xref: /dragonfly/sbin/hammer/cmd_snapshot.c (revision 73610d44)
1 /*
2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sbin/hammer/cmd_snapshot.c,v 1.7 2008/07/10 18:47:22 mneumann Exp $
35  */
36 
37 #include "hammer.h"
38 
39 #define DEFAULT_SNAPSHOT_NAME "snap-%Y%m%d-%H%M"
40 
41 static void snapshot_usage(int exit_code);
42 static void snapshot_add(int fd, const char *fsym, const char *tsym,
43 		const char *label, hammer_tid_t tid);
44 static void snapshot_ls(const char *path);
45 static void snapshot_del(int fsfd, hammer_tid_t tid);
46 static char *dirpart(const char *path);
47 
48 /*
49  * hammer snap <path> [<note>]
50  *
51  * Path may be a directory, softlink, or non-existent (a softlink will be
52  * created).
53  */
54 void
55 hammer_cmd_snap(char **av, int ac, int tostdout, int fsbase)
56 {
57 	struct hammer_ioc_synctid synctid;
58 	struct hammer_ioc_version version;
59 	char *dirpath;
60 	char *fsym = NULL;
61 	char *tsym = NULL;
62 	struct stat st;
63 	char note[64];
64 	int fsfd;
65 
66 	if (ac == 0 || ac > 2) {
67 		snapshot_usage(1);
68 		/* not reached */
69 	}
70 
71 	if (ac == 2)
72 		snprintf(note, sizeof(note), "%s", av[1]);
73 	else
74 		note[0] = 0;
75 
76 	/*
77 	 * Figure out the softlink path and directory path
78 	 */
79 	if (stat(av[0], &st) < 0) {
80 		dirpath = dirpart(av[0]);
81 		tsym = strdup(av[0]);
82 	} else if (S_ISDIR(st.st_mode)) {
83 		time_t t = time(NULL);
84 		struct tm *tp;
85 		char extbuf[64];
86 
87 		tp = localtime(&t);
88 		strftime(extbuf, sizeof(extbuf), DEFAULT_SNAPSHOT_NAME, tp);
89 
90 		dirpath = strdup(av[0]);
91 		asprintf(&tsym, "%s/%s", dirpath, extbuf);
92 	} else {
93 		err(2, "hammer snap: File %s exists and is not a directory\n",
94 		    av[0]);
95 		/* not reached */
96 	}
97 
98 	/*
99 	 * Get a handle on some directory in the filesystem for the
100 	 * ioctl (so it is stored in the correct PFS).
101 	 */
102 	fsfd = open(dirpath, O_RDONLY);
103 	if (fsfd < 0) {
104 		err(2, "hammer snap: Cannot open directory %s\n", dirpath);
105 		/* not reached */
106 	}
107 
108 	/*
109 	 * Must be at least version 3 to use this command.
110 	 */
111         bzero(&version, sizeof(version));
112 
113         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
114 		err(2, "Unable to create snapshot");
115 		/* not reached */
116 	} else if (version.cur_version < 3) {
117 		errx(2, "Unable to create snapshot: This directive requires "
118 			"you to upgrade\n"
119 			"the filesystem to version 3.  "
120 			"Use 'hammer snapshot' for legacy operation.");
121 		/* not reached */
122 	}
123 
124 	/*
125 	 * Synctid to get a transaction id for the snapshot.
126 	 */
127 	bzero(&synctid, sizeof(synctid));
128 	synctid.op = HAMMER_SYNCTID_SYNC2;
129 	if (ioctl(fsfd, HAMMERIOC_SYNCTID, &synctid) < 0) {
130 		err(2, "hammer snap: Synctid %s failed",
131 		    dirpath);
132 	}
133 	if (tostdout) {
134 		if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
135 			printf("%s/@@0x%016jx\n",
136 				dirpath, (uintmax_t)synctid.tid);
137 		} else {
138 			printf("%s@@0x%016jx\n",
139 				dirpath, (uintmax_t)synctid.tid);
140 		}
141 		fsym = NULL;
142 		tsym = NULL;
143 	}
144 
145 	/*
146 	 * Contents of the symlink being created.
