]>
Commit | Line | Data |
---|---|---|
53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
34829a32 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2015 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
21 | #include <sys/mount.h> | |
22 | ||
b5efdb8a | 23 | #include "alloc-util.h" |
3ffd4af2 | 24 | #include "fd-util.h" |
07630cea LP |
25 | #include "fileio.h" |
26 | #include "mkdir.h" | |
60e76d48 | 27 | #include "mount-util.h" |
3ffd4af2 | 28 | #include "nspawn-cgroup.h" |
f0bef277 | 29 | #include "rm-rf.h" |
07630cea LP |
30 | #include "string-util.h" |
31 | #include "strv.h" | |
32 | #include "util.h" | |
34829a32 | 33 | |
f0bef277 | 34 | static int chown_cgroup_path(const char *path, uid_t uid_shift) { |
34829a32 LP |
35 | _cleanup_close_ int fd = -1; |
36 | const char *fn; | |
34829a32 | 37 | |
f0bef277 | 38 | fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY); |
34829a32 | 39 | if (fd < 0) |
f0bef277 | 40 | return -errno; |
34829a32 LP |
41 | |
42 | FOREACH_STRING(fn, | |
43 | ".", | |
44 | "tasks", | |
45 | "notify_on_release", | |
46 | "cgroup.procs", | |
aa3be0dd | 47 | "cgroup.events", |
34829a32 LP |
48 | "cgroup.clone_children", |
49 | "cgroup.controllers", | |
ab2c3861 | 50 | "cgroup.subtree_control") |
34829a32 LP |
51 | if (fchownat(fd, fn, uid_shift, uid_shift, 0) < 0) |
52 | log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, | |
bd68e99b | 53 | "Failed to chown \"%s/%s\", ignoring: %m", path, fn); |
34829a32 LP |
54 | |
55 | return 0; | |
56 | } | |
57 | ||
f0bef277 EV |
58 | int chown_cgroup(pid_t pid, uid_t uid_shift) { |
59 | _cleanup_free_ char *path = NULL, *fs = NULL; | |
f0bef277 EV |
60 | int r; |
61 | ||
62 | r = cg_pid_get_path(NULL, pid, &path); | |
63 | if (r < 0) | |
64 | return log_error_errno(r, "Failed to get container cgroup path: %m"); | |
65 | ||
66 | r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs); | |
67 | if (r < 0) | |
68 | return log_error_errno(r, "Failed to get file system path for container cgroup: %m"); | |
69 | ||
70 | r = chown_cgroup_path(fs, uid_shift); | |
71 | if (r < 0) | |
72 | return log_error_errno(r, "Failed to chown() cgroup %s: %m", fs); | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t arg_uid_shift) { | |
34829a32 LP |
78 | _cleanup_free_ char *cgroup = NULL; |
79 | char tree[] = "/tmp/unifiedXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1]; | |
80 | bool undo_mount = false; | |
81 | const char *fn; | |
b4cccbc1 | 82 | int r, unified_controller; |
34829a32 | 83 | |
c22800e4 | 84 | unified_controller = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); |
b4cccbc1 LP |
85 | if (unified_controller < 0) |
86 | return log_error_errno(unified_controller, "Failed to determine whether the systemd hierarchy is unified: %m"); | |
87 | if ((unified_controller > 0) == (unified_requested >= CGROUP_UNIFIED_SYSTEMD)) | |
34829a32 LP |
88 | return 0; |
89 | ||
90 | /* When the host uses the legacy cgroup setup, but the | |
91 | * container shall use the unified hierarchy, let's make sure | |
92 | * we copy the path from the name=systemd hierarchy into the | |
93 | * unified hierarchy. Similar for the reverse situation. */ | |
94 | ||
95 | r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup); | |
96 | if (r < 0) | |
97 | return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid); | |
98 | ||
99 | /* In order to access the unified hierarchy we need to mount it */ | |
100 | if (!mkdtemp(tree)) | |
101 | return log_error_errno(errno, "Failed to generate temporary mount point for unified hierarchy: %m"); | |
