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BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff888106e0f228 of 8 bytes by interrupt on cpu 1:
 instrument_read_write include/linux/instrumented.h:56 [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:922 [inline]
 __xa_clear_mark+0xf5/0x1e0 lib/xarray.c:2103
 __folio_end_writeback+0xe7/0x530 mm/page-writeback.c:2967
 folio_end_writeback_no_dropbehind+0x6d/0x200 mm/filemap.c:1682
 folio_end_writeback+0x72/0x110 mm/filemap.c:1721
 ext4_finish_bio+0x454/0x770 fs/ext4/page-io.c:140
 ext4_end_bio+0x281/0x3a0 fs/ext4/page-io.c:387
 bio_endio+0x390/0x570 block/bio.c:1908
 blk_update_request+0x33a/0x710 block/blk-mq.c:1036
 scsi_end_request+0x4b/0x4c0 drivers/scsi/scsi_lib.c:671
 scsi_io_completion+0x7f/0x1d0 drivers/scsi/scsi_lib.c:1125
 scsi_finish_command+0x1c7/0x1e0 drivers/scsi/scsi.c:198
 scsi_complete+0x12c/0x4a0 drivers/scsi/scsi_lib.c:1604
 blk_complete_reqs block/blk-mq.c:1242 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1247
 handle_softirqs+0x109/0x310 kernel/softirq.c:669
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1133
 smpboot_thread_fn+0x372/0x560 kernel/smpboot.c:162
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888106e0f228 of 8 bytes by task 24151 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x211/0x650 lib/xarray.c:1513
 find_get_entry mm/filemap.c:2116 [inline]
 filemap_get_folios_tag+0xf7/0x400 mm/filemap.c:2382
 __filemap_fdatawait_range mm/filemap.c:522 [inline]
 filemap_fdatawait_keep_errors+0x6c/0x190 mm/filemap.c:625
 wait_sb_inodes fs/fs-writeback.c:2942 [inline]
 sync_inodes_sb+0x42a/0x4d0 fs/fs-writeback.c:3075
 sync_inodes_one_sb+0x3d/0x50 fs/sync.c:77
 __iterate_supers+0x205/0x360 fs/super.c:953
 iterate_supers+0x1f/0x30 fs/super.c:969
 ksys_sync fs/sync.c:102 [inline]
 __ia32_sys_sync+0x5c/0xb0 fs/sync.c:111
 x64_sys_call+0x1e8b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:163
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff000000000000 -> 0xfffc000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 24151 Comm: syz.4.5084 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
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