bcachefs: Fix missing write refs in fs fio paths

bch2_journal_flush_seq requires us to have a write ref

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

bcachefs: Reconstruct missing snapshot nodes

When the snapshots btree is going, we'll have to delete huge amounts of
data - unless we can reconstruct it by looking at the keys that refer to
it.

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

bcachefs: Flag btrees with missing data

We need this to know when we should attempt to reconstruct the snapshots
btree

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

bcachefs: Repair pass for scanning for btree nodes

If a btree root or interior btree node goes bad, we're going to lose a
lot of data, unless we can recover the nodes that it pointed to by
scanning.

Fortunately btree node headers are fully self describing, and
additionally the magic number is xored with the filesytem UUID, so we
can do so safely.

This implements the scanning - next patch will rework topology repair to
make use of the found nodes.

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

bcachefs: Split out recovery_passes.c

We've grown a fair amount of code for managing recovery passes; tracking
which ones we're running, which ones need to be run, and flagging in the
superblock which ones need to be run on the next recovery.

So it's worth splitting out into its own file, this code is pretty
different from the code in recovery.c.

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

bcachefs: Move snapshot table size to struct snapshot_table

We need to add bounds checking for snapshot table accesses - it turns
out there are cases where we do need to use the snapshots table before
fsck checks have completed (and indeed, fsck may not have been run).

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

bcachefs: Split out btree_node_rewrite_worker

This fixes a deadlock due to using btree_interior_update_worker for non
interior updates - async btree node rewrites were blocking, and then
blocking other interior updates.

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

bcachefs: time_stats: split stats-with-quantiles into a separate structure

Currently, struct time_stats has the optional ability to quantize the
information that it collects. This is /probably/ useful for callers who
want to see quantized information, but it more than doubles the size of
the structure from 224 bytes to 464. For users who don't care about
that (e.g. upcoming xfs patches) and want to avoid wasting 240 bytes per
counter, split the two into separate pieces.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: pull out time_stats.[ch]

prep work for lifting out of fs/bcachefs/

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

bcachefs: Rename journal_keys.d -> journal_keys.data

This will let us use some darray helpers in the next patch.

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

bcachefs: Split out discard fastpath

Buckets usually can't be discarded until the transaction that made them
empty has been committed in the journal.

Tracing has indicated that we're queuing the discard worker excessively,
only for it to skip over many buckets that are still waiting on a
journal commit, discarding only one or two buckets per iteration.

We want to switch to only queuing the discard worker after a journal
flush write, but there's an important optimization we need to preserve:
if a bucket becomes empty and it was never committed in the journal
while it was in use, we want to discard it and reuse it right away -
since overwriting it before the previous writes are flushed from the
device cache eans those writes only cost bus bandwidth.

So, this patch implements a fast path for buckets that can be discarded
right away. We need new locking between the two discard workers; the new
list of buckets being discarded provides that locking.

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

bcachefs: bch2_print_opts()

Make sure early error messages get redirected, for
kernel-fsck-from-userland.

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

bcachefs: BTREE_ID_subvolume_children

Add a btree to record a parent -> child subvolume relationships,
according to the filesystem heirarchy.

The subvolume_children btree is a bitset btree: if a bit is set at pos
p, that means p.offset is a child of subvolume p.inode.

This will be used for efficiently listing subvolumes, as well as
recursive deletion.

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

bcachefs: Clamp replicas_required to replicas

This prevents going emergency read only when the user has specified
replicas_required > replicas.

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

bcachefs: Prep work for variable size btree node buffers

bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.

And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.

Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.

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

bcachefs: add time_stats for btree_node_read_done()

Seeing weird latency issues in the btree node read path - add one
bch2_btree_node_read_done().

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

bcachefs: Online fsck can now fix errors

BCH_FS_fsck_done -> BCH_FS_fsck_running; set when we might be fixing
fsck errors. Also; set fix_errors to ask by default when fsck is
running.

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

bcachefs: factor out thread_with_file, thread_with_stdio

thread_with_stdio now knows how to handle input - fsck can now prompt to
fix errors.

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

bcachefs: track transaction durations

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

bcachefs: Make sure allocation failure errors are logged

The previous patch fixed a bug in allocation path error handling, and it
would've been noticed sooner had it been logged properly.

Generally speaking, errors that shouldn't happen in normal operation and
are being returned up the stack should be logged: the write path was
already logging IO errors, but non IO errors were missed.

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

bcachefs: bch_err_(fn|msg) check if should print

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

bcachefs: fix userspace build errors

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

bcachefs: kill btree_trans->wb_updates

the btree write buffer path now creates a journal entry directly

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

bcachefs: btree write buffer now slurps keys from journal

Previosuly, the transaction commit path would have to add keys to the
btree write buffer as a separate operation, requiring additional global
synchronization.

This patch introduces a new journal entry type, which indicates that the
keys need to be copied into the btree write buffer prior to being
written out. We switch the journal entry type back to
JSET_ENTRY_btree_keys prior to write, so this is not an on disk format
change.

Flushing the btree write buffer may require pulling keys out of journal
entries yet to be written, and quiescing outstanding journal
reservations; we previously added journal->buf_lock for synchronization
with the journal write path.

We also can't put strict bounds on the number of keys in the journal
destined for the write buffer, which means we might overflow the size of
the preallocated buffer and have to reallocate - this introduces a
potentially fatal memory allocation failure. This is something we'll
have to watch for, if it becomes an issue in practice we can do
additional mitigation.

The transaction commit path no longer has to explicitly check if the
write buffer is full and wait on flushing; this is another performance
optimization. Instead, when the btree write buffer is close to full we
change the journal watermark, so that only reservations for journal
reclaim are allowed.

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

bcachefs: Improve trans->extra_journal_entries

Instead of using a darray, we now allocate journal entries for the
transaction commit path with our normal bump allocator - with an inlined
fastpath, and using btree_transaction_stats to remember how much to
initially allocate so as to avoid transaction restarts.

This is prep work for converting write buffer updates to use this
mechanism.

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

bcachefs: Fix snapshot.c assertion for online fsck

c->curr_recovery_pass can go backwards; this adds a non rewinding
version, c->recovery_pass_done.

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

bcachefs: BCH_IOCTL_FSCK_ONLINE

This adds a new ioctl for running fsck on a mounted, in use filesystem.

This reuses the fsck_thread code from the previous patch for running
fsck on an offline, unmounted filesystem, so that log messages for the
fsck thread are redirected to userspace.

Only one running fsck instance is allowed at a time; a new semaphore
(since the lock will be taken by one thread and released by another) is
added for this.

