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

write to 0xffff888132d8c238 of 8 bytes by task 19118 on cpu 0:
 instrument_write include/linux/instrumented.h:42 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:79 [inline]
 __test_and_clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:109 [inline]
 node_clear_mark lib/xarray.c:100 [inline]
 xas_clear_mark lib/xarray.c:911 [inline]
 xas_init_marks+0x1b0/0x340 lib/xarray.c:944
 xas_store+0x201/0xcf0 lib/xarray.c:806
 page_cache_delete_batch mm/filemap.c:337 [inline]
 delete_from_page_cache_batch+0x3f4/0x820 mm/filemap.c:358
 truncate_inode_pages_range+0x482/0x10e0 mm/truncate.c:366
 truncate_inode_pages mm/truncate.c:476 [inline]
 truncate_pagecache+0x4f/0x70 mm/truncate.c:845
 ext4_setattr+0xae3/0xf60 fs/ext4/inode.c:5500
 notify_change+0x86d/0xa60 fs/attr.c:336
 do_truncate+0xe0/0x120 fs/open.c:64
 handle_truncate fs/namei.c:2912 [inline]
 do_open fs/namei.c:3258 [inline]
 path_openat+0x1a30/0x20a0 fs/namei.c:3371
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_openat fs/open.c:1204 [inline]
 __se_sys_openat fs/open.c:1199 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1199
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888132d8c238 of 8 bytes by task 3068 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1660 [inline]
 xas_next_marked include/linux/xarray.h:1691 [inline]
 find_get_pages_range_tag+0x35c/0x600 mm/filemap.c:2107
 pagevec_lookup_range_tag+0x37/0x50 mm/swap.c:1122
 mpage_prepare_extent_to_map+0x195/0x640 fs/ext4/inode.c:2578
 ext4_writepages+0x674/0x1e70 fs/ext4/inode.c:2755
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __writeback_single_inode+0x80/0x500 fs/fs-writeback.c:1461
 writeback_sb_inodes+0x6a7/0xff0 fs/fs-writeback.c:1723
 wb_writeback+0x27d/0x660 fs/fs-writeback.c:1896
 wb_do_writeback+0x101/0x5d0 fs/fs-writeback.c:2041
 wb_workfn+0xc8/0x430 fs/fs-writeback.c:2082
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3068 Comm: kworker/u4:4 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
==================================================================