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38683db4 CB |
1 | /* |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Daniel Lezcano <daniel.lezcano at free.fr> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | */ | |
23 | ||
24 | #define _GNU_SOURCE | |
25 | #include <errno.h> | |
26 | #include <stdio.h> | |
27 | #include <stdlib.h> | |
28 | #include <string.h> | |
29 | ||
38683db4 CB |
30 | #include "conf.h" |
31 | #include "confile.h" | |
32 | #include "log.h" | |
33 | #include "lxccontainer.h" | |
28d832c4 CB |
34 | #include "overlay.h" |
35 | #include "rsync.h" | |
36 | #include "storage.h" | |
ba115175 | 37 | #include "storage_utils.h" |
38683db4 CB |
38 | #include "utils.h" |
39 | ||
10bc1861 | 40 | lxc_log_define(overlay, lxc); |
38683db4 | 41 | |
5c484f79 | 42 | static char *ovl_name; |
88232d3f | 43 | static char *ovl_version[] = {"overlay", "overlayfs"}; |
5c484f79 | 44 | |
5c484f79 | 45 | static char *ovl_detect_name(void); |
10bc1861 | 46 | static int ovl_do_rsync(struct lxc_storage *orig, struct lxc_storage *new, |
3188197d | 47 | struct lxc_conf *conf); |
88232d3f CB |
48 | static int ovl_remount_on_enodev(const char *lower, const char *target, |
49 | const char *name, unsigned long mountflags, | |
50 | const void *options); | |
38683db4 | 51 | |
10bc1861 | 52 | int ovl_clonepaths(struct lxc_storage *orig, struct lxc_storage *new, const char *oldname, |
83e79752 CB |
53 | const char *cname, const char *oldpath, const char *lxcpath, |
54 | int snap, uint64_t newsize, struct lxc_conf *conf) | |
38683db4 | 55 | { |
241978fa CB |
56 | int ret; |
57 | char *src; | |
4d463f62 | 58 | |
38683db4 | 59 | if (!snap) { |
241978fa CB |
60 | ERROR("The overlay storage driver can only be used for " |
61 | "snapshots"); | |
38683db4 CB |
62 | return -22; |
63 | } | |
64 | ||
65 | if (!orig->src || !orig->dest) | |
66 | return -1; | |
67 | ||
241978fa | 68 | new->dest = must_make_path(lxcpath, cname, "rootfs", NULL); |
ba115175 | 69 | |
241978fa CB |
70 | ret = mkdir_p(new->dest, 0755); |
71 | if (ret < 0 && errno != EEXIST) { | |
72 | SYSERROR("Failed to create directory \"%s\"", new->dest); | |
38683db4 | 73 | return -1; |
241978fa | 74 | } |
38683db4 | 75 | |
241978fa CB |
76 | if (am_unpriv()) { |
77 | ret = chown_mapped_root(new->dest, conf); | |
78 | if (ret < 0) | |
79 | WARN("Failed to update ownership of %s", new->dest); | |
80 | } | |
38683db4 CB |
81 | |
82 | if (strcmp(orig->type, "dir") == 0) { | |
83 | char *delta, *lastslash; | |
84 | char *work; | |
85 | int ret, len, lastslashidx; | |
86 | ||
241978fa CB |
87 | /* If we have "/var/lib/lxc/c2/rootfs" then delta will be |
88 | * "/var/lib/lxc/c2/delta0". | |
5c484f79 | 89 | */ |
38683db4 | 90 | lastslash = strrchr(new->dest, '/'); |
241978fa CB |
91 | if (!lastslash) { |
92 | ERROR("Failed to detect \"/\" in string \"%s\"", | |
93 | new->dest); | |
38683db4 | 94 | return -22; |
241978fa CB |
95 | } |
96 | ||
97 | if (strlen(lastslash) < (sizeof("/rootfs") - 1)) { | |
98 | ERROR("Failed to detect \"/rootfs\" in string \"%s\"", | |
99 | new->dest); | |
38683db4 | 100 | return -22; |
241978fa CB |
101 | } |
102 | ||
38683db4 CB |
103 | lastslash++; |
104 | lastslashidx = lastslash - new->dest; | |
105 | ||
106 | delta = malloc(lastslashidx + 7); | |
241978fa CB |
107 | if (!delta) { |
108 | ERROR("Failed to allocate memory"); | |
38683db4 | 109 | return -1; |
241978fa CB |
110 | } |
111 | ||
5c484f79 | 112 | strncpy(delta, new->dest, lastslashidx + 1); |
241978fa CB |
113 | strncpy(delta + lastslashidx, "delta0", sizeof("delta0") - 1); |
114 | delta[lastslashidx + sizeof("delta0")] = '\0'; | |
115 | ||
116 | ret = mkdir(delta, 0755); | |
117 | if (ret < 0 && errno != EEXIST) { | |
118 | SYSERROR("Failed to create directory \"%s\"", delta); | |
38683db4 CB |
119 | free(delta); |
120 | return -1; | |
121 | } | |
38683db4 | 122 | |
241978fa CB |
123 | if (am_unpriv()) { |
124 | ret = chown_mapped_root(delta, conf); | |
125 | if (ret < 0) | |
126 | WARN("Failed to update ownership of %s", delta); | |
127 | } | |
128 | ||
129 | /* Make workdir for overlayfs.v22 or higher: | |
5c484f79 CB |
130 | * The workdir will be |
131 | * /var/lib/lxc/c2/olwork | |
132 | * and is used to prepare files before they are atomically | |
