syzbot

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BUG: KCSAN: data-race in xas_find_marked / xas_set_mark

read-write to 0xffff888107cf7b50 of 8 bytes by task 27842 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_set_bit include/asm-generic/bitops/instrumented-non-atomic.h:99 [inline]
 node_set_mark lib/xarray.c:95 [inline]
 xas_set_mark+0x86/0x150 lib/xarray.c:885
 tag_pages_for_writeback+0xaa/0x2b0 mm/page-writeback.c:2350
 ext4_do_writepages+0x694/0x2110 fs/ext4/inode.c:2615
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2768
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2612
 filemap_fdatawrite_wbc+0xdb/0x100 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 filemap_write_and_wait_range+0xb6/0x1f0 mm/filemap.c:685
 filemap_write_and_wait include/linux/pagemap.h:64 [inline]
 ext4_bmap+0x14e/0x180 fs/ext4/inode.c:3109
 bmap+0x5d/0x90 fs/inode.c:1792
 ioctl_fibmap fs/ioctl.c:77 [inline]
 file_ioctl fs/ioctl.c:328 [inline]
 do_vfs_ioctl+0x1353/0x1560 fs/ioctl.c:883
 __do_sys_ioctl fs/ioctl.c:902 [inline]
 __se_sys_ioctl+0x81/0x150 fs/ioctl.c:890
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:890
 x64_sys_call+0x155d/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888107cf7b50 of 8 bytes by task 27828 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1723 [inline]
 xas_find_marked+0x216/0x660 lib/xarray.c:1354
 find_get_entry+0x5d/0x290 mm/filemap.c:1968
 filemap_get_folios_tag+0x136/0x210 mm/filemap.c:2218
 mpage_prepare_extent_to_map+0x329/0xb80 fs/ext4/inode.c:2392
 ext4_do_writepages+0xa20/0x2110 fs/ext4/inode.c:2677
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2768
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2612
 filemap_fdatawrite_wbc+0xdb/0x100 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 filemap_write_and_wait_range+0xb6/0x1f0 mm/filemap.c:685
 ext4_punch_hole+0xc5/0x7e0 fs/ext4/inode.c:3893
 ext4_fallocate+0x209/0x1190 fs/ext4/extents.c:4741
 vfs_fallocate+0x380/0x3e0 fs/open.c:330
 do_vfs_ioctl+0x1481/0x1560 fs/ioctl.c:883
 __do_sys_ioctl fs/ioctl.c:902 [inline]
 __se_sys_ioctl+0x81/0x150 fs/ioctl.c:890
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:890
 x64_sys_call+0x155d/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000003ffffffffff -> 0xffffffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27828 Comm: syz-executor.3 Tainted: G        W          6.9.0-rc5-syzkaller-00025-ga2c63a3f3d68 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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