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truncate spotted in mem i_size < btree i_size: 68717 < 1048576
WARNING: CPU: 1 PID: 6644 at fs/bcachefs/fs-io.c:457 bchfs_truncate+0x974/0xa64 fs/bcachefs/fs-io.c:454
Modules linked in:
CPU: 1 UID: 0 PID: 6644 Comm: syz.2.8 Not tainted 6.15.0-rc2-syzkaller-gc72692105976 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : bchfs_truncate+0x974/0xa64 fs/bcachefs/fs-io.c:454
lr : bchfs_truncate+0x974/0xa64 fs/bcachefs/fs-io.c:454
sp : ffff8000a5907740
x29: ffff8000a5907960
 x28: ffff0000f1800000 x27: ffff0000f4e20c40
x26: 0000000000100000 x25: ffff80009340c000 x24: ffff700014b20efc
x23: ffff0000f4e20c38 x22: ffff0000f4e20d00 x21: 0000000000010c6d
x20: dfff800000000000 x19: ffff0000f4e20798 x18: 0000000000000008
x17: 0000000000000000 x16: ffff80008b8e90cc x15: ffff700011ff5f6c
x14: 1ffff00011ff5f6c x13: 0000000000000004 x12: ffffffffffffffff
x11: 0000000000080000 x10: 00000000000021c2 x9 : 31f86d722b4a5600
x8 : 31f86d722b4a5600 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a5906ed8 x4 : ffff8000900254e0 x3 : ffff8000804b6aa8
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 bchfs_truncate+0x974/0xa64 fs/bcachefs/fs-io.c:454 (P)
 bch2_setattr+0x1a0/0x214 fs/bcachefs/fs.c:1218
 notify_change+0x9f0/0xca0 fs/attr.c:552
 do_truncate+0x1c0/0x28c fs/open.c:65
 vfs_truncate+0x3ec/0x450 fs/open.c:115
 do_sys_truncate+0xe8/0x1ac fs/open.c:138
 __do_sys_truncate fs/open.c:150 [inline]
 __se_sys_truncate fs/open.c:148 [inline]
 __arm64_sys_truncate+0x5c/0x74 fs/open.c:148
 __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+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
irq event stamp: 138
hardirqs last  enabled at (137): [<ffff8000804beb9c>] __up_console_sem kernel/printk/printk.c:344 [inline]
hardirqs last  enabled at (137): [<ffff8000804beb9c>] __console_unlock+0x70/0xc4 kernel/printk/printk.c:2885
hardirqs last disabled at (138): [<ffff80008b985884>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:488
softirqs last  enabled at (8): [<ffff80008012c108>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (6): [<ffff80008012c0d4>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---