==================================================================
BUG: KCSAN: data-race in __ext4_new_inode / find_next_zero_bit

write to 0xffff88812bdd4010 of 8 bytes by task 19932 on cpu 0:
 __test_and_set_bit include/asm-generic/bitops-instrumented.h:168 [inline]
 __test_and_set_bit_le include/asm-generic/bitops/le.h:90 [inline]
 __ext4_new_inode+0xf04/0x2ec0 fs/ext4/ialloc.c:944
 ext4_create+0x152/0x370 fs/ext4/namei.c:2587
 lookup_open fs/namei.c:3224 [inline]
 do_last fs/namei.c:3314 [inline]
 path_openat+0x2b4b/0x36e0 fs/namei.c:3525
 do_filp_open+0x11e/0x1b0 fs/namei.c:3555
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 __do_sys_openat fs/open.c:1124 [inline]
 __se_sys_openat fs/open.c:1118 [inline]
 __x64_sys_openat+0x62/0x80 fs/open.c:1118
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812bdd4010 of 8 bytes by task 8096 on cpu 1:
 _find_next_bit lib/find_bit.c:39 [inline]
 find_next_zero_bit+0x4e/0xe0 lib/find_bit.c:79
 find_next_zero_bit_le include/asm-generic/bitops/le.h:15 [inline]
 find_inode_bit.isra.0+0x82/0x300 fs/ext4/ialloc.c:715
 __ext4_new_inode+0xd10/0x2ec0 fs/ext4/ialloc.c:914
 ext4_mkdir+0x289/0x820 fs/ext4/namei.c:2763
 vfs_mkdir+0x283/0x390 fs/namei.c:3807
 do_mkdirat+0x1ac/0x1f0 fs/namei.c:3830
 __do_sys_mkdir fs/namei.c:3846 [inline]
 __se_sys_mkdir fs/namei.c:3844 [inline]
 __x64_sys_mkdir+0x40/0x50 fs/namei.c:3844
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8096 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================