133 | * switched to the overlay destination. Workdirs need to be on | |
134 | * the same filesystem as the upperdir so it's OK for it to be | |
135 | * empty. | |
136 | */ | |
38683db4 CB |
137 | work = malloc(lastslashidx + 7); |
138 | if (!work) { | |
241978fa | 139 | ERROR("Failed to allocate memory"); |
38683db4 CB |
140 | free(delta); |
141 | return -1; | |
142 | } | |
241978fa | 143 | |
5c484f79 | 144 | strncpy(work, new->dest, lastslashidx + 1); |
241978fa CB |
145 | strncpy(work + lastslashidx, "olwork", sizeof("olwork") - 1); |
146 | work[lastslashidx + sizeof("olwork")] = '\0'; | |
147 | ||
38683db4 CB |
148 | if (mkdir(work, 0755) < 0) { |
149 | SYSERROR("error: mkdir %s", work); | |
150 | free(delta); | |
151 | free(work); | |
152 | return -1; | |
153 | } | |
241978fa CB |
154 | |
155 | if (am_unpriv()) { | |
156 | ret = chown_mapped_root(work, conf); | |
157 | if (ret < 0) | |
158 | WARN("Failed to update ownership of %s", work); | |
159 | } | |
38683db4 CB |
160 | free(work); |
161 | ||
241978fa CB |
162 | /* strlen("overlay:") = 8 |
163 | * + | |
164 | * strlen(delta) | |
165 | * + | |
166 | * : | |
167 | * + | |
168 | * strlen(src) | |
169 | * + | |
170 | * \0 | |
171 | */ | |
4d463f62 | 172 | src = lxc_storage_get_path(orig->src, orig->type); |
241978fa | 173 | len = 8 + strlen(delta) + 1 + strlen(src) + 1; |
38683db4 CB |
174 | new->src = malloc(len); |
175 | if (!new->src) { | |
241978fa | 176 | ERROR("Failed to allocate memory"); |
38683db4 CB |
177 | free(delta); |
178 | return -ENOMEM; | |
179 | } | |
241978fa | 180 | |
ba115175 | 181 | ret = snprintf(new->src, len, "overlay:%s:%s", src, delta); |
38683db4 | 182 | free(delta); |
241978fa CB |
183 | if (ret < 0 || (size_t)ret >= len) { |
184 | ERROR("Failed to create string"); | |
ba115175 | 185 | return -1; |
241978fa CB |
186 | } |
187 | } else if (!strcmp(orig->type, "overlayfs") || | |
188 | !strcmp(orig->type, "overlay")) { | |
70e95c8d CB |
189 | char *clean_old_path, *clean_new_path; |
190 | char *lastslash, *ndelta, *nsrc, *odelta, *osrc, *s1, *s2, *s3, | |
191 | *work; | |
241978fa | 192 | int ret, lastslashidx; |
70e95c8d | 193 | size_t len, name_len; |
ba115175 CB |
194 | |
195 | osrc = strdup(orig->src); | |
196 | if (!osrc) { | |
241978fa | 197 | ERROR("Failed to duplicate string \"%s\"", orig->src); |
38683db4 | 198 | return -22; |
241978fa | 199 | } |
ba115175 | 200 | |
38683db4 | 201 | nsrc = strchr(osrc, ':') + 1; |
ba115175 CB |
202 | if ((nsrc != osrc + 8) && (nsrc != osrc + 10)) { |
203 | free(osrc); | |
241978fa CB |
204 | ERROR("Detected \":\" in \"%s\" at wrong position", |
205 | osrc); | |
ba115175 | 206 | return -22; |
241978fa | 207 | } |
ba115175 CB |
208 | |
209 | odelta = strchr(nsrc, ':'); | |
210 | if (!odelta) { | |
38683db4 | 211 | free(osrc); |
241978fa | 212 | ERROR("Failed to find \":\" in \"%s\"", nsrc); |
38683db4 CB |
213 | return -22; |
214 | } | |
ba115175 | 215 | |
38683db4 CB |
216 | *odelta = '\0'; |
217 | odelta++; | |
241978fa | 218 | ndelta = must_make_path(lxcpath, cname, "delta0", NULL); |
ba115175 CB |
219 | |
220 | ret = mkdir(ndelta, 0755); | |
221 | if (ret < 0 && errno != EEXIST) { | |
38683db4 CB |
222 | free(osrc); |
223 | free(ndelta); | |
241978fa | 224 | SYSERROR("Failed to create directory \"%s\"", ndelta); |
38683db4 CB |
225 | return -1; |
226 | } | |
ba115175 | 227 | |
241978fa CB |
228 | if (am_unpriv()) { |
229 | ret = chown_mapped_root(ndelta, conf); | |
230 | if (ret < 0) | |
231 | WARN("Failed to update ownership of %s", | |
232 | ndelta); | |
233 | } | |
38683db4 | 234 | |
241978fa CB |
235 | /* Make workdir for overlayfs.v22 or higher (See the comment |
236 | * further up.). | |
5c484f79 | 237 | */ |
38683db4 | 238 | lastslash = strrchr(ndelta, '/'); |
278d97f7 SH |
239 | if (!lastslash) { |
240 | free(osrc); | |
241 | free(ndelta); | |
ba115175 | 242 | ERROR("Failed to detect \"/\" in \"%s\"", ndelta); |
38683db4 | 243 | return -1; |
278d97f7 | 244 | } |
38683db4 CB |
245 | lastslash++; |
246 | lastslashidx = lastslash - ndelta; | |
247 | ||
248 | work = malloc(lastslashidx + 7); | |
278d97f7 SH |
249 | if (!work) { |
250 | free(osrc); | |
251 | free(ndelta); | |
ba115175 | 252 | ERROR("Failed to allocate memory"); |
