bcachefs (loop4): bucket incorrectly unset in freespace btree
  u64s 5 type deleted 0:1:0 len 0 ver 0, , continuing
------------[ cut here ]------------
btree trans held srcu lock (delaying memory reclaim) for 33 seconds
WARNING: CPU: 1 PID: 13 at fs/bcachefs/btree_iter.c:3179 check_srcu_held_too_long fs/bcachefs/btree_iter.c:3177 [inline]
WARNING: CPU: 1 PID: 13 at fs/bcachefs/btree_iter.c:3179 bch2_trans_srcu_unlock+0x50d/0x620 fs/bcachefs/btree_iter.c:3193
Modules linked in:
CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: btree_update btree_interior_update_work
RIP: 0010:check_srcu_held_too_long fs/bcachefs/btree_iter.c:3177 [inline]
RIP: 0010:bch2_trans_srcu_unlock+0x50d/0x620 fs/bcachefs/btree_iter.c:3193
Code: 7d 00 49 c1 ef 02 48 b9 c3 f5 28 5c 8f c2 f5 28 4c 89 f8 48 f7 e1 48 c1 ea 02 48 c7 c7 20 cb b2 8b 48 89 d6 e8 f4 85 68 fd 90 <0f> 0b 90 90 e9 a6 fe ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 1c fb ff
RSP: 0018:ffffc90000127658 EFLAGS: 00010246
RAX: 4fa1185650fe0500 RBX: 1ffff1100d254008 RCX: ffff88801c6d0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 1ffff1100d254011 R08: ffff8880b8923e93 R09: 1ffff110171247d2
R10: dffffc0000000000 R11: ffffed10171247d3 R12: ffff8880692a0042
R13: ffff8880692a0088 R14: 1ffff1100d254008 R15: 0000000000000350
FS:  0000000000000000(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6431118310 CR3: 0000000031844000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_trans_begin+0x19b0/0x1f10 fs/bcachefs/btree_iter.c:3270
 btree_update_nodes_written fs/bcachefs/btree_update_interior.c:726 [inline]
 btree_interior_update_work+0x1054/0x25e0 fs/bcachefs/btree_update_interior.c:843
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>