This fixes an infinite loop when repairing "extent past end of inode",
when the extent is an older snapshot than the inode that needs repair.

Without the snaphsots_seen_add_inorder() we keep trying to delete the
same extent, even though it's no longer visible in the inode's snapshot.

Fixes: 63d6e9311999 ("bcachefs: bch2_fpunch_snapshot()")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

When flushing the btree write buffer, we pull write buffer keys directly
from the journal instead of letting the journal write path copy them to
the write buffer.

When flushing from the currently open journal buffer, we have to block
new reservations and wait for outstanding reservations to complete.

Recheck the reservation state after blocking new reservations:
previously, we were checking the reservation count from before calling
__journal_block().

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

If the btree node is encrypted, this caused us to initialize
found_btree_node from the encrypted header.

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

maybe_casefold() shouldn't have been nooped, just bch2_casefold().

Fixes: 94426e4201fb ("bcachefs: opts.casefold_disabled")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

94426e4201fb, which added the killswitch for casefolding, accidentally
removed some of the ifdefs we need to avoid build errors.

It appears we need better build testing for different configurations, it
took two weeks for the robots to catch this one.

Fixes: 94426e4201fb ("bcachefs: opts.casefold_disabled")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Use bch2_dev_bucket_tryget() instead of bch2_dev_tryget() before
checking the bucket bitmap.

Reported-by: syzbot+3168625f36f4a539237e@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bch2_btree_node_drop_keys_outside_node() will (re)build aux search
trees, because it's also called by topology repair.

bch2_btree_node_read_done() was calling it before validating individual
keys; invalid ones have to be dropped.

If we call drop_keys_outside_node() first, then
bch2_bset_build_aux_tree() doesn't run because the node already has an
aux search tree - which was invalidated by the repair.

Reported-by: syzbot+c5e7a66b3b23ae65d44f@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

The allocator path has a "if we're really low on free buckets, check if
we should issue discards" - tweak this to also trigger discards if more
than 1/128th of the device is in need_discard state.

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

It becomes possible to do discards after a journal flush, which
naturally the journal code is reponsible for.

A prior refactoring seems to have broken this - which went unnoticed
because the foreground allocator path can also trigger discards.

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

Previously, only split rbios allocated in io_read.c would be removed
from the async obj list.

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