]> Dogcows Code - chaz/tar/blob - src/incremen.c
(purge_directory): Skip the member and return if the archive is not in incremental...
[chaz/tar] / src / incremen.c
1 /* GNU dump extensions to tar.
2
3 Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,
4 2003, 2004, 2005 Free Software Foundation, Inc.
5
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any later
9 version.
10
11 This program 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 General
14 Public License for more details.
15
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20 #include <system.h>
21 #include <getline.h>
22 #include <hash.h>
23 #include <quotearg.h>
24 #include "common.h"
25
26 /* Incremental dump specialities. */
27
28 /* Which child files to save under a directory. */
29 enum children {NO_CHILDREN, CHANGED_CHILDREN, ALL_CHILDREN};
30
31 /* Directory attributes. */
32 struct directory
33 {
34 struct timespec mtime; /* Modification time */
35 dev_t device_number; /* device number for directory */
36 ino_t inode_number; /* inode number for directory */
37 enum children children;
38 bool nfs;
39 bool found;
40 char name[1]; /* file name of directory */
41 };
42
43 static Hash_table *directory_table;
44
45 #if HAVE_ST_FSTYPE_STRING
46 static char const nfs_string[] = "nfs";
47 # define NFS_FILE_STAT(st) (strcmp ((st).st_fstype, nfs_string) == 0)
48 #else
49 # define ST_DEV_MSB(st) (~ (dev_t) 0 << (sizeof (st).st_dev * CHAR_BIT - 1))
50 # define NFS_FILE_STAT(st) (((st).st_dev & ST_DEV_MSB (st)) != 0)
51 #endif
52
53 /* Calculate the hash of a directory. */
54 static size_t
55 hash_directory (void const *entry, size_t n_buckets)
56 {
57 struct directory const *directory = entry;
58 return hash_string (directory->name, n_buckets);
59 }
60
61 /* Compare two directories for equality. */
62 static bool
63 compare_directories (void const *entry1, void const *entry2)
64 {
65 struct directory const *directory1 = entry1;
66 struct directory const *directory2 = entry2;
67 return strcmp (directory1->name, directory2->name) == 0;
68 }
69
70 /* Create and link a new directory entry for directory NAME, having a
71 device number DEV and an inode number INO, with NFS indicating
72 whether it is an NFS device and FOUND indicating whether we have
73 found that the directory exists. */
74 static struct directory *
75 note_directory (char const *name, struct timespec mtime,
76 dev_t dev, ino_t ino, bool nfs, bool found)
77 {
78 size_t size = offsetof (struct directory, name) + strlen (name) + 1;
79 struct directory *directory = xmalloc (size);
80
81 directory->mtime = mtime;
82 directory->device_number = dev;
83 directory->inode_number = ino;
84 directory->children = CHANGED_CHILDREN;
85 directory->nfs = nfs;
86 directory->found = found;
87 strcpy (directory->name, name);
88
89 if (! ((directory_table
90 || (directory_table = hash_initialize (0, 0, hash_directory,
91 compare_directories, 0)))
92 && hash_insert (directory_table, directory)))
93 xalloc_die ();
94
95 return directory;
96 }
97
98 /* Return a directory entry for a given file NAME, or zero if none found. */
99 static struct directory *
100 find_directory (char *name)
101 {
102 if (! directory_table)
103 return 0;
104 else
105 {
106 size_t size = offsetof (struct directory, name) + strlen (name) + 1;
107 struct directory *dir = alloca (size);
108 strcpy (dir->name, name);
109 return hash_lookup (directory_table, dir);
110 }
111 }
112
113 void
114 update_parent_directory (const char *name)
115 {
116 struct directory *directory;
117 char *p, *name_buffer;
118
119 p = dir_name (name);
120 name_buffer = xmalloc (strlen (p) + 2);
121 strcpy (name_buffer, p);
122 if (! ISSLASH (p[strlen (p) - 1]))
123 strcat (name_buffer, "/");
124
125 directory = find_directory (name_buffer);
126 free (name_buffer);
127 if (directory)
128 {
129 struct stat st;
130 if (deref_stat (dereference_option, p, &st) != 0)
131 stat_diag (name);
132 else
133 directory->mtime = get_stat_mtime (&st);
134 }
135 free (p);
136 }
137
138 static int
139 compare_dirents (const void *first, const void *second)
140 {
141 return strcmp ((*(char *const *) first) + 1,
142 (*(char *const *) second) + 1);
143 }
144
145 enum children
146 procdir (char *name_buffer, struct stat *stat_data,
147 dev_t device,
148 enum children children,
149 bool verbose)
150 {
151 struct directory *directory;
152 bool nfs = NFS_FILE_STAT (*stat_data);
153
154 if ((directory = find_directory (name_buffer)) != NULL)
155 {
156 /* With NFS, the same file can have two different devices
157 if an NFS directory is mounted in multiple locations,
158 which is relatively common when automounting.
