bcachefs: Fix repair path for missing indirect extents

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

bcachefs: opts->compression can now also be applied in the background

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: Reduce would_deadlock restarts

We don't have to take locks in any particular ordering - we'll make
forward progress just fine - but if we try to stick to an ordering, it
can help to avoid excessive would_deadlock transaction restarts.

This tweaks the reflink path to take extents btree locks in the right
order.

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

bcachefs: BTREE_TRIGGER_ATOMIC

Add a new flag to be explicit about when we're running atomic triggers.

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

bcachefs: move "ptrs not changing" optimization to bch2_trigger_extent()

This is useful for btree ptrs as well, when we're just updating
sectors_written.

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

bcachefs: fsck_err()s don't need to manually check c->sb.version anymore

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

bcachefs: Combine .trans_trigger, .atomic_trigger

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

bcachefs: unify extent trigger

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

bcachefs: unify reflink_p trigger

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

bcachefs: kill mem_trigger_run_overwrite_then_insert()

now that type signatures are unified, redundant

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

bcachefs: mark now takes bkey_s

Prep work for disk space accounting rewrite: we're going to want to use
a single callback for both of our current triggers, so we need to change
them to have the same type signature first.

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

bcachefs: trans_mark now takes bkey_s

Prep work for disk space accounting rewrite: we're going to want to use
a single callback for both of our current triggers, so we need to change
them to have the same type signature first.

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

bcachefs: drop extra semicolon

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

bcachefs: Move reflink_p triggers into reflink.c

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

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>

bcachefs: Don't run indirect extent trigger unless inserting/deleting

This fixes a transaction path overflow reported in the snapshot deletion
path, when moving extents to the correct snapshot.

The root of the issue is that creating/deleting a reflink pointer can
generate an unbounded number of updates, if it is allowed to reference
an unbounded number of indirect extents; to prevent this, merging of
reflink pointers has been disabled.

But there's a hole, which is that copygc/rebalance may fragment existing
extents in the course of moving them around, and if an indirect extent
becomes too fragmented we'll then become unable to delete the reflink
pointer.

The eventual solution is going to be to tweak trigger handling so that
we can process large reflink pointers incrementally when necessary, and
notice that trigger updates don't need to be run for the part of the
reflink pointer not changing. That is going to be a bigger project
though, for another patch.

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

bcachefs: Enumerate fsck errors

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>

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>

bcachefs: All triggers are BTREE_TRIGGER_WANTS_OLD_AND_NEW

Upcoming rebalance_work btree will require extent triggers to be
BTREE_TRIGGER_WANTS_OLD_AND_NEW - so to reduce potential confusion,
let's just make all triggers BTREE_TRIGGER_WANTS_OLD_AND_NEW.

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

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>

bcachefs: Fix W=12 build errors

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

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>

bcachefs: Change check for invalid key types

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>

bcachefs: Don't reuse reflink btree keyspace

We've been seeing difficult to debug "missing indirect extent" bugs,
that fsck doesn't seem to find.

One possibility is that there was a missing indirect extent, but then a
new indirect extent was created at the location of the previous indirect
extent.

This patch eliminates that possibility by always creating new indirect
extents right after the last one, at the end of the reflink btree.

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

bcachefs: bkey_ops.min_val_size

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>

bcachefs: Don't use BTREE_ITER_INTENT in make_extent_indirect()

This is a workaround for a btree path overflow - searching with
BTREE_ITER_INTENT periodically saves the iterator position for updates,
which eventually overflows.

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

bcachefs: Drop some anonymous structs, unions

Rust bindgen doesn't cope well with anonymous structs and unions. This
patch drops the fancy anonymous structs & unions in bkey_i that let us
use the same helpers for bkey_i and bkey_packed; since bkey_packed is an
internal type that's never exposed to outside code, it's only a minor
inconvenienc.

