syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / __mark_inode_dirty

write to 0xffff88810e805928 of 4 bytes by task 8037 on cpu 1:
 __mark_inode_dirty+0x24e/0x7e0 fs/fs-writeback.c:2524
 fat_update_time+0x1f5/0x210 fs/fat/misc.c:357
 inode_update_time fs/inode.c:2055 [inline]
 touch_atime+0x14f/0x350 fs/inode.c:2128
 file_accessed include/linux/fs.h:2528 [inline]
 filemap_splice_read+0x8a5/0x910 mm/filemap.c:2977
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x39b/0x970 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810e805928 of 4 bytes by task 8042 on cpu 0:
 __mark_inode_dirty+0x198/0x7e0 fs/fs-writeback.c:2515
 fat_update_time+0x1f5/0x210 fs/fat/misc.c:357
 inode_update_time fs/inode.c:2055 [inline]
 touch_atime+0x14f/0x350 fs/inode.c:2128
 file_accessed include/linux/fs.h:2528 [inline]
 filemap_splice_read+0x8a5/0x910 mm/filemap.c:2977
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x39b/0x970 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000038

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8042 Comm: syz.3.1604 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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