starnix_core/task/
limits.rs

1// Copyright 2025 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::mm::PAGE_SIZE;
6use starnix_sync::{IcmpPingGidsLock, LockDepMutex};
7use std::ops::Range;
8use std::sync::atomic::{AtomicI32, AtomicUsize};
9
10/// Corresponds to files in /proc/sys/fs/inotify/, but cannot be negative.
11#[derive(Debug)]
12pub struct InotifyLimits {
13    // This value is used when creating an inotify instance.
14    // Updating this value does not affect already-created inotify instances.
15    pub max_queued_events: AtomicI32,
16
17    // TODO(b/297439734): Make this a real user limit on inotify instances.
18    pub max_user_instances: AtomicI32,
19
20    // TODO(b/297439734): Make this a real user limit on inotify watches.
21    pub max_user_watches: AtomicI32,
22}
23
24#[derive(Default, Debug)]
25pub struct SocketLimits {
26    /// The maximum backlog size for a socket.
27    pub max_connections: AtomicI32,
28
29    // Range of GIDs that can create ICMP Ping sockets.
30    pub icmp_ping_gids: LockDepMutex<Range<u32>, IcmpPingGidsLock>,
31}
32
33#[derive(Debug)]
34pub struct SystemLimits {
35    /// Limits applied to inotify objects.
36    pub inotify: InotifyLimits,
37
38    /// Limits applied to socket objects.
39    pub socket: SocketLimits,
40
41    /// The maximum size of pipes in the system.
42    pub pipe_max_size: AtomicUsize,
43
44    /// Whether IoUring is disabled.
45    ///
46    ///  0 -> io_uring is enabled (default)
47    ///  1 -> io_uring is enabled for processes in the io_uring_group
48    ///  2 -> io_uring is disabled
49    ///
50    /// See https://docs.kernel.org/admin-guide/sysctl/kernel.html#io-uring-disabled
51    pub io_uring_disabled: AtomicI32,
52
53    /// If io_uring_disabled is 1, then io_uring is enabled only for processes with CAP_SYS_ADMIN
54    /// or that are members of this group.
55    ///
56    /// See https://docs.kernel.org/admin-guide/sysctl/kernel.html#io-uring-group
57    pub io_uring_group: AtomicI32,
58}
59
60impl Default for SystemLimits {
61    fn default() -> SystemLimits {
62        SystemLimits {
63            inotify: InotifyLimits {
64                max_queued_events: AtomicI32::new(16384),
65                max_user_instances: AtomicI32::new(128),
66                max_user_watches: AtomicI32::new(1048576),
67            },
68            socket: SocketLimits {
69                max_connections: AtomicI32::new(4096),
70                icmp_ping_gids: LockDepMutex::new(1..1),
71            },
72            pipe_max_size: AtomicUsize::new((*PAGE_SIZE * 256) as usize),
73            io_uring_disabled: AtomicI32::new(0),
74            io_uring_group: AtomicI32::new(-1),
75        }
76    }
77}
starnix_core/task/limits.rs

starnix_core/task/
limits.rs