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

bcachefs: bch2_run_online_recovery_passes()

Add a new helper for running online recovery passes - i.e. online fsck.
This is a subset of our normal recovery passes, and does not - for now -
use or follow c->curr_recovery_pass.

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

bcachefs: Add ability to redirect log output

Upcoming patches are going to add two new ioctls for running fsck in the
kernel, but pretending that we're running our normal userspace fsck.

This patch adds some plumbing for redirecting our normal log messages
away from the dmesg log to a thread_with_file file descriptor - via a
struct log_output, which will be consumed by the fsck f_op's read method.

The new ioctls will allow for running fsck in the kernel against an
offline filesystem (without mounting it), and an online filesystem. For
an offline filesystem we need a way to pass in a pointer to the
log_output, which is done via a new hidden opts.h option.

For online fsck, we can set c->output directly, but only want to
redirect log messages from the thread running fsck - hence the new
c->output_filter method.

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

bcachefs: c->ro_ref

Add a new refcount for async ops that don't necessarily need the fs to
be RW, with similar lifetime/rules otherwise as c->writes.

To be used by online fsck.

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

bcachefs: count_event()

Small helper for event counters.

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

bcachefs: Clean up btree write buffer write ref handling

__bch2_btree_write_buffer_flush() now assumes a write ref is already
held (as called by the transaction commit path); and the wrappers
bch2_write_buffer_flush() and flush_sync() take an explicit write ref.

This means internally the write buffer code can always use
BTREE_INSERT_NOCHECK_RW, instead of in the previous code passing flags
around and hoping the NOCHECK_RW flag was always carried around
correctly.

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

bcachefs: convert bch_fs_flags to x-macro

Now we can print out filesystem flags in sysfs, useful for debugging
various "what's my filesystem doing" issues.

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

bcachefs: track_event_change()

This introduces a new helper for connecting time_stats to state changes,
i.e. when taking journal reservations is blocked for some reason.

We use this to track separately the different reasons the journal might
be blocked - i.e. space in the journal full, or the journal pin fifo
full.

Also do some cleanup and improvements on the time stats code.

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

bcachefs: bch_sb.recovery_passes_required

Add two new superblock fields. Since the main section of the superblock
is now fully, we have to add a new variable length section for them -
bch_sb_field_ext.

- recovery_passes_requried: recovery passes that must be run on the
next mount
- errors_silent: errors that will be silently fixed

These are to improve upgrading and dwongrading: these fields won't be
cleared until after recovery successfully completes, so there won't be
any issues with crashing partway through an upgrade or a downgrade.

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

bcachefs: Fix zstd compress workspace size

zstd apparently lies about the size of the compression workspace it
requires; if we double it compression succeeds.

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

bcachefs: Proper refcounting for journal_keys

The btree iterator code overlays keys from the journal until journal
replay is finished; since we're now starting copygc/rebalance etc.
before replay is finished, this is multithreaded access and thus needs
refcounting.

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

bcachefs: Fix multiple -Warray-bounds warnings

Transform zero-length array `entries` into a proper flexible-array
member in `struct journal_seq_blacklist_table`; and fix the following
-Warray-bounds warnings:

fs/bcachefs/journal_seq_blacklist.c:148:26: warning: array subscript idx is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:150:30: warning: array subscript idx is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:154:27: warning: array subscript idx is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:176:27: warning: array subscript i is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:177:27: warning: array subscript i is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:297:34: warning: array subscript i is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:298:34: warning: array subscript i is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]
fs/bcachefs/journal_seq_blacklist.c:300:31: warning: array subscript i is outside array bounds of 'struct journal_seq_blacklist_table_entry[0]' [-Warray-bounds=]

This results in no differences in binary output.

This helps with the ongoing efforts to globally enable -Warray-bounds.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: bch_sb_field_errors

Add a new superblock section to keep counts of errors seen since
filesystem creation: we'll be addingcounters for every distinct fsck
error.

The new superblock section has entries of the for [ id, count,
time_of_last_error ]; this is intended to let us see what errors are
occuring - and getting fixed - via show-super output.

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

bcachefs: Add IO error counts to bch_member

We now track IO errors per device since filesystem creation.

IO error counts can be viewed in sysfs, or with the 'bcachefs
show-super' command.

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: 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>

bcachefs: Split out disk_groups_types.h

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

bcachefs: Don't run bch2_delete_dead_snapshots() unnecessarily

Be a bit more careful about when bch2_delete_dead_snapshots needs to
run: it only needs to run synchronously if we're running fsck, and it
only needs to run at all if we have snapshot nodes to delete or if fsck
has noticed that it needs to run.

Also:
Rename BCH_FS_HAVE_DELETED_SNAPSHOTS -> BCH_FS_NEED_DELETE_DEAD_SNAPSHOTS

Kill bch2_delete_dead_snapshots_hook(), move functionality to
bch2_mark_snapshot()

Factor out bch2_check_snapshot_needs_deletion(), to explicitly check
if we need to be running snapshot deletion.

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

bcachefs: snapshot_create_lock

Add a new lock for snapshot creation - this addresses a few races with
logged operations and snapshot deletion.

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

bcachefs: bch_err_msg(), bch_err_fn() now filters out transaction restart errors

These errors aren't actual errors, and should never be printed - do this
in the common helpers.

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: BTREE_ID_logged_ops

Add a new btree for long running logged operations - i.e. for logging
operations that we can't do within a single btree transaction, so that
they can be resumed if we crash.

Keys in the logged operations btree will represent operations in
progress, with the state of the operation stored in the value.

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

bcachefs: Add logging to bch2_inode_peek() & related

Add error messages when we fail to lookup an inode, and also add a few
missing bch2_err_class() calls.

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

bcachefs: Ensure topology repair runs

This fixes should_restart_for_topology_repair() - previously it was
returning false if the btree io path had already seleceted topology
repair to run, even if it hadn't run yet.

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

bcachefs: Log a message when running an explicit recovery pass

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

bcachefs: bcachefs_metadata_version_deleted_inodes

Add a new bitset btree for inodes pending deletion; this means we no
longer have to scan the full inodes btree after an unclean shutdown.

Specifically, this adds:
- a trigger to update the deleted_inodes btree based on changes to the
inodes btree
- a new recovery pass
- and check_inodes is now only a fsck pass.

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

bcachefs: recovery_types.h

Move some code out of bcachefs.h, which is too much of an everything
header.

