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truncate spotted in mem i_size < btree i_size: 130235 < 1048576
WARNING: CPU: 0 PID: 6945 at fs/bcachefs/fs-io.c:457 bchfs_truncate+0x8a0/0x990 fs/bcachefs/fs-io.c:454
Modules linked in:
CPU: 0 UID: 0 PID: 6945 Comm: syz.4.57 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+0x8a0/0x990 fs/bcachefs/fs-io.c:454
lr : bchfs_truncate+0x8a0/0x990 fs/bcachefs/fs-io.c:454
sp : ffff8000a38f77e0
x29: ffff8000a38f79f0 x28: 0000000000100000 x27: ffff0000f29ba628
x26: ffff0000f29baaa0 x25: ffff0000fcc49580 x24: ffff70001471ef0c
x23: 000000000001fcbb x22: ffff0000f29bab60 x21: ffff0000f29baa98
x20: dfff800000000000 x19: ffff0000f29ba5f8 x18: 00000000ffffffff
x17: 0000000000000000 x16: ffff80008ad04488 x15: ffff700011e6bf2c
x14: 1ffff00011e6bf2c x13: 0000000000000004 x12: ffffffffffffffff
x11: 0000000000080000 x10: 0000000000005b97 x9 : 79f1e04e672af300
x8 : 79f1e04e672af300 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a38f7138 x4 : ffff80008f3d4f00 x3 : ffff80008054049c
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 bchfs_truncate+0x8a0/0x990 fs/bcachefs/fs-io.c:454 (P)
 bch2_setattr+0x198/0x20c fs/bcachefs/fs.c:1218
 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+0x58/0x150 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
irq event stamp: 1188
hardirqs last  enabled at (1187): [<ffff8000805479c8>] __up_console_sem kernel/printk/printk.c:344 [inline]
hardirqs last  enabled at (1187): [<ffff8000805479c8>] __console_unlock+0x70/0xc4 kernel/printk/printk.c:2885
hardirqs last disabled at (1188): [<ffff80008ad96544>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:488
softirqs last  enabled at (942): [<ffff8000801fab4c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (940): [<ffff8000801fab18>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---