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

bcachefs: Change bkey_invalid() rw param to flags

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

bcachefs: Unwritten extents support

- bch2_extent_merge checks unwritten bit
- read path returns 0s for unwritten extents without actually reading
- reflink path skips over unwritten extents
- bch2_bkey_ptrs_invalid() checks for extents with both written and
unwritten extents, and non-normal extents (stripes, btree ptrs) with
unwritten ptrs
- fiemap checks for unwritten extents and returns
FIEMAP_EXTENT_UNWRITTEN

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

bcachefs: Debug mode for c->writes references

This adds a debug mode where we split up the c->writes refcount into
distinct refcounts for every codepath that takes a reference, and adds
sysfs code to print the value of each ref.

This will make it easier to debug shutdown hangs due to refcount leaks.

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

bcachefs: Use for_each_btree_key_upto() more consistently

It's important that in BTREE_ITER_FILTER_SNAPSHOTS mode we always use
peek_upto() and provide an end for the interval we're searching for -
otherwise, when we hit the end of the inode the next inode be in a
different subvolume and not have any keys in the current snapshot, and
we'd iterate over arbitrarily many keys before returning one.

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

bcachefs: Convert EROFS errors to private error codes

More error code improvements - this gets us more useful error messages.

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

bcachefs: More errcode cleanup

We shouldn't be overloading standard error codes now that we have
provisions for bcachefs-specific errorcodes: this patch converts super.c
and super-io.c to per error site errcodes, with a bit of cleanup.

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

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>

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>

bcachefs: EINTR -> BCH_ERR_transaction_restart

Now that we have error codes, with subtypes, we can switch to our own
error code for transaction restarts - and even better, a distinct error
code for each transaction restart reason: clearer code and better
debugging.

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

bcachefs: Always use percpu_ref_tryget_live() on c->writes

If we're trying to get a ref and the refcount has been killed, it means
we're doing an emergency shutdown - we always want tryget_live().

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

bcachefs: Printbuf rework

This converts bcachefs to the modern printbuf interface/implementation,
synced with the version to be submitted upstream.

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

bcachefs: Plumb btree_id & level to trans_mark

For backpointers, we'll need the full key location - that means btree_id
and btree level. This patch plumbs it through.

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

bcachefs: Add rw to .key_invalid()

This adds a new parameter to .key_invalid() methods for whether the key
is being read or written; the idea being that methods can do more
aggressive checks when a key is newly created and being written, when we
wouldn't want to delete the key because of those checks.

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

bcachefs: Convert .key_invalid methods to printbufs

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

bcachefs: Move deletion of refcount=0 indirect extents to their triggers

For backpointers, we need to switch the order triggers are run in: we
need to run triggers for deletions/overwrites before triggers for
inserts.

To avoid breaking the reflink triggers, this patch moves deleting of
indirect extents with refcount=0 to their triggers, instead of doing it
when we update those keys.

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

bcachefs: Fix reflink path for snapshots

make_extent_indirect() was missing the
BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE - it's updating the extent in the
original snapshot, not the curret one.

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

bcachefs: Improve bch2_reflink_p_to_text()

.to_text methods generally ought to print all the value fields.

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

bcachefs: Inode updates should generally be BTREE_INSERT_NOFAIL

This fixes a bug where i_size may become inconsistent between the VFS
cache and the btree, when the filesystem is nearly full.

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

bcachefs: Switch fsync to use bi_journal_seq

Now that we're recording in each inode the journal sequence number of
the most recent update, fsync becomes a lot simpler and we can delete
all the plumbing for ei_journal_seq.

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

bcachefs: Fix restart handling in for_each_btree_key()

Code that uses for_each_btree_key often wants transaction restarts to be
handled locally and not returned. Originally, we wouldn't return
transaction restarts if there was a single iterator in the transaction -
the reasoning being if there weren't other iterators being invalidated,
and the current iterator was being advanced/retraversed, there weren't
any locks or iterators we were required to preserve.

