==================================================================
BUG: KCSAN: data-race in find_group_orlov / percpu_counter_add_batch

read to 0xffff88821870f0e0 of 8 bytes by task 8379 on cpu 0:
 find_group_orlov+0x15c/0x8d0 fs/ext4/ialloc.c:443
 __ext4_new_inode+0xad2/0x3070 fs/ext4/ialloc.c:871
 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

write to 0xffff88821870f0e0 of 8 bytes by task 11432 on cpu 1:
 percpu_counter_add_batch+0xca/0x150 lib/percpu_counter.c:91
 percpu_counter_add include/linux/percpu_counter.h:55 [inline]
 ext4_free_blocks+0xb4d/0x17e0 fs/ext4/mballoc.c:4928
 ext4_remove_blocks fs/ext4/extents.c:2678 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2831 [inline]
 ext4_ext_remove_space+0x1841/0x32c0 fs/ext4/extents.c:3076
 ext4_punch_hole+0x9c4/0xab0 fs/ext4/inode.c:4363
 ext4_fallocate+0x2bc/0x13d0 fs/ext4/extents.c:4889
 vfs_fallocate+0x3be/0x650 fs/open.c:309
 ksys_fallocate+0x61/0xa0 fs/open.c:332
 __do_sys_fallocate fs/open.c:340 [inline]
 __se_sys_fallocate fs/open.c:338 [inline]
 __x64_sys_fallocate+0x5e/0x80 fs/open.c:338
 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: 11432 Comm: syz-executor.5 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================