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

bcachefs: Make topology repair a normal recovery pass

This adds bch2_run_explicit_recovery_pass(), for rewinding recovery and
explicitly running a specific recovery pass - this is a more general
replacement for how we were running topology repair before.

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

bcachefs: bch2_run_explicit_recovery_pass()

This introduces bch2_run_explicit_recovery_pass() and uses it for when
fsck detects that we need to re-run dead snaphots cleanup, and makes
dead snapshot cleanup more like a normal recovery pass.

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

bcachefs: Upgrade path fixes

Some minor fixes to not print errors that are actually due to a verson
upgrade.

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

bcachefs: Convert snapshot table to RCU array

This switches the generic radix tree for the in-memory table of snapshot
nodes to a simple rcu array. This means we have to add new locking to
deal with reallocations, but is faster than traversing the radix tree.

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

bcachefs: Version table now lists required recovery passes

Now that we've got forward compatibility sorted out, we should be doing
more frequent version upgrades in the future.

To avoid having to run a full fsck for every version upgrade, this
improves the BCH_METADATA_VERSIONS() table to explicitly specify a
bitmask of recovery passes to run when upgrading to or past a given
version.

This means we can also delete PASS_UPGRADE().

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

bcachefs: bcachefs_metadata_version_major_minor

This introduces major/minor versioning to the superblock version number.
Major version number changes indicate incompatible releases; we can move
forward to a new major version number, but not backwards. Minor version
numbers indicate compatible changes - these add features, but can still
be mounted and used by old versions.

With the recent patches that make it possible to roll out new btrees and
key types without breaking compatibility, we should be able to roll out
most new features without incompatible changes.

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

bcachefs: Enumerate recovery passes

Recovery and fsck have many different passes/jobs to do, which always
run in the same order - but not all of them run all the time. Some are
for fsck, some for unclean shutdown, some for version upgrades.

This adds some new structure: a defined list of recovery passes that we
can run in a loop, as well as consolidating the log messages.

The main benefit is consolidating the "should run this recovery pass"
logic, as well as cleaning up the "this recovery pass has finished"
state; instead of having a bunch of ad-hoc state bits in c->flags, we've
now got c->curr_recovery_pass.

By consolidating the "should run this recovery pass" logic, in the
future on disk format upgrades will be able to say "upgrading to this
version requires x passes to run", instead of forcing all of fsck to
run.

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

bcachefs: Stash journal replay params in bch_fs

For the upcoming enumeration of recovery passes, we need all recovery
passes to be called the same way - including journal replay.

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

bcachefs: version_upgrade is now an enum

The version_upgrade parameter is now an enum, not a bool, and it's
persistent in the superblock:
- compatible (default): upgrade to the latest compatible version
- incompatible: upgrade to latest incompatible version
- none

Currently all upgrades are incompatible upgrades, but the next release
will introduce major:minor versions.

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

bcachefs: BCH_SB_VERSION_UPGRADE_COMPLETE()

Version upgrades are not atomic operations: when we do a version upgrade
we need to update the superblock before we start using new features, and
then when the upgrade completes we need to update the superblock again.
This adds a new superblock field so we can detect and handle incomplete
version upgrades.

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

bcachefs: Allow for unknown btree IDs

We need to allow filesystems with metadata from newer versions to be
mountable and usable by older versions.

This patch enables us to roll out new btrees without a new major version
number; we can now handle btree roots for unknown btree types.

The unknown btree roots will be retained, and fsck (including
backpointers) will check them, the same as other btree types.

We add a dynamic array for the extra, unknown btree roots, in addition
to the fixed size btree root array, and add new helpers for looking up
btree roots.

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

bcachefs: New error message helpers

Add two new helpers for printing error messages with __func__ and
bch2_err_str():
- bch_err_fn
- bch_err_msg

Also kill the old error strings in the recovery path, which were causing
us to incorrectly report memory allocation failures - they're not needed
anymore.

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

bcachefs: seqmutex; fix a lockdep splat

We can't be holding btree_trans_lock while copying to user space, which
might incur a page fault. To fix this, convert it to a seqmutex so we
can unlock/relock.

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: BTREE_ID_snapshot_tree

This adds a new btree which gets us a persistent per-snapshot-tree
identifier.

- BTREE_ID_snapshot_trees
- KEY_TYPE_snapshot_tree
- bch_snapshot now has a field that points to a snapshot_tree

This is going to be used to designate one snapshot ID/subvolume out of a
given tree of snapshots as the "main" subvolume, so that we can do quota
accounting in that subvolume and not the rest.

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

bcachefs: move snapshot_t to subvolume_types.h

this doesn't need to be in bcachefs.h

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

bcachefs: Improved copygc wait debugging

This just adds a line for how long copygc has been waiting to sysfs
copygc_wait, helpful for debugging why copygc isn't running.

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

bcachefs: use dedicated workqueue for tasks holding write refs

A workqueue resource deadlock has been observed when running fsck
on a filesystem with a full/stuck journal. fsck is not currently
able to repair the fs due to fairly rapid emergency shutdown, but
rather than exit gracefully the fsck process hangs during the
shutdown sequence. Fortunately this is easily recoverable from
userspace, but the root cause involves code shared between the
kernel and userspace and so should be addressed.

The deadlock scenario involves the main task in the bch2_fs_stop()
-> bch2_fs_read_only() path waiting on write references to drain
with the fs state lock held. A bch2_read_only_work() workqueue task
is scheduled on the system_long_wq, blocked on the state lock.
Finally, various other write ref holding workqueue tasks are
scheduled to run on the same workqueue and must complete in order to
release references that the initial task is waiting on.

To avoid this problem, we can split the dependent workqueue tasks
across different workqueues. It's a bit of a waste to create a
dedicated wq for the read-only worker, but there are several tasks
throughout the fs that follow the pattern of acquiring a write
reference and then scheduling to the system wq. Use a local wq
for such tasks to break the subtle dependency between these and the
read-only worker.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix bch2_evict_subvolume_inodes()

This fixes a bug in bch2_evict_subvolume_inodes(): d_mark_dontcache()
doesn't handle the case where i_count is already 0, we need to grab and
put the inode in order for it to be dropped.

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

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>

bcachefs: bch2_fs_moving_ctxts_to_text()

This also adds bch2_write_op_to_text(): now we can see outstand moves,
useful for debugging shutdown with the upcoming BCH_WRITE_WAIT_FOR_EC
and likely for other things in the future.

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

bcachefs: BKEY_PADDED_ONSTACK()

Rust bindgen doesn't do anonymous structs very nicely: BKEY_PADDED()
only needs the anonymous struct when it's used on the stack, to
guarantee layout, not when it's embedded in another struct.

