bcachefs: Etyzinger cleanups

Pull out eytzinger.c and kill eytzinger_cmp_fn. We now provide
eytzinger0_sort and eytzinger0_sort_r, which use the standard cmp_func_t
and cmp_r_func_t callbacks.

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

bcachefs: Prefer struct_size over open coded arithmetic

This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].

As the "op" variable is a pointer to "struct promote_op" and this
structure ends in a flexible array:

struct promote_op {
[...]
struct bio_vec bi_inline_vecs[];
};

and the "t" variable is a pointer to "struct journal_seq_blacklist_table"
and this structure also ends in a flexible array:

struct journal_seq_blacklist_table {
[...]
struct journal_seq_blacklist_table_entry {
u64 start;
u64 end;
bool dirty;
} entries[];
};

the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the argument "size + size * count" in the
kzalloc() functions.

This way, the code is more readable and safer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: journal_seq_blacklist_add() now handles entries being added out of order

bch2_journal_seq_blacklist_add() was bugged when the new entry
overlapped with multiple existing entries, and it also assumed new
entries are being added in increasing order.

This is true on any sane filesystem, but when trying to recover from
very badly mangled filesystems we might end up with the journal sequence
number rewinding vs. what the blacklist list knows about - easiest to
just handle that here.

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: bch2_sb_field_get() refactoring

Instead of using token pasting to generate methods for each superblock
section, just make the type a parameter to bch2_sb_field_get().

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: Private error codes: ENOMEM

This adds private error codes for most (but not all) of our ENOMEM uses,
which makes it easier to track down assorted allocation failures.

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: 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: 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: Add .to_text() methods for all superblock sections

This patch improves the superblock .to_text() methods and adds methods
for all types that were missing them. It also improves printbufs by
allowing them to specfiy what units we want to be printing in, and adds
new wrapper methods for unifying our kernel and userspace environments.

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: Fix bch2_journal_seq_blacklist_add()

The old code correctly handled the case where we were blacklisting a
range that exactly matched an existing entry, but not the case where the
new range partially overlaps an existing entry.

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

bcachefs: Improved superblock-related error messages

This patch converts bch2_sb_validate() and the .validate methods for the
various superblock sections to take printbuf, to which they can print
detailed error messages, including printing the entire section that was
invalid.

This is a great improvement over the previous situation, where we could
only return static strings that didn't have precise information about
what was wrong.

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: Handle transaction restarts in bch2_blacklist_entries_gc()

It shouldn't be necessary when we're only using a single iterator and
not doing updates, but that's harder to debug at the moment.

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

bcachefs: for_each_btree_node() now returns errors directly

This changes for_each_btree_node() to work like for_each_btree_key(),
and to that end bch2_btree_iter_peek_node() and next_node() also return
error ptrs.

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: Assorted endianness fixes

Found by sparse

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

bcachefs: Don't require flush/fua on every journal write

This patch adds a flag to journal entries which, if set, indicates that
they weren't done as flush/fua writes.

- non flush/fua journal writes don't update last_seq (i.e. they don't
free up space in the journal), thus the journal free space
calculations now check whether nonflush journal writes are currently
allowed (i.e. are we low on free space, or would doing a flush write
free up a lot of space in the journal)

- write_delay_ms, the user configurable option for when open journal
entries are automatically written, is now interpreted as the max
delay between flush journal writes (default 1 second).

- bch2_journal_flush_seq_async is changed to ensure a flush write >=
the requested sequence number has happened

- journal read/replay must now ignore, and blacklist, any journal
entries newer than the most recent flush entry in the journal. Also,
the way the read_entire_journal option is handled has been improved;
struct journal_replay now has an entry, 'ignore', for entries that
were read but should not be used.

- assorted refactoring and improvements related to journal read in
journal_io.c and recovery.c

Previously, we'd have to issue a flush/fua write every time we
accumulated a full journal entry - typically the bucket size. Now we
need to issue them much less frequently: when an fsync is requested, or
it's been more than write_delay_ms since the last flush, or when we need
to free up space in the journal. This is a significant performance
improvement on many write heavy workloads.

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

bcachefs: Fix a bug with the journal_seq_blacklist mechanism

Previously, we would start doing btree updates before writing the first
journal entry; if this was after an unclean shutdown, this could cause
those btree updates to not be blacklisted.

Also, move some code to headers for userspace debug tools.

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

bcachefs: 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: More work to avoid transaction restarts

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

bcachefs: cmp_int()

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: Only get btree iters from btree transactions

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>