147 	 */
148 	if (fsbase) {
149 		struct statfs buf;
150 
151 		if (statfs(dirpath, &buf) < 0) {
152 			err(2, "hammer snap: Cannot determine mount for %s",
153 			    dirpath);
154 		}
155 		asprintf(&fsym, "%s/@@0x%016jx",
156 			 buf.f_mntonname, (uintmax_t)synctid.tid);
157 	} else if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
158 		asprintf(&fsym, "%s/@@0x%016jx",
159 			 dirpath, (uintmax_t)synctid.tid);
160 	} else {
161 		asprintf(&fsym, "%s@@0x%016jx",
162 			 dirpath, (uintmax_t)synctid.tid);
163 	}
164 
165 	/*
166 	 * Create the snapshot.
167 	 */
168 	snapshot_add(fsfd, fsym, tsym, note, synctid.tid);
169 	free(dirpath);
170 	free(fsym);
171 	free(tsym);
172 }
173 
174 /*
175  * hammer snapls [<path> ...]
176  *
177  * If no arguments are specified snapshots for the PFS containing the
178  * current directory are listed.
179  */
180 void
181 hammer_cmd_snapls(char **av, int ac)
182 {
183 	int i;
184 
185 	for (i = 0; i < ac; ++i)
186 		snapshot_ls(av[i]);
187 	if (ac == 0)
188 		snapshot_ls(".");
189 }
190 
191 /*
192  * hammer snaprm <path> ...
193  * hammer snaprm <transid> ...
194  * hammer snaprm <filesystem> <transid> ...
195  */
196 void
197 hammer_cmd_snaprm(char **av, int ac)
198 {
199 	struct stat st;
200 	char linkbuf[1024];
201 	intmax_t tid;
202 	int fsfd = -1;
203 	int i;
204 	int delete;
205 	enum snaprm_mode { none_m, path_m, tid_m } mode = none_m;
206 	char *dirpath;
207 	char *ptr, *ptr2;
208 
209 	if (ac == 0) {
210 		snapshot_usage(1);
211 		/* not reached */
212 	}
213 
214 	for (i = 0; i < ac; ++i) {
215 		if (lstat(av[i], &st) < 0) {
216 			tid = strtoull(av[i], &ptr, 16);
217 			if (*ptr) {
218 				err(2, "hammer snaprm: not a file or tid: %s",
219 				    av[i]);
220 				/* not reached */
221 			}
222 			if (mode == path_m) {
223 				snapshot_usage(1);
224 				/* not reached */
225 			}
226 			mode = tid_m;
227 			if (fsfd < 0)
228 				fsfd = open(".", O_RDONLY);
229 			snapshot_del(fsfd, tid);
230 		} else if (S_ISDIR(st.st_mode)) {
231 			if (i != 0 || ac < 2) {
232 				snapshot_usage(1);
233 				/* not reached */
234 			}
235 			if (fsfd >= 0)
236 				close(fsfd);
237 			fsfd = open(av[i], O_RDONLY);
238 			if (fsfd < 0) {
239 				err(2, "hammer snaprm: cannot open dir %s",
240 				    av[i]);
241 				/* not reached */
242 			}
243 			mode = tid_m;
244 		} else if (S_ISLNK(st.st_mode)) {
245 			dirpath = dirpart(av[i]);
246 			bzero(linkbuf, sizeof(linkbuf));
247 			if (readlink(av[i], linkbuf, sizeof(linkbuf) - 1) < 0) {
248 				err(2, "hammer snaprm: cannot read softlink: "
249 				       "%s", av[i]);
250 				/* not reached */
251 			}
252 			if (linkbuf[0] == '/') {
253 				free(dirpath);
254 				dirpath = dirpart(linkbuf);
255 			} else {
256 				asprintf(&ptr, "%s/%s", dirpath, linkbuf);
257 				free(dirpath);
258 				dirpath = dirpart(ptr);
259 				free(ptr);
260 			}
261 
262 			if (fsfd >= 0)
263 				close(fsfd);
264 			fsfd = open(dirpath, O_RDONLY);
265 			if (fsfd < 0) {
266 				err(2, "hammer snaprm: cannot open dir %s",
267 				    dirpath);
268 				/* not reached */
269 			}
270 
271 			delete = 1;
272 			if (i == 0 && ac > 1) {
273 				mode = path_m;
274 				if (lstat(av[1], &st) < 0) {
275 					tid = strtoull(av[1], &ptr, 16);
276 					if (*ptr == '\0') {
277 						delete = 0;
278 						mode = tid_m;
279 					}
280 				}
281 			} else {
282 				if (mode == tid_m) {
283 					snapshot_usage(1);
284 					/* not reached */
285 				}
286 				mode = path_m;
287 			}
288 			if (delete && (ptr = strrchr(linkbuf, '@')) &&
289 			    ptr > linkbuf && ptr[-1] == '@' && ptr[1]) {
290 				tid = strtoull(ptr + 1, &ptr2, 16);
291 				if (*ptr2 == '\0') {
292 					snapshot_del(fsfd, tid);
293 					remove(av[i]);
294 				}
295 			}
296 			free(dirpath);
297 		} else {
298 			err(2, "hammer snaprm: not directory or snapshot "
