syzbot

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BUG: KCSAN: data-race in __xa_clear_mark / filemap_write_and_wait_range

write to 0xffff888115b669a4 of 4 bytes by interrupt on cpu 0:
 xa_mark_clear lib/xarray.c:77 [inline]
 xas_clear_mark lib/xarray.c:932 [inline]
 __xa_clear_mark+0x1c6/0x1e0 lib/xarray.c:2097
 __folio_end_writeback+0x177/0x470 mm/page-writeback.c:3024
 folio_end_writeback+0x71/0x3d0 mm/filemap.c:1660
 ext4_finish_bio+0x459/0x8c0 fs/ext4/page-io.c:144
 ext4_end_bio+0x22a/0x330 fs/ext4/page-io.c:-1
 bio_endio+0x374/0x410 block/bio.c:1645
 blk_update_request+0x336/0x730 block/blk-mq.c:987
 blk_mq_end_request+0x26/0x50 block/blk-mq.c:1149
 lo_complete_rq+0x98/0x140 drivers/block/loop.c:304
 blk_complete_reqs block/blk-mq.c:1224 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1229
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x32b/0x530 kernel/smpboot.c:164
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888115b669a4 of 4 bytes by task 10319 on cpu 1:
 xa_marked include/linux/xarray.h:424 [inline]
 mapping_tagged include/linux/fs.h:542 [inline]
 filemap_fdatawrite_wbc mm/filemap.c:382 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 filemap_write_and_wait_range+0xfc/0x340 mm/filemap.c:691
 filemap_invalidate_pages+0xa4/0x1a0 mm/filemap.c:2815
 kiocb_invalidate_pages+0x6e/0x80 mm/filemap.c:2834
 __iomap_dio_rw+0x5d4/0x1250 fs/iomap/direct-io.c:703
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:823
 ext4_dio_write_iter fs/ext4/file.c:580 [inline]
 ext4_file_write_iter+0xad9/0xf00 fs/ext4/file.c:721
 iter_file_splice_write+0x5ef/0x970 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x153/0x2a0 fs/splice.c:1158
 splice_direct_to_actor+0x30f/0x680 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0e000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 10319 Comm: syz.6.1925 Not tainted 6.16.0-rc7-syzkaller-00142-gb711733e89a3 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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