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

bcachefs: Single open_bucket_partial list

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

bcachefs: Erasure coding: Track open stripes

This adds a new hash table for stripes being created or updated, instead
of hackily relying on the stripes heap.

This lets us reserve the slot for the new stripe up front, at the same
time as we would pick an existing stripe - if we were updating an
existing stripe - making the overall code more consistent.

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

bcachefs: Switch ec_stripes_heap_lock to a mutex

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

bcachefs: Fragmentation LRU

Now that we have much more efficient updates to the LRU btree, this
patch adds a new LRU that indexes buckets by fragmentation.

This means copygc no longer has to scan every bucket to find buckets
that need to be evacuated.

Changes:
- A new field in bch_alloc_v4, fragmentation_lru - this corresponds to
the bucket's position in the fragmentation LRU. We add a new field
for this instead of calculating it as needed because we may make the
fragmentation LRU optional; this field indicates whether a bucket is
on the fragmentation LRU.

Also, zoned devices will introduce variable bucket sizes; explicitly
recording the LRU position will be safer for them.

- A new copygc path for using the fragmentation LRU instead of
scanning every bucket and building up an in-memory heap.

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

bcachefs: Handle btree node rewrites before going RW

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

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>

bcachefs: bucket_gens btree

To improve mount times, add a btree for just bucket gens, 256 of them
per key: this means we'll have to scan drastically less metadata at
startup.

This adds
- trigger for keeping it in sync with the all btree
- initialization code, for filesystems from previous versions
- new path for reading bucket gens
- new fsck code

And a new on disk format version.

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

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>

bcachefs: New on disk format: Backpointers

This patch adds backpointers: we now have a reverse index from device
and offset on that device (specifically, offset within a bucket) back to
btree nodes and (non cached) data extents.

The first 40 backpointers within a bucket are stored in the alloc key;
after that backpointers spill over to the next backpointers btree. This
is to help avoid performance regressions from additional btree updates
on large streaming workloads.

This patch adds all the code for creating, checking and repairing
backpointers. The next patch in the series is going to use backpointers
for copygc - finally getting rid of the need to scan all extents to do
copygc.

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

bcachefs: Btree write buffer

This adds a new method of doing btree updates - a straight write buffer,
implemented as a flat fixed size array.

This is only useful when we don't need to read from the btree in order
to do the update, and when reading is infrequent - perfect for the LRU
btree.

This will make LRU btree updates fast enough that we'll be able to use
it for persistently indexing buckets by fragmentation, which will be a
massive boost to copygc performance.

Changes:
- A new btree_insert_type enum, for btree_insert_entries. Specifies
btree, btree key cache, or btree write buffer.

- bch2_trans_update_buffered(): updates via the btree write buffer
don't need a btree path, so we need a new update path.

- Transaction commit path changes:
The update to the btree write buffer both mutates global, and can
fail if there isn't currently room. Therefore we do all write buffer
updates in the transaction all at once, and also if it fails we have
to revert filesystem usage counter changes.

If there isn't room we flush the write buffer in the transaction
commit error path and retry.

- A new persistent option, for specifying the number of entries in the
write buffer.

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

bcachefs: Go RW before check_alloc_info()

It's possible to do btree updates before going RW by adding them to the
list of updates for journal replay to do, but this is limited by what
fits in RAM. This patch switches the second alloc info phase to run
after going RW - btree_gc has already ensured the alloc btree itself is
correct - and tweaks the allocation path to deal with the potential
small inconsistencies.

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: Fix a race with b->write_type

b->write_type needs to be set atomically with setting the
btree_node_need_write flag, so move it into b->flags.

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

bcachefs: Error message improvement

- Centralize format strings in bcachefs.h
- Add bch2_fmt_inum_offset() and related helpers
- Switch error messages for inodes to also print out the offset, in
bytes

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

bcachefs: Fixes for building in userspace

- Marking a non-static function as inline doesn't actually work and is
now causing problems - drop that

- Introduce BCACHEFS_LOG_PREFIX for when we want to prefix log messages
with bcachefs (filesystem name)

- Userspace doesn't have real percpu variables (maybe we can get this
fixed someday), put an #ifdef around bch2_disk_reservation_add()
fastpath

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

bcachefs: More style fixes

Fixes for various checkpatch errors.

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

bcachefs: Improved btree write statistics

This replaces sysfs btree_avg_write_size with btree_write_stats, which
now breaks out statistics by the source of the btree write.

Btree writes that are too small are a source of inefficiency, and
excessive btree resort overhead - this will let us see what's causing
them.

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

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>

bcachefs: Optimize bch2_trans_init()

Now we store the transaction's fn idx in a local variable, instead of
redoing the lookup every time we call bch2_trans_init().

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

bcachefs: Improve bch2_fsck_err()

- factor out fsck_err_get()
- if the "bcachefs (%s):" prefix has already been applied, don't
duplicate it
- convert to printbufs instead of static char arrays
- tidy up control flow a bit
- use bch2_print_string_as_lines(), to avoid messages getting truncated

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

bcachefs: Kill journal_keys->journal_seq_base

This removes an optimization that didn't actually save us any memory,
due to alignment, but did make the code more complicated than it needed
to be. We were also seeing a bug where journal_seq_base wasn't getting
correctly initailized, so hopefully it'll fix that too.

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

bcachefs: Delete time_stats for lock contended times

Since we've now got time_stats for lock hold times (per btree
transaction), we don't need this anymore.

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

bcachefs: Add persistent counters for all tracepoints

Also, do some reorganizing/renaming, convert atomic counters in bch_fs
to persistent counters, and add a few missing counters.

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

bcachefs: Track maximum transaction memory

This patch
- tracks maximum bch2_trans_kmalloc() memory used in btree_transaction_stats
- makes it available in debugfs
- switches bch2_trans_init() to using that for the amount of memory to
preallocate, instead of the parameter passed in

This drastically reduces transaction restarts, and means we no longer
need to track this in the source code.

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

bcachefs: Track the maximum btree_paths ever allocated by each transaction

We need a way to check if the machinery for handling btree_paths with in
a transaction is behaving reasonably, as it often has not been - we've
had bugs with transaction path overflows caused by duplicate paths and
plenty of other things.

This patch tracks, per transaction fn, the most btree paths ever
allocated by that transaction and makes it available in debugfs.

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

bcachefs: Rename lock_held_stats -> btree_transaction_stats

Going to be adding more things to this in the next patch.

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

bcachefs: added lock held time stats

We now record the length of time btree locks are held and expose this in debugfs.

