syzbot

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

read-write to 0xffff888109bf0fb0 of 8 bytes by task 34 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:100 [inline]
 xas_clear_mark lib/xarray.c:916 [inline]
 __xa_clear_mark+0xf4/0x1e0 lib/xarray.c:1924
 __folio_end_writeback+0x1e3/0x500 mm/page-writeback.c:2977
 folio_end_writeback+0x5b/0x150 mm/filemap.c:1618
 ext4_finish_bio+0x3f2/0x870 fs/ext4/page-io.c:145
 ext4_release_io_end+0x8c/0x1e0 fs/ext4/page-io.c:160
 ext4_end_io_end fs/ext4/page-io.c:194 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline]
 ext4_end_io_rsv_work+0x2d3/0x360 fs/ext4/page-io.c:273
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2405
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552
 kthread+0x1d7/0x210 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff888109bf0fb0 of 8 bytes by task 6729 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1705 [inline]
 xas_find_marked+0x216/0x660 lib/xarray.c:1356
 find_get_entry+0x5d/0x290 mm/filemap.c:2007
 filemap_get_folios_tag+0x136/0x230 mm/filemap.c:2305
 __filemap_fdatawait_range+0x82/0x140 mm/filemap.c:516
 filemap_write_and_wait_range+0x120/0x220 mm/filemap.c:687
 filemap_write_and_wait include/linux/pagemap.h:60 [inline]
 ext4_bmap+0x14e/0x180 fs/ext4/inode.c:3093
 bmap+0x60/0x90 fs/inode.c:1798
 ioctl_fibmap fs/ioctl.c:77 [inline]
 file_ioctl fs/ioctl.c:327 [inline]
 do_vfs_ioctl+0x1170/0x1360 fs/ioctl.c:849
 __do_sys_ioctl fs/ioctl.c:868 [inline]
 __se_sys_ioctl+0x81/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000001fffff -> 0x00000000001fffe0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6729 Comm: syz-executor.3 Not tainted 6.4.0-rc5-syzkaller-00024-g5f63595ebd82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
==================================================================