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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
432cea00 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 | ||
a8fbdf54 TA |
21 | #include <errno.h> |
22 | #include <fcntl.h> | |
23 | #include <linux/loop.h> | |
24 | #include <signal.h> | |
25 | #include <stdbool.h> | |
26 | #include <stdio.h> | |
27 | #include <stdlib.h> | |
e306723e | 28 | #include <sys/file.h> |
a8fbdf54 | 29 | #include <sys/ioctl.h> |
07630cea | 30 | #include <sys/mount.h> |
432cea00 | 31 | #include <sys/prctl.h> |
a8fbdf54 TA |
32 | #include <sys/stat.h> |
33 | #include <sys/statfs.h> | |
432cea00 | 34 | #include <sys/statvfs.h> |
a8fbdf54 TA |
35 | #include <unistd.h> |
36 | ||
37 | #include "sd-bus-protocol.h" | |
38 | #include "sd-bus.h" | |
432cea00 | 39 | |
b5efdb8a | 40 | #include "alloc-util.h" |
07630cea | 41 | #include "btrfs-util.h" |
3ffd4af2 | 42 | #include "fd-util.h" |
0d39fa9c | 43 | #include "fileio.h" |
f4f15635 | 44 | #include "fs-util.h" |
cd2eb9e9 | 45 | #include "lockfile-util.h" |
a8fbdf54 | 46 | #include "log.h" |
3ffd4af2 | 47 | #include "machine-pool.h" |
a8fbdf54 TA |
48 | #include "macro.h" |
49 | #include "missing.h" | |
432cea00 | 50 | #include "mkdir.h" |
f4f15635 | 51 | #include "mount-util.h" |
6bedfcbb | 52 | #include "parse-util.h" |
432cea00 | 53 | #include "path-util.h" |
07630cea | 54 | #include "process-util.h" |
24882e06 | 55 | #include "signal-util.h" |
8fcde012 | 56 | #include "stat-util.h" |
07630cea | 57 | #include "string-util.h" |
432cea00 LP |
58 | |
59 | #define VAR_LIB_MACHINES_SIZE_START (1024UL*1024UL*500UL) | |
60 | #define VAR_LIB_MACHINES_FREE_MIN (1024UL*1024UL*750UL) | |
61 | ||
62 | static int check_btrfs(void) { | |
63 | struct statfs sfs; | |
64 | ||
65 | if (statfs("/var/lib/machines", &sfs) < 0) { | |
66 | if (errno != ENOENT) | |
67 | return -errno; | |
68 | ||
69 | if (statfs("/var/lib", &sfs) < 0) | |
70 | return -errno; | |
71 | } | |
72 | ||
73 | return F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC); | |
74 | } | |
75 | ||
4cee5eed | 76 | static int setup_machine_raw(uint64_t size, sd_bus_error *error) { |
432cea00 LP |
77 | _cleanup_free_ char *tmp = NULL; |
78 | _cleanup_close_ int fd = -1; | |
79 | struct statvfs ss; | |
80 | pid_t pid = 0; | |
81 | siginfo_t si; | |
82 | int r; | |
83 | ||
84 | /* We want to be able to make use of btrfs-specific file | |
85 | * system features, in particular subvolumes, reflinks and | |
86 | * quota. Hence, if we detect that /var/lib/machines.raw is | |
87 | * not located on btrfs, let's create a loopback file, place a | |
88 | * btrfs file system into it, and mount it to | |
89 | * /var/lib/machines. */ | |
90 | ||
91 | fd = open("/var/lib/machines.raw", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); | |
92 | if (fd >= 0) { | |
93 | r = fd; | |
94 | fd = -1; | |
95 | return r; | |
96 | } | |
97 | ||
98 | if (errno != ENOENT) | |
99 | return sd_bus_error_set_errnof(error, errno, "Failed to open /var/lib/machines.raw: %m"); | |
100 | ||
14bcf25c | 101 | r = tempfn_xxxxxx("/var/lib/machines.raw", NULL, &tmp); |