159 To avoid spurious incremental redumping of
160 directories, consider all NFS devices as equal,
161 relying on the i-node to establish differences. */
162
163 if (! (((directory->nfs & nfs)
164 || directory->device_number == stat_data->st_dev)
165 && directory->inode_number == stat_data->st_ino))
166 {
167 if (verbose)
168 WARN ((0, 0, _("%s: Directory has been renamed"),
169 quotearg_colon (name_buffer)));
170 directory->children = ALL_CHILDREN;
171 directory->nfs = nfs;
172 directory->device_number = stat_data->st_dev;
173 directory->inode_number = stat_data->st_ino;
174 }
175 else if (listed_incremental_option)
176 /* Newer modification time can mean that new files were
177 created in the directory or some of the existing files
178 were renamed. */
179 directory->children =
180 timespec_cmp (get_stat_mtime (stat_data), directory->mtime) > 0
181 ? ALL_CHILDREN : CHANGED_CHILDREN;
182
183 directory->found = true;
184 }
185 else
186 {
187 if (verbose)
188 WARN ((0, 0, _("%s: Directory is new"),
189 quotearg_colon (name_buffer)));
190 directory = note_directory (name_buffer,
191 get_stat_mtime(stat_data),
192 stat_data->st_dev,
193 stat_data->st_ino,
194 nfs,
195 true);
196
197 directory->children =
198 (listed_incremental_option
199 || (OLDER_STAT_TIME (*stat_data, m)
200 || (after_date_option
201 && OLDER_STAT_TIME (*stat_data, c))))
202 ? ALL_CHILDREN
203 : CHANGED_CHILDREN;
204 }
205
206 if (one_file_system_option && device != stat_data->st_dev)
207 directory->children = NO_CHILDREN;
208 else if (children == ALL_CHILDREN)
209 directory->children = ALL_CHILDREN;
210
211 return directory->children;
212 }
213
214
215 /* Recursively scan the given directory. */
216 static void
217 scan_directory (struct obstack *stk, char *dir_name, dev_t device)
218 {
219 char *dirp = savedir (dir_name); /* for scanning directory */
220 char const *entry; /* directory entry being scanned */
221 size_t entrylen; /* length of directory entry */
222 char *name_buffer; /* directory, `/', and directory member */
223 size_t name_buffer_size; /* allocated size of name_buffer, minus 2 */
224 size_t name_length; /* used length in name_buffer */
225 enum children children;
226 struct stat stat_data;
227
228 if (! dirp)
229 savedir_error (dir_name);
230
231 name_buffer_size = strlen (dir_name) + NAME_FIELD_SIZE;
232 name_buffer = xmalloc (name_buffer_size + 2);
233 strcpy (name_buffer, dir_name);
234 if (! ISSLASH (dir_name[strlen (dir_name) - 1]))
235 strcat (name_buffer, "/");
236 name_length = strlen (name_buffer);
237
238 if (deref_stat (dereference_option, name_buffer, &stat_data))
239 {
240 stat_diag (name_buffer);
241 children = CHANGED_CHILDREN;
242 }
243 else
244 children = procdir (name_buffer, &stat_data, device, NO_CHILDREN, false);
245
246 if (dirp && children != NO_CHILDREN)
247 for (entry = dirp;
248 (entrylen = strlen (entry)) != 0;
249 entry += entrylen + 1)
250 {
251 if (name_buffer_size <= entrylen + name_length)
252 {
253 do
254 name_buffer_size += NAME_FIELD_SIZE;
255 while (name_buffer_size <= entrylen + name_length);
256 name_buffer = xrealloc (name_buffer, name_buffer_size + 2);
257 }
