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BUG: KCSAN: data-race in find_group_orlov / percpu_counter_add_batch

read to 0xffff8882191450e0 of 8 bytes by task 15468 on cpu 0:
 find_group_orlov+0x15c/0x8d0 fs/ext4/ialloc.c:438
 __ext4_new_inode+0xaea/0x2f10 fs/ext4/ialloc.c:866
 ext4_mkdir+0x270/0x820 fs/ext4/namei.c:2774
 vfs_mkdir+0x283/0x390 fs/namei.c:3819
 ovl_do_mkdir fs/overlayfs/overlayfs.h:125 [inline]
 ovl_mkdir_real fs/overlayfs/dir.c:122 [inline]
 ovl_create_real+0x1ec/0x2c0 fs/overlayfs/dir.c:169
 ovl_create_upper fs/overlayfs/dir.c:303 [inline]
 ovl_create_or_link+0x286/0xc80 fs/overlayfs/dir.c:577
 ovl_create_object+0x18c/0x1d0 fs/overlayfs/dir.c:613
 ovl_mkdir+0x31/0x50 fs/overlayfs/dir.c:632
 vfs_mkdir+0x283/0x390 fs/namei.c:3819
 do_mkdirat+0x1ac/0x1f0 fs/namei.c:3842
 __do_sys_mkdir fs/namei.c:3858 [inline]
 __se_sys_mkdir fs/namei.c:3856 [inline]
 __x64_sys_mkdir+0x40/0x50 fs/namei.c:3856
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8882191450e0 of 8 bytes by task 15467 on cpu 1:
 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:4556
 ext4_ext_map_blocks+0x1c0f/0x2320 fs/ext4/extents.c:4481
 ext4_map_blocks+0x23a/0xff0 fs/ext4/inode.c:623
 ext4_alloc_file_blocks+0x1e6/0x6e0 fs/ext4/extents.c:4670
 ext4_fallocate+0x57a/0x1460 fs/ext4/extents.c:4955
 vfs_fallocate+0x3be/0x650 fs/open.c:309
 ioctl_preallocate+0x12b/0x190 fs/ioctl.c:491
 file_ioctl fs/ioctl.c:537 [inline]
 do_vfs_ioctl+0xb14/0xcf0 fs/ioctl.c:732
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:754
 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: 15467 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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