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BUG: KCSAN: data-race in atime_needs_update / inode_update_timestamps

write to 0xffff888119c01728 of 8 bytes by task 7122 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1717 [inline]
 inode_update_timestamps+0x136/0x270 fs/inode.c:2022
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 __file_update_time fs/inode.c:2305 [inline]
 file_modified_flags+0x2aa/0x350 fs/inode.c:2376
 file_modified+0x17/0x20 fs/inode.c:2392
 ext4_dio_write_checks fs/ext4/file.c:491 [inline]
 ext4_dio_write_iter fs/ext4/file.c:557 [inline]
 ext4_file_write_iter+0x9b1/0xf00 fs/ext4/file.c:721
 iter_file_splice_write+0x5f2/0x970 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1158
 splice_direct_to_actor+0x312/0x680 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888119c01728 of 8 bytes by task 7127 on cpu 0:
 inode_get_mtime_sec include/linux/fs.h:1699 [inline]
 inode_get_mtime include/linux/fs.h:1709 [inline]
 relatime_need_update fs/inode.c:1971 [inline]
 atime_needs_update+0x27b/0x3e0 fs/inode.c:2117
 touch_atime+0x4a/0x340 fs/inode.c:2132
 file_accessed include/linux/fs.h:2652 [inline]
 filemap_read+0x960/0xa00 mm/filemap.c:2783
 generic_file_read_iter+0x79/0x330 mm/filemap.c:2903
 ext4_file_read_iter+0x1cc/0x290 fs/ext4/file.c:-1
 io_iter_do_read io_uring/rw.c:828 [inline]
 __io_read+0xa3c/0xc20 io_uring/rw.c:1004
 io_read+0x1c/0x60 io_uring/rw.c:1020
 __io_issue_sqe+0xfb/0x2e0 io_uring/io_uring.c:1738
 io_issue_sqe+0x53/0x970 io_uring/io_uring.c:1761
 io_queue_sqe io_uring/io_uring.c:1968 [inline]
 io_submit_sqe io_uring/io_uring.c:2224 [inline]
 io_submit_sqes+0x667/0xfd0 io_uring/io_uring.c:2337
 __do_sys_io_uring_enter io_uring/io_uring.c:3404 [inline]
 __se_sys_io_uring_enter+0x1c1/0x1b70 io_uring/io_uring.c:3338
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3338
 x64_sys_call+0x28c8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000687dc611 -> 0x00000000687dc612

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7127 Comm: syz.5.918 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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