432cea00 LP |
102 | if (r < 0) |
103 | return r; | |
104 | ||
105 | (void) mkdir_p_label("/var/lib", 0755); | |
106 | fd = open(tmp, O_RDWR|O_CREAT|O_EXCL|O_NOCTTY|O_CLOEXEC, 0600); | |
107 | if (fd < 0) | |
108 | return sd_bus_error_set_errnof(error, errno, "Failed to create /var/lib/machines.raw: %m"); | |
109 | ||
110 | if (fstatvfs(fd, &ss) < 0) { | |
111 | r = sd_bus_error_set_errnof(error, errno, "Failed to determine free space on /var/lib/machines.raw: %m"); | |
112 | goto fail; | |
113 | } | |
114 | ||
115 | if (ss.f_bsize * ss.f_bavail < VAR_LIB_MACHINES_FREE_MIN) { | |
116 | r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Not enough free disk space to set up /var/lib/machines."); | |
117 | goto fail; | |
118 | } | |
119 | ||
4cee5eed | 120 | if (ftruncate(fd, size) < 0) { |
432cea00 LP |
121 | r = sd_bus_error_set_errnof(error, errno, "Failed to enlarge /var/lib/machines.raw: %m"); |
122 | goto fail; | |
123 | } | |
124 | ||
125 | pid = fork(); | |
126 | if (pid < 0) { | |
127 | r = sd_bus_error_set_errnof(error, errno, "Failed to fork mkfs.btrfs: %m"); | |
128 | goto fail; | |
129 | } | |
130 | ||
131 | if (pid == 0) { | |
132 | ||
133 | /* Child */ | |
134 | ||
ce30c8dc LP |
135 | (void) reset_all_signal_handlers(); |
136 | (void) reset_signal_mask(); | |
432cea00 LP |
137 | assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); |
138 | ||
139 | fd = safe_close(fd); | |
140 | ||
141 | execlp("mkfs.btrfs", "-Lvar-lib-machines", tmp, NULL); | |
142 | if (errno == ENOENT) | |
579afbea | 143 | _exit(99); |
432cea00 LP |
144 | |
145 | _exit(EXIT_FAILURE); | |
146 | } | |
147 | ||
148 | r = wait_for_terminate(pid, &si); | |
149 | if (r < 0) { | |
150 | sd_bus_error_set_errnof(error, r, "Failed to wait for mkfs.btrfs: %m"); | |
151 | goto fail; | |
152 | } | |
153 | ||
154 | pid = 0; | |
155 | ||
156 | if (si.si_code != CLD_EXITED) { | |
157 | r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "mkfs.btrfs died abnormally."); | |
158 | goto fail; | |
159 | } | |
160 | if (si.si_status == 99) { | |
161 | r = sd_bus_error_set_errnof(error, ENOENT, "Cannot set up /var/lib/machines, mkfs.btrfs is missing"); | |
162 | goto fail; | |
163 | } | |
164 | if (si.si_status != 0) { | |
165 | r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "mkfs.btrfs failed with error code %i", si.si_status); | |
166 | goto fail; | |
167 | } | |
168 | ||
f85ef957 AC |
169 | r = rename_noreplace(AT_FDCWD, tmp, AT_FDCWD, "/var/lib/machines.raw"); |
170 | if (r < 0) { | |
171 | sd_bus_error_set_errnof(error, r, "Failed to move /var/lib/machines.raw into place: %m"); | |
432cea00 LP |
172 | goto fail; |
173 | } | |
174 | ||
175 | r = fd; | |
176 | fd = -1; | |
177 | ||
178 | return r; | |
179 | ||
180 | fail: | |
132764a2 | 181 | unlink_noerrno(tmp); |
432cea00 LP |
182 | |
183 | if (pid > 1) | |
184 | kill_and_sigcont(pid, SIGKILL); | |
185 | ||
186 | return r; | |
187 | } | |
188 | ||
4cee5eed | 189 | int setup_machine_directory(uint64_t size, sd_bus_error *error) { |
403e5b32 | 190 | _cleanup_release_lock_file_ LockFile lock_file = LOCK_FILE_INIT; |
432cea00 LP |