38683db4 | 253 | return -1; |
278d97f7 | 254 | } |
241978fa | 255 | |
5c484f79 | 256 | strncpy(work, ndelta, lastslashidx + 1); |
241978fa CB |
257 | strncpy(work + lastslashidx, "olwork", sizeof("olwork") - 1); |
258 | work[lastslashidx + sizeof("olwork")] = '\0'; | |
259 | ||
ba115175 CB |
260 | ret = mkdir(work, 0755); |
261 | if (ret < 0 && errno != EEXIST) { | |
278d97f7 SH |
262 | free(osrc); |
263 | free(ndelta); | |
38683db4 | 264 | free(work); |
241978fa | 265 | SYSERROR("Failed to create directory \"%s\"", ndelta); |
38683db4 CB |
266 | return -1; |
267 | } | |
ba115175 | 268 | |
241978fa CB |
269 | if (am_unpriv()) { |
270 | ret = chown_mapped_root(work, conf); | |
271 | if (ret < 0) | |
272 | WARN("Failed to update ownership of %s", work); | |
273 | } | |
38683db4 CB |
274 | free(work); |
275 | ||
241978fa CB |
276 | /* strlen("overlay:") = 8 |
277 | * + | |
278 | * strlen(delta) | |
279 | * + | |
280 | * : | |
281 | * + | |
282 | * strlen(src) | |
283 | * + | |
284 | * \0 | |
285 | */ | |
286 | len = 8 + strlen(ndelta) + 1 + strlen(nsrc) + 1; | |
38683db4 CB |
287 | new->src = malloc(len); |
288 | if (!new->src) { | |
289 | free(osrc); | |
290 | free(ndelta); | |
ba115175 | 291 | ERROR("Failed to allocate memory"); |
38683db4 CB |
292 | return -ENOMEM; |
293 | } | |
ba115175 | 294 | ret = snprintf(new->src, len, "overlay:%s:%s", nsrc, ndelta); |
38683db4 CB |
295 | free(osrc); |
296 | free(ndelta); | |
241978fa | 297 | if (ret < 0 || (size_t)ret >= len) { |
ba115175 CB |
298 | ERROR("Failed to create string"); |
299 | return -1; | |
241978fa | 300 | } |
38683db4 | 301 | |
70e95c8d CB |
302 | ret = ovl_do_rsync(orig, new, conf); |
303 | if (ret < 0) | |
304 | return -1; | |
305 | ||
306 | /* When we create an overlay snapshot of an overlay container in | |
307 | * the snapshot directory under "<lxcpath>/<name>/snaps/" we | |
308 | * don't need to record a dependency. If we would restore would | |
309 | * also fail. | |
310 | */ | |
311 | clean_old_path = lxc_deslashify(oldpath); | |
312 | if (!clean_old_path) | |
313 | return -1; | |
314 | ||
315 | clean_new_path = lxc_deslashify(lxcpath); | |
316 | if (!clean_new_path) { | |
317 | free(clean_old_path); | |
318 | return -1; | |
319 | } | |
320 | ||
321 | s1 = strrchr(clean_old_path, '/'); | |
322 | if (!s1) { | |
323 | ERROR("Failed to detect \"/\" in string \"%s\"", s1); | |
324 | free(clean_old_path); | |
325 | free(clean_new_path); | |
326 | return -1; | |
327 | } | |
328 | ||
329 | s2 = strrchr(clean_new_path, '/'); | |
330 | if (!s2) { | |
331 | ERROR("Failed to detect \"/\" in string \"%s\"", s2); | |
332 | free(clean_old_path); | |
333 | free(clean_new_path); | |
334 | return -1; | |
335 | } | |
336 | ||
337 | if (!strncmp(s1, "/snaps", sizeof("/snaps") - 1)) { | |
338 | s1 = clean_new_path; | |
339 | s2 = clean_old_path; | |
340 | s3 = (char *)cname; | |
341 | name_len = strlen(cname); | |
342 | len = strlen(clean_new_path); | |
343 | } else if (!strncmp(s2, "/snaps", sizeof("/snaps") - 1)) { | |
344 | s1 = clean_old_path; | |
345 | s2 = clean_new_path; | |
346 | s3 = (char *)oldname; | |
347 | name_len = strlen(oldname); | |
348 | len = strlen(clean_old_path); | |
349 | } else { | |
350 | free(clean_old_path); | |
351 | free(clean_new_path); | |
352 | return 0; | |
353 | } | |
354 | ||
355 | if (!strncmp(s1, s2, len)) { | |
356 | char *tmp; | |
357 | ||
358 | tmp = (char *)(s2 + len + 1); | |
359 | if (*tmp == '\0') { | |
360 | free(clean_old_path); | |
361 | free(clean_new_path); | |
362 | return 0; | |
363 | } | |
364 | ||
365 | name_len = strlen(s3); | |
366 | if (strncmp(s3, tmp, name_len)) { | |
367 | free(clean_old_path); | |
368 | free(clean_new_path); | |
369 | return 0; | |
370 | } | |
371 | ||
372 | tmp += name_len + 1; | |
373 | if (*tmp == '\0') { | |
374 | free(clean_old_path); | |
375 | free(clean_new_path); | |
376 | return 0; | |
377 | } | |
378 | ||
379 | if (!strncmp(tmp, "snaps", sizeof("snaps") - 1)) { | |
380 | free(clean_old_path); | |
381 | free(clean_new_path); | |
382 | return LXC_CLONE_SNAPSHOT; | |
383 | } | |
384 | } | |
385 | ||
386 | free(clean_old_path); | |
387 | free(clean_new_path); | |
388 | return 0; | |
38683db4 | 389 | } else { |
ba115175 | 390 | ERROR("overlay clone of %s container is not yet supported", |
