==================================================================
BUG: KCSAN: data-race in xas_find_marked / xas_init_marks

read-write to 0xffff888108291d98 of 8 bytes by task 9551 on cpu 0:
 instrument_read_write include/linux/instrumented.h:55 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:84 [inline]
 ___test_and_clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:114 [inline]
 node_clear_mark lib/xarray.c:102 [inline]
 xas_clear_mark lib/xarray.c:914 [inline]
 xas_init_marks+0x17e/0x320 lib/xarray.c:947
 xas_store+0x216/0xc90 lib/xarray.c:809
 page_cache_delete mm/filemap.c:139 [inline]
 __filemap_remove_folio+0x1a8/0x2d0 mm/filemap.c:222
 filemap_remove_folio+0x6c/0x1e0 mm/filemap.c:254
 truncate_inode_folio mm/truncate.c:195 [inline]
 truncate_inode_pages_range+0x582/0x6a0 mm/truncate.c:424
 truncate_inode_pages mm/truncate.c:448 [inline]
 truncate_pagecache+0x53/0x70 mm/truncate.c:741
 ext4_setattr+0xa03/0xea0 fs/ext4/inode.c:5471
 notify_change+0x866/0x8e0 fs/attr.c:499
 do_truncate+0x116/0x150 fs/open.c:66
 do_sys_ftruncate+0x2ba/0x3b0 fs/open.c:194
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x33/0x40 fs/open.c:203
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888108291d98 of 8 bytes by task 8770 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1723 [inline]
 xas_find_marked+0x216/0x660 lib/xarray.c:1354
 find_get_entry+0x5d/0x290 mm/filemap.c:1960
 filemap_get_folios_tag+0x136/0x210 mm/filemap.c:2210
 mpage_prepare_extent_to_map+0x321/0xb70 fs/ext4/inode.c:2398
 ext4_do_writepages+0x6ea/0x2100 fs/ext4/inode.c:2638
 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2774
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 __writeback_single_inode+0x91/0x860 fs/fs-writeback.c:1625
 writeback_sb_inodes+0x514/0xad0 fs/fs-writeback.c:1916
 wb_writeback+0x252/0x6e0 fs/fs-writeback.c:2092
 wb_do_writeback fs/fs-writeback.c:2239 [inline]
 wb_workfn+0x1a8/0x8d0 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700
 worker_thread+0x525/0x730 kernel/workqueue.c:2781
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x0003ffff00000000 -> 0x0003fc0000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8770 Comm: kworker/u4:1 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: writeback wb_workfn (flush-7:0)
==================================================================
EXT4-fs error (device loop5): ext4_mb_generate_buddy:1217: group 0, 
block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters
EXT4-fs (loop5): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 720 with error 28
EXT4-fs (loop5): This should not happen!! Data will be lost

EXT4-fs (loop5): Total free blocks count 0
EXT4-fs (loop5): Free/Dirty block details
EXT4-fs (loop5): free_blocks=2415919104
EXT4-fs (loop5): dirty_blocks=928
EXT4-fs (loop5): Block reservation details
EXT4-fs (loop5): i_reserved_data_blocks=67
EXT4-fs error (device loop0): ext4_mb_generate_buddy:1217: group 0, block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters
EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 2048 with error 28
EXT4-fs (loop0): This should not happen!! Data will be lost

EXT4-fs (loop0): Total free blocks count 0
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=2415919104
EXT4-fs (loop0): dirty_blocks=4208
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=263
EXT4-fs error (device loop0): ext4_mb_generate_buddy:1217: group 0, block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters
EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 1752 with error 28
EXT4-fs (loop0): This should not happen!! Data will be lost

EXT4-fs (loop0): Total free blocks count 0
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=2415919104
EXT4-fs (loop0): dirty_blocks=1792
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=112