299 			       "softlink: %s", av[i]);
300 			/* not reached */
301 		}
302 	}
303 	if (fsfd >= 0)
304 		close(fsfd);
305 }
306 
307 /*
308  * snapshot <softlink-dir>
309  * snapshot <filesystem> <softlink-dir> [<note>]
310  */
311 void
312 hammer_cmd_snapshot(char **av, int ac)
313 {
314 	const char *filesystem;
315 	const char *softlink_dir;
316 	char *softlink_fmt;
317 	struct statfs buf;
318 	struct stat st;
319 	struct hammer_ioc_synctid synctid;
320 	char *from;
321 	char *to;
322 	char *note = NULL;
323 
324 	if (ac == 1) {
325 		filesystem = NULL;
326 		softlink_dir = av[0];
327 	} else if (ac == 2) {
328 		filesystem = av[0];
329 		softlink_dir = av[1];
330 	} else if (ac == 3) {
331 		filesystem = av[0];
332 		softlink_dir = av[1];
333 		note = av[2];
334 	} else {
335 		snapshot_usage(1);
336 		/* not reached */
337 		softlink_dir = NULL;
338 		filesystem = NULL;
339 	}
340 
341 	if (stat(softlink_dir, &st) == 0) {
342 		if (!S_ISDIR(st.st_mode))
343 			err(2, "File %s already exists", softlink_dir);
344 
345 		if (filesystem == NULL) {
346 			if (statfs(softlink_dir, &buf) != 0) {
347 				err(2, "Unable to determine filesystem of %s",
348 				    softlink_dir);
349 			}
350 			filesystem = buf.f_mntonname;
351 		}
352 
353 		softlink_fmt = malloc(strlen(softlink_dir) + 1 + 1 +
354 		                      sizeof(DEFAULT_SNAPSHOT_NAME));
355 		if (softlink_fmt == NULL)
356 			err(2, "Failed to allocate string");
357 
358 		strcpy(softlink_fmt, softlink_dir);
359 		if (softlink_fmt[strlen(softlink_fmt)-1] != '/')
360 			strcat(softlink_fmt, "/");
361 		strcat(softlink_fmt, DEFAULT_SNAPSHOT_NAME);
362 	} else {
363 		softlink_fmt = strdup(softlink_dir);
364 
365 		if (filesystem == NULL) {
366 			/*
367 			 * strip-off last '/path' segment to get the softlink
368 			 * directory, which we need to determine the filesystem
369 			 * we are on.
370 			 */
371 			char *pos = strrchr(softlink_fmt, '/');
372 			if (pos != NULL)
373 				*pos = '\0';
374 
375 			if (stat(softlink_fmt, &st) != 0 ||
376 			    !S_ISDIR(st.st_mode)) {
377 				err(2, "Unable to determine softlink dir %s",
378 				    softlink_fmt);
379 			}
380 			if (statfs(softlink_fmt, &buf) != 0) {
381 				err(2, "Unable to determine filesystem of %s",
382 				    softlink_fmt);
383 			}
384 			filesystem = buf.f_mntonname;
385 
386 			/* restore '/' */
387 			if (pos != NULL)
388 				*pos = '/';
389 		}
390 	}
391 
392 	/*
393 	 * Synctid
394 	 */
395 	bzero(&synctid, sizeof(synctid));
396 	synctid.op = HAMMER_SYNCTID_SYNC2;
397 
398 	int fd = open(filesystem, O_RDONLY);
399 	if (fd < 0)
400 		err(2, "Unable to open %s", filesystem);
401 	if (ioctl(fd, HAMMERIOC_SYNCTID, &synctid) < 0)
402 		err(2, "Synctid %s failed", filesystem);
403 
404 	asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
405 	if (from == NULL)
406 		err(2, "Couldn't generate string");
407 
408 	int sz = strlen(softlink_fmt) + 50;
409 	to = malloc(sz);
410 	if (to == NULL)
411 		err(2, "Failed to allocate string");
412 
413 	time_t t = time(NULL);
414 	if (strftime(to, sz, softlink_fmt, localtime(&t)) == 0)
415 		err(2, "String buffer too small");
416 
417 	asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
418 
419 	snapshot_add(fd, from, to, note, synctid.tid);
420 
421 	close(fd);
422 	printf("%s\n", to);
423 
424 	free(softlink_fmt);
425 	free(from);
426 	free(to);
427 }
428 
429 static
430 void
431 snapshot_add(int fd, const char *fsym, const char *tsym, const char *label,
432 	     hammer_tid_t tid)
433 {
434 	struct hammer_ioc_version version;
435 	struct hammer_ioc_snapshot snapshot;
436 
437         bzero(&version, sizeof(version));
438         bzero(&snapshot, sizeof(snapshot));
439 
440 	/*
441 	 * For HAMMER filesystem v3+ the snapshot is recorded in meta-data.