5c484f79 | 391 | orig->type); |
241978fa | 392 | /* Note, supporting this will require ovl_mount supporting |
5c484f79 CB |
393 | * mounting of the underlay. No big deal, just needs to be done. |
394 | */ | |
38683db4 CB |
395 | return -1; |
396 | } | |
397 | ||
398 | return 0; | |
399 | } | |
400 | ||
241978fa CB |
401 | /* To say "lxc-create -t ubuntu -n o1 -B overlay" means you want |
402 | * "<lxcpath>/<lxcname>/rootfs" to have the created container, while all changes | |
403 | * after starting the container are written to "<lxcpath>/<lxcname>/delta0". | |
38683db4 | 404 | */ |
10bc1861 | 405 | int ovl_create(struct lxc_storage *bdev, const char *dest, const char *n, |
241978fa | 406 | struct bdev_specs *specs) |
38683db4 CB |
407 | { |
408 | char *delta; | |
241978fa CB |
409 | int ret; |
410 | size_t len, newlen; | |
38683db4 | 411 | |
241978fa CB |
412 | len = strlen(dest); |
413 | if (len < 8 || strcmp(dest + len - 7, "/rootfs")) { | |
414 | ERROR("Failed to detect \"/rootfs\" in \"%s\"", dest); | |
38683db4 | 415 | return -1; |
241978fa | 416 | } |
38683db4 | 417 | |
241978fa CB |
418 | bdev->dest = strdup(dest); |
419 | if (!bdev->dest) { | |
420 | ERROR("Failed to duplicate string \"%s\"", dest); | |
38683db4 CB |
421 | return -1; |
422 | } | |
423 | ||
241978fa CB |
424 | delta = malloc(len + 1); |
425 | if (!delta) { | |
426 | ERROR("Failed to allocate memory"); | |
427 | return -1; | |
428 | } | |
429 | ||
430 | strncpy(delta, dest, len); | |
431 | strncpy(delta + len - 6, "delta0", sizeof("delta0") - 1); | |
432 | delta[len + sizeof("delta0")] = '\0'; | |
38683db4 | 433 | |
241978fa CB |
434 | ret = mkdir_p(delta, 0755); |
435 | if (ret < 0) { | |
436 | SYSERROR("Failed to create directory \"%s\"", delta); | |
437 | free(delta); | |
38683db4 CB |
438 | return -1; |
439 | } | |
440 | ||
241978fa | 441 | /* overlay:lower:upper */ |
ba115175 | 442 | newlen = (2 * len) + strlen("overlay:") + 2; |
38683db4 CB |
443 | bdev->src = malloc(newlen); |
444 | if (!bdev->src) { | |
241978fa CB |
445 | ERROR("Failed to allocate memory"); |
446 | free(delta); | |
38683db4 CB |
447 | return -1; |
448 | } | |
241978fa | 449 | |
ba115175 | 450 | ret = snprintf(bdev->src, newlen, "overlay:%s:%s", dest, delta); |
241978fa CB |
451 | if (ret < 0 || (size_t)ret >= newlen) { |
452 | ERROR("Failed to create string"); | |
453 | free(delta); | |
38683db4 | 454 | return -1; |
241978fa | 455 | } |
38683db4 | 456 | |
241978fa CB |
457 | ret = mkdir_p(bdev->dest, 0755); |
458 | if (ret < 0) { | |
459 | SYSERROR("Failed to create directory \"%s\"", bdev->dest); | |
460 | free(delta); | |
38683db4 CB |
461 | return -1; |
462 | } | |
463 | ||
241978fa | 464 | free(delta); |
38683db4 CB |
465 | return 0; |
466 | } | |
467 | ||
10bc1861 | 468 | int ovl_destroy(struct lxc_storage *orig) |
5c484f79 | 469 | { |
241978fa | 470 | bool ovl; |
ba115175 | 471 | char *upper = orig->src; |
5c484f79 | 472 | |
241978fa | 473 | ovl = !strncmp(upper, "overlay:", 8); |
ba115175 | 474 | if (!ovl && strncmp(upper, "overlayfs:", 10)) |
5c484f79 | 475 | return -22; |
ba115175 | 476 | |
241978fa CB |
477 | if (ovl) |
478 | upper += 8; | |
479 | else | |
480 | upper += 10; | |
ba115175 CB |
481 | |
482 | upper = strchr(upper, ':'); | |
5c484f79 CB |
483 | if (!upper) |
484 | return -22; | |
485 | upper++; | |
ba115175 | 486 | |
5c484f79 CB |
487 | return lxc_rmdir_onedev(upper, NULL); |
488 | } | |
489 | ||
3d2ae1e2 | 490 | bool ovl_detect(const char *path) |
5c484f79 | 491 | { |
f7ac4459 | 492 | if (!strncmp(path, "overlayfs:", 10)) |
3d2ae1e2 | 493 | return true; |
f7ac4459 CB |
494 | |
495 | if (!strncmp(path, "overlay:", 8)) | |
3d2ae1e2 | 496 | return true; |
f7ac4459 | 497 | |
3d2ae1e2 | 498 | return false; |
5c484f79 CB |
499 | } |
500 | ||
10bc1861 | 501 | int ovl_mount(struct lxc_storage *bdev) |
5c484f79 | 502 | { |
9208af16 | 503 | char *tmp, *options, *dup, *lower, *upper; |
5c484f79 CB |
504 | char *options_work, *work, *lastslash; |
505 | int lastslashidx; | |
241978fa | 506 | size_t len, len2; |
5c484f79 CB |
507 | unsigned long mntflags; |
508 | char *mntdata; | |
509 | int ret, ret2; | |
510 | ||
ba115175 | 511 | if (strcmp(bdev->type, "overlay") && strcmp(bdev->type, "overlayfs")) |
