bcachefs: bch_member.btree_allocated_bitmap

This adds a small (64 bit) per-device bitmap that tracks ranges that
have btree nodes, for accelerating btree node scan if it is ever needed.

- New helpers, bch2_dev_btree_bitmap_marked() and
bch2_dev_bitmap_mark(), for checking and updating the bitmap

- Interior btree update path updates the bitmaps when required

- The check_allocations pass has a new fsck_err check,
btree_bitmap_not_marked

- New on disk format version, mi_btree_mitmap, which indicates the new
bitmap is present

- Upgrade table lists the required recovery pass and expected fsck error

- Btree node scan uses the bitmap to skip ranges if we're on the new
version

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

bcachefs: port block device access to file

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-18-adbd023e19cc@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

bcachefs: simplify bch_devs_list

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

bcachefs: Convert to bdev_open_by_path()

Convert bcachefs to use bdev_open_by_path() and pass the handle around.

CC: Kent Overstreet <kent.overstreet@linux.dev>
CC: Brian Foster <bfoster@redhat.com>
CC: <linux-bcachefs@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231101174325.10596-1-jack@suse.cz
Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

bcachefs: preserve device path as device name

Various userspace scripts/tools may expect mount entries in
/proc/mounts to reflect the device path names used to mount the
associated filesystem. bcachefs seems to normalize the device path
to the underlying device name based on the block device. This
confuses tools like fstests when the test devices might be lvm or
device-mapper based.

The default behavior for show_vfsmnt() appers to be to use the
string passed to alloc_vfsmnt(), so tweak bcachefs to copy the path
at device superblock read time and to display it via
->show_devname().

Signed-off-by: Brian Foster <bfoster@redhat.com>
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: Use struct_size()

Use struct_size() instead of hand writing it.
This is less verbose and more robust.

While at it, prepare for the coming implementation by GCC and Clang of the
__counted_by attribute. Flexible array members annotated with __counted_by
can have their accesses bounds-checked at run-time checking via
CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for
strcpy/memcpy-family functions).

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs: Fix bch_sb_handle type

blk_mode_t was recently introduced; we should be using it now, instead
of fmode_t.

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: Kill non-lru cache replacement policies

Prep work for persistent LRUs and getting rid of the in memory bucket
array.

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

bcachefs: Eliminate more PAGE_SIZE uses

In userspace, we don't really have a well defined PAGE_SIZE and shouln't
be relying on it. This is some more incremental work to remove
references to it.

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

bcachefs: Add BCH_BKEY_PTRS_MAX

This now means "the maximum number of pointers within a bkey" - and
bch_devs_list is updated to use it instead of BCH_REPLICAS_MAX, since
stripes can contain more than BCH_REPLICAS_MAX pointers.

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

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>