191 | struct loop_info64 info = { |
192 | .lo_flags = LO_FLAGS_AUTOCLEAR, | |
193 | }; | |
194 | _cleanup_close_ int fd = -1, control = -1, loop = -1; | |
195 | _cleanup_free_ char* loopdev = NULL; | |
5bcd08db | 196 | char tmpdir[] = "/tmp/machine-pool.XXXXXX", *mntdir = NULL; |
432cea00 | 197 | bool tmpdir_made = false, mntdir_made = false, mntdir_mounted = false; |
26166c88 | 198 | char buf[FORMAT_BYTES_MAX]; |
432cea00 LP |
199 | int r, nr = -1; |
200 | ||
4cee5eed LP |
201 | /* btrfs cannot handle file systems < 16M, hence use this as minimum */ |
202 | if (size == (uint64_t) -1) | |
203 | size = VAR_LIB_MACHINES_SIZE_START; | |
204 | else if (size < 16*1024*1024) | |
205 | size = 16*1024*1024; | |
206 | ||
403e5b32 LP |
207 | /* Make sure we only set the directory up once at a time */ |
208 | r = make_lock_file("/run/systemd/machines.lock", LOCK_EX, &lock_file); | |
209 | if (r < 0) | |
210 | return r; | |
211 | ||
432cea00 LP |
212 | r = check_btrfs(); |
213 | if (r < 0) | |
214 | return sd_bus_error_set_errnof(error, r, "Failed to determine whether /var/lib/machines is located on btrfs: %m"); | |
215 | if (r > 0) { | |
216 | (void) btrfs_subvol_make_label("/var/lib/machines"); | |
217 | ||
218 | r = btrfs_quota_enable("/var/lib/machines", true); | |
219 | if (r < 0) | |
5bcd08db | 220 | log_warning_errno(r, "Failed to enable quota for /var/lib/machines, ignoring: %m"); |
432cea00 | 221 | |
5bcd08db LP |
222 | r = btrfs_subvol_auto_qgroup("/var/lib/machines", 0, true); |
223 | if (r < 0) | |
224 | log_warning_errno(r, "Failed to set up default quota hierarchy for /var/lib/machines, ignoring: %m"); | |
225 | ||
226 | return 1; | |
227 | } | |
228 | ||
e1873695 | 229 | if (path_is_mount_point("/var/lib/machines", NULL, AT_SYMLINK_FOLLOW) > 0) { |
5bcd08db | 230 | log_debug("/var/lib/machines is already a mount point, not creating loopback file for it."); |
432cea00 LP |
231 | return 0; |
232 | } | |
233 | ||
5bcd08db LP |
234 | r = dir_is_populated("/var/lib/machines"); |
235 | if (r < 0 && r != -ENOENT) | |
236 | return r; | |
237 | if (r > 0) { | |
238 | log_debug("/var/log/machines is already populated, not creating loopback file for it."); | |
239 | return 0; | |
240 | } | |
241 | ||
242 | r = mkfs_exists("btrfs"); | |
c3b0e5ac EV |
243 | if (r == 0) |
244 | return sd_bus_error_set_errnof(error, ENOENT, "Cannot set up /var/lib/machines, mkfs.btrfs is missing"); | |
5bcd08db LP |
245 | if (r < 0) |
246 | return r; | |
432cea00 | 247 | |
4cee5eed | 248 | fd = setup_machine_raw(size, error); |
432cea00 LP |
249 | if (fd < 0) |
250 | return fd; | |
251 | ||
252 | control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); | |
253 | if (control < 0) | |
254 | return sd_bus_error_set_errnof(error, errno, "Failed to open /dev/loop-control: %m"); | |
255 | ||
256 | nr = ioctl(control, LOOP_CTL_GET_FREE); | |
257 | if (nr < 0) | |
258 | return sd_bus_error_set_errnof(error, errno, "Failed to allocate loop device: %m"); | |
259 | ||
260 | if (asprintf(&loopdev, "/dev/loop%i", nr) < 0) { | |
261 | r = -ENOMEM; | |
262 | goto fail; | |
263 | } | |
264 | ||