5c484f79 | 512 | return -22; |
ba115175 | 513 | |
5c484f79 CB |
514 | if (!bdev->src || !bdev->dest) |
515 | return -22; | |
516 | ||
517 | if (!ovl_name) | |
518 | ovl_name = ovl_detect_name(); | |
519 | ||
241978fa CB |
520 | /* Separately mount it first: |
521 | * mount -t overlay * -o upperdir=${upper},lowerdir=${lower} lower dest | |
5c484f79 | 522 | */ |
241978fa CB |
523 | dup = strdup(bdev->src); |
524 | if (!dup) { | |
525 | ERROR("Failed to allocate memory"); | |
526 | return -1; | |
527 | } | |
528 | ||
9208af16 | 529 | /* support multiple lower layers */ |
241978fa CB |
530 | lower = strstr(dup, ":/"); |
531 | if (!lower) { | |
532 | ERROR("Failed to detect \":/\" in string \"%s\"", dup); | |
533 | free(dup); | |
534 | return -22; | |
535 | } | |
536 | ||
9208af16 CB |
537 | lower++; |
538 | upper = lower; | |
539 | while ((tmp = strstr(++upper, ":/"))) { | |
540 | upper = tmp; | |
541 | } | |
241978fa CB |
542 | |
543 | upper--; | |
544 | if (upper == lower) { | |
545 | free(dup); | |
5c484f79 | 546 | return -22; |
241978fa | 547 | } |
5c484f79 CB |
548 | *upper = '\0'; |
549 | upper++; | |
550 | ||
241978fa CB |
551 | /* if delta doesn't yet exist, create it */ |
552 | ret = mkdir_p(upper, 0755) < 0; | |
553 | if (ret < 0 && errno != EEXIST) { | |
554 | SYSERROR("Failed to create directory \"%s\"", upper); | |
555 | free(dup); | |
5c484f79 | 556 | return -22; |
241978fa | 557 | } |
5c484f79 | 558 | |
241978fa | 559 | /* overlayfs.v22 or higher needs workdir option: |
5c484f79 CB |
560 | * if upper is |
561 | * /var/lib/lxc/c2/delta0 | |
562 | * then workdir is | |
563 | * /var/lib/lxc/c2/olwork | |
564 | */ | |
565 | lastslash = strrchr(upper, '/'); | |
241978fa CB |
566 | if (!lastslash) { |
567 | ERROR("Failed to detect \"/\" in string \"%s\"", upper); | |
568 | free(dup); | |
5c484f79 | 569 | return -22; |
241978fa CB |
570 | } |
571 | ||
5c484f79 CB |
572 | lastslash++; |
573 | lastslashidx = lastslash - upper; | |
574 | ||
241978fa CB |
575 | work = malloc(lastslashidx + 7); |
576 | if (!work) { | |
577 | ERROR("Failed to allocate memory"); | |
578 | free(dup); | |
579 | return -22; | |
580 | } | |
5c484f79 | 581 | |
241978fa CB |
582 | strncpy(work, upper, lastslashidx + 1); |
583 | strncpy(work + lastslashidx, "olwork", sizeof("olwork") - 1); | |
584 | work[lastslashidx + sizeof("olwork")] = '\0'; | |
585 | ||
586 | ret = parse_mntopts(bdev->mntopts, &mntflags, &mntdata); | |
587 | if (ret < 0) { | |
588 | ERROR("Failed to parse mount options"); | |
5c484f79 | 589 | free(mntdata); |
241978fa CB |
590 | free(dup); |
591 | free(work); | |
5c484f79 CB |
592 | return -22; |
593 | } | |
594 | ||
241978fa CB |
595 | ret = mkdir_p(work, 0755); |
596 | if (ret < 0 && errno != EEXIST) { | |
597 | SYSERROR("Failed to create directory \"%s\"", work); | |
5c484f79 | 598 | free(mntdata); |
241978fa CB |
599 | free(dup); |
600 | free(work); | |
5c484f79 CB |
601 | return -22; |
602 | } | |
603 | ||
604 | /* | |
605 | * TODO: | |
606 | * We should check whether bdev->src is a blockdev but for now only | |
607 | * support overlays of a basic directory | |
608 | */ | |
609 | ||
610 | if (mntdata) { | |
241978fa CB |
611 | len = strlen(lower) + strlen(upper) + |
612 | strlen("upperdir=,lowerdir=,") + strlen(mntdata) + 1; | |
5c484f79 | 613 | options = alloca(len); |
241978fa CB |
614 | ret = snprintf(options, len, "upperdir=%s,lowerdir=%s,%s", |
615 | upper, lower, mntdata); | |
5c484f79 | 616 | |
241978fa CB |
617 | len2 = strlen(lower) + strlen(upper) + strlen(work) + |
618 | strlen("upperdir=,lowerdir=,workdir=") + | |
619 | strlen(mntdata) + 1; | |
5c484f79 | 620 | options_work = alloca(len2); |
241978fa CB |
621 | ret2 = snprintf(options, len2, |
622 | "upperdir=%s,lowerdir=%s,workdir=%s,%s", upper, | |
623 | lower, work, mntdata); | |
5c484f79 | 624 | } else { |
241978fa CB |
625 | len = strlen(lower) + strlen(upper) + |
626 | strlen("upperdir=,lowerdir=") + 1; | |
5c484f79 | 627 | options = alloca(len); |
241978fa CB |
628 | ret = snprintf(options, len, "upperdir=%s,lowerdir=%s", upper, |
629 | lower); | |
5c484f79 | 630 | |
241978fa CB |
631 | len2 = strlen(lower) + strlen(upper) + strlen(work) + |
632 | strlen("upperdir=,lowerdir=,workdir=") + 1; | |