258 strcpy (name_buffer + name_length, entry);
259
260 if (excluded_name (name_buffer))
261 obstack_1grow (stk, 'N');
262 else
263 {
264
265 if (deref_stat (dereference_option, name_buffer, &stat_data))
266 {
267 stat_diag (name_buffer);
268 continue;
269 }
270
271 if (S_ISDIR (stat_data.st_mode))
272 {
273 procdir (name_buffer, &stat_data, device, children,
274 verbose_option);
275 obstack_1grow (stk, 'D');
276 }
277
278 else if (one_file_system_option && device != stat_data.st_dev)
279 obstack_1grow (stk, 'N');
280
281 #ifdef S_ISHIDDEN
282 else if (S_ISHIDDEN (stat_data.st_mode))
283 {
284 obstack_1grow (stk, 'D');
285 obstack_grow (stk, entry, entrylen);
286 obstack_grow (stk, "A", 2);
287 continue;
288 }
289 #endif
290
291 else
292 if (children == CHANGED_CHILDREN
293 && OLDER_STAT_TIME (stat_data, m)
294 && (!after_date_option || OLDER_STAT_TIME (stat_data, c)))
295 obstack_1grow (stk, 'N');
296 else
297 obstack_1grow (stk, 'Y');
298 }
299
300 obstack_grow (stk, entry, entrylen + 1);
301 }
302
303 obstack_grow (stk, "\000\000", 2);
304
305 free (name_buffer);
306 if (dirp)
307 free (dirp);
308 }
309
310 /* Sort the contents of the obstack, and convert it to the char * */
311 static char *
312 sort_obstack (struct obstack *stk)
313 {
314 char *pointer = obstack_finish (stk);
315 size_t counter;
316 char *cursor;
317 char *buffer;
318 char **array;
319 char **array_cursor;
320
321 counter = 0;
322 for (cursor = pointer; *cursor; cursor += strlen (cursor) + 1)
323 counter++;
324
325 if (!counter)
326 return NULL;
327
328 array = obstack_alloc (stk, sizeof (char *) * (counter + 1));
329
330 array_cursor = array;
331 for (cursor = pointer; *cursor; cursor += strlen (cursor) + 1)
332 *array_cursor++ = cursor;
333 *array_cursor = 0;
334
335 qsort (array, counter, sizeof (char *), compare_dirents);
336
337 buffer = xmalloc (cursor - pointer + 2);
338
339 cursor = buffer;
340 for (array_cursor = array; *array_cursor; array_cursor++)
341 {
342 char *string = *array_cursor;
343
344 while ((*cursor++ = *string++))
345 continue;
346 }
347 *cursor = '\0';
348 return buffer;
349 }
350
351 char *
352 get_directory_contents (char *dir_name, dev_t device)
353 {
354 struct obstack stk;
355 char *buffer;
356
357 obstack_init (&stk);
358 scan_directory (&stk, dir_name, device);
359 buffer = sort_obstack (&stk);
360 obstack_free (&stk, NULL);
361 return buffer;
362 }
363
364 size_t
365 dumpdir_size (const char *p)
366 {
367 size_t totsize = 0;
368
369 while (*p)
370 {
371 size_t size = strlen (p) + 1;
372 totsize += size;
373 p += size;
374 }
375 return totsize + 1;
376 }
377
378 \f
379
380 static FILE *listed_incremental_stream;
381
382 /* Version of incremental format snapshots (directory files) used by this
383 tar. Currently it is supposed to be a single decimal number. 0 means
384 incremental snapshots as per tar version before 1.15.2.
385
386 The current tar version supports incremental versions from
387 0 up to TAR_INCREMENTAL_VERSION, inclusive.
388 It is able to create only snapshots of TAR_INCREMENTAL_VERSION */
389
390 #define TAR_INCREMENTAL_VERSION 1
391
392 /* Read incremental snapshot file (directory file).
