loop9: detected capacity change from 0 to 1024
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BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff888119e27470 of 8 bytes by interrupt on cpu 1:
 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:922 [inline]
 __xa_clear_mark+0xf5/0x1e0 lib/xarray.c:2100
 __folio_end_writeback+0x177/0x470 mm/page-writeback.c:3022
 folio_end_writeback+0x71/0x3d0 mm/filemap.c:1660
 ext4_finish_bio+0x459/0x8c0 fs/ext4/page-io.c:144
 ext4_end_bio+0x298/0x3b0 fs/ext4/page-io.c:-1
 bio_endio+0x377/0x410 block/bio.c:1651
 blk_update_request+0x336/0x730 block/blk-mq.c:989
 blk_mq_end_request+0x26/0x50 block/blk-mq.c:1151
 lo_complete_rq+0x98/0x140 drivers/block/loop.c:304
 blk_complete_reqs block/blk-mq.c:1226 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1231
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:160
 kthread+0x486/0x510 kernel/kthread.c:463
 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 0xffff888119e27470 of 8 bytes by task 10895 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x218/0x620 lib/xarray.c:1510
 find_get_entry+0x5d/0x380 mm/filemap.c:2039
 filemap_get_folios_tag+0x13b/0x210 mm/filemap.c:2307
 __filemap_fdatawait_range mm/filemap.c:530 [inline]
 file_write_and_wait_range+0x1ea/0x2c0 mm/filemap.c:798
 generic_buffers_fsync_noflush+0x45/0x120 fs/buffer.c:609
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x1ab/0x690 fs/ext4/fsync.c:147
 vfs_fsync_range+0x10d/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:3042 [inline]
 ext4_buffered_write_iter+0x34f/0x3c0 fs/ext4/file.c:305
 ext4_dio_write_iter fs/ext4/file.c:613 [inline]
 ext4_file_write_iter+0xdbf/0xf00 fs/ext4/file.c:721
 do_iter_readv_writev+0x421/0x4c0 fs/read_write.c:-1
 vfs_writev+0x2df/0x8b0 fs/read_write.c:1057
 do_pwritev fs/read_write.c:1153 [inline]
 __do_sys_pwritev2 fs/read_write.c:1211 [inline]
 __se_sys_pwritev2+0xfc/0x1c0 fs/read_write.c:1202
 __x64_sys_pwritev2+0x67/0x80 fs/read_write.c:1202
 x64_sys_call+0x2c55/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:329
 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: 0x000000ffffff0000 -> 0x000000ffc0000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10895 Comm: syz.9.3137 Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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