5c484f79 | 633 | options_work = alloca(len2); |
241978fa CB |
634 | ret2 = snprintf(options_work, len2, |
635 | "upperdir=%s,lowerdir=%s,workdir=%s", upper, | |
636 | lower, work); | |
5c484f79 CB |
637 | } |
638 | ||
639 | if (ret < 0 || ret >= len || ret2 < 0 || ret2 >= len2) { | |
241978fa | 640 | ERROR("Failed to create string"); |
5c484f79 | 641 | free(mntdata); |
241978fa CB |
642 | free(dup); |
643 | free(work); | |
5c484f79 CB |
644 | return -1; |
645 | } | |
646 | ||
241978fa | 647 | /* Assume we need a workdir as we are on a overlay version >= v22. */ |
88232d3f CB |
648 | ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name, |
649 | MS_MGC_VAL | mntflags, options_work); | |
5c484f79 | 650 | if (ret < 0) { |
241978fa CB |
651 | INFO("Failed to mount \"%s\" on \"%s\" with options \"%s\". " |
652 | "Retrying without workdir: %s", | |
88232d3f | 653 | lower, bdev->dest, options_work, strerror(errno)); |
5c484f79 | 654 | |
241978fa CB |
655 | /* Assume we cannot use a workdir as we are on a version <= v21. |
656 | */ | |
88232d3f | 657 | ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name, |
241978fa | 658 | MS_MGC_VAL | mntflags, options); |
5c484f79 | 659 | if (ret < 0) |
241978fa CB |
660 | SYSERROR("Failed to mount \"%s\" on \"%s\" with " |
661 | "options \"%s\": %s", | |
662 | lower, bdev->dest, options, strerror(errno)); | |
5c484f79 | 663 | else |
241978fa | 664 | INFO("Mounted \"%s\" on \"%s\" with options \"%s\"", |
88232d3f | 665 | lower, bdev->dest, options); |
5c484f79 | 666 | } else { |
241978fa | 667 | INFO("Mounted \"%s\" on \"%s\" with options \"%s\"", lower, |
88232d3f | 668 | bdev->dest, options_work); |
5c484f79 | 669 | } |
241978fa CB |
670 | |
671 | free(dup); | |
672 | free(work); | |
5c484f79 CB |
673 | return ret; |
674 | } | |
675 | ||
10bc1861 | 676 | int ovl_umount(struct lxc_storage *bdev) |
5c484f79 | 677 | { |
241978fa CB |
678 | int ret; |
679 | ||
ba115175 | 680 | if (strcmp(bdev->type, "overlay") && strcmp(bdev->type, "overlayfs")) |
5c484f79 | 681 | return -22; |
ba115175 | 682 | |
5c484f79 CB |
683 | if (!bdev->src || !bdev->dest) |
684 | return -22; | |
ba115175 | 685 | |
241978fa CB |
686 | ret = umount(bdev->dest); |
687 | if (ret < 0) | |
688 | SYSERROR("Failed to unmount \"%s\"", bdev->dest); | |
689 | else | |
690 | TRACE("Unmounted \"%s\"", bdev->dest); | |
691 | ||
692 | return ret; | |
5c484f79 CB |
693 | } |
694 | ||
ba115175 CB |
695 | char *ovl_get_lower(const char *rootfs_path) |
696 | { | |
697 | char *s1; | |
241978fa | 698 | |
ba115175 CB |
699 | s1 = strstr(rootfs_path, ":/"); |
700 | if (!s1) | |
701 | return NULL; | |
702 | s1++; | |
703 | ||
704 | s1 = strstr(s1, ":/"); | |
705 | if (!s1) | |
706 | return NULL; | |
707 | s1++; | |
708 | ||
709 | return s1; | |
710 | } | |
711 | ||
5c484f79 CB |
712 | char *ovl_get_rootfs(const char *rootfs_path, size_t *rootfslen) |
713 | { | |
714 | char *rootfsdir = NULL; | |
715 | char *s1 = NULL; | |
716 | char *s2 = NULL; | |
717 | char *s3 = NULL; | |
718 | ||
719 | if (!rootfs_path || !rootfslen) | |
720 | return NULL; | |
721 | ||
722 | s1 = strdup(rootfs_path); | |
723 | if (!s1) | |
724 | return NULL; | |
725 | ||
241978fa CB |
726 | s2 = strstr(s1, ":/"); |
727 | if (s2) { | |
5c484f79 CB |
728 | s2 = s2 + 1; |
729 | if ((s3 = strstr(s2, ":/"))) | |
730 | *s3 = '\0'; | |
731 | rootfsdir = strdup(s2); | |
732 | if (!rootfsdir) { | |
733 | free(s1); | |
734 | return NULL; | |
735 | } | |
736 | } | |
737 | ||
738 | if (!rootfsdir) | |
739 | rootfsdir = s1; | |
740 | else | |
741 | free(s1); | |
742 | ||
743 | *rootfslen = strlen(rootfsdir); | |
744 | ||
745 | return rootfsdir; | |
746 | } | |
747 | ||
748 | int ovl_mkdir(const struct mntent *mntent, const struct lxc_rootfs *rootfs, | |
749 | const char *lxc_name, const char *lxc_path) | |
750 | { | |
751 | char lxcpath[MAXPATHLEN]; | |
241978fa CB |
752 | char **opts; |
753 | int ret; | |
754 | size_t arrlen, dirlen, i, len, rootfslen; | |
5c484f79 | 755 | int fret = -1; |
241978fa CB |
756 | char *rootfs_dir = NULL, *rootfs_path = NULL, *upperdir = NULL, |
757 | *workdir = NULL; | |
5c484f79 | 758 | |
9769034f CB |
759 | /* When rootfs == NULL we have a container without a rootfs. */ |
760 | if (rootfs && rootfs->path) | |