393 If the file has older incremental version, make sure that it is processed
394 correctly and that tar will use the most conservative backup method among
395 possible alternatives (i.e. prefer ALL_CHILDREN over CHANGED_CHILDREN,
396 etc.) This ensures that the snapshots are updated to the recent version
397 without any loss of data. */
398 void
399 read_directory_file (void)
400 {
401 int fd;
402 FILE *fp;
403 char *buf = 0;
404 size_t bufsize;
405
406 /* Open the file for both read and write. That way, we can write
407 it later without having to reopen it, and don't have to worry if
408 we chdir in the meantime. */
409 fd = open (listed_incremental_option, O_RDWR | O_CREAT, MODE_RW);
410 if (fd < 0)
411 {
412 open_error (listed_incremental_option);
413 return;
414 }
415
416 fp = fdopen (fd, "r+");
417 if (! fp)
418 {
419 open_error (listed_incremental_option);
420 close (fd);
421 return;
422 }
423
424 listed_incremental_stream = fp;
425
426 if (0 < getline (&buf, &bufsize, fp))
427 {
428 char *ebuf;
429 int n;
430 long lineno = 1;
431 uintmax_t u;
432 time_t t = u;
433 int incremental_version;
434
435 if (strncmp (buf, PACKAGE_NAME, sizeof PACKAGE_NAME - 1) == 0)
436 {
437 ebuf = buf + sizeof PACKAGE_NAME - 1;
438 if (*ebuf++ != '-')
439 ERROR((1, 0, _("Bad incremental file format")));
440 for (; *ebuf != '-'; ebuf++)
441 if (!*ebuf)
442 ERROR((1, 0, _("Bad incremental file format")));
443
444 incremental_version = (errno = 0, strtoumax (ebuf+1, &ebuf, 10));
445 if (getline (&buf, &bufsize, fp) <= 0)
446 {
447 read_error (listed_incremental_option);
448 free (buf);
449 return;
450 }
451 ++lineno;
452 }
453 else
454 incremental_version = 0;
455
456 if (incremental_version > TAR_INCREMENTAL_VERSION)
457 ERROR((1, 0, _("Unsupported incremental format version: %s"),
458 incremental_version));
459
460 t = u = (errno = 0, strtoumax (buf, &ebuf, 10));
461 if (buf == ebuf || (u == 0 && errno == EINVAL))
462 ERROR ((0, 0, "%s:%ld: %s",
463 quotearg_colon (listed_incremental_option),
464 lineno,
465 _("Invalid time stamp")));
466 else if (t != u)
467 ERROR ((0, 0, "%s:%ld: %s",
468 quotearg_colon (listed_incremental_option),
469 lineno,
470 _("Time stamp out of range")));
471 else if (incremental_version == 1)
472 {
473 newer_mtime_option.tv_sec = t;
474
475 t = u = (errno = 0, strtoumax (buf, &ebuf, 10));
476 if (buf == ebuf || (u == 0 && errno == EINVAL))
477 ERROR ((0, 0, "%s:%ld: %s",
478 quotearg_colon (listed_incremental_option),
479 lineno,
480 _("Invalid time stamp")));
481 else if (t != u)
482 ERROR ((0, 0, "%s:%ld: %s",
483 quotearg_colon (listed_incremental_option),
484 lineno,
485 _("Time stamp out of range")));
486 newer_mtime_option.tv_nsec = t;
487 }
488 else
489 {
490 /* pre-1 incremental format does not contain nanoseconds */
491 newer_mtime_option.tv_sec = t;
492 newer_mtime_option.tv_nsec = 0;
493 }
494
495 while (0 < (n = getline (&buf, &bufsize, fp)))
496 {
497 dev_t dev;
498 ino_t ino;
499 bool nfs = buf[0] == '+';
500 char *strp = buf + nfs;
501 struct timespec mtime;
502
503 lineno++;
504
505 if (buf[n - 1] == '\n')
506 buf[n - 1] = '\0';
507
508 if (incremental_version == 1)
509 {
510 errno = 0;
511 mtime.tv_sec = u = strtoumax (strp, &ebuf, 10);
512 if (!isspace (*ebuf))
513 ERROR ((0, 0, "%s:%ld: %s",
