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BUG: KCSAN: data-race in __mark_inode_dirty / __mark_inode_dirty

write to 0xffff8881195c6460 of 4 bytes by task 6839 on cpu 0:
 __mark_inode_dirty+0x240/0x760 fs/fs-writeback.c:2558
 generic_update_time fs/inode.c:2063 [inline]
 inode_update_time fs/inode.c:2076 [inline]
 __file_update_time fs/inode.c:2304 [inline]
 file_modified_flags+0x324/0x350 fs/inode.c:2375
 file_modified+0x17/0x20 fs/inode.c:2391
 ext4_write_checks fs/ext4/file.c:279 [inline]
 ext4_buffered_write_iter+0x1d0/0x3c0 fs/ext4/file.c:295
 ext4_file_write_iter+0x383/0xf00 fs/ext4/file.c:-1
 iter_file_splice_write+0x5f2/0x970 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x153/0x2a0 fs/splice.c:1158
 splice_direct_to_actor+0x30f/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+0x2bb0/0x2ff0 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 0xffff8881195c6460 of 4 bytes by task 6828 on cpu 1:
 __mark_inode_dirty+0x52/0x760 fs/fs-writeback.c:2509
 generic_update_time fs/inode.c:2063 [inline]
 inode_update_time fs/inode.c:2076 [inline]
 touch_atime+0x229/0x340 fs/inode.c:2148
 file_accessed include/linux/fs.h:2663 [inline]
 filemap_splice_read+0x629/0x6b0 mm/filemap.c:3047
 ext4_file_splice_read+0x8f/0xb0 fs/ext4/file.c:158
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1083
 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+0x2bb0/0x2ff0 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

value changed: 0x00000000 -> 0x00000028

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6828 Comm: syz.4.770 Tainted: G        W           6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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