But with the btree_path conversion that approach doesn't work anymore -
even when we're using for_each_btree_key() with a single iterator there
will still be two paths in the transaction, since we now always preserve
the path at the pos the iterator was initialized at - the reason being
that on restart we often restart from the same place.

And it turns out there's now a lot of for_each_btree_key() uses that _do
not_ want transaction restarts handled locally, and should be returning
them.

This patch splits out for_each_btree_key_norestart() and
for_each_btree_key_continue_norestart(), and converts existing users as
appropriate. for_each_btree_key(), for_each_btree_key_continue(), and
for_each_btree_node() now handle transaction restarts themselves by
calling bch2_trans_begin() when necessary - and the old hack to not
return transaction restarts when there's a single path in the
transaction has been deleted.

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

bcachefs: Fix for leaking of reflinked extents

When a reflink pointer points to only part of an indirect extent, and
then that indirect extent is fragmented (e.g. by copygc), if the reflink
pointer only points to one of the fragments we leak a reference.

Fix this by storing front/back pad values in reflink pointers - when
inserting reflink pointesr, we initialize them to cover the full range
of the indirect extents we reference.

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

bcachefs: bch2_trans_exit() no longer returns errors

Now that peek_node()/next_node() are converted to return errors
directly, we don't need bch2_trans_exit() to return errors - it's
cleaner this way and wasn't used much anymore.

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

bcachefs: Zero out reflink_p val in bch2_make_extent_indirect()

This bug was only discovered when we started using the 2nd word in the
val, which should have been zeroed out as those fields had never been
used before - ouch.

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

bcachefs: Convert io paths for snapshots

This plumbs around the subvolume ID as was done previously for other
filesystem code, but now for the IO paths - the control flow in the IO
paths is trickier so the changes in this patch are more involved.

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

bcachefs: Plumb through subvolume id

To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.

This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.

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

bcachefs: btree_path

This splits btree_iter into two components: btree_iter is now the
externally visible componont, and it points to a btree_path which is now
reference counted.

This means we no longer have to clone iterators up front if they might
be mutated - btree_path can be shared by multiple iterators, and cloned
if an iterator would mutate a shared btree_path. This will help us use
iterators more efficiently, as well as slimming down the main long lived
state in btree_trans, and significantly cleans up the logic for iterator
lifetimes.

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

bcachefs: Use bch2_trans_begin() more consistently

Upcoming patch will require that a transaction restart is always
immediately followed by bch2_trans_begin().

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

bcachefs: Always check for transaction restarts

On transaction restart iterators won't be locked anymore - make sure
we're always checking for errors.

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

bcachefs: Improve iter->should_be_locked

Adding iter->should_be_locked introduced a regression where it ended up
not being set on the iterator passed to bch2_btree_update_start(), which
is definitely not what we want.

This patch requires it to be set when calling bch2_trans_update(), and
adds various fixups to make that happen.

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

bcachefs: Merging for indirect extents

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

bcachefs: Clean up key merging

This patch simplifies the key merging code by getting rid of partial
merges - it's simpler and saner if we just don't merge extents when
they'd overflow k->size.

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

bcachefs: Fix a buffer overrun

In make_extent_indirect(), we were allocating too small of a buffer for
the new indirect extent.

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

bcachefs: Don't fragment extents when making them indirect

This fixes a "disk usage increased without a reservation" bug, when
reflinking compressed extents. Also, there's no good reason for reflink
to be fragmenting extents anyways.

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

bcachefs: Fsck for reflink refcounts

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

bcachefs: Fix for buffered writes getting -ENOSPC

Buffered writes may have to increase their disk reservation at btree
update time, due to compression and erasure coding being unpredictable:
O_DIRECT writes should be checking for -ENOSPC, but buffered writes have
already been accepted and should not.

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

bcachefs: Split extents if necessary in bch2_trans_update()

Currently, we handle multiple overlapping extents in the same
transaction commit by doing fixups in bch2_trans_update() - this patch
extents that to split updates when necessary. The next patch that
changes the reflink code to not fragment extents when making them
indirect will require this.