514 quotearg_colon (listed_incremental_option), lineno,
515 _("Invalid modification time (seconds)")));
516 else if (mtime.tv_sec != u)
517 ERROR ((0, 0, "%s:%ld: %s",
518 quotearg_colon (listed_incremental_option), lineno,
519 _("Modification time (seconds) out of range")));
520 strp = ebuf;
521
522 errno = 0;
523 mtime.tv_nsec = u = strtoumax (strp, &ebuf, 10);
524 if (!isspace (*ebuf))
525 ERROR ((0, 0, "%s:%ld: %s",
526 quotearg_colon (listed_incremental_option), lineno,
527 _("Invalid modification time (nanoseconds)")));
528 else if (mtime.tv_nsec != u)
529 ERROR ((0, 0, "%s:%ld: %s",
530 quotearg_colon (listed_incremental_option), lineno,
531 _("Modification time (nanoseconds) out of range")));
532 strp = ebuf;
533 }
534 else
535 memset (&mtime, 0, sizeof mtime);
536
537 errno = 0;
538 dev = u = strtoumax (strp, &ebuf, 10);
539 if (!isspace (*ebuf))
540 ERROR ((0, 0, "%s:%ld: %s",
541 quotearg_colon (listed_incremental_option), lineno,
542 _("Invalid device number")));
543 else if (dev != u)
544 ERROR ((0, 0, "%s:%ld: %s",
545 quotearg_colon (listed_incremental_option), lineno,
546 _("Device number out of range")));
547 strp = ebuf;
548
549 errno = 0;
550 ino = u = strtoumax (strp, &ebuf, 10);
551 if (!isspace (*ebuf))
552 ERROR ((0, 0, "%s:%ld: %s",
553 quotearg_colon (listed_incremental_option), lineno,
554 _("Invalid inode number")));
555 else if (ino != u)
556 ERROR ((0, 0, "%s:%ld: %s",
557 quotearg_colon (listed_incremental_option), lineno,
558 _("Inode number out of range")));
559 strp = ebuf;
560
561 strp++;
562 unquote_string (strp);
563 note_directory (strp, mtime, dev, ino, nfs, 0);
564 }
565 }
566
567 if (ferror (fp))
568 read_error (listed_incremental_option);
569 if (buf)
570 free (buf);
571 }
572
573 /* Output incremental data for the directory ENTRY to the file DATA.
574 Return nonzero if successful, preserving errno on write failure. */
575 static bool
576 write_directory_file_entry (void *entry, void *data)
577 {
578 struct directory const *directory = entry;
579 FILE *fp = data;
580
581 if (directory->found)
582 {
583 int e;
584 char buf[UINTMAX_STRSIZE_BOUND];
585 char *str = quote_copy_string (directory->name);
586
587 if (directory->nfs)
588 fprintf (fp, "+");
589 fprintf (fp, "%s ", umaxtostr (directory->mtime.tv_sec, buf));
590 fprintf (fp, "%s ", umaxtostr (directory->mtime.tv_nsec, buf));
591 fprintf (fp, "%s ", umaxtostr (directory->device_number, buf));
592 fprintf (fp, "%s ", umaxtostr (directory->inode_number, buf));
593 fprintf (fp, "%s\n", str ? str : directory->name);
594
595 e = errno;
596 if (str)
597 free (str);
598 errno = e;
599 }
600
601 return ! ferror (fp);
602 }
603
604 void
605 write_directory_file (void)
606 {
607 FILE *fp = listed_incremental_stream;
608
609 if (! fp)
610 return;
611
612 if (fseek (fp, 0L, SEEK_SET) != 0)
613 seek_error (listed_incremental_option);
614 if (sys_truncate (fileno (fp)) != 0)
615 truncate_error (listed_incremental_option);
616
617 fprintf (fp, "%s-%s-%d\n", PACKAGE_NAME, PACKAGE_VERSION,
618 TAR_INCREMENTAL_VERSION);
619
620 fprintf (fp, "%lu %lu\n",
621 (unsigned long int) start_time.tv_sec,
622 (unsigned long int) start_time.tv_nsec);
623 if (! ferror (fp) && directory_table)
624 hash_do_for_each (directory_table, write_directory_file_entry, fp);
