syzbot

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BUG: KCSAN: data-race in get_tree_bdev / kmmpd

read-write to 0xffff88810ac30850 of 8 bytes by task 6372 on cpu 0:
 get_tree_bdev+0x32a/0x3b0 fs/super.c:1324
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5728
 vfs_get_tree+0x51/0x190 fs/super.c:1519
 do_new_mount+0x203/0x660 fs/namespace.c:3335
 path_mount+0x496/0xb30 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3861
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810ac30850 of 8 bytes by task 6373 on cpu 1:
 sb_rdonly include/linux/fs.h:1982 [inline]
 kmmpd+0x152/0x600 fs/ext4/mmp.c:165
 kthread+0x1d7/0x210 kernel/kthread.c:389
 ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296

value changed: 0x0000000010810000 -> 0x0000000070810000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6373 Comm: kmmpd-loop1 Not tainted 6.5.0-rc2-syzkaller-00052-gbfa3037d8280 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
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