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BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff8881068073f0 of 8 bytes by task 47 on cpu 0:
 __writeback_single_inode+0x201/0x860 fs/fs-writeback.c:1661
 writeback_sb_inodes+0x514/0xad0 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:1987
 wb_writeback+0x264/0x6e0 fs/fs-writeback.c:2094
 wb_check_start_all fs/fs-writeback.c:2220 [inline]
 wb_do_writeback fs/fs-writeback.c:2246 [inline]
 wb_workfn+0x4ea/0x8d0 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffff8881068073f0 of 8 bytes by task 9302 on cpu 1:
 __mark_inode_dirty+0x199/0x7d0 fs/fs-writeback.c:2474
 mark_buffer_dirty+0x165/0x240 fs/buffer.c:1204
 __block_commit_write fs/buffer.c:2191 [inline]
 block_write_end+0x158/0x2e0 fs/buffer.c:2267
 ext4_da_do_write_end fs/ext4/inode.c:2961 [inline]
 ext4_da_write_end+0x1fc/0x9c0 fs/ext4/inode.c:3033
 generic_perform_write+0x267/0x410 mm/filemap.c:3929
 ext4_buffered_write_iter+0x1f6/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x297/0xe10
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000020085 -> 0x0000000000020004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9302 Comm: syz-executor.0 Tainted: G        W          6.7.0-rc2-syzkaller-00095-gd3fa86b1a7b4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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