bcachefs: bch2_disk_path_to_text() no longer takes sb_lock

We're going to be using bch2_target_to_text() ->
bch2_disk_path_to_text() from bch2_bkey_ptrs_to_text() and
bch2_bkey_ptrs_invalid(), which can be called in any context.

This patch adds the actual label to bch_disk_group_cpu so that it can be
used by bch2_disk_path_to_text, and splits out bch2_disk_path_to_text()
into two variants - like the previous patch, one for when we have a
running filesystem and another for when we only have a superblock.

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: Split apart bch2_target_to_text(), bch2_target_to_text_sb()

Previously we just had bch2_opt_target_to_text() which could be passed
either a filesystem object or just a superblock - depending on if we
have a running filesystem or not.

Split these into two functions for clarity.

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

bcachefs: bch_opt_fn

Minor refactoring to get rid of some unneeded token pasting.

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

bcachefs: don't spin in rebalance when background target is not usable

If a bcachefs filesystem is configured with a background device
(disk group), rebalance will relocate data to this device in the
background by checking extent keys for whether they currently reside
in the specified target. For keys that do not, rebalance performs a
read/write cycle to allow the write path to properly relocate data.

If the background target is not usable (read-only, for example),
however, the write path doesn't actually move data to another
device. Instead, rebalance spins indefinitely reading and rewriting
the same data over and over to the same device. If the background
target is made available again, the rebalance picks this up,
relocates the data, and eventually terminates.

To avoid this spinning behavior, update the rebalance background
target logic to not only check whether the extent is not in the
target, but whether the target is actually usable as well. If not,
then don't mark the key for rewrite.

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

bcachefs: create internal disk_groups sysfs file

We have bch2_sb_disk_groups_to_text() to dump disk group labels, but
no good information on device group membership at runtime. Add
bch2_disk_groups_to_text() and an associated 'disk_groups' sysfs
file to print group and device relationships.

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

bcachefs: Fix adding a device with a label

Device labels are represented as pointers in the member info section: we
need to get and then set the label for it to be kept correctly.

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

bcachefs: Convert bch2_sb_to_text to master option list

Options no longer have to be manually added to bch2_sb_to_text() - it
now uses the master list of options in opts.h. Also, improve some of the
formatting by converting it to tabstops.

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

bcachefs: Fix disk groups not being updated when set via sysfs

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

bcachefs: Erasure coding

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

bcachefs: revamp to_text methods

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>