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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_single_inode

write to 0xffff888137bbb7b0 of 8 bytes by task 5175 on cpu 1:
 writeback_single_inode+0x109/0x4f0 fs/fs-writeback.c:1705
 sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2743
 __generic_file_fsync+0xf5/0x140 fs/libfs.c:1126
 fat_file_fsync+0x48/0x100 fs/fat/file.c:190
 vfs_fsync_range+0x107/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2731 [inline]
 generic_file_write_iter+0x103/0x130 mm/filemap.c:3943
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:868
 vfs_iter_write+0x4c/0x70 fs/read_write.c:909
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3bf/0x910 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1324 [inline]
 __se_sys_sendfile64 fs/read_write.c:1316 [inline]
 __x64_sys_sendfile64+0xb9/0x150 fs/read_write.c:1316
 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 0xffff888137bbb7b0 of 8 bytes by task 5176 on cpu 0:
 __mark_inode_dirty+0xd5/0x620 fs/fs-writeback.c:2402
 fat_update_time+0x2c9/0x300 fs/fat/misc.c:359
 inode_update_time fs/inode.c:1868 [inline]
 touch_atime+0x16e/0x2e0 fs/inode.c:1941
 file_accessed include/linux/fs.h:2386 [inline]
 generic_file_splice_read+0x237/0x2c0 fs/splice.c:314
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3bf/0x910 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1330 [inline]
 __se_sys_sendfile64 fs/read_write.c:1316 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1316
 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: 0x0000000000000007 -> 0x0000000000000080

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5176 Comm: syz-executor.1 Not tainted 5.19.0-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
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