syzbot

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BUG: KCSAN: data-race in xas_find_marked / xas_init_marks

read-write to 0xffff8881099c8b28 of 8 bytes by task 13012 on cpu 0:
 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]
 xas_init_marks+0x17e/0x320 lib/xarray.c:949
 page_cache_delete mm/filemap.c:143 [inline]
 __filemap_remove_folio+0x1fd/0x320 mm/filemap.c:225
 __remove_mapping+0x35b/0x480 mm/vmscan.c:1467
 shrink_folio_list+0x137a/0x2550 mm/vmscan.c:2111
 shrink_inactive_list mm/vmscan.c:2603 [inline]
 shrink_list mm/vmscan.c:2844 [inline]
 shrink_lruvec+0xd80/0x17a0 mm/vmscan.c:6280
 shrink_node_memcgs mm/vmscan.c:6467 [inline]
 shrink_node+0xaa0/0x1500 mm/vmscan.c:6502
 shrink_zones mm/vmscan.c:6737 [inline]
 do_try_to_free_pages+0x40d/0xc80 mm/vmscan.c:6799
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:7114
 reclaim_high+0xca/0x110 mm/memcontrol.c:2432
 mem_cgroup_handle_over_high+0x8c/0x1a0 mm/memcontrol.c:2617
 try_charge_memcg+0xb35/0xd20 mm/memcontrol.c:2855
 try_charge mm/memcontrol.c:2866 [inline]
 charge_memcg+0x51/0x200 mm/memcontrol.c:7021
 __mem_cgroup_charge+0x29/0xa0 mm/memcontrol.c:7042
 mem_cgroup_charge include/linux/memcontrol.h:679 [inline]
 __filemap_add_folio+0x454/0x730 mm/filemap.c:857
 filemap_add_folio+0x6f/0x150 mm/filemap.c:939
 __filemap_get_folio+0x313/0x500 mm/filemap.c:1976
 mext_folio_double_lock fs/ext4/move_extent.c:141 [inline]
 move_extent_per_page+0x45d/0x17f0 fs/ext4/move_extent.c:309
 ext4_move_extents+0x5d2/0x750 fs/ext4/move_extent.c:683
 __ext4_ioctl fs/ext4/ioctl.c:1352 [inline]
 ext4_ioctl+0x1fd5/0x3110 fs/ext4/ioctl.c:1608
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xc9/0x140 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

read to 0xffff8881099c8b28 of 8 bytes by task 7870 on cpu 1:
 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
 mpage_prepare_extent_to_map+0x321/0xb50 fs/ext4/inode.c:2415
 ext4_do_writepages+0x717/0x21e0 fs/ext4/inode.c:2656
 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2792
 do_writepages+0x1c5/0x340 mm/page-writeback.c:2551
 __writeback_single_inode+0x91/0x860 fs/fs-writeback.c:1603
 writeback_sb_inodes+0x511/0xaa0 fs/fs-writeback.c:1894
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:1965
 wb_writeback+0x24d/0x6c0 fs/fs-writeback.c:2070
 wb_check_start_all fs/fs-writeback.c:2192 [inline]
 wb_do_writeback fs/fs-writeback.c:2218 [inline]
 wb_workfn+0x4ea/0x8d0 fs/fs-writeback.c:2251
 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

value changed: 0x00000003fe7fe01f -> 0x000000000078e01f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7870 Comm: kworker/u4:1 Not tainted 6.4.0-rc4-syzkaller-00268-g51f269a6ecc7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: writeback wb_workfn (flush-8:0)
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