r0 = openat$sysfs(0xffffffffffffff9c, &(0x7f0000000080)='/sys/power/freeze_filesystems', 0x0, 0x0)
preadv(r0, &(0x7f00000000c0)=[{&(0x7f0000000300)=""/159, 0x9f}], 0x1, 0x0, 0x0)