syzbot

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BUG: KCSAN: data-race in __xa_set_mark / xas_find_marked

read-write to 0xffff88814a588228 of 8 bytes by task 7327 on cpu 1:
 instrument_read_write include/linux/instrumented.h:57 [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:93 [inline]
 xas_set_mark lib/xarray.c:887 [inline]
 __xa_set_mark+0xe0/0x1a0 lib/xarray.c:1906
 __folio_mark_dirty+0xfb/0x130 mm/page-writeback.c:2616
 __set_page_dirty include/linux/pagemap.h:1057 [inline]
 mark_buffer_dirty+0x152/0x390 fs/buffer.c:1105
 __block_commit_write+0x11d/0x1c0 fs/buffer.c:2080
 block_write_end fs/buffer.c:2159 [inline]
 generic_write_end+0x81/0x350 fs/buffer.c:2173
 ext4_da_write_end+0x26c/0x620 fs/ext4/inode.c:3089
 generic_perform_write+0x264/0x3f0 mm/filemap.c:3749
 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270
 ext4_file_write_iter+0x2e3/0x1210
 call_write_iter include/linux/fs.h:2187 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x468/0x760 fs/read_write.c:584
 ksys_write+0xe8/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88814a588228 of 8 bytes by task 7332 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1704 [inline]
 xas_find_marked+0x22f/0x6a0 lib/xarray.c:1356
 find_get_entry mm/filemap.c:2010 [inline]
 find_get_pages_range_tag+0x103/0x4f0 mm/filemap.c:2284
 pagevec_lookup_range_tag+0x37/0x50 mm/swap.c:1062
 mpage_prepare_extent_to_map+0x1a4/0xa50 fs/ext4/inode.c:2588
 ext4_writepages+0x9b8/0x1cf0 fs/ext4/inode.c:2825
 do_writepages+0x1db/0x350 mm/page-writeback.c:2468
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 __filemap_fdatawrite mm/filemap.c:427 [inline]
 filemap_flush+0x93/0xc0 mm/filemap.c:454
 ext4_alloc_da_blocks+0x47/0x100 fs/ext4/inode.c:3133
 __ext4_ioctl fs/ext4/ioctl.c:1403 [inline]
 ext4_ioctl+0xf5e/0x2bf0 fs/ext4/ioctl.c:1606
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x000fffffffffffff -> 0x003fffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7332 Comm: syz-executor.1 Not tainted 6.0.0-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
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