syzbot

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BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

write to 0xffff888237c28478 of 8 bytes by task 17529 on cpu 0:
 bh_lru_install fs/buffer.c:1250 [inline]
 __find_get_block+0x22c/0x6c0 fs/buffer.c:1309
 __getblk_gfp+0x2d/0x1c0 fs/buffer.c:1329
 sb_getblk include/linux/buffer_head.h:363 [inline]
 ext4_getblk+0x178/0x4b0 fs/ext4/inode.c:868
 ext4_bread+0x28/0x100 fs/ext4/inode.c:914
 ext4_append+0x171/0x270 fs/ext4/namei.c:83
 ext4_init_new_dir+0x177/0x500 fs/ext4/namei.c:2943
 ext4_mkdir+0x329/0x760 fs/ext4/namei.c:2989
 vfs_mkdir+0x27a/0x380 fs/namei.c:4013
 do_mkdirat+0x101/0x270 fs/namei.c:4038
 __do_sys_mkdirat fs/namei.c:4053 [inline]
 __se_sys_mkdirat fs/namei.c:4051 [inline]
 __x64_sys_mkdirat+0x4c/0x60 fs/namei.c:4051
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237c28478 of 8 bytes by task 7027 on cpu 1:
 has_bh_in_lru+0x31/0x1c0 fs/buffer.c:1414
 smp_call_function_many_cond+0x34a/0x790 kernel/smp.c:936
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1154
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x26/0x30 fs/buffer.c:1423
 kill_bdev block/bdev.c:74 [inline]
 blkdev_flush_mapping+0xb6/0x1c0 block/bdev.c:661
 blkdev_put_whole block/bdev.c:692 [inline]
 blkdev_put+0x32d/0x420 block/bdev.c:952
 kill_block_super+0x7b/0x90 fs/super.c:1430
 deactivate_locked_super+0x6a/0xb0 fs/super.c:332
 deactivate_super+0x85/0x90 fs/super.c:363
 cleanup_mnt+0x2b6/0x320 fs/namespace.c:1186
 __cleanup_mnt+0x15/0x20 fs/namespace.c:1193
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffff8881380adb60 -> 0xffff8881381f1e38

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7027 Comm: syz-executor.1 Not tainted 6.0.0-rc7-syzkaller-00250-ga962b54e162c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
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