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

write to 0xffff8881297b00e0 of 8 bytes by task 31764 on cpu 0:
 percpu_counter_add_batch+0xca/0x150 lib/percpu_counter.c:91
 percpu_counter_add include/linux/percpu_counter.h:55 [inline]
 percpu_counter_sub include/linux/percpu_counter.h:189 [inline]
 ext4_mb_mark_diskspace_used+0x525/0x9d0 fs/ext4/mballoc.c:3010
 ext4_mb_new_blocks+0x6fc/0x1de0 fs/ext4/mballoc.c:4560
 ext4_ext_map_blocks+0x1c11/0x2320 fs/ext4/extents.c:4440
 ext4_map_blocks+0x23a/0xdb0 fs/ext4/inode.c:622
 ext4_iomap_alloc fs/ext4/inode.c:3401 [inline]
 ext4_iomap_begin+0x27d/0x490 fs/ext4/inode.c:3440
 iomap_apply+0xdc/0x6a0 fs/iomap/apply.c:46
 iomap_dio_rw+0x67e/0x9a0 fs/iomap/direct-io.c:498
 ext4_dio_write_iter fs/ext4/file.c:532 [inline]
 ext4_file_write_iter+0xb15/0xd70 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:998 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:979
 vfs_iter_write+0x5c/0x80 fs/read_write.c:1039
 iter_file_splice_write+0x536/0x850 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1581 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881297b00e0 of 8 bytes by task 8023 on cpu 1:
 find_group_orlov+0x15c/0x8d0 fs/ext4/ialloc.c:441
 __ext4_new_inode+0xaea/0x2f30 fs/ext4/ialloc.c:869
 ext4_mkdir+0x270/0x820 fs/ext4/namei.c:2782
 vfs_mkdir+0x283/0x390 fs/namei.c:3889
 do_mkdirat+0x1ac/0x1f0 fs/namei.c:3912
 __do_sys_mkdir fs/namei.c:3928 [inline]
 __se_sys_mkdir fs/namei.c:3926 [inline]
 __x64_sys_mkdir+0x40/0x50 fs/namei.c:3926
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8023 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================