761 | rootfs_path = rootfs->path; | |
5c484f79 CB |
762 | |
763 | opts = lxc_string_split(mntent->mnt_opts, ','); | |
764 | if (opts) | |
765 | arrlen = lxc_array_len((void **)opts); | |
766 | else | |
767 | goto err; | |
768 | ||
769 | for (i = 0; i < arrlen; i++) { | |
241978fa CB |
770 | if (strstr(opts[i], "upperdir=") && |
771 | (strlen(opts[i]) > (len = strlen("upperdir=")))) | |
5c484f79 | 772 | upperdir = opts[i] + len; |
241978fa CB |
773 | else if (strstr(opts[i], "workdir=") && |
774 | (strlen(opts[i]) > (len = strlen("workdir=")))) | |
5c484f79 CB |
775 | workdir = opts[i] + len; |
776 | } | |
777 | ||
9769034f | 778 | if (rootfs_path) { |
241978fa CB |
779 | ret = |
780 | snprintf(lxcpath, MAXPATHLEN, "%s/%s", lxc_path, lxc_name); | |
9769034f CB |
781 | if (ret < 0 || ret >= MAXPATHLEN) |
782 | goto err; | |
5c484f79 | 783 | |
241978fa CB |
784 | rootfs_dir = ovl_get_rootfs(rootfs_path, &rootfslen); |
785 | if (!rootfs_dir) | |
9769034f | 786 | goto err; |
5c484f79 | 787 | |
9769034f CB |
788 | dirlen = strlen(lxcpath); |
789 | } | |
5c484f79 CB |
790 | |
791 | /* | |
792 | * We neither allow users to create upperdirs and workdirs outside the | |
793 | * containerdir nor inside the rootfs. The latter might be debatable. | |
9769034f | 794 | * When we have a container without a rootfs we skip the checks. |
5c484f79 | 795 | */ |
9769034f CB |
796 | ret = 0; |
797 | if (upperdir) { | |
798 | if (!rootfs_path) | |
799 | ret = mkdir_p(upperdir, 0755); | |
241978fa CB |
800 | else if (!strncmp(upperdir, lxcpath, dirlen) && |
801 | strncmp(upperdir, rootfs_dir, rootfslen)) | |
9769034f CB |
802 | ret = mkdir_p(upperdir, 0755); |
803 | if (ret < 0) | |
241978fa CB |
804 | WARN("Failed to create directory \"%s\": %s", upperdir, |
805 | strerror(errno)); | |
9769034f CB |
806 | } |
807 | ||
808 | ret = 0; | |
809 | if (workdir) { | |
810 | if (!rootfs_path) | |
811 | ret = mkdir_p(workdir, 0755); | |
241978fa CB |
812 | else if (!strncmp(workdir, lxcpath, dirlen) && |
813 | strncmp(workdir, rootfs_dir, rootfslen)) | |
9769034f CB |
814 | ret = mkdir_p(workdir, 0755); |
815 | if (ret < 0) | |
241978fa CB |
816 | WARN("Failed to create directory \"%s\": %s", workdir, |
817 | strerror(errno)); | |
9769034f | 818 | } |
5c484f79 CB |
819 | |
820 | fret = 0; | |
821 | ||
822 | err: | |
241978fa | 823 | free(rootfs_dir); |
5c484f79 CB |
824 | lxc_free_array((void **)opts, free); |
825 | return fret; | |
826 | } | |
827 | ||
241978fa | 828 | /* To be called from lxcapi_clone() in lxccontainer.c: When we clone a container |
38683db4 CB |
829 | * with overlay lxc.mount.entry entries we need to update absolute paths for |
830 | * upper- and workdir. This update is done in two locations: | |
831 | * lxc_conf->unexpanded_config and lxc_conf->mount_list. Both updates are done | |
241978fa CB |
832 | * independent of each other since lxc_conf->mountlist may contain more mount |
833 | * entries (e.g. from other included files) than lxc_conf->unexpanded_config. | |
38683db4 | 834 | */ |
83e79752 CB |
835 | int ovl_update_abs_paths(struct lxc_conf *lxc_conf, const char *lxc_path, |
836 | const char *lxc_name, const char *newpath, | |
837 | const char *newname) | |
38683db4 | 838 | { |
241978fa CB |
839 | char new_upper[MAXPATHLEN], new_work[MAXPATHLEN], old_upper[MAXPATHLEN], |
840 | old_work[MAXPATHLEN]; | |
84760c11 | 841 | size_t i; |
241978fa CB |
842 | struct lxc_list *iterator; |
843 | char *cleanpath = NULL; | |
38683db4 CB |
844 | int fret = -1; |
845 | int ret = 0; | |
38683db4 CB |
846 | const char *ovl_dirs[] = {"br", "upperdir", "workdir"}; |
847 | ||
848 | cleanpath = strdup(newpath); | |
849 | if (!cleanpath) | |
850 | goto err; | |
851 | ||
852 | remove_trailing_slashes(cleanpath); | |
853 | ||
5c484f79 CB |
854 | /* |
855 | * We have to update lxc_conf->unexpanded_config separately from | |
856 | * lxc_conf->mount_list. | |
857 | */ | |
38683db4 CB |
858 | for (i = 0; i < sizeof(ovl_dirs) / sizeof(ovl_dirs[0]); i++) { |
859 | if (!clone_update_unexp_ovl_paths(lxc_conf, lxc_path, newpath, | |
860 | lxc_name, newname, | |
861 | ovl_dirs[i])) | |
862 | goto err; | |
863 | } | |
864 | ||
241978fa CB |
865 | ret = |
866 | snprintf(old_work, MAXPATHLEN, "workdir=%s/%s", lxc_path, lxc_name); | |
