syzbot

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BUG: KCSAN: data-race in __fsnotify_parent / d_make_discardable

write to 0xffff888113ead480 of 4 bytes by task 1393 on cpu 0:
 d_make_discardable+0x4f/0x90 fs/dcache.c:1050
 simple_unlink+0x68/0x80 fs/libfs.c:808
 shmem_unlink+0x12d/0x140 mm/shmem.c:3917
 shmem_rename2+0x185/0x310 mm/shmem.c:3998
 vfs_rename+0x963/0xac0 fs/namei.c:6074
 filename_renameat2+0x3a4/0x6a0 fs/namei.c:6192
 __do_sys_rename fs/namei.c:6236 [inline]
 __se_sys_rename+0x4a/0x1c0 fs/namei.c:6232
 __x64_sys_rename+0x31/0x40 fs/namei.c:6232
 x64_sys_call+0x2b3/0x3020 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888113ead480 of 4 bytes by task 2009 on cpu 1:
 __fsnotify_parent+0xbc/0x3a0 fs/notify/fsnotify.c:192
 fsnotify_parent include/linux/fsnotify.h:96 [inline]
 fsnotify_path include/linux/fsnotify.h:113 [inline]
 fsnotify_file include/linux/fsnotify.h:127 [inline]
 fsnotify_close include/linux/fsnotify.h:461 [inline]
 __fput+0x1e2/0x630 fs/file_table.c:498
 fput_close_sync+0xad/0x190 fs/file_table.c:617
 __do_sys_close fs/open.c:1511 [inline]
 __se_sys_close fs/open.c:1496 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1496
 x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x08200080 -> 0x00200180

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2009 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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