Enabled via CONFIG_BCACHEFS_LOCK_TIME_STATS.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix subvol/snapshot deleting in recovery

fsck doesn't want to run while we're cleaning up deleted snapshots - if
that work needs to be done, we want it to have finished before fsck
runs, otherwise fsck will get confused when it finds multiple keys in
the same snapshot ID equivalence class (i.e. the mechanism that
snapshot deletion uses for cleaning up redundant keys).

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

bcachefs: data jobs, including rebalance wait for copygc.

move_ratelimit() now has a bool that specifies whether we want to
wait for copygc to finish.

When copygc is running, we're probably low on free buckets instead
of consuming the remaining buckets, we want to wait for copygc to
finish.

This should help with performance, and run away bucket fragmentation.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Go RW before bch2_check_lrus()

btree updates before going RW are expensive if they're in random order,
since they use the list of keys for journal replay to insert, which is
just a gap buffer.

This patch improves the bucket invalidate path so that if
bch2_check_lrus() hasn't finished it only prints warnings instead of
doing an emergency shutdown, which means we can now set BCH_FS_MAY_GO_RW
before bch2_check_lrus().

Also, the filesystem state bits are reorganized a bit.

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

bcachefs: Add persistent counters

This adds a new superblock field for persisting counters
and adds a sysfs interface in counters/ exposing these counters.

The superblock field is ignored by older versions letting us avoid
an on disk version bump.

Each sysfs file outputs a counter that tracks since filesystem
creation and a counter for the current mount session.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Shutdown path improvements

We're seeing occasional firings of the assertion in the key cache
shutdown code that nr_dirty == 0, which means we must sometimes be doing
transaction commits after we've gone read only.

Cleanups & changes:
- BCH_FS_ALLOC_CLEAN renamed to BCH_FS_CLEAN_SHUTDOWN
- new helper bch2_btree_interior_updates_flush(), which returns true if
it had to wait
- bch2_btree_flush_writes() now also returns true if there were btree
writes in flight
- __bch2_fs_read_only now checks if btree writes were in flight in the
shutdown loop: btree write completion does a transaction update, to
update the pointer in the parent node
- assert that !BCH_FS_CLEAN_SHUTDOWN in __bch2_trans_commit

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

bcachefs: Kill old rebuild_replicas option

This option was useful when the replicas mechism was new and still being
debugged, but hasn't been used in ages - let's delete it.

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

bcachefs: Use a genradix for reading journal entries

Previously, the journal read path used a linked list for storing the
journal entries we read from disk. But there's been a bug that's been
causing journal_flush_delay to incorrectly be set to 0, leading to far
more journal entries than is normal being written out, which then means
filesystems are no longer able to start due to the O(n^2) behaviour of
inserting into/searching that linked list.

Fix this by switching to a radix tree.

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

bcachefs: Gap buffer for journal keys

Btree updates before we go RW work by inserting into the array of keys
that journal replay will insert - but inserting into a flat array is
O(n), meaning if btree_gc needs to update many alloc keys, we're O(n^2).

Fortunately, the updates btree_gc does happens in sequential order,
which means a gap buffer works nicely here - this patch implements a gap
buffer for journal keys.

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

bcachefs: Kill main in-memory bucket array

All code using the in-memory bucket array, excluding GC, has now been
converted to use the alloc btree directly - so we can finally delete it.

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

bcachefs: New bucket invalidate path

In the old allocator code, preparing an existing empty bucket was part
of the same code path that invalidated buckets containing cached data.
In the new allocator code this is no longer the case: the main allocator
path finds empty buckets (via the new freespace btree), and can't
allocate buckets that contain cached data.

We now need a separate code path to invalidate buckets containing cached
data when we're low on empty buckets, which this patch implements. When
the number of free buckets decreases that triggers the new invalidate
path to run, which uses the LRU btree to pick cached data buckets to
invalidate until we're above our watermark.

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

bcachefs: New discard implementation

In the old allocator code, buckets would be discarded just prior to
being used - this made sense in bcache where we were discarding buckets
just after invalidating the cached data they contain, but in a
filesystem where we typically have more free space we want to be
discarding buckets when they become empty.

This patch implements the new behaviour - it checks the need_discard
btree for buckets awaiting discards, and then clears the appropriate
bit in the alloc btree, which moves the buckets to the freespace btree.

Additionally, discards are now enabled by default.

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

bcachefs: Kill allocator threads & freelists

Now that we have new persistent data structures for the allocator, this
patch converts the allocator to use them.

Now, foreground bucket allocation uses the freespace btree to find
buckets to allocate, instead of popping buckets off the freelist.

The background allocator threads are no longer needed and are deleted,
as well as the allocator freelists. Now we only need background tasks
for invalidating buckets containing cached data (when we are low on
empty buckets), and for issuing discards.

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

bcachefs: Freespace, need_discard btrees

This adds two new btrees for the upcoming allocator rewrite: an extents
btree of free buckets, and a btree for buckets awaiting discards.

We also add a new trigger for alloc keys to keep the new btrees up to
date, and a compatibility path to initialize them on existing
filesystems.

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

bcachefs: LRU btree

This implements new persistent LRUs, to be used for buckets containing
cached data, as well as stripes ordered by time when a block became
empty.

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

bcachefs: darrays

Inspired by CCAN darray - simple, stupid resizable (dynamic) arrays.

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

bcachefs: Start moving debug info from sysfs to debugfs

In sysfs, files can only output at most PAGE_SIZE. This is a problem for
debug info that needs to list an arbitrary number of times, and because
of this limit some of our debug info has been terser and harder to read
than we'd like.

This patch moves info about journal pins and cached btree nodes to
debugfs, and greatly expands and improves the output we return.

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

bcachefs: Kill BCH_FS_HOLD_BTREE_WRITES

This was just dead code.

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

bcachefs: Normal update/commit path now works before going RW

This improves __bch2_trans_commit - early in the recovery process, when
we're running btree_gc and before we want to go RW, it now uses
bch2_journal_key_insert() to add the update to the list of updates for
journal replay to do, instead of btree_gc having to use separate
interfaces depending on whether we're running at bringup or, later,
runtime.

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

bcachefs: Delete some flag bits that are no longer used

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

bcachefs: Kill bch2_bkey_debugcheck

The old .debugcheck methods are no more and this just calls the .invalid
method, which doesn't add much since we already check that when doing
btree updates and when reading metadata in.

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

bcachefs: bch2_gc_gens() no longer uses bucket array

Like the previous patches, this converts bch2_gc_gens() to use the alloc
btree directly, and private arrays of generation numbers for its own
recalculation of oldest_gen.