38683db4 CB |
867 | if (ret < 0 || ret >= MAXPATHLEN) |
868 | goto err; | |
869 | ||
241978fa CB |
870 | ret = |
871 | snprintf(new_work, MAXPATHLEN, "workdir=%s/%s", cleanpath, newname); | |
38683db4 CB |
872 | if (ret < 0 || ret >= MAXPATHLEN) |
873 | goto err; | |
874 | ||
875 | lxc_list_for_each(iterator, &lxc_conf->mount_list) { | |
241978fa CB |
876 | char *mnt_entry = NULL, *new_mnt_entry = NULL, *tmp = NULL, |
877 | *tmp_mnt_entry = NULL; | |
878 | ||
38683db4 CB |
879 | mnt_entry = iterator->elem; |
880 | ||
881 | if (strstr(mnt_entry, "overlay")) | |
882 | tmp = "upperdir"; | |
883 | else if (strstr(mnt_entry, "aufs")) | |
884 | tmp = "br"; | |
885 | ||
886 | if (!tmp) | |
887 | continue; | |
888 | ||
241978fa CB |
889 | ret = snprintf(old_upper, MAXPATHLEN, "%s=%s/%s", tmp, lxc_path, |
890 | lxc_name); | |
38683db4 CB |
891 | if (ret < 0 || ret >= MAXPATHLEN) |
892 | goto err; | |
893 | ||
241978fa CB |
894 | ret = snprintf(new_upper, MAXPATHLEN, "%s=%s/%s", tmp, |
895 | cleanpath, newname); | |
38683db4 CB |
896 | if (ret < 0 || ret >= MAXPATHLEN) |
897 | goto err; | |
898 | ||
899 | if (strstr(mnt_entry, old_upper)) { | |
241978fa CB |
900 | tmp_mnt_entry = |
901 | lxc_string_replace(old_upper, new_upper, mnt_entry); | |
38683db4 CB |
902 | } |
903 | ||
904 | if (strstr(mnt_entry, old_work)) { | |
905 | if (tmp_mnt_entry) | |
241978fa CB |
906 | new_mnt_entry = lxc_string_replace( |
907 | old_work, new_work, tmp_mnt_entry); | |
38683db4 | 908 | else |
241978fa CB |
909 | new_mnt_entry = lxc_string_replace( |
910 | old_work, new_work, mnt_entry); | |
38683db4 CB |
911 | } |
912 | ||
913 | if (new_mnt_entry) { | |
914 | free(iterator->elem); | |
915 | iterator->elem = strdup(new_mnt_entry); | |
916 | } else if (tmp_mnt_entry) { | |
917 | free(iterator->elem); | |
918 | iterator->elem = strdup(tmp_mnt_entry); | |
919 | } | |
920 | ||
921 | free(new_mnt_entry); | |
922 | free(tmp_mnt_entry); | |
923 | } | |
924 | ||
925 | fret = 0; | |
926 | err: | |
927 | free(cleanpath); | |
928 | return fret; | |
929 | } | |
930 | ||
88232d3f CB |
931 | static int ovl_remount_on_enodev(const char *lower, const char *target, |
932 | const char *name, unsigned long mountflags, | |
933 | const void *options) | |
934 | { | |
241978fa CB |
935 | int ret; |
936 | ret = mount(lower, target, ovl_name, MS_MGC_VAL | mountflags, options); | |
937 | if (ret < 0 && errno == ENODEV) /* Try other module name. */ | |
88232d3f CB |
938 | ret = mount(lower, target, |
939 | ovl_name == ovl_version[0] ? ovl_version[1] | |
940 | : ovl_version[0], | |
941 | MS_MGC_VAL | mountflags, options); | |
241978fa | 942 | return ret; |
5c484f79 CB |
943 | } |
944 | ||
945 | static char *ovl_detect_name(void) | |
946 | { | |
241978fa | 947 | FILE *f; |
88232d3f | 948 | char *v = ovl_version[0]; |
5c484f79 CB |
949 | char *line = NULL; |
950 | size_t len = 0; | |
241978fa CB |
951 | |
952 | f = fopen("/proc/filesystems", "r"); | |
5c484f79 CB |
953 | if (!f) |
954 | return v; | |
955 | ||
956 | while (getline(&line, &len, f) != -1) { | |
88232d3f CB |
957 | if (strcmp(line, "nodev\toverlayfs\n") == 0) { |
958 | v = ovl_version[1]; | |
5c484f79 CB |
959 | break; |
960 | } | |
961 | } | |
962 | ||
963 | fclose(f); | |
964 | free(line); | |
965 | return v; | |
966 | } | |
967 | ||
10bc1861 | 968 | static int ovl_do_rsync(struct lxc_storage *orig, struct lxc_storage *new, |
241978fa | 969 | struct lxc_conf *conf) |
5c484f79 CB |
970 | { |
971 | int ret = -1; | |
241978fa CB |
972 | struct rsync_data rdata = {0, 0}; |
973 | char cmd_output[MAXPATHLEN] = {0}; | |
5c484f79 CB |
974 | |
975 | rdata.orig = orig; | |
976 | rdata.new = new; | |
241978fa CB |
977 | if (am_unpriv()) { |
978 | ret = userns_exec_1(conf, lxc_rsync_exec_wrapper, &rdata, | |
979 | "lxc_rsync_exec_wrapper"); | |
980 | if (ret < 0) | |
981 | ERROR("Failed to rsync from \"%s\" into \"%s\"", | |
982 | orig->dest, new->dest); | |
983 | } else { | |
984 | ret = run_command(cmd_output, sizeof(cmd_output), | |
985 | lxc_rsync_exec_wrapper, (void *)&rdata); | |
986 | if (ret < 0) | |
987 | ERROR("Failed to rsync from \"%s\" into \"%s\": %s", | |
988 | orig->dest, new->dest, cmd_output); | |
989 | } | |
5c484f79 CB |
990 | |
991 | return ret; | |
992 | } |