Hello, This is a known problem I was speaking about here [1]. It is a generic mm/fs problem but there's no solution to it yet. We'll discuss it at LSF/MM next week so after that we may have some solution... Honza [1] https://www.spinics.net/lists/linux-xfs/msg14468.html On Sun 01-04-18 01:05:00, syzbot wrote: > syzbot hit the following crash on upstream commit > 10b84daddbec72c6b440216a69de9a9605127f7a (Sat Mar 31 17:59:00 2018 +0000) > Merge branch 'perf-urgent-for-linus' of > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=9a44753ac327c557796a > > So far this crash happened 3 times on upstream. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=5118663967375360 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-2760467897697295172 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+9a44753ac327c557796a@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > WARNING: CPU: 0 PID: 7377 at fs/ext4/inode.c:3895 > ext4_set_page_dirty+0x242/0x2b0 fs/ext4/inode.c:3895 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 7377 Comm: syz-executor1 Not tainted 4.16.0-rc7+ #9 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > panic+0x1e4/0x41c kernel/panic.c:183 > __warn+0x1dc/0x200 kernel/panic.c:547 > report_bug+0x1f4/0x2b0 lib/bug.c:186 > fixup_bug.part.10+0x37/0x80 arch/x86/kernel/traps.c:178 > fixup_bug arch/x86/kernel/traps.c:247 [inline] > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 > RIP: 0010:ext4_set_page_dirty+0x242/0x2b0 fs/ext4/inode.c:3895 > RSP: 0000:ffff88018b725df0 EFLAGS: 00010216 > RAX: 0000000000040000 RBX: ffffea0006713040 RCX: ffffffff81ee1072 > RDX: 0000000000002ee2 RSI: ffffc900074f3000 RDI: ffffea0006713040 > RBP: ffff88018b725ec0 R08: 1ffff100316e4c1c R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff100316e4bbf > R13: ffffea0006713040 R14: ffff88018b725e98 R15: ffffea0006713060 > set_page_dirty+0x2c5/0x5d0 mm/page-writeback.c:2565 > set_page_dirty_lock+0xf2/0x160 mm/page-writeback.c:2590 > dio_bio_complete+0x514/0x750 fs/direct-io.c:560 > dio_await_completion fs/direct-io.c:581 [inline] > do_blockdev_direct_IO+0x7270/0xc960 fs/direct-io.c:1392 > __blockdev_direct_IO+0x9d/0xd0 fs/direct-io.c:1421 > ext4_direct_IO_read fs/ext4/inode.c:3830 [inline] > ext4_direct_IO+0xfe5/0x1980 fs/ext4/inode.c:3866 > generic_file_read_iter+0x4cc/0x28e0 mm/filemap.c:2343 > ext4_file_read_iter+0x113/0x160 fs/ext4/file.c:77 > call_read_iter include/linux/fs.h:1776 [inline] > new_sync_read fs/read_write.c:401 [inline] > __vfs_read+0x6a7/0xa00 fs/read_write.c:413 > vfs_read+0x11e/0x350 fs/read_write.c:447 > SYSC_pread64 fs/read_write.c:611 [inline] > SyS_pread64+0x15b/0x190 fs/read_write.c:598 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x454e79 > RSP: 002b:00007feb4557bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 > RAX: ffffffffffffffda RBX: 00007feb4557c6d4 RCX: 0000000000454e79 > RDX: 00000000ffffff72 RSI: 0000000020003c00 RDI: 0000000000000018 > RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff > R13: 000000000000046d R14: 00000000006f8ad8 R15: 0000000000000000 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
