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truncate spotted in mem i_size < btree i_size: 65535 < 1048576
WARNING: CPU: 1 PID: 7226 at fs/bcachefs/fs-io.c:472 bchfs_truncate+0x88c/0xa70 fs/bcachefs/fs-io.c:469
Modules linked in:
CPU: 1 UID: 0 PID: 7226 Comm: syz.3.120 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : bchfs_truncate+0x88c/0xa70 fs/bcachefs/fs-io.c:469
lr : bchfs_truncate+0x88c/0xa70 fs/bcachefs/fs-io.c:469
sp : ffff8000a0b97760
x29: ffff8000a0b979f0 x28: 0000000000100000 x27: ffff0000f76107c8
x26: ffff0000f7610c40 x25: ffff8000a0b97b70 x24: ffff700014172efc
x23: 000000000000ffff x22: ffff0000f7610d00 x21: ffff0000f7610c38
x20: dfff800000000000 x19: ffff0000f7610798 x18: 00000000ffffffff
x17: 0000000000000000 x16: ffff80008ad27e48 x15: ffff700011e740c0
x14: 1ffff00011e740c0 x13: 0000000000000004 x12: ffffffffffffffff
x11: 0000000000080000 x10: 0000000000002fe2 x9 : b479f74e16e2cc00
x8 : b479f74e16e2cc00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a0b970b8 x4 : ffff80008f415ba0 x3 : ffff800080548ef0
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 bchfs_truncate+0x88c/0xa70 fs/bcachefs/fs-io.c:469 (P)
 bch2_setattr+0x198/0x20c fs/bcachefs/fs.c:1245
 notify_change+0x9a4/0xc50 fs/attr.c:552
 do_truncate+0x178/0x1f0 fs/open.c:65
 do_ftruncate+0x3bc/0x458 fs/open.c:192
 do_sys_ftruncate fs/open.c:207 [inline]
 __do_sys_ftruncate fs/open.c:212 [inline]
 __se_sys_ftruncate fs/open.c:210 [inline]
 __arm64_sys_ftruncate+0x90/0xe8 fs/open.c:210
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
irq event stamp: 234
hardirqs last  enabled at (233): [<ffff80008055041c>] __up_console_sem kernel/printk/printk.c:344 [inline]
hardirqs last  enabled at (233): [<ffff80008055041c>] __console_unlock+0x70/0xc4 kernel/printk/printk.c:2885
hardirqs last disabled at (234): [<ffff80008adb9eb8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:511
softirqs last  enabled at (220): [<ffff8000803cf71c>] softirq_handle_end kernel/softirq.c:425 [inline]
softirqs last  enabled at (220): [<ffff8000803cf71c>] handle_softirqs+0xaf8/0xc88 kernel/softirq.c:607
softirqs last disabled at (211): [<ffff800080020efc>] __do_softirq+0x14/0x20 kernel/softirq.c:613
---[ end trace 0000000000000000 ]---