the information we have available, including exactly why the extent
wasn't updated.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:59 -04:00
Kent Overstreet
25d8f40560 bcachefs: Data update path no longer leaves cached replicas
It turns out that it's currently impossible to invalidate buckets
containing only cached data if they're part of a stripe. The normal
bucket invalidate path can't do it because we have to be able to
incerement the bucket's gen, which isn't correct becasue it's still a
member of the stripe - and the bucket invalidate path makes the bucket
availabel for reuse right away, which also isn't correct for buckets in
stripes.

What would work is invalidating cached data by following backpointers,
except that cached replicas don't currently get backpointers - because
they would be awkward for the existing bucket invalidate path to delete
and they haven't been needed elsewhere.

So for the time being, to prevent running out of space in stripes,
switch the data update path to not leave cached replicas; we may revisit
this in the future.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:58 -04:00
Kent Overstreet
b40901b0f7 bcachefs: New erasure coding shutdown path
This implements a new shutdown path for erasure coding, which is needed
for the upcoming BCH_WRITE_WAIT_FOR_EC write path.

The process is:
 - Cancel new stripes being built up
 - Close out/cancel open buckets on write points or the partial list
   that are for stripes
 - Shutdown rebalance/copygc
 - Then wait for in flight new stripes to finish

With BCH_WRITE_WAIT_FOR_EC, move ops will be waiting on stripes to fill
up before they complete; the new ec shutdown path is needed for shutting
down copygc/rebalance without deadlocking.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:57 -04:00
Kent Overstreet
57c723de7d bcachefs: Rework __bch2_data_update_index_update()
This makes some improvements to the logic for adding/removing replicas,
as part of the larger erasure coding improvements. We now directly
consider number of replicas desired for the given inode, and
extent/pointer durability: this ensures that the extent ends up with the
desired number of replicas when we're replacing multiple pointers with
one that has higher durability (e.g. erasure coded).

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:56 -04:00
Kent Overstreet
702ffea204 bcachefs: Extent helper improvements
- __bch2_bkey_drop_ptr() -> bch2_bkey_drop_ptr_noerror(), now available
   outside extents.

 - Split bch2_bkey_has_device() and bch2_bkey_has_device_c(), const and
   non const versions

 - bch2_extent_has_ptr() now returns the pointer it found

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:56 -04:00
Kent Overstreet
2f528663c5 bcachefs: moving_context->stats is allowed to be NULL
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:55 -04:00
Kent Overstreet
11bb67a4a3 bcachefs: bch2_data_update_init() considers ptr durability
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:55 -04:00
Kent Overstreet
039c45feef bcachefs: bch2_data_update_index_update() -> bch2_trans_run()
Convert to use the standard helper

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:54 -04:00
Kent Overstreet
33669e0cc9 bcachefs: Add option for completely disabling nocow
This adds an option for completely disabling nocow mode, including the
locking in the data move path.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:54 -04:00
Kent Overstreet
c9163bb03b bcachefs: Cached pointers should not be erasure coded
There's no reason to erasure code cached pointers: we'll always have
another copy, and it'll be cheaper to read the other copy than do a
reconstruct read. And erasure coded cached pointers would add
complications that we'd rather not have to deal with, so let's make sure
to disallow them.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:54 -04:00
Kent Overstreet
f2a53270c7 bcachefs: Fix insert_snapshot_whiteouts()
- We were failing to set the key type on the whiteouts it was creating,
   oops.

 - Also, we need to create whiteouts when generating front splits, not
   just back splits.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:53 -04:00
Kent Overstreet
2798143aa8 bcachefs: bch2_btree_insert_nonextent()
This adds a new helper to delete some redundant code in
bch2_trans_update_extent().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:53 -04:00
Kent Overstreet
09d70d0be1 bcachefs: Nocow locking fixup
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00
Daniel Hill
3482dd6a25 bcachefs: don't block reads if we're promoting
The promote path calls data_update_init() and now that we take locks here,
there's potential for promote to block our read path, just error
when we can't take the lock instead of blocking.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00
Kent Overstreet
7ffb6a7ec6 bcachefs: Fix deadlock on nocow locks in data move path
The recent nocow locking rework introduced a deadlock in the data move
path: the new nocow locking scheme uses a hash table with a fixed size
array for chaining, meaning on hash collision we may have to wait for
other locks to be released before we can lock a bucket.

And since the data move path needs to submit writes from the same thread
that's taking nocow locks and submitting reads, this introduces a
deadlock.

This shouldn't happen often in practice, but since the data move path
can keep large numbers of IOs in flight simultaneously, it's something
we have to handle.

This patch makes move_ctxt_wait_event() available to
bch2_data_update_init() and uses it when appropriate, which is our
normal solution to this kind of thing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00
Kent Overstreet
350175bf9b bcachefs: Improved nocow locking
This improves the nocow lock table so that hash table entries have
multiple locks, and locks specify which bucket they're for - i.e. we can
now resolve hash collisions.

This is important because the allocator has to skip buckets that are
locked in the nocow lock table, and previously hash collisions would
cause it to spuriously skip unlocked buckets.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00
Daniel Hill
f3a37e76ca bcachefs: handle failed data_update_init cleanup
data_update_init allocates several resources, but we forget to clean
these up when it fails.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00
Kent Overstreet
a8b3a677e7 bcachefs: Nocow support
This adds support for nocow mode, where we do writes in-place when
possible. Patch components:

 - New boolean filesystem and inode option, nocow: note that when nocow
   is enabled, data checksumming and compression are implicitly disabled

 - To prevent in-place writes from racing with data moves
   (data_update.c) or bucket reuse (i.e. a bucket being reused and
   re-allocated while a nocow write is in flight, we have a new locking
   mechanism.

   Buckets can be locked for either data update or data move, using a
   fixed size hash table of two_state_shared locks. We don't have any
   chaining, meaning updates and moves to different buckets that hash to
   the same lock will wait unnecessarily - we'll want to watch for this
   becoming an issue.

 - The allocator path also needs to check for in-place writes in flight
   to a given bucket before giving it out: thus we add another counter
   to bucket_alloc_state so we can track this.

 - Fsync now may need to issue cache flushes to block devices instead of
   flushing the journal. We add a device bitmask to bch_inode_info,
   ei_devs_need_flush, which tracks devices that need to have flushes
   issued - note that this will lead to unnecessary flushes when other
   codepaths have already issued flushes, we may want to replace this with
   a sequence number.

 - New nocow write path: look up extents, and if they're writable write
   to them - otherwise fall back to the normal COW write path.

XXX: switch to sequence numbers instead of bitmask for devs needing
journal flush

XXX: ei_quota_lock being a mutex means bch2_nocow_write_done() needs to
run in process context - see if we can improve this

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:51 -04:00
Kent Overstreet
4dcd1cae72 bcachefs: Data update support for unwritten extents
The data update path requires special support for unwritten extents - we
still need to be able to move them, but there's no need to read or write
anything.

This patch adds a new error code to tell bch2_move_extent() that we're
short circuiting the read, and adds bch2_update_unwritten_extent() to
create a reservation then call __bch2_data_update_index_update().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:51 -04:00
Kent Overstreet
b08b492ed3 bcachefs: Drop old maybe_extending optimization
The extend update path had an optimization to avoid updating the inode
if we knew we were definitely not extending the file. But now that we're
updating inodes on every extent update - for fsync - that code can be
deleted.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:51 -04:00
Kent Overstreet
c9828cea31 bcachefs: Delete in memory ec backpointers
Post btree backpointers, these aren't needed anymore.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:51 -04:00
Kent Overstreet
d7dd3fb84f bcachefs: Fix rereplicate when we already have a cached pointer
When we need to add more replicas to an extent, it might be the case
that we already have a replica on every device, but some of them are
cached.

This patch fixes a bug where we'd spin on that extent because the write
path fails to find a device we can allocate from: we allow allocating
from devices that already have cached replicas on them, and change
bch2_data_update_index_update() to drop the cached replica if needed.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:49 -04:00
Kent Overstreet
e88a75ebe8 bcachefs: New bpos_cmp(), bkey_cmp() replacements
This patch introduces
 - bpos_eq()
 - bpos_lt()
 - bpos_le()
 - bpos_gt()
 - bpos_ge()

and equivalent replacements for bkey_cmp().

Looking at the generated assembly these could probably be improved
further, but we already see a significant code size improvement with
this patch.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:47 -04:00
Kent Overstreet
a1ee777bfc bcachefs: Kill BCH_WRITE_FLUSH
BCH_WRITE_FLUSH is a write flag that causes a journal flush.  It's only
used in the direct IO path, and this will allow for some consolidation
with the regular fsync path, which will help with the upcoming nocow
mode.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:45 -04:00
Kent Overstreet
d4bce63636 bcachefs: Kill BCH_WRITE_JOURNAL_SEQ_PTR
Dead code, delete.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:45 -04:00
Kent Overstreet
3e3e02e6bc bcachefs: Assorted checkpatch fixes
checkpatch.pl gives lots of warnings that we don't want - suggested
ignore list:

 ASSIGN_IN_IF
 UNSPECIFIED_INT	- bcachefs coding style prefers single token type names
 NEW_TYPEDEFS		- typedefs are occasionally good
 FUNCTION_ARGUMENTS	- we prefer to look at functions in .c files
			  (hopefully with docbook documentation), not .h
			  file prototypes
 MULTISTATEMENT_MACRO_USE_DO_WHILE
			- we have _many_ x-macros and other macros where
			  we can't do this

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:44 -04:00
Kent Overstreet
1be887979b bcachefs: Handle dropping pointers in data_update path
Cached pointers are generally dropped, not moved: this led to an
assertion firing in the data update path when there were no new replicas
being written.

This path adds a data_options field for pointers to be dropped, and
tweaks move_extent() to check if we're only dropping pointers, not
writing new ones, before kicking off a data update operation.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:42 -04:00