f2fs: kernel BUG at fs/f2fs/segment.h:543

[Sasha Levin <sasha.levin@oracle.com>]

Hi all,

While fuzzing with trinity inside a KVM tools guest running the latest
-next kernel I've stumbled on the following:

[ 1789.220942] kernel BUG at fs/f2fs/segment.h:543!
[ 1789.220942] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 1789.220942] Dumping ftrace buffer:
[ 1789.220942]    (ftrace buffer empty)
[ 1789.220942] Modules linked in:
[ 1789.220942] CPU: 0 PID: 28161 Comm: trinity-c0 Not tainted 3.14.0-next-20140403-sasha-00019-g7474aa9-dirty #376
[ 1789.220942] task: ffff88032a598000 ti: ffff880329c3e000 task.ti: ffff880329c3e000
[ 1789.220942] RIP: f2fs_submit_page_mbio (fs/f2fs/segment.h:543 fs/f2fs/data.c:181)
[ 1789.220942] RSP: 0018:ffff880329c3fc08  EFLAGS: 00010287
[ 1789.220942] RAX: 000000000000ffff RBX: ffff88012ac66a00 RCX: 0000000000000009
[ 1789.220942] RDX: 0000000000000200 RSI: ffffea0001dd92c0 RDI: ffff88012ac667b0
[ 1789.220942] RBP: ffff880329c3fc58 R08: 00000000000ba28e R09: ffff88032a598d98
[ 1789.220942] R10: 0000000000000000 R11: 0000000000000000 R12: ffffea0001dd92c0
[ 1789.220942] R13: ffff88012ac667b0 R14: 0000000000000000 R15: ffff880329c3fc70
[ 1789.220942] FS:  00007f3599003700(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
[ 1789.220942] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1789.220942] CR2: 00007faf4246a018 CR3: 0000000329b6f000 CR4: 00000000000006b0
[ 1789.220942] DR0: 0000000000696000 DR1: 0000000000696000 DR2: 0000000000000000
[ 1789.261947] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
[ 1789.261947] Stack:
[ 1789.261947]  ffff88032a598000 ffff880d2a478278 0000000000000006 0000000000000082
[ 1789.261947]  ffffffffaa289475 ffffea0001dd92c0 ffff88012ac667b0 ffff880329c3fd30
[ 1789.261947]  0000000000000000 ffffea0001dd92c0 ffff880329c3fc88 ffffffffaa9da033
[ 1789.278327] Call Trace:
[ 1789.278327] ? clear_page_dirty_for_io (arch/x86/include/asm/paravirt.h:809 include/linux/backing-dev.h:176 mm/page-writeback.c:2355)
[ 1789.278327] write_meta_page (fs/f2fs/segment.c:922)
[ 1789.278327] f2fs_write_meta_page (arch/x86/include/asm/atomic.h:103 fs/f2fs/f2fs.h:692 fs/f2fs/checkpoint.c:172)
[ 1789.288220] trinity-c32: vm86 mode not supported on 64 bit kernel
[ 1789.278327] sync_meta_pages (fs/f2fs/checkpoint.c:247)
[ 1789.278327] ? get_parent_ip (kernel/sched/core.c:2472)
[ 1789.278327] ? preempt_count_sub (kernel/sched/core.c:2527)
[ 1789.278327] ? _raw_spin_unlock_irqrestore (arch/x86/include/asm/preempt.h:98 include/linux/spinlock_api_smp.h:161 kernel/locking/spinlock.c:191)
[ 1789.278327] write_checkpoint (fs/f2fs/checkpoint.c:875 fs/f2fs/checkpoint.c:913)
[ 1789.310911] waiting module removal not supported: please upgrade
[ 1789.278327] ? SyS_tee (fs/sync.c:77)
[ 1789.278327] ? mutex_lock_nested (arch/x86/include/asm/paravirt.h:809 kernel/locking/mutex.c:569 kernel/locking/mutex.c:587)
[ 1789.278327] ? get_parent_ip (kernel/sched/core.c:2472)
[ 1789.278327] ? bit_waitqueue (kernel/sched/wait.c:291)
[ 1789.278327] ? SyS_tee (fs/sync.c:77)
[ 1789.278327] f2fs_sync_fs (fs/f2fs/super.c:456)
[ 1789.278327] sync_fs_one_sb (fs/sync.c:80)
[ 1789.278327] iterate_supers (fs/super.c:512)
[ 1789.278327] sys_sync (fs/sync.c:110)
[ 1789.278327] tracesys (arch/x86/kernel/entry_64.S:749)
[ 1789.278327] Code: 48 c1 e0 04 48 8d 9c 07 f0 00 00 00 49 8b 45 38 41 8b 8d d0 06 00 00 8b 50 78 8b 80 84 00 00 00 d3 e0 41 39 d6 8d 44 02 ff 73 09 <0f> 0b 0f 1f 80 00 00 00 00 41 39 c6 76 03 0f 0b 90 48 8d 43 20
[ 1789.278327] RIP f2fs_submit_page_mbio (fs/f2fs/segment.h:543 fs/f2fs/data.c:181)
[ 1789.278327]  RSP <ffff880329c3fc08>


Thanks,
Sasha

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