442 	 */
443         if (ioctl(fd, HAMMERIOC_GET_VERSION, &version) == 0 &&
444 	    version.cur_version >= 3) {
445 		snapshot.index = 0;
446 		snapshot.count = 1;
447 		snapshot.snaps[0].tid = tid;
448 		snapshot.snaps[0].ts = time(NULL) * 1000000ULL;
449 		if (label) {
450 			snprintf(snapshot.snaps[0].label,
451 				 sizeof(snapshot.snaps[0].label),
452 				 "%s",
453 				 label);
454 		}
455 		if (ioctl(fd, HAMMERIOC_ADD_SNAPSHOT, &snapshot) < 0) {
456 			err(2, "Unable to create snapshot");
457 		} else if (snapshot.head.error &&
458 			   snapshot.head.error != EEXIST) {
459 			errx(2, "Unable to create snapshot: %s\n",
460 				strerror(snapshot.head.error));
461 		}
462         }
463 
464 	/*
465 	 * Create a symlink for the snapshot.  If a file exists with the same
466 	 * name the new symlink will replace it.
467 	 */
468 	if (fsym && tsym) {
469 		remove(tsym);
470 		if (symlink(fsym, tsym) < 0) {
471 			err(2, "Unable to create symlink %s", tsym);
472 		}
473 	}
474 }
475 
476 static
477 void
478 snapshot_ls(const char *path)
479 {
480 	/*struct hammer_ioc_version version;*/
481 	struct hammer_ioc_info info;
482 	struct hammer_ioc_snapshot snapshot;
483 	struct hammer_ioc_pseudofs_rw pfs;
484 	struct hammer_pseudofs_data pfs_od;
485 	struct hammer_snapshot_data *snap;
486 	struct tm *tp;
487 	time_t t;
488 	u_int32_t i;
489 	int fd;
490 	char snapts[64];
491 	char *mntpoint;
492 
493 	fd = open(path, O_RDONLY);
494 	if (fd < 0) {
495 		err(2, "hammer snapls: cannot open %s", path);
496 		/* not reached */
497 	}
498 
499 	bzero(&pfs, sizeof(pfs));
500 	bzero(&pfs_od, sizeof(pfs_od));
501 	pfs.pfs_id = -1;
502 	pfs.ondisk = &pfs_od;
503 	pfs.bytes = sizeof(struct hammer_pseudofs_data);
504 	if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
505 		err(2, "hammer snapls: cannot retrieve PFS info on %s", path);
506 		/* not reached */
507 	}
508 
509 	bzero(&info, sizeof(info));
510 	if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0) {
511                 err(2, "hammer snapls: cannot retrieve HAMMER info");
512 		/* not reached */
513         }
514 
515 	mntpoint = libhammer_find_pfs_mount(&pfs.ondisk->unique_uuid);
516 
517 	printf("Snapshots on %s\tPFS #%d\n",
518 	    mntpoint ? mntpoint : path, pfs.pfs_id);
519 	printf("Transaction ID\t\tTimestamp\t\tNote\n");
520 
521 	if (mntpoint)
522 		free(mntpoint);
523 
524 	bzero(&snapshot, sizeof(snapshot));
525 	do {
526 		if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapshot) < 0) {
527 			err(2, "hammer snapls: %s: not HAMMER fs or "
528 				"version < 3", path);
529 			/* not reached */
530 		}
531 		for (i = 0; i < snapshot.count; ++i) {
532 			snap = &snapshot.snaps[i];
533 
534 			t = snap->ts / 1000000ULL;
535 			tp = localtime(&t);
536 			strftime(snapts, sizeof(snapts),
537 				 "%Y-%m-%d %H:%M:%S %Z", tp);
538 			printf("0x%016jx\t%s\t%s\n",
539 				(uintmax_t)snap->tid, snapts,
540 				strlen(snap->label) ? snap->label : "-");
541 		}
542 	} while (snapshot.head.error == 0 && snapshot.count);
543 }
544 
545 static
546 void
547 snapshot_del(int fsfd, hammer_tid_t tid)
548 {
549 	struct hammer_ioc_snapshot snapshot;
550 	struct hammer_ioc_version version;
551 
552         bzero(&version, sizeof(version));
553 
554         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
555 		err(2, "hammer snaprm 0x%016jx", (uintmax_t)tid);
556 	}
557 	if (version.cur_version < 3) {
558 		errx(2, "hammer snaprm 0x%016jx: You must upgrade to version "
559 			" 3 to use this directive", (uintmax_t)tid);
560 	}
561 
562 	bzero(&snapshot, sizeof(snapshot));
563 	snapshot.count = 1;
564 	snapshot.snaps[0].tid = tid;
565 
566 	/*
567 	 * Do not abort if we are unable to remove the meta-data.