265 | loop = open(loopdev, O_CLOEXEC|O_RDWR|O_NOCTTY|O_NONBLOCK); | |
266 | if (loop < 0) { | |
267 | r = sd_bus_error_set_errnof(error, errno, "Failed to open loopback device: %m"); | |
268 | goto fail; | |
269 | } | |
270 | ||
271 | if (ioctl(loop, LOOP_SET_FD, fd) < 0) { | |
272 | r = sd_bus_error_set_errnof(error, errno, "Failed to bind loopback device: %m"); | |
273 | goto fail; | |
274 | } | |
275 | ||
276 | if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0) { | |
277 | r = sd_bus_error_set_errnof(error, errno, "Failed to enable auto-clear for loopback device: %m"); | |
278 | goto fail; | |
279 | } | |
280 | ||
281 | /* We need to make sure the new /var/lib/machines directory | |
282 | * has an access mode of 0700 at the time it is first made | |
283 | * available. mkfs will create it with 0755 however. Hence, | |
284 | * let's mount the directory into an inaccessible directory | |
285 | * below /tmp first, fix the access mode, and move it to the | |
286 | * public place then. */ | |
287 | ||
288 | if (!mkdtemp(tmpdir)) { | |
289 | r = sd_bus_error_set_errnof(error, errno, "Failed to create temporary mount parent directory: %m"); | |
290 | goto fail; | |
291 | } | |
292 | tmpdir_made = true; | |
293 | ||
294 | mntdir = strjoina(tmpdir, "/mnt"); | |
295 | if (mkdir(mntdir, 0700) < 0) { | |
296 | r = sd_bus_error_set_errnof(error, errno, "Failed to create temporary mount directory: %m"); | |
297 | goto fail; | |
298 | } | |
299 | mntdir_made = true; | |
300 | ||
301 | if (mount(loopdev, mntdir, "btrfs", 0, NULL) < 0) { | |
302 | r = sd_bus_error_set_errnof(error, errno, "Failed to mount loopback device: %m"); | |
303 | goto fail; | |
304 | } | |
305 | mntdir_mounted = true; | |
306 | ||
307 | r = btrfs_quota_enable(mntdir, true); | |
308 | if (r < 0) | |
309 | log_warning_errno(r, "Failed to enable quota, ignoring: %m"); | |
310 | ||
5bcd08db LP |
311 | r = btrfs_subvol_auto_qgroup(mntdir, 0, true); |
312 | if (r < 0) | |
313 | log_warning_errno(r, "Failed to set up default quota hierarchy, ignoring: %m"); | |
314 | ||
432cea00 LP |
315 | if (chmod(mntdir, 0700) < 0) { |
316 | r = sd_bus_error_set_errnof(error, errno, "Failed to fix owner: %m"); | |
317 | goto fail; | |
318 | } | |
319 | ||
320 | (void) mkdir_p_label("/var/lib/machines", 0700); | |
321 | ||
322 | if (mount(mntdir, "/var/lib/machines", NULL, MS_BIND, NULL) < 0) { | |
323 | r = sd_bus_error_set_errnof(error, errno, "Failed to mount directory into right place: %m"); | |
324 | goto fail; | |
325 | } | |
326 | ||
26166c88 LP |
327 | (void) syncfs(fd); |
328 | ||
329 | log_info("Set up /var/lib/machines as btrfs loopback file system of size %s mounted on /var/lib/machines.raw.", format_bytes(buf, sizeof(buf), size)); | |
330 | ||
432cea00 LP |
331 | (void) umount2(mntdir, MNT_DETACH); |
332 | (void) rmdir(mntdir); | |
333 | (void) rmdir(tmpdir); | |
334 | ||
5bcd08db | 335 | return 1; |
432cea00 LP |
336 | |
337 | fail: | |
338 | if (mntdir_mounted) | |
339 | (void) umount2(mntdir, MNT_DETACH); | |
340 | ||
341 | if (mntdir_made) | |
342 | (void) rmdir(mntdir); | |
343 | if (tmpdir_made) | |
