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BUG: KCSAN: data-race in xas_clear_mark / xas_find_marked

read-write to 0xffff8881218a5d98 of 8 bytes by task 18794 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+0x90/0x180 lib/xarray.c:915
 __folio_start_writeback+0x2f1/0x430 mm/page-writeback.c:3166
 __block_write_full_folio+0x506/0x8c0 fs/buffer.c:1899
 block_write_full_folio+0x293/0x2b0
 write_cache_pages+0x62/0x100 mm/page-writeback.c:2665
 blkdev_writepages+0x59/0x90 block/fops.c:433
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2708
 filemap_fdatawrite_wbc mm/filemap.c:388 [inline]
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 filemap_write_and_wait_range+0x146/0x360 mm/filemap.c:675
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:218
 loop_set_status+0x103/0x540 drivers/block/loop.c:1262
 lo_ioctl+0x7f1/0x11c0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
 x64_sys_call+0x1690/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881218a5d98 of 8 bytes by task 14150 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1733 [inline]
 xas_find_marked+0x216/0x660 lib/xarray.c:1370
 find_get_entry+0x54/0x390 mm/filemap.c:1984
 filemap_get_folios_tag+0x136/0x210 mm/filemap.c:2251
 writeback_get_folio mm/page-writeback.c:2514 [inline]
 writeback_iter+0x4b0/0x830 mm/page-writeback.c:2615
 write_cache_pages+0xad/0x100 mm/page-writeback.c:2664
 blkdev_writepages+0x59/0x90 block/fops.c:433
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2708
 filemap_fdatawrite_wbc mm/filemap.c:388 [inline]
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 filemap_write_and_wait_range+0x146/0x360 mm/filemap.c:675
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:218
 bdev_disk_changed+0xd7/0xb90 block/partitions/core.c:656
 blkdev_get_whole+0x1eb/0x2d0 block/bdev.c:706
 bdev_open+0x289/0x860 block/bdev.c:915
 blkdev_open+0x246/0x280 block/fops.c:627
 do_dentry_open+0x621/0xa20 fs/open.c:945
 vfs_open+0x38/0x1f0 fs/open.c:1075
 do_open fs/namei.c:3828 [inline]
 path_openat+0x1ac2/0x1fa0 fs/namei.c:3987
 do_filp_open+0x107/0x230 fs/namei.c:4014
 do_sys_openat2+0xab/0x120 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1428
 x64_sys_call+0x2b30/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffffffffe0000000 -> 0xfffffffc00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14150 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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