568 	 */
569 	if (ioctl(fsfd, HAMMERIOC_DEL_SNAPSHOT, &snapshot) < 0) {
570 		err(2, "hammer snaprm 0x%016jx",
571 		      (uintmax_t)tid);
572 	} else if (snapshot.head.error == ENOENT) {
573 		fprintf(stderr, "Warning: hammer snaprm 0x%016jx: "
574 				"meta-data not found\n",
575 			(uintmax_t)tid);
576 	} else if (snapshot.head.error) {
577 		fprintf(stderr, "Warning: hammer snaprm 0x%016jx: %s\n",
578 			(uintmax_t)tid, strerror(snapshot.head.error));
579 	}
580 }
581 
582 static
583 void
584 snapshot_usage(int exit_code)
585 {
586 	fprintf(stderr,
587     "hammer snap <path> [<note>]\t\tcreate snapshot & link, points to\n"
588 				"\t\t\t\t\tbase of PFS mount\n"
589     "hammer snaplo <path> [<note>]\t\tcreate snapshot & link, points to\n"
590 				"\t\t\t\t\ttarget dir\n"
591     "hammer snapq <dir> [<note>]\t\tcreate snapshot, output path to stdout\n"
592     "hammer snaprm <path> ...\t\tdelete snapshots; filesystem is CWD\n"
593     "hammer snaprm <transid> ...\t\tdelete snapshots\n"
594     "hammer snaprm <filesystem> <transid> ...\tdelete snapshots\n"
595     "hammer snapls [<path> ...]\t\tlist available snapshots\n"
596     "\n"
597     "NOTE: Snapshots are created in filesystem meta-data, any directory\n"
598     "      in a HAMMER filesystem or PFS may be specified.  If the path\n"
599     "      specified does not exist this function will also create a\n"
600     "      softlink.\n"
601     "\n"
602     "      When deleting snapshots transaction ids may be directly specified\n"
603     "      or file paths to snapshot softlinks may be specified.  If a\n"
604     "      softlink is specified the softlink will also be deleted.\n"
605     "\n"
606     "NOTE: The old 'hammer snapshot [<filesystem>] <snapshot-dir>' form\n"
607     "      is still accepted but is a deprecated form.  This form will\n"
608     "      work for older hammer versions.  The new forms only work for\n"
609     "      HAMMER version 3 or later filesystems.  HAMMER can be upgraded\n"
610     "      to version 3 in-place.\n"
611 	);
612 	exit(exit_code);
613 }
614 
615 static
616 char *
617 dirpart(const char *path)
618 {
619 	const char *ptr;
620 	char *res;
621 
622 	ptr = strrchr(path, '/');
623 	if (ptr) {
624 		while (ptr > path && ptr[-1] == '/')
625 			--ptr;
626 		if (ptr == path)
627 			ptr = NULL;
628 	}
629 	if (ptr == NULL) {
630 		path = ".";
631 		ptr = path + 1;
632 	}
633 	res = malloc(ptr - path + 1);
634 	bcopy(path, res, ptr - path);
635 	res[ptr - path] = 0;
636 	return(res);
637 }
638