102 | ||
b4cccbc1 | 103 | if (unified_controller > 0) |
60e76d48 ZJS |
104 | r = mount_verbose(LOG_ERR, "cgroup", tree, "cgroup", |
105 | MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr"); | |
34829a32 | 106 | else |
60e76d48 ZJS |
107 | r = mount_verbose(LOG_ERR, "cgroup", tree, "cgroup2", |
108 | MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); | |
109 | if (r < 0) | |
34829a32 | 110 | goto finish; |
34829a32 LP |
111 | |
112 | undo_mount = true; | |
113 | ||
f0bef277 EV |
114 | /* If nspawn dies abruptly the cgroup hierarchy created below |
115 | * its unit isn't cleaned up. So, let's remove it | |
116 | * https://github.com/systemd/systemd/pull/4223#issuecomment-252519810 */ | |
117 | fn = strjoina(tree, cgroup); | |
118 | (void) rm_rf(fn, REMOVE_ROOT|REMOVE_ONLY_DIRECTORIES); | |
119 | ||
34829a32 LP |
120 | fn = strjoina(tree, cgroup, "/cgroup.procs"); |
121 | (void) mkdir_parents(fn, 0755); | |
122 | ||
123 | sprintf(pid_string, PID_FMT, pid); | |
124 | r = write_string_file(fn, pid_string, 0); | |
f0bef277 | 125 | if (r < 0) { |
34829a32 | 126 | log_error_errno(r, "Failed to move process: %m"); |
f0bef277 EV |
127 | goto finish; |
128 | } | |
34829a32 | 129 | |
f0bef277 EV |
130 | fn = strjoina(tree, cgroup); |
131 | r = chown_cgroup_path(fn, arg_uid_shift); | |
132 | if (r < 0) | |
133 | log_error_errno(r, "Failed to chown() cgroup %s: %m", fn); | |
34829a32 LP |
134 | finish: |
135 | if (undo_mount) | |
60e76d48 | 136 | (void) umount_verbose(tree); |
34829a32 LP |
137 | |
138 | (void) rmdir(tree); | |
139 | return r; | |
140 | } | |
141 | ||
5da38d07 | 142 | int create_subcgroup(pid_t pid, CGroupUnified unified_requested) { |
34829a32 LP |
143 | _cleanup_free_ char *cgroup = NULL; |
144 | const char *child; | |
415fc41c | 145 | int r; |
34829a32 LP |
146 | CGroupMask supported; |
147 | ||
61233823 | 148 | /* In the unified hierarchy inner nodes may only contain |
34829a32 LP |
149 | * subgroups, but not processes. Hence, if we running in the |
150 | * unified hierarchy and the container does the same, and we | |
151 | * did not create a scope unit for the container move us and | |
152 | * the container into two separate subcgroups. */ | |
153 | ||
5da38d07 | 154 | if (unified_requested == CGROUP_UNIFIED_NONE) |
34829a32 LP |
155 | return 0; |
156 | ||
c22800e4 | 157 | r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); |
b4cccbc1 LP |
158 | if (r < 0) |
159 | return log_error_errno(r, "Failed to determine whether the systemd controller is unified: %m"); | |
160 | if (r == 0) | |
34829a32 LP |
161 | return 0; |
162 | ||
163 | r = cg_mask_supported(&supported); | |
164 | if (r < 0) | |
165 | return log_error_errno(r, "Failed to determine supported controllers: %m"); | |
166 | ||
167 | r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); | |
168 | if (r < 0) | |
169 | return log_error_errno(r, "Failed to get our control group: %m"); | |
170 | ||
171 | child = strjoina(cgroup, "/payload"); | |
172 | r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid); | |
173 | if (r < 0) | |
174 | return log_error_errno(r, "Failed to create %s subcgroup: %m", child); | |
175 | ||
176 | child = strjoina(cgroup, "/supervisor"); | |
177 | r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0); | |
178 | if (r < 0) | |
179 | return log_error_errno(r, "Failed to create %s subcgroup: %m", child); | |
180 | ||
181 | /* Try to enable as many controllers as possible for the new payload. */ | |
182 | (void) cg_enable_everywhere(supported, supported, cgroup); | |
183 | return 0; | |
184 | } |