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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_sb_inodes

write to 0xffff88810ad957d0 of 8 bytes by task 3157 on cpu 0:
 writeback_sb_inodes+0x494/0xdd0 fs/fs-writeback.c:1867
 __writeback_inodes_wb+0xb0/0x2a0 fs/fs-writeback.c:1949
 wb_writeback+0x280/0x650 fs/fs-writeback.c:2054
 wb_check_start_all fs/fs-writeback.c:2176 [inline]
 wb_do_writeback+0x418/0x600 fs/fs-writeback.c:2202
 wb_workfn+0x88/0x260 fs/fs-writeback.c:2235
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff88810ad957d0 of 8 bytes by task 4585 on cpu 1:
 __mark_inode_dirty+0x4f/0x730 fs/fs-writeback.c:2390
 generic_update_time fs/inode.c:1859 [inline]
 inode_update_time fs/inode.c:1872 [inline]
 __file_update_time fs/inode.c:2057 [inline]
 file_modified_flags+0x424/0x450 fs/inode.c:2130
 file_modified+0x13/0x20 fs/inode.c:2146
 ext4_dio_write_checks fs/ext4/file.c:473 [inline]
 ext4_dio_write_iter fs/ext4/file.c:537 [inline]
 ext4_file_write_iter+0x76a/0x11b0 fs/ext4/file.c:698
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 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: 0x0000000000020007 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4585 Comm: syz-executor.3 Not tainted 6.1.0-syzkaller-11611-g851f657a8642-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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