summaryrefslogtreecommitdiff
path: root/hlink.c
blob: 5f0f5a6fbc017ebc17c7343dd1a087f4b60fbc8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
/*
 * Routines to support hard-linking.
 *
 * Copyright (C) 1996 Andrew Tridgell
 * Copyright (C) 1996 Paul Mackerras
 * Copyright (C) 2002 Martin Pool <mbp@samba.org>
 * Copyright (C) 2004-2008 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, visit the http://fsf.org website.
 */

#include "rsync.h"
#include "inums.h"

extern int dry_run;
extern int list_only;
extern int am_sender;
extern int inc_recurse;
extern int do_xfers;
extern int link_dest;
extern int preserve_acls;
extern int make_backups;
extern int protocol_version;
extern int remove_source_files;
extern int stdout_format_has_i;
extern int maybe_ATTRS_REPORT;
extern int unsort_ndx;
extern char *basis_dir[MAX_BASIS_DIRS+1];
extern struct file_list *cur_flist;

#ifdef SUPPORT_HARD_LINKS

/* Starting with protocol 30, we use a simple hashtable on the sending side
 * for hashing the st_dev and st_ino info.  The receiving side gets told
 * (via flags and a "group index") which items are hard-linked together, so
 * we can avoid the pool of dev+inode data.  For incremental recursion mode,
 * the receiver will use a ndx hash to remember old pathnames. */

static struct hashtable *dev_tbl;

static struct hashtable *prior_hlinks;

static struct file_list *hlink_flist;

void init_hard_links(void)
{
	if (am_sender || protocol_version < 30)
		dev_tbl = hashtable_create(16, SIZEOF_INT64 == 8);
	else if (inc_recurse)
		prior_hlinks = hashtable_create(1024, 0);
}

struct ht_int64_node *idev_find(int64 dev, int64 ino)
{
	static struct ht_int64_node *dev_node = NULL;
	struct hashtable *tbl;

	if (!dev_node || dev_node->key != dev) {
		/* We keep a separate hash table of inodes for every device. */
		dev_node = hashtable_find(dev_tbl, dev, 1);
		if (!(tbl = dev_node->data)) {
			tbl = dev_node->data = hashtable_create(512, SIZEOF_INT64 == 8);
			if (DEBUG_GTE(HLINK, 3)) {
				rprintf(FINFO,
				    "[%s] created hashtable for dev %s\n",
				    who_am_i(), big_num(dev));
			}
		}
	} else
		tbl = dev_node->data;

	return hashtable_find(tbl, ino, 1);
}

void idev_destroy(void)
{
	int i;

	for (i = 0; i < dev_tbl->size; i++) {
		struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
		if (node->data)
			hashtable_destroy(node->data);
	}

	hashtable_destroy(dev_tbl);
}

static int hlink_compare_gnum(int *int1, int *int2)
{
	struct file_struct *f1 = hlink_flist->sorted[*int1];
	struct file_struct *f2 = hlink_flist->sorted[*int2];
	int32 gnum1 = F_HL_GNUM(f1);
	int32 gnum2 = F_HL_GNUM(f2);

	if (gnum1 != gnum2)
		return gnum1 > gnum2 ? 1 : -1;

	return *int1 > *int2 ? 1 : -1;
}

static void match_gnums(int32 *ndx_list, int ndx_count)
{
	int32 from, prev;
	struct file_struct *file, *file_next;
	struct ht_int32_node *node = NULL;
	int32 gnum, gnum_next;

	qsort(ndx_list, ndx_count, sizeof ndx_list[0],
	     (int (*)()) hlink_compare_gnum);

	for (from = 0; from < ndx_count; from++) {
		file = hlink_flist->sorted[ndx_list[from]];
		gnum = F_HL_GNUM(file);
		if (inc_recurse) {
			node = hashtable_find(prior_hlinks, gnum, 1);
			if (!node->data) {
				if (!(node->data = new_array0(char, 5)))
					out_of_memory("match_gnums");
				assert(gnum >= hlink_flist->ndx_start);
				file->flags |= FLAG_HLINK_FIRST;
				prev = -1;
			} else if (CVAL(node->data, 0) == 0) {
				struct file_list *flist;
				prev = IVAL(node->data, 1);
				flist = flist_for_ndx(prev, NULL);
				if (flist)
					flist->files[prev - flist->ndx_start]->flags &= ~FLAG_HLINK_LAST;
				else {
					/* We skipped all prior files in this
					 * group, so mark this as a "first". */
					file->flags |= FLAG_HLINK_FIRST;
					prev = -1;
				}
			} else
				prev = -1;
		} else {
			file->flags |= FLAG_HLINK_FIRST;
			prev = -1;
		}
		for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
			file_next = hlink_flist->sorted[ndx_list[from+1]];
			gnum_next = F_HL_GNUM(file_next);
			if (gnum != gnum_next)
				break;
			F_HL_PREV(file) = prev;
			/* The linked list uses over-the-wire ndx values. */
			if (unsort_ndx)
				prev = F_NDX(file);
			else
				prev = ndx_list[from] + hlink_flist->ndx_start;
		}
		if (prev < 0 && !inc_recurse) {
			/* Disable hard-link bit and set DONE so that
			 * HLINK_BUMP()-dependent values are unaffected. */
			file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
			file->flags |= FLAG_HLINK_DONE;
			continue;
		}

		file->flags |= FLAG_HLINK_LAST;
		F_HL_PREV(file) = prev;
		if (inc_recurse && CVAL(node->data, 0) == 0) {
			if (unsort_ndx)
				prev = F_NDX(file);
			else
				prev = ndx_list[from] + hlink_flist->ndx_start;
			SIVAL(node->data, 1, prev);
		}
	}
}

