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BUG: KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks

write to 0xffff88810189bb54 of 4 bytes by task 1840 on cpu 1:
 mb_free_blocks+0x156/0xb40 fs/ext4/mballoc.c:1798
 ext4_free_blocks+0x1418/0x1b50 fs/ext4/mballoc.c:5989
 ext4_remove_blocks+0x61a/0x800 fs/ext4/extents.c:2502
 ext4_ext_rm_leaf+0x670/0xd20 fs/ext4/extents.c:2668
 ext4_ext_remove_space+0x901/0x1300 fs/ext4/extents.c:2916
 ext4_ext_truncate+0xfe/0x170 fs/ext4/extents.c:4377
 ext4_truncate+0x76e/0xa80 fs/ext4/inode.c:4261
 ext4_evict_inode+0xa54/0xdb0 fs/ext4/inode.c:288
 evict+0x1c8/0x3c0 fs/inode.c:586
 iput_final fs/inode.c:1662 [inline]
 iput+0x430/0x580 fs/inode.c:1688
 dentry_unlink_inode+0x273/0x290 fs/dcache.c:376
 d_delete+0x78/0xe0 fs/dcache.c:2505
 vfs_rmdir+0x2e6/0x300 fs/namei.c:3984
 do_rmdir+0x15d/0x310 fs/namei.c:4032
 __do_sys_rmdir fs/namei.c:4051 [inline]
 __se_sys_rmdir fs/namei.c:4049 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:4049
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88810189bb54 of 4 bytes by task 1772 on cpu 0:
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2492 [inline]
 ext4_mb_regular_allocator+0xae9/0x2520 fs/ext4/mballoc.c:2729
 ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5515
 ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4245
 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638
 ext4_getblk+0xb1/0x3d0 fs/ext4/inode.c:848
 ext4_bread+0x28/0x100 fs/ext4/inode.c:900
 ext4_append+0xd1/0x1c0 fs/ext4/namei.c:67
 ext4_init_new_dir+0x177/0x500 fs/ext4/namei.c:2885
 ext4_mkdir+0x329/0x760 fs/ext4/namei.c:2931
 vfs_mkdir+0x2c3/0x3e0 fs/namei.c:3885
 do_mkdirat+0x12e/0x2e0 fs/namei.c:3911
 __do_sys_mkdir fs/namei.c:3931 [inline]
 __se_sys_mkdir fs/namei.c:3929 [inline]
 __x64_sys_mkdir+0x40/0x50 fs/namei.c:3929
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000595b -> 0x0000595c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1772 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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