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

bcachefs: Make sure to pass a disk reservation to bch2_extent_update()

It's needed when we split an existing compressed extent - we get a null
ptr deref without it.

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

bcachefs: Require all btree iterators to be freed

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>

bcachefs: Fix a btree iterator leak

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

bcachefs: Kill reflink option

An option was added to control whether reflink support was on or off
because for a long time, reflink + inline data extent support was
missing - but that's since been fixed, so we can drop the option now.

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

bcachefs: Rename BTREE_ID enums for consistency with other enums

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

bcachefs: Reduce/kill BKEY_PADDED use

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>

bcachefs: Indirect inline data extents

When inline data extents were added, reflink was forgotten about - we
need indirect inline data extents for reflink + inline data to work
correctly.

This patch adds them, and a new feature bit that's flipped when they're
used.

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: Kill TRANS_RESET_MEM|TRANS_RESET_ITERS

All iterators should be released now with bch2_trans_iter_put(), so
TRANS_RESET_ITERS shouldn't be needed anymore, and TRANS_RESET_MEM is
always used.

Also convert more code to __bch2_trans_do().

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

bcachefs: Make sure we're releasing btree iterators

This wasn't originally required, but this is the model we're moving
towards.

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

bcachefs: Split out btree_trigger_flags

The trigger flags really belong with individual btree_insert_entries,
not the transaction commit flags - this splits out those flags and
unifies them with the BCH_BUCKET_MARK flags. Todo - split out
btree_trigger.c from buckets.c

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

bcachefs: Convert some enums to x-macros

Helps for preventing things from getting out of sync.

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

bcachefs: Kill BTREE_INSERT_ATOMIC

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

bcachefs: bch2_trans_reset() calls should be at the tops of loops

It needs to be called when we get -EINTR due to e.g. lock restart - this
fixes a transaction iterators overflow bug.

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

bcachefs: bch2_check_set_feature()

New helper function for setting incompatible feature bits

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

bcachefs: bkey_on_stack_reassemble()

Small helper function.

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

bcachefs: Rework of cut_front & cut_back

This changes bch2_cut_front and bch2_cut_back so that they're able to
shorten the size of the value, and it also changes the extent update
path to update the accounting in the btree node when this happens.

When the size of the value is shortened, they zero out the space that's
no longer used, so it's interpreted as noops (as implemented in the last
patch).

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

bcachefs: bkey_on_stack

This implements code for storing small bkeys on the stack and allocating
out of a mempool if they're too big.

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

bcachefs: Some reflink fixes

len might fit into a loff_t when aligned_len does not - make sure we use
a u64 for aligned_len. Also, we weren't always extending the inode
correctly.

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

bcachefs: Refactor bch2_trans_commit() path

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

bcachefs: Convert bch2_fpunch to bch2_extent_update()

As before - we're moving non Linux specific code out of fs-io.c.

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

bcachefs: Split out bchfs_extent_update()

The next few patches are going to be more moving the logic around
i_size/i_sectors updates to io.c, and better separating the Linux VFS
specific code from core bcachefs code, to better support the fuse port.

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

bcachefs: Check if extending inode differently

In bch2_extent_update(), we have to update the inode if i_size is
changing (the file is being extend) or if i_sectors is changing, but we
want to avoid touching the inode if it's not necessary.

Change sum_sector_overwrites() to also check if there's already data
above where we're writing to - this means we're definitely not extending
the file.

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

bcachefs: Can't be holding read locks while taking write locks

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

bcachefs: Rework btree iterator lifetimes

The btree_trans struct needs to memoize/cache btree iterators, so that
on transaction restart we don't have to completely redo btree lookups,
and so that we can do them all at once in the correct order when the
transaction had to restart to avoid a deadlock.

This switches the btree iterator lookups to work based on iterator
position, instead of trying to match them up based on the stack trace.

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

bcachefs: Kill deferred btree updates

Will be replaced by cached btree iterators

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

bcachefs: Reflink

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