syzbot

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BUG: KCSAN: data-race in ext4_mb_find_by_goal / mb_free_blocks

read-write to 0xffff8881417181c4 of 4 bytes by task 8479 on cpu 0:
 mb_free_blocks+0x13d/0xe00 fs/ext4/mballoc.c:1486
 ext4_free_blocks+0x13b2/0x1c80 fs/ext4/mballoc.c:5470
 ext4_remove_blocks+0x7d5/0x9e0 fs/ext4/extents.c:2498
 ext4_ext_rm_leaf+0x69e/0xe60 fs/ext4/extents.c:2664
 ext4_ext_remove_space+0x936/0x13e0 fs/ext4/extents.c:2912
 ext4_ext_truncate+0xf9/0x160 fs/ext4/extents.c:4370
 ext4_truncate+0x82b/0xbb0 fs/ext4/inode.c:4254
 ext4_evict_inode+0x938/0xc00 fs/ext4/inode.c:280
 evict+0x19f/0x470 fs/inode.c:578
 iput_final fs/inode.c:1654 [inline]
 iput+0x421/0x510 fs/inode.c:1680
 do_unlinkat+0x2c9/0x4d0 fs/namei.c:3903
 __do_sys_unlink fs/namei.c:3943 [inline]
 __se_sys_unlink fs/namei.c:3941 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:3941
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881417181c4 of 4 bytes by task 685 on cpu 1:
 ext4_mb_find_by_goal+0x129/0xb30 fs/ext4/mballoc.c:1889
 ext4_mb_regular_allocator+0x10f/0x18a0 fs/ext4/mballoc.c:2320
 ext4_mb_new_blocks+0x6e8/0x1140 fs/ext4/mballoc.c:4997
 ext4_ext_map_blocks+0x15a0/0x1fc0 fs/ext4/extents.c:4238
 ext4_map_blocks+0x700/0xfc0 fs/ext4/inode.c:628
 ext4_alloc_file_blocks+0x26f/0x700 fs/ext4/extents.c:4426
 ext4_fallocate+0x2a7/0x540 fs/ext4/extents.c:4705
 vfs_fallocate+0x43d/0x5d0 fs/open.c:309
 file_ioctl fs/ioctl.c:494 [inline]
 do_vfs_ioctl+0xdc9/0xec0 fs/ioctl.c:732
 __do_sys_ioctl fs/ioctl.c:751 [inline]
 __se_sys_ioctl+0x83/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 685 Comm: syz-executor.5 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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