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