==================================================================
BUG: KCSAN: data-race in ext4_mb_find_by_goal / mb_free_blocks

write to 0xffff8881017f6b54 of 4 bytes by task 27055 on cpu 0:
 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:4262
 ext4_truncate_failed_write fs/ext4/truncate.h:20 [inline]
 ext4_handle_inode_extension fs/ext4/file.c:358 [inline]
 ext4_dio_write_iter fs/ext4/file.c:574 [inline]
 ext4_file_write_iter+0x106c/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 aio_write+0x287/0x360 fs/aio.c:1578
 __io_submit_one fs/aio.c:1837 [inline]
 io_submit_one+0x82f/0x1350 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0xf5/0x260 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 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 0xffff8881017f6b54 of 4 bytes by task 886 on cpu 1:
 ext4_mb_find_by_goal+0x129/0x890 fs/ext4/mballoc.c:2203
 ext4_mb_regular_allocator+0x11c/0x2520 fs/ext4/mballoc.c:2636
 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
 mpage_map_one_extent+0x10d/0x360 fs/ext4/inode.c:2395
 mpage_map_and_submit_extent fs/ext4/inode.c:2448 [inline]
 ext4_writepages+0xc1a/0x1d10 fs/ext4/inode.c:2800
 do_writepages+0x7b/0x150 mm/page-writeback.c:2355
 __writeback_single_inode+0x80/0x440 fs/fs-writeback.c:1613
 writeback_sb_inodes+0x563/0xd10 fs/fs-writeback.c:1878
 wb_writeback+0x28e/0x700 fs/fs-writeback.c:2051
 wb_do_writeback+0x101/0x510 fs/fs-writeback.c:2196
 wb_workfn+0xc8/0x520 fs/fs-writeback.c:2237
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

value changed: 0x000000d1 -> 0x000000d6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 886 Comm: kworker/u4:3 Not tainted 5.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
==================================================================
EXT4-fs: 54 callbacks suppressed
EXT4-fs (sda1): Delayed block allocation failed for inode 15750 at logical offset 1171 with max blocks 75 with error 28
EXT4-fs (sda1): This should not happen!! Data will be lost

EXT4-fs (sda1): Total free blocks count 17899
EXT4-fs (sda1): Free/Dirty block details
EXT4-fs (sda1): free_blocks=257937
EXT4-fs (sda1): dirty_blocks=6484
EXT4-fs (sda1): Block reservation details
EXT4-fs (sda1): i_reserved_data_blocks=75
EXT4-fs (sda1): Delayed block allocation failed for inode 15750 at logical offset 1607 with max blocks 4 with error 28
EXT4-fs (sda1): This should not happen!! Data will be lost

EXT4-fs (sda1): Delayed block allocation failed for inode 16367 at logical offset 1620 with max blocks 12 with error 28
EXT4-fs (sda1): This should not happen!! Data will be lost