344 | (void) rmdir(tmpdir); | |
345 | ||
346 | if (loop >= 0) { | |
347 | (void) ioctl(loop, LOOP_CLR_FD); | |
348 | loop = safe_close(loop); | |
349 | } | |
350 | ||
351 | if (control >= 0 && nr >= 0) | |
352 | (void) ioctl(control, LOOP_CTL_REMOVE, nr); | |
353 | ||
354 | return r; | |
355 | } | |
26166c88 LP |
356 | |
357 | static int sync_path(const char *p) { | |
358 | _cleanup_close_ int fd = -1; | |
359 | ||
360 | fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
361 | if (fd < 0) | |
362 | return -errno; | |
363 | ||
364 | if (syncfs(fd) < 0) | |
365 | return -errno; | |
366 | ||
367 | return 0; | |
368 | } | |
369 | ||
370 | int grow_machine_directory(void) { | |
371 | char buf[FORMAT_BYTES_MAX]; | |
372 | struct statvfs a, b; | |
373 | uint64_t old_size, new_size, max_add; | |
374 | int r; | |
375 | ||
376 | /* Ensure the disk space data is accurate */ | |
377 | sync_path("/var/lib/machines"); | |
378 | sync_path("/var/lib/machines.raw"); | |
379 | ||
380 | if (statvfs("/var/lib/machines.raw", &a) < 0) | |
381 | return -errno; | |
382 | ||
383 | if (statvfs("/var/lib/machines", &b) < 0) | |
384 | return -errno; | |
385 | ||
386 | /* Don't grow if not enough disk space is available on the host */ | |
387 | if (((uint64_t) a.f_bavail * (uint64_t) a.f_bsize) <= VAR_LIB_MACHINES_FREE_MIN) | |
388 | return 0; | |
389 | ||
390 | /* Don't grow if at least 1/3th of the fs is still free */ | |
391 | if (b.f_bavail > b.f_blocks / 3) | |
392 | return 0; | |
393 | ||
a8eaaee7 | 394 | /* Calculate how much we are willing to add at most */ |
26166c88 LP |
395 | max_add = ((uint64_t) a.f_bavail * (uint64_t) a.f_bsize) - VAR_LIB_MACHINES_FREE_MIN; |
396 | ||
397 | /* Calculate the old size */ | |
398 | old_size = (uint64_t) b.f_blocks * (uint64_t) b.f_bsize; | |
399 | ||
400 | /* Calculate the new size as three times the size of what is used right now */ | |
401 | new_size = ((uint64_t) b.f_blocks - (uint64_t) b.f_bavail) * (uint64_t) b.f_bsize * 3; | |
402 | ||
403 | /* Always, grow at least to the start size */ | |
404 | if (new_size < VAR_LIB_MACHINES_SIZE_START) | |
405 | new_size = VAR_LIB_MACHINES_SIZE_START; | |
406 | ||
407 | /* If the new size is smaller than the old size, don't grow */ | |
408 | if (new_size < old_size) | |
409 | return 0; | |
410 | ||
411 | /* Ensure we never add more than the maximum */ | |
412 | if (new_size > old_size + max_add) | |
413 | new_size = old_size + max_add; | |
414 | ||
415 | r = btrfs_resize_loopback("/var/lib/machines", new_size, true); | |
416 | if (r <= 0) | |
417 | return r; | |
418 | ||
5bcd08db LP |
419 | /* Also bump the quota, of both the subvolume leaf qgroup, as |
420 | * well as of any subtree quota group by the same id but a | |
421 | * higher level, if it exists. */ | |
422 | (void) btrfs_qgroup_set_limit("/var/lib/machines", 0, new_size); | |
423 | (void) btrfs_subvol_set_subtree_quota_limit("/var/lib/machines", 0, new_size); | |
26166c88 LP |
424 | |
425 | log_info("Grew /var/lib/machines btrfs loopback file system to %s.", format_bytes(buf, sizeof(buf), new_size)); | |
426 | return 1; | |
427 | } |