/* Analyze the hard-links in the file-list by creating a list of all the
 * items that have hlink data, sorting them, and matching up identical
 * values into clusters.  These will be a single linked list from last
 * to first when we're done. */
void match_hard_links(struct file_list *flist)
{
	if (!list_only && flist->used) {
		int i, ndx_count = 0;
		int32 *ndx_list;

		if (!(ndx_list = new_array(int32, flist->used)))
			out_of_memory("match_hard_links");

		for (i = 0; i < flist->used; i++) {
			if (F_IS_HLINKED(flist->sorted[i]))
				ndx_list[ndx_count++] = i;
		}

		hlink_flist = flist;

		if (ndx_count)
			match_gnums(ndx_list, ndx_count);

		free(ndx_list);
	}
	if (protocol_version < 30)
		idev_destroy();
}

static int maybe_hard_link(struct file_struct *file, int ndx,
			   const char *fname, int statret, stat_x *sxp,
			   const char *oldname, STRUCT_STAT *old_stp,
			   const char *realname, int itemizing, enum logcode code)
{
	if (statret == 0) {
		if (sxp->st.st_dev == old_stp->st_dev
		 && sxp->st.st_ino == old_stp->st_ino) {
			if (itemizing) {
				itemize(fname, file, ndx, statret, sxp,
					ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
					0, "");
			}
			if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
				rprintf(FCLIENT, "%s is uptodate\n", fname);
			file->flags |= FLAG_HLINK_DONE;
			return 0;
		}
		if (make_backups > 0) {
			if (!make_backup(fname))
				return -1;
		} else if (robust_unlink(fname)) {
			rsyserr(FERROR_XFER, errno, "unlink %s failed",
				full_fname(fname));
			return -1;
		}
	}

	if (hard_link_one(file, fname, oldname, 0)) {
		if (itemizing) {
			itemize(fname, file, ndx, statret, sxp,
				ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
				realname);
		}
		if (code != FNONE && INFO_GTE(NAME, 1))
			rprintf(code, "%s => %s\n", fname, realname);
		return 0;
	}
	return -1;
}

/* Figure out if a prior entry is still there or if we just have a
 * cached name for it. */
static char *check_prior(struct file_struct *file, int gnum,
			 int *prev_ndx_p, struct file_list **flist_p)
{
	struct file_struct *fp;
	struct ht_int32_node *node;
	int prev_ndx = F_HL_PREV(file);

	while (1) {
		struct file_list *flist;
		if (prev_ndx < 0
		 || (flist = flist_for_ndx(prev_ndx, NULL)) == NULL)
			break;
		fp = flist->files[prev_ndx - flist->ndx_start];
		if (!(fp->flags & FLAG_SKIP_HLINK)) {
			*prev_ndx_p = prev_ndx;
			*flist_p = flist;
			return NULL;
		}
		F_HL_PREV(file) = prev_ndx = F_HL_PREV(fp);
	}

	if (inc_recurse
	 && (node = hashtable_find(prior_hlinks, gnum, 0)) != NULL) {
		assert(node->data != NULL);
		if (CVAL(node->data, 0) != 0) {
			*prev_ndx_p = -1;
			*flist_p = NULL;
			return node->data;
		}
		/* The prior file must have been skipped. */
		F_HL_PREV(file) = -1;
	}

	*prev_ndx_p = -1;
	*flist_p = NULL;
	return NULL;
}

/* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not.  Returns:
 * 0 = process the file, 1 = skip the file, -1 = error occurred. */
int hard_link_check(struct file_struct *file, int ndx, const char *fname,
		    int statret, stat_x *sxp, int itemizing,
		    enum logcode code)
{
	STRUCT_STAT prev_st;
	char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
	char *realname, *prev_name;
	struct file_list *flist;
	int gnum = inc_recurse ? F_HL_GNUM(file) : -1;
	int prev_ndx;

	prev_name = realname = check_prior(file, gnum, &prev_ndx, &flist);

	if (!prev_name) {
		struct file_struct *prev_file;

		if (!flist) {
			/* The previous file was skipped, so this one is
			 * treated as if it were the first in its group. */
			if (DEBUG_GTE(HLINK, 2)) {
				rprintf(FINFO, "hlink for %d (%s,%d): virtual first\n",
					ndx, f_name(file, NULL), gnum);
			}
			return 0;
		}

		prev_file = flist->files[prev_ndx - flist->ndx_start];

		/* Is the previous link not complete yet? */
		if (!(prev_file->flags & FLAG_HLINK_DONE)) {
			/* Is the previous link being transferred? */
			if (prev_file->flags & FLAG_FILE_SENT) {
				/* Add ourselves to the list of files that will
				 * be updated when the transfer completes, and
				 * mark ourself as waiting for the transfer. */
				F_HL_PREV(file) = F_HL_PREV(prev_file);
				F_HL_PREV(prev_file) = ndx;
				file->flags |= FLAG_FILE_SENT;
				cur_flist->in_progress++;
				if (DEBUG_GTE(HLINK, 2)) {
					rprintf(FINFO, "hlink for %d (%s,%d): waiting for %d\n",
						ndx, f_name(file, NULL), gnum, F_HL_PREV(file));
				}
				return 1;
			}
			if (DEBUG_GTE(HLINK, 2)) {
				rprintf(FINFO, "hlink for %d (%s,%d): looking for a leader\n",
					ndx, f_name(file, NULL), gnum);
			}
			return 0;
		}

		/* There is a finished file to link with! */
		if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
			/* The previous previous is FIRST when prev is not. */
			prev_name = realname = check_prior(prev_file, gnum, &prev_ndx, &flist);
			/* Update our previous pointer to point to the FIRST. */
			F_HL_PREV(file) = prev_ndx;
		}

		if (!prev_