bcachefs: kill kvpmalloc()

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

bcachefs: Remove obsolete comment about zstd

Remove obsolete comment about zstd, since approach changed during
development of commit bbc3a46065d08f9ab3412b1f26bbfa778c444833

Signed-off-by: Richard Davies <richard@arachsys.com>
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: 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: Guard against unknown compression options

Since compression options now include compression level, proper
validation is a bit more involved.

This adds bch2_compression_opt_valid(), and plumbs it around
appropriately.

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

bcachefs: Fix W=12 build errors

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

bcachefs: Break up io.c

More reorganization, this splits up io.c into
- io_read.c
- io_misc.c - fallocate, fpunch, truncate
- io_write.c

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

bcachefs: Fix assorted checkpatch nits

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

bcachefs: Suppresss various error messages in no_data_io mode

We commonly use no_data_io mode when debugging filesystem metadata
dumps, where data checksum/compression errors are expected and
unimportant - this patch suppresses these.

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

bcachefs: Compression levels

This allows including a compression level when specifying a compression
type, e.g.
compression=zstd:15

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

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

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

XXX: perhaps we could add a warning for this

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

bcachefs: Delete redundant log messages

Now that we have distinct error codes for different memory allocation
failures, the early init log messages are no longer needed.

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

bcachefs: GFP_NOIO -> GFP_NOFS

GFP_NOIO dates from the bcache days, when we operated under the block
layer. Now, GFP_NOFS is more appropriate, so switch all GFP_NOIO uses to
GFP_NOFS.

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: __bio_compress() fix up.

A single block can't be compressed, so it's incompressible.
This stops rebalance repeatably marking extents as uncompressed.

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

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: Work around a zstd bug

The zstd compression code seems to have a bug where it will write just
past the end of the destination buffer - probably only when the
compressed output isn't going to fit in the destination buffer, which
will never happen if you're always allocating a bigger buffer than the
source buffer which would explain other users not hitting it. But, we
size the buffer according to how much contiguous space on disk we have,
so...

generally, bugs like this don't write more than a word past the end of
the buffer, so an easy workaround is to subtract a fudge factor from the
buffer size.

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

bcachefs: Improve check for when bios are physically contiguous

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

bcachefs: Wrap write path in memalloc_nofs_save()

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

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

bcachefs: Add vmalloc fallback for decompress workspace

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

bcachefs: Wrap vmap() in memalloc_nofs_save()/restore()

vmalloc() and vmap() don't take GFP_NOFS - this should be pushed further
up the IO path, but for now just doing the simple fix.

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

bcachefs: Fix initialization of bounce mempools

When they were converted to kvpmalloc pools they weren't converted to
pass the actual size of the allocation. Oops.

Also, validate the real length in the zstd decompression path.

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

bcachefs: Some compression improvements

In __bio_map_or_bounce(), the check for if the bio is physically
contiguous is improved; it's now more readable and handles multi page
but contiguous bios.

Also when decompressing, we were doing a redundant memcpy in the case
where we were able to use vmap to map a bio contigiously.

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

bcachefs: Use kvpmalloc mempools for compression bounce

This fixes an issue where mounting would fail because of memory
fragmentation - previously the compression bounce buffers were using
get_free_pages().

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

bcachefs: Track incompressible data

This fixes the background_compression option: wihout some way of marking
data as incompressible, rebalance will keep rewriting incompressible
data over and over.

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: Fix moving compressed data

bio_uncompress_inplace() used to potentially need to extend the bio to
be big enough for the uncompressed data, which has become problematic
with multipage bvecs - but, the move extent path actually already
allocated the bios to be big enough for the uncompressed data.

The promote path needed to be fixed, though.

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

bcachefs: kill bio_for_each_contig_segment()

With multipage bvecs it's not needed anymore

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

bcachefs: Kill direct access to bi_io_vec

Switch to always using bio_add_page(), which merges contiguous pages now
that we have multipage bvecs.

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

bcachefs: fix mempool double initialization

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>