syzbot

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BUG: KCSAN: data-race in filemap_fdatawrite_wbc / xas_set_mark

write to 0xffff888106d054ec of 4 bytes by task 23560 on cpu 0:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark+0x131/0x150 lib/xarray.c:892
 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
 kiocb_write_and_wait+0x79/0x110 mm/filemap.c:2687
 __iomap_dio_rw+0x4d9/0x1090 fs/iomap/direct-io.c:593
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:749
 ext4_dio_read_iter fs/ext4/file.c:94 [inline]
 ext4_file_read_iter+0x220/0x2a0 fs/ext4/file.c:145
 call_read_iter include/linux/fs.h:2104 [inline]
 copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x28e/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x970 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 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 0xffff888106d054ec of 4 bytes by task 23559 on cpu 1:
 xa_marked include/linux/xarray.h:420 [inline]
 mapping_tagged include/linux/fs.h:500 [inline]
 filemap_fdatawrite_wbc+0x5c/0x100 mm/filemap.c:393
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 filemap_write_and_wait_range+0xb6/0x1f0 mm/filemap.c:685
 kiocb_write_and_wait+0x79/0x110 mm/filemap.c:2687
 __iomap_dio_rw+0x4d9/0x1090 fs/iomap/direct-io.c:593
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:749
 ext4_dio_read_iter fs/ext4/file.c:94 [inline]
 ext4_file_read_iter+0x220/0x2a0 fs/ext4/file.c:145
 call_read_iter include/linux/fs.h:2104 [inline]
 copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x28e/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x970 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 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: 0x01000021 -> 0x02000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23559 Comm: syz-executor.0 Not tainted 6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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