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BUG: KCSAN: data-race in atime_needs_update / inode_update_timestamps

write to 0xffff8881089ab3c8 of 8 bytes by task 8114 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1596 [inline]
 inode_update_timestamps+0x16f/0x280 fs/inode.c:1865
 generic_update_time fs/inode.c:1900 [inline]
 inode_update_time fs/inode.c:1920 [inline]
 __file_update_time fs/inode.c:2109 [inline]
 file_modified_flags+0x2a7/0x340 fs/inode.c:2180
 file_modified+0x17/0x20 fs/inode.c:2196
 ext4_dio_write_checks fs/ext4/file.c:485 [inline]
 ext4_dio_write_iter fs/ext4/file.c:551 [inline]
 ext4_file_write_iter+0x8b8/0xe30 fs/ext4/file.c:696
 call_write_iter include/linux/fs.h:2110 [inline]
 iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
 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 0xffff8881089ab3c8 of 8 bytes by task 8118 on cpu 1:
 inode_get_mtime include/linux/fs.h:1590 [inline]
 relatime_need_update fs/inode.c:1814 [inline]
 atime_needs_update+0x2d2/0x3f0 fs/inode.c:1960
 touch_atime+0x4a/0x350 fs/inode.c:1975
 file_accessed include/linux/fs.h:2459 [inline]
 ext4_dio_read_iter fs/ext4/file.c:97 [inline]
 ext4_file_read_iter+0x275/0x2a0 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: 0x000000000b02f90a -> 0x000000000b9b8f8a

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8118 Comm: syz-executor.0 Not tainted 6.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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