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

bcachefs: btree_gc no longer uses main in-memory bucket array

This changes the btree_gc code to only use the second bucket array, the
one dedicated to GC. On completion, it compares what's in its in memory
bucket array to the allocation information in the btree and writes it
directly, instead of updating the main in-memory bucket array and
writing that.

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

bcachefs: btree_id_cached()

Add a new helper that returns true if the given btree ID uses the btree
key cache. This enables some new cleanups, since the helper can check
the options for whether caching is enabled on a given btree.

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

bcachefs: Fix freeing in bch2_dev_buckets_resize()

We were double-freeing old_buckets and not freeing old_buckets_gens:
also, the code was supposed to free buckets, not old_buckets;
old_buckets is only needed because we have to use rcu_assign_pointer()
instead of swap(), and won't be set if we hit the error path.

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

bcachefs: New data structure for buckets waiting on journal commit

Implement a hash table, using cuckoo hashing, for empty buckets that are
waiting on a journal commit before they can be reused.

This replaces the journal_seq field of bucket_mark, and is part of
eventually getting rid of the in memory bucket array.

We may need to make bch2_bucket_needs_journal_commit() lockless, pending
profiling and testing.

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

Revert "bcachefs: Delete some obsolete journal_seq_blacklist code"

This reverts commit f95b61228efd04c9c158123da5827c96e9773b29.

It turns out, we're seeing filesystems in the wild end up with
blacklisted btree node bsets - this should not be happening, and until
we understand why and fix it we need to keep this code around.

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

bcachefs: Log & error message improvements

- Add a shim uuid_unparse_lower() in the kernel, since %pU doesn't work
in userspace

- We don't need to print the bcachefs: or the filesystem name prefix in
userspace

- Improve a few error messages

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

bcachefs: Add verbose log messages for journal read

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

bcachefs: bch_dev->dev

Add a field to bch_dev for the dev_t of the underlying block device -
this fixes a null ptr deref in tracepoints.

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

bcachefs: Simplify journal replay

With BTREE_ITER_WITH_JOURNAL, there's no longer any restrictions on the
order we have to replay keys from the journal in, and we can also start
up journal reclaim right away - and delete a bunch of code.

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

bcachefs: BTREE_ITER_WITH_JOURNAL

This adds a new btree iterator flag, BTREE_ITER_WITH_JOURNAL, that is
automatically enabled when initializing a btree iterator before journal
replay has completed - it overlays the contents of the journal with the
btree.

This lets us delete bch2_btree_and_journal_walk() and just use the
normal btree iterator interface instead - which also lets us delete a
significant amount of duplicated code.

Note that BTREE_ITER_WITH_JOURNAL is still unoptimized in this patch -
we're redoing the binary search over keys in the journal every time we
call bch2_btree_iter_peek().

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

bcachefs: Fix race between btree updates & journal replay

Add a flag to indicate whether a journal replay key has been
overwritten, and set/test it with appropriate btree locks held.

This fixes a race between the allocator - invalidating buckets, and
doing btree updates - and journal replay, which before this patch could
clobber the allocator thread's update with an older version of the key
from the journal.

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

bcachefs: New in-memory array for bucket gens

The main in-memory bucket array is going away, but we'll still need to
keep bucket generations in memory, at least for now - ptr_stale() needs
to be an efficient operation.

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

bcachefs: Put open_buckets in a hashtable

This is so that the copygc code doesn't have to refer to
bucket_mark.owned_by_allocator - assisting in getting rid of the in
memory bucket array.

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

bcachefs: Delete some obsolete journal_seq_blacklist code

Since metadata version bcachefs_metadata_version_btree_ptr_sectors_written,
we haven't needed the journal seq blacklist mechanism for ignoring
blacklisted btree node writes - we now only need it for ignoring journal
entries that were written after the newest flush journal entry, and then
we only need to keep those blacklist entries around until journal replay
is finished.

That means we can delete the code for scanning btree nodes to GC
journal_seq_blacklist entries.

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

bcachefs: Don't start allocator threads too early

If the allocator threads start before journal replay has finished
replaying alloc keys, journal replay might overwrite the allocator's
btree updates.

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

bcachefs: Rewrite bch2_bucket_alloc_new_fs()

This changes bch2_bucket_alloc_new_fs() to a simple bump allocator that
doesn't need to use the in memory bucket array, part of a larger patch
series to entirely get rid of the in memory bucket array, except for
gc/fsck.

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

bcachefs: Turn encoded_extent_max into a regular option

It'll now be handled at format time and in sysfs like other options - it
still can only be set at format time, though.

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

bcachefs: Option improvements

This adds flags for options that must be a power of two (block size and
btree node size), and options that are stored in the superblock as a
power of two (encoded extent max).

Also: options are now stored in memory in the same units they're
displayed in (bytes): we now convert when getting and setting from the
superblock.

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

bcachefs: Fix some shutdown path bugs

This fixes some bugs when we hit an error very early in the filesystem
startup path, before most things have been initialized.

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

bcachefs: Add more time_stats

This adds more latency/event measurements and breaks some apart into
more events. Journal writes are broken apart into flush writes and
noflush writes, btree compactions are broken out from btree splits,
btree mergers are added, as well as btree_interior_updates - foreground
and total.

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

bcachefs: Split out struct gc_stripe from struct stripe

We have two radix trees of stripes - one that mirrors some information
from the stripes btree in normal operation, and another that GC uses to
recalculate block usage counts.

The normal one is now only used for finding partially empty stripes in
order to reuse them - the normal stripes radix tree and the GC stripes
radix tree are used significantly differently, so this patch splits them
into separate types.

In an upcoming patch we'll be replacing c->stripes with a btree that
indexes stripes by the order we want to reuse them.

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

bcachefs: Convert bucket_alloc_ret to negative error codes

Start a new header, errcode.h, for bcachefs-private error codes - more
error codes will be converted later.

This patch just converts bucket_alloc_ret so that they can be mixed with
standard error codes and passed as ERR_PTR errors - the ec.c code was
doing this already, but incorrectly.

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

bcachefs: Disk space accounting fix on brand-new fs

The filesystem initialization path first marks superblock and journal
buckets non transactionally, since the btree isn't functional yet. That
path was updating the per-journal-buf percpu counters via
bch2_dev_usage_update(), and updating the wrong set of counters so those
updates didn't get written out until journal entry 4.

The relevant code is going to get significantly rewritten in the future
as we transition away from the in memory bucket array, so this just
hacks around it for now.