625 if (ferror (fp))
626 write_error (listed_incremental_option);
627 if (fclose (fp) != 0)
628 close_error (listed_incremental_option);
629 }
630
631 \f
632 /* Restoration of incremental dumps. */
633
634 void
635 get_gnu_dumpdir ()
636 {
637 size_t size;
638 size_t copied;
639 union block *data_block;
640 char *to;
641 char *archive_dir;
642
643 size = current_stat_info.stat.st_size;
644 if (size != current_stat_info.stat.st_size)
645 xalloc_die ();
646
647 archive_dir = xmalloc (size);
648 to = archive_dir;
649
650 set_next_block_after (current_header);
651 mv_begin (&current_stat_info);
652
653 for (; size > 0; size -= copied)
654 {
655 mv_size_left (size);
656 data_block = find_next_block ();
657 if (!data_block)
658 ERROR ((1, 0, _("Unexpected EOF in archive")));
659 copied = available_space_after (data_block);
660 if (copied > size)
661 copied = size;
662 memcpy (to, data_block->buffer, copied);
663 to += copied;
664 set_next_block_after ((union block *)
665 (data_block->buffer + copied - 1));
666 }
667
668 mv_end ();
669
670 current_stat_info.stat.st_size = 0; /* For skip_member() and friends
671 to work correctly */
672 current_stat_info.dumpdir = archive_dir;
673 }
674
675
676 /* Examine the directories under directory_name and delete any
677 files that were not there at the time of the back-up. */
678 void
679 purge_directory (char const *directory_name)
680 {
681 char *current_dir;
682 char *cur, *arc;
683
684 if (!current_stat_info.dumpdir)
685 {
686 skip_member ();
687 return;
688 }
689
690 current_dir = savedir (directory_name);
691
692 if (!current_dir)
693 {
694 /* The directory doesn't exist now. It'll be created. In any
695 case, we don't have to delete any files out of it. */
696
697 skip_member ();
698 return;
699 }
700
701 for (cur = current_dir; *cur; cur += strlen (cur) + 1)
702 {
703 for (arc = current_stat_info.dumpdir; *arc; arc += strlen (arc) + 1)
704 {
705 arc++;
706 if (!strcmp (arc, cur))
707 break;
708 }
709 if (*arc == '\0')
710 {
711 struct stat st;
712 char *p = new_name (directory_name, cur);
713
714 if (deref_stat (false, p, &st))
715 {
716 stat_diag (p);
717 WARN((0, 0, _("%s: Not purging directory: unable to stat"),
718 quotearg_colon (p)));
719 continue;
720 }
721 else if (one_file_system_option && st.st_dev != root_device)
722 {
723 WARN((0, 0,
724 _("%s: directory is on a different device: not purging"),
725 quotearg_colon (p)));
726 continue;
727 }
728
729 if (! interactive_option || confirm ("delete", p))
730 {
731 if (verbose_option)
732 fprintf (stdlis, _("%s: Deleting %s\n"),
733 program_name, quote (p));
734 if (! remove_any_file (p, RECURSIVE_REMOVE_OPTION))
735 {
736 int e = errno;
737 ERROR ((0, e, _("%s: Cannot remove"), quotearg_colon (p)));
738 }
739 }
740 free (p);
741 }
742
743 }
744 free (current_dir);
745 }
746
747 void
748 list_dumpdir (char *buffer, size_t size)
749 {
750 while (size)
751 {
752 switch (*buffer)
753 {
754 case 'Y':
755 case 'N':
756 case 'D':
757 fprintf (stdlis, "%c ", *buffer);
758 buffer++;
759 size--;
760 break;
761
762 case 0:
763 fputc ('\n', stdlis);
764 buffer++;
765 size--;
766 break;
767
768 default:
769 fputc (*buffer, stdlis);
770 buffer++;
771 size--;
772 }
773 }
774 }
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