==================================================================
BUG: KCSAN: data-race in atime_needs_update / inode_update_timestamps

write to 0xffff8881221573c8 of 8 bytes by task 12911 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1594 [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:2108 [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
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff8881221573c8 of 8 bytes by task 12909 on cpu 0:
 inode_get_mtime include/linux/fs.h:1588 [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:2457 [inline]
 splice_direct_to_actor+0x521/0x670 fs/splice.c:1126
 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
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x00000000313df747 -> 0x00000000326f2447

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12909 Comm: syz-executor.1 Tainted: G        W          6.9.0-rc1-syzkaller-00206-g4535e1a4174c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================