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

bcachefs: Also log device name in userspace

Change log messages in userspace to be closer to what they are in kernel
space, and include the device name - it's also useful in userspace.

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

bcachefs: Add BCH_SUBVOLUME_UNLINKED

Snapshot deletion needs to become a multi step process, where we unlink,
then tear down the page cache, then delete the subvolume - the deleting
flag is equivalent to an inode with i_nlink = 0.

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

bcachefs: Subvolumes, snapshots

This patch adds subvolume.c - support for the subvolumes and snapshots
btrees and related data types and on disk data structures. The next
patches will start hooking up this new code to existing code.

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: add progress stats to sysfs

This adds progress stats to sysfs for copygc, rebalance, recovery, and the
cmd_job ioctls.

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

bcachefs: Update btree ptrs after every write

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>

bcachefs: Don't loop into topology repair

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

bcachefs: Fsck for reflink refcounts

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

bcachefs: Split out btree_error_wq

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>

bcachefs: Don't use uuid in tracepoints

%pU for printing out pointers to uuids doesn't work in perf trace

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

bcachefs: Add a workqueue for btree io completions

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>

bcachefs: Add a debug mode that always reads from every btree replica

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>

bcachefs: Ratelimiting for writeback IOs

Writeback throttling is a kernel config option and not always enabled.
When it's not enabled we need a fallback, to avoid unbounded memory
pinning and work item backlogs.

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

bcachefs: Fix time handling

There were some overflows in the time conversion functions - fix this by
converting tv_sec and tv_nsec separately. Also, set sb->time_min and
sb->time_max.

Fixes xfstest generic/258.

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

bcachefs: New and improved topology repair code

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>

bcachefs: Fix key cache assertion

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

bcachefs: Update bch2_btree_verify()

bch2_btree_verify() verifies that the btree node on disk matches what we
have in memory. This patch changes it to verify every replica, and also
fixes it for interior btree nodes - there's a mem_ptr field which is
used as a scratch space and needs to be zeroed out for comparing with
what's on disk.

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

bcachefs: gc shouldn't care about owned_by_allocator

The owned_by_allocator field is a purely in memory thing, even if/when
we bring back GC at runtime there's no need for it to be recalculating
this field. This is prep work for pulling it out of struct bucket, and
eventually getting rid of the bucket array.

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

bcachefs: Add the status of bucket gen gc to sysfs

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

bcachefs: Add a sysfs var for average btree write size

Useful number for performance tuning.

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

bcachefs: Validate bset version field against sb version fields

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>

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: Add a mempool for the replicas delta list

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

bcachefs: Add a mempool for btree_trans bump allocator

This allocation is required for filesystem operations to make forward
progress, thus needs a mempool.

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

bcachefs: Add allocator thread state to sysfs

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

bcachefs: Rip out copygc pd controller

We have a separate mechanism for ratelimiting copygc now - the pd
controller has only been causing problems.

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

bcachefs: Add copygc wait to sysfs

Currently debugging an issue with copygc not running when it's supposed
to, and this is an obvious first step.

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

bcachefs: Fix copygc threshold

Awhile back the meaning of is_available_bucket() and thus also
bch_dev_usage->buckets_unavailable changed to include buckets that are
owned by the allocator - this was so that the stat could be persisted
like other allocation information, and wouldn't have to be regenerated
by walking each bucket at mount time.

This broke copygc, which needs to consider buckets that are reclaimable
and haven't yet been grabbed by the allocator thread and moved onta
freelist. This patch fixes that by adding dev_buckets_reclaimable() for
copygc and the allocator thread, and cleans up some of the callers a bit.

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

bcachefs: Fixes/improvements for journal entry reservations

This fixes some arithmetic bugs in "bcachefs: Journal updates to dev
usage" - additionally, it cleans things up by switching everything that
goes in every journal entry to the journal_entry_res mechanism.

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

bcachefs: Journal updates to dev usage

This eliminates the need to scan every bucket to regenerate dev_usage at
mount time.

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

bcachefs: Persist 64 bit io clocks

Originally, bcachefs - going back to bcache - stored, for each bucket, a
16 bit counter corresponding to how long it had been since the bucket
was read from. But, this required periodically rescaling counters on
every bucket to avoid wraparound. That wasn't an issue in bcache, where
we'd perodically rewrite the per bucket metadata all at once, but in
bcachefs we're trying to avoid having to walk every single bucket.

This patch switches to persisting 64 bit io clocks, corresponding to the
64 bit bucket timestaps introduced in the previous patch with
KEY_TYPE_alloc_v2.

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

bcachefs: Add an assertion to check for journal writes to same location

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

bcachefs: Add (partial) support for fixing btree topology

When we walk the btrees during recovery, part of that is checking that
btree topology is correct: for every interior btree node, its child
nodes should exactly span the range the parent node covers.

Previously, we had checks for this, but not repair code. Now that we
have the ability to do btree updates during initial GC, this patch adds
that repair code.

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

bcachefs: Add support for doing btree updates prior to journal replay

Some errors may need to be fixed in order for GC to successfully run -
walk and mark all metadata. But we can't start the allocators and do
normal btree updates until after GC has completed, and allocation
information is known to be consistent, so we need a different method of
doing btree updates.

Fortunately, we already have code for walking the btree while overlaying
keys from the journal to be replayed. This patch adds an update path
that adds keys to the list of keys to be replayed by journal replay, and
also fixes up iterators.

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

bcachefs: bch2_alloc_write() should be writing for all devices

Alloc info isn't stored on a particular device, it makes no sense to
only be writing it out for rw members - this was causing fsck to not fix
alloc info errors, oops.

Also, make sure we write out alloc info in other repair paths.

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

bcachefs: Improve some IO error messages

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>

bcachefs: Refactor filesystem usage accounting

Various filesystem usage counters are kept in percpu counters, with one
set per in flight journal buffer. Right now all the code that deals with
it assumes that there's only two buffers/sets of counters, but the
number of journal bufs is getting increased to 4 in the next patch - so
refactor that code to not assume a constant.

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

bcachefs: Move journal reclaim to a kthread

This is to make tracing easier.

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

bcachefs: Take a SRCU lock in btree transactions

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

bcachefs: Add a single slot percpu buf for btree iters

Allocating our array of btree iters is a big enough allocation that it
hits the buddy allocator, and we're seeing lots of lock contention.
Sticking a single element buffer in front of it should help.

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

bcachefs: Improved inode create optimization

This shards new inodes into different btree nodes by using the processor
ID for the high bits of the new inode number. Much faster than the
previous inode create optimization - this also helps with sharding in
the other btrees that index by inode number.

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

bcachefs: Split out debug_check_btree_accounting

This check is very expensive

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

bcachefs: Drop sysfs interface to debug parameters

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>

bcachefs: Inode create optimization

On workloads that do a lot of multithreaded creates all at once, lock
contention on the inodes btree turns out to still be an issue.

This patch adds a small buffer of inode numbers that are known to be
free, so that we can avoid touching the btree on every create. Also,
this changes inode creates to update via the btree key cache for the
initial create.

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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: Be more rigorous about marking the filesystem clean

Previously, there was at least one error path where we could mark the
filesystem clean when we hadn't sucessfully written out alloc info.

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

bcachefs: Add an option for keeping journal entries after startup

This will be used by the userspace debug tools.

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

bcachefs: Seralize btree_update operations at btree_update_nodes_written()

Prep work for journalling updates to interior nodes - enforcing ordering
will greatly simplify those changes.

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 ca->freelist_lock

All uses were supposed to be switched over to c->freelist_lock

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: Trust btree alloc info at runtime

This lets us avoid a cache miss in the write path.

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: Switch reconstruct_alloc to a mount option

Right now this is the only way of repairing bucket gens in the future

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

bcachefs: Refactor bch2_alloc_write()

Major simplification - gets rid of the need for marking buckets as
dirty, instead we write buckets if the in memory mark is different from
what's in the btree.

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

bcachefs: Add a hint for allocating new stripes

This way we aren't doing a full linear scan every time we create a new
stripe.

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

bcachefs: Reflink

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

bcachefs: Write out fs usage consistently

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

bcachefs: Avoid write lock on mark_lock

mark_lock is a frequently taken lock, and there's also potential for
deadlocks since currently bch2_clear_page_bits which is called from
memory reclaim has to take it to drop disk reservations.

The disk reservation get path takes it when it recalculates the number
of sectors known to be available, but it's not really needed for
consistency. We just want to make sure we only have one thread updating
the sectors_available count, which we can do with a dedicated mutex.

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

bcachefs: bch2_bkey_ptrs_invalid()

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

bcachefs: use same timesource as current_time()

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

bcachefs: Fix hang while shutting down

If the allocator thread exited before bch2_dev_allocator_stop() was
called (because of an error), bch2_dev_allocator_quiesce() could hang.

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

bcachefs: Rewrite journal_seq_blacklist machinery

Now, we store blacklisted journal sequence numbers in the superblock,
not the journal: this helps to greatly simplify the code, and more
importantly it's now implemented in a way that doesn't require all btree
nodes to be visited before starting the journal - instead, we
unconditionally blacklist the next 4 journal sequence numbers after an
unclean shutdown.

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

bcachefs: ratelimit copygc warning

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

bcachefs: Track whether filesystem has errors in superblock

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

bcachefs: move some checks to expensive_debug_checks

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

bcachefs: Verify fs hasn't been modified before going rw

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

bcachefs: Go rw lazily

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

bcachefs: More debug params for testing of recovery paths

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

bcachefs: Add time stats for btree updates

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

bcachefs: Add more time stats for being blocked on allocator

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

bcachefs: Allocate fs_usage in do_btree_insert_at()

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

bcachefs: Fix oldest_gen handling

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

bcachefs: don't do initial gc if have alloc info feature

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

bcachefs: reserve space in journal for fs usage entries

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

bcachefs: Fix a bug when shutting down before allocator started

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

bcachefs: Persist alloc info on clean shutdown

- Does not persist alloc info for stripes yet
- Also does not yet include filesystem block/sector counts yet, from
struct fs_usage
- Not made use of just yet

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

bcachefs: Fix check for if extent update is allocating

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

bcachefs: Fix some reserve calculations

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

bcachefs: Add a workqueue for journal reclaim

journal reclaim writes btree nodes, which can end up waiting for in
flight btree writes to complete, and btree write completions run out of
workqueues - so we can't run out of the same workqueue or we risk
deadlock

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

bcachefs: Lots of option handling improvements

Add helptext to option definitions - so we can unify the option
handling with the format command

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

bcachefs: refactor bch_fs_usage

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

bcachefs: Switch replicas to mark_lock

Prep work for upcoming disk accounting changes

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

bcachefs: s/usage_lock/mark_lock

better describes what it's for, and we're going to call a new lock
usage_lock

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

bcachefs: move dirty into bucket_mark

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

bcachefs: Add new alloc fields

prep work for persistent alloc info

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

bcachefs: Track nr_inodes with the key marking machinery

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

bcachefs: Make bkey types globally unique

this lets us get rid of a lot of extra switch statements - in a lot of
places we dispatch on the btree node type, and then the key type, so
this is a nice cleanup across a lot of code.

Also improve the on disk format versioning stuff.

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

bcachefs: Stripes now properly subject to gc

gc now verifies the contents of the stripes radix tree, important for
persistent alloc info

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

bcachefs: gc now operates on second set of bucket marks

This means we can now use gc to verify the allocation information -
important for testing persistant alloc info

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

bcachefs: Allocator startup improvements

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

bcachefs: Erasure coding

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

bcachefs: Assorted fixes for running on very small devices

It's now possible to create and use a filesystem on a 512k device with
4k buckets (though at that size we still waste almost half to internal
reserves)

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

bcachefs: Scale down number of writepoints when low on space

this means we don't have to reserve space for them when calculating
filesystem capacity

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

bcachefs: kill struct bch_replicas_cpu_entry

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

bcachefs: mempoolify btree_trans

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

bcachefs: Better calculation of copygc threshold

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

bcachefs: Invalidate buckets when writing to alloc btree

Prep work for persistent alloc information. Refactoring also lets us
make free_inc much smaller, which means a lot fewer buckets stranded on
freelists.

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

bcachefs: kill bucket mark sector count saturation

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

bcachefs: don't call bch2_bucket_seq_cleanup from journal_buf_switch

journal_buf_switch is called from the foreground when getting a journal
reservation and thus is somewhat latency sensitive;
bch2_bucket_seq_cleanup has to run infrequently but is a bit expensive
when it does run.

Call it from the journal write path instead, and punt the journal write
to worqueue context.

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

bcachefs: Only check inode i_nlink during full fsck

Now that all filesystem operatinos that manipulate the filesystem
heirachy and i_nlink are fully atomic, we can add a feature bit to
indicate i_nlink doesn't need to be checked.

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

bcachefs: Initial commit

Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.

Website: https://bcachefs.org

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