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BUG: KCSAN: data-race in atime_needs_update / touch_atime

write to 0xffff88810a0a6178 of 8 bytes by task 6811 on cpu 0:
 inode_update_timestamps fs/inode.c:1907 [inline]
 generic_update_time fs/inode.c:1929 [inline]
 inode_update_time fs/inode.c:1949 [inline]
 touch_atime+0x31f/0x4a0 fs/inode.c:2020
 file_accessed include/linux/fs.h:2320 [inline]
 filemap_splice_read+0x76e/0x7f0 mm/filemap.c:2978
 ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
 vfs_splice_read fs/splice.c:993 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810a0a6178 of 8 bytes by task 6808 on cpu 1:
 timespec64_equal include/linux/time64.h:49 [inline]
 atime_needs_update+0x3f2/0x5b0 fs/inode.c:1992
 touch_atime+0x58/0x4a0 fs/inode.c:2003
 file_accessed include/linux/fs.h:2320 [inline]
 filemap_splice_read+0x76e/0x7f0 mm/filemap.c:2978
 ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
 vfs_splice_read fs/splice.c:993 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000027548658 -> 0x0000000027ed1cd8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6808 Comm: syz-executor.5 Not tainted 6.5.0-syzkaller-08262-gef2a0b7cdbc5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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