syzbot

 sysfs_warn_dup.cold+0x1c/0x29 fs/sysfs/dir.c:30
 sysfs_create_dir_ns+0x228/0x280 fs/sysfs/dir.c:63
gfs2: fsid=syz:syz: error -17 adding sysfs files
 create_dir lib/kobject.c:88 [inline]
 kobject_add_internal+0x2a5/0x9c0 lib/kobject.c:247
 kobject_add_varg lib/kobject.c:382 [inline]
 kobject_init_and_add+0x101/0x160 lib/kobject.c:453
WARNING: CPU: 1 PID: 25278 at fs/fs-writeback.c:2390 __writeback_inodes_sb_nr.cold+0x11/0x18 fs/fs-writeback.c:2390
Kernel panic - not syncing: panic_on_warn set ...

 gfs2_sys_fs_add+0x18e/0x440 fs/gfs2/sys.c:659
 fill_super+0x1240/0x2550 fs/gfs2/ops_fstype.c:1103
 gfs2_mount+0x4c0/0x5a0 fs/gfs2/ops_fstype.c:1316
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x113c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x46797a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f11d34a9fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 000000000046797a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f11d34aa000
RBP: 00007f11d34aa040 R08: 00007f11d34aa040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f11d34aa000 R15: 0000000020000180
CPU: 1 PID: 25278 Comm: btrfs-transacti Not tainted 4.19.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
gfs2: fsid=syz:syz.0: jid=0: Looking at journal...
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x5a kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
kobject_add_internal failed for syz:syz with -EEXIST, don't try to register things with the same name in the same directory.
gfs2: fsid=syz:syz: error -17 adding sysfs files
gfs2: fsid=syz:syz.0: jid=0: Done
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__writeback_inodes_sb_nr.cold+0x11/0x18 fs/fs-writeback.c:2390
Code: bb e8 9d 02 6f f9 48 c7 c7 a0 f3 74 88 e8 76 ea fe ff 0f 0b e9 6c 50 ba f9 e8 85 02 6f f9 48 c7 c7 a0 f3 74 88 e8 5e ea fe ff <0f> 0b e9 c0 72 ba f9 e8 6d 02 6f f9 48 c7 c7 a0 f3 74 88 e8 46 ea
gfs2: fsid=syz:syz.0: first mount done, others may mount
RSP: 0018:ffff88801f58fc48 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 1ffff11003eb1f8b RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814ddd51 RDI: ffffed1003eb1f7b
RBP: ffff888043b80c00 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000006400
R13: ffff88803e6da100 R14: ffff888043b80d30 R15: ffff88801f58fc88
 btrfs_start_delalloc_flush fs/btrfs/transaction.c:1925 [inline]
 btrfs_commit_transaction+0x1bb1/0x2480 fs/btrfs/transaction.c:2076
 transaction_kthread+0x385/0x490 fs/btrfs/disk-io.c:1794
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Kernel Offset: disabled
Rebooting in 86400 seconds..