bcachefs: Fix assertion popping in transaction commit path

We can't be holding read locks on btree nodes when we go to take write
locks: this would deadlock if another thread is holding an intent lock
on the node we have a read lock on, and it tries to commit and upgrade
to a write lock.

But instead of triggering an assertion, if this happens we can just
upgrade the read lock to an intent lock.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Perf improvements for bch_alloc_read()

On large filesystems reading in the alloc info takes a significant
amount of time. But we don't need to be calling into the fully general
bch2_mark_key() path, just open code what we need in
bch2_alloc_read_fn().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix copygc dying on startup

The copygc threads errors out and makes the filesystem go RO if it ever
tries to run and discovers it has no reserve allocated - which is a
problem if it races with the allocator thread and its reserve hasn't
been filled yet.

The allocator thread doesn't start filling the copygc reserve until
after BCH_FS_STARTED has been set, so make sure to wake up the allocator
threads after setting that and before starting copygc.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix copygc of compressed data

The check for when we need to get a disk reservation was wrong.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix another lockdep splat

vfree() can allocate memory, so we need to call memalloc_nofs_save().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix errors early in the fs init process

At some point bch2_fs_alloc() was changed to always call bch2_fs_free()
in the error path, which means we need c->cl to always be initialized.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Copy ptr->cached when migrating data

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix gc of stale ptr gens

Awhile back, gcing of stale pointers was split out from full
mark-and-sweep gc - but, the bit to actually drop those stale pointers
wasn't implemnted. Whoops.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix off-by-one error in ptr gen check

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a lockdep splat

We can't allocate memory with GFP_FS while holding the btree cache lock,
and vfree() can allocate memory.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix __bch2_truncate_page()

__bch2_truncate_page() will mark some of the blocks in a page as
unallocated. But, if the page is mmapped (and writable), every block in
the page needs to be marked dirty, else those blocks won't be written by
__bch2_writepage().

The solution is to change those userspace mappings to RO, so that we
force bch2_page_mkwrite() to be called again.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix journal_seq_copy()

We also need to update the journal's bloom filter of inode numbers that
each journal write has upudates for - in case the inode gets evicted
before it gets fsynced.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix unmount path

There was a long standing race in the mount/unmount code - the VFS
intends for mount/unmount synchronizatino to be handled by the list of
superblocks, but we were still holding devices open after tearing down
our superblock in the unmount path.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't fail mount if device has been removed

Also - make sure to show the devices we actually have open in /proc

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Improvements to the journal read error paths

 - Print out more information in error messages
 - On checksum error, keep the journal entry but mark it bad so that we
   can prefer entries from other devices that don't have bad checksums

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Make sure to go rw if lazy in fsck

The paths where we delete or truncate inodes don't pass commit flags for
BTREE_INSERT_LAZY_RW, so just go rw if necessary in the fsck code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Some project id fixes

Inode options that are accessible via the xattr interface are stored
with a +1 bias, so that a value of 0 means unset. We weren't handling
this consistently.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't report inodes to statfs

We don't have a limit on the number of inodes in a filesystem, so this
is apparently the right way to report that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add a cond_resched() to bch2_alloc_write()

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a couple null ptr derefs when no disk groups exist

Normally successfully parsing a target means disk groups should exist,
but we don't want a BUG() or null ptr deref if we end up with an invalid
target.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix disk groups not being updated when set via sysfs

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Change copygc to consider bucket fragmentation

When devices have different sized buckets this is more correct.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't block on allocations when only writing to specific device

Since the copygc thread is now global and not per device, we're not
freeing up space on any one device in bounded time - and indeed we never
really were, since rebalance wasn't moving data around between devices
with that objective.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a bug with the journal_seq_blacklist mechanism

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>

bcachefs: Fix bch2_new_stripes_to_text()

painful looking typo, fortunately difficult to hit.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't disallow btree writes to RO devices

There's an inherent race with setting devices RO when they have dirty
btree nodes on them. We already check if a btree node is on an RO device
before we dirty it, so this patch just allows those writes so that we
don't have errors forcing the entire filesystem read only when trying to
remove a device.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix maximum btree node size

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Convert various code to printbuf

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>

bcachefs: Remove some uses of PAGE_SIZE in the btree code

For portability to userspace, we should try to avoid working in kernel
pages.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Ensure we wake up threads locking node when reusing it

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix bch2_btree_node_insert_fits()

It should be checking for the recently added flag
btree_node_needs_rewrite.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Ensure we only allocate one EC bucket per writepoint

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a race with BCH_WRITE_SKIP_CLOSURE_PUT

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't let copygc buckets be stolen by other threads

And assorted other copygc fixes.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Delete unused arguments

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix an error path

We were missing a 'goto retry' and continuing on with an error pointer.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Refactor replicas code

Awhile back the mechanism for garbage collecting unused replicas entries
was significantly improved, but some cleanup was missed - this patch
does that now.

This is also prep work for a patch to account for erasure coded parity
blocks separately - we need to consolidate the logic for
checking/marking the various replicas entries from one bkey into a
single function.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't restrict copygc writes to the same device

This no longer makes any sense, since copygc is now one thread per
filesystem, not per device, with a single write point.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add bch2_blk_status_to_str()

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>

bcachefs: Fix a faulty assertion

Now that updates to interior nodes are journalled, we shouldn't be
checking topology of interior nodes until we've finished replaying
updates to that node.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Wrap write path in memalloc_nofs_save()

This fixes a lockdep splat where we're allocating memory with vmalloc in
the compression bounce path, which doesn't always obey GFP_NOFS.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add an option for rebuilding the replicas section

There is a bug where we cnan end up clearing the data_has field in the
superblock members section, which causes us to skip reading the journal
and thus journal replay fails. This option tells the recovery path to
not trust those fields.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Make copygc thread global

Per device copygc threads don't move data to different devices and they
make fragmentation works - they don't make much sense anymore.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Drop extra pointers when marking data as in a stripe

We ideally want the buckets used for the extra initial replicas to be
reused right away.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix extent_ptr_durability() calculation for erasure coded data

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Use x-macros for data types

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix short buffered writes

In the buffered write path, we have to check for short writes that write
to the full page, where the page wasn't UpToDate; when this happens, the
page is partly garbage, so we have to zero it out and revert that part
of the write.

This check was wrong - we reverted total from copied, but didn't revert
the iov_iter, probably also leading to corrupted writes.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Allow existing stripes to be updated with new data buckets

This solves internal fragmentation within stripes. We already have
copygc, which evacuates buckets that are partially or mostly empty, but
it's up to the ec code that manages stripes to deal with stripes that
have empty buckets in them.

This patch changes the path for creating new stripes to check if there's
existing stripes with empty buckets - and if so, update them with new
data buckets instead of creating new stripes.

TODO: improve the disk space accounting so that we can only use this
(more expensive path) when we have too much fragmentation in existing
stripes.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Refactor stripe creation

Prep work for the patch to update existing stripes with new data blocks.
This moves allocating new stripes into ec.c, and also sets up the data
structures so that we can handly only allocating some of the blocks in a
stripe.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Move stripe creation to workqueue

This is mainly to solve a lock ordering issue, and also simplifies the
code a bit.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Improve stripe triggers/heap code

Soon we'll be able to modify existing stripes - replacing empty blocks
with new blocks and new p/q blocks. This patch updates the trigger code
to handle pointers changing in an existing stripe; also, it
significantly improves how the stripes heap works, which means we can
get rid of the stripe creation/deletion lock.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Rework triggers interface

The trigger for stripe keys is shortly going to need both the old and
the new key passed to the trigger - this patch does that rework.

For now, this just changes the in memory triggers, and this doesn't
change how extent triggers work.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Kill BTREE_TRIGGER_NOOVERWRITES

This is prep work for reworking the triggers machinery - we have
triggers that need to know both the old and the new key.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Mark btree nodes as needing rewrite when not all replicas are RW

This fixes a bug where recovery fails when one of the devices is read
only.

Also - consolidate the "must rewrite this node to insert it" behind a
new btree node flag.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Use blk_status_to_str()

Improved error messages are always a good thing

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't cap ios in dio write path at 2 MB

It appears this was erronious, a different bug was responsible

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Refactor dio write code to reinit bch_write_op

This fixes a bug where the BCH_WRITE_SKIP_CLOSURE_PUT was set
incorrectly, causing the completion to be delivered multiple times.
oops.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix bch2_extent_can_insert() not being called

It's supposed to check whether we're splitting a compressed extent and
if so get a bigger disk reservation - hence this fixes a "disk usage
increased by x without a reservaiton" bug.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a null ptr deref in bch2_btree_iter_traverse_one()

We use sentinal values that aren't NULL to indicate there's a btree node
at a higher level; occasionally, this may result in
btree_iter_up_until_good_node() stopping at one of those sentinal
values.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Track sectors of erasure coded data

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Use btree reserve when appropriate

Whenever we're doing an update that has pointers, that generally means
we need to do the update in order to release open bucket references - so
we should be using the btree open bucket reserve.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add a kthread_should_stop() check to allocator thread

Turns out it's possible during shutdown for the allocator to get stuck
spinning on bch2_invalidate_buckets() without hitting any of the other
checks.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Change bch2_dump_bset() to also print key values

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a deadlock in the RO path

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix incorrect gfp check

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix lock ordering with new btree cache code

The code that checks lock ordering was recently changed to go off of the
pos of the btree node, rather than the iterator, but the btree cache
code didn't update to handle iterators that point to cached bkeys. Oops

Also, update various debug code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: delete a slightly faulty assertion

state lock isn't held at startup

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Increase size of btree node reserve

Also tweak the allocator to be more aggressive about keeping it full.
The recent changes to make updates to interior nodes transactional (and
thus generate updates to the alloc btree) all put more stress on the
btree node reserves.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Give bkey_cached_key same attributes as bpos

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Use cached iterators for alloc btree

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Btree key cache

This introduces a new kind of btree iterator, cached iterators, which
point to keys cached in a hash table. The cache also acts as a write
cache - in the update path, we journal the update but defer updating the
btree until the cached entry is flushed by journal reclaim.

Cache coherency is for now up to the users to handle, which isn't ideal
but should be good enough for now.

These new iterators will be used for updating inodes and alloc info (the
alloc and stripes btrees).

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Implement a new gc that only recalcs oldest gen

Full mark and sweep gc doesn't (yet?) work with the new btree key cache
code, but it also blocks updates to interior btree nodes for the
duration and isn't really necessary in practice; we aren't currently
attempting to repair errors in allocation info at runtime.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Turn c->state_lock into an rwsem

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add an internal option for reading entire journal

To be used the debug tool that dumps the contents of the journal.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't deadlock when btree node reuse changes lock ordering

Btree node lock ordering is based on the logical key. However, 'struct
btree' may be reused for a different btree node under memory pressure.
This patch uses the new six lock callback to check if a btree node is no
longer the node we wanted to lock before blocking.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a deadlock

__bch2_btree_node_lock() was incorrectly using iter->pos as a proxy for
btree node lock ordering, this caused an off by one error that was
triggered by bch2_btree_node_get_sibling() getting the previous node.

This refactors the code to compare against btree node keys directly.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Refactor btree insert path

This splits out the journalling code from the btree update code; prep
work for the btree key cache.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Always give out journal pre-res if we already have one

This is better than skipping the journal pre-reservation if we already
have one - we should still acount for the journal reservation we're
going to have to get.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: More open buckets

We need a larger open bucket reserve now that the btree interior update
path holds onto open bucket references; filesystems with many high
through devices may need more open buckets now.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't allocate memory under the btree cache lock

The btree cache lock is needed for reclaiming from the btree node cache,
and memory allocation can potentially spin and sleep (for 100 ms at a
time), so.. don't do that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a linked list bug

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Make open bucket reserves more conservative

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: btree_update_nodes_written() requires alloc reserve

Also, in the btree_update_start() path, if we already have a journal
pre-reservation we don't want to take another - that's a deadlock.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Check gfp_flags correctly in bch2_btree_cache_scan()

bch2_btree_node_mem_alloc() uses memalloc_nofs_save()/GFP_NOFS, but
GFP_NOFS does include __GFP_IO - oops. We used to use GFP_NOIO, but as
we're a filesystem now GFP_NOFS makes more sense now and is looser.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Call bch2_btree_iter_traverse() if necessary in commit path

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: bch2_trans_downgrade()

bch2_btree_iter_downgrade() was looping over all iterators in a
transaction; bch2_trans_downgrade() should be doing that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Improve warning for copygc failing to move data

This will help narrow down which code is at fault when this happens.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Always increment bucket gen on bucket reuse

Not doing so confuses copygc

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Kill old allocator startup code

It's not needed anymore since we can now write to buckets before
updating the alloc btree.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Improve assorted error messages

This also consolidates the various checks in bch2_mark_pointer() and
bch2_trans_mark_pointer().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix a deadlock in bch2_btree_node_get_sibling()

There was a bad interaction with bch2_btree_iter_set_pos_same_leaf(),
which can leave a btree node locked that is just outside iter->pos,
breaking the lock ordering checks in __bch2_btree_node_lock(). Ideally
we should get rid of this corner case, but for now fix it locally with
verbose comments.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add debug code to print btree transactions

Intented to help debug deadlocks, since we can't use lockdep to check
btree node lock ordering.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Set filesystem features earlier in fs init path

Before we were setting features after allocating btree nodes, which
meant we were using the old btree pointer format.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add an option to disable reflink support

Reflink might be buggy, so we're adding an option so users can help
bisect what's going on.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fixes for going RO

Now that interior btree updates are fully transactional, we don't need
to write out alloc info in a loop. However, interior btree updates do
put more things in the journal, so we still need a loop in the RO
sequence.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Don't require alloc btree to be updated before buckets are used

This is to break a circular dependency in the shutdown path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: fsck_error_lock requires GFP_NOFS

this fixes a lockdep splat

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Interior btree updates are now fully transactional

We now update the alloc info (bucket sector counts) atomically with
journalling the update to the interior btree nodes, and we also set new
btree roots atomically with the journalled part of the btree update.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Factor out bch2_fs_btree_interior_update_init()

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Add a mechanism for passing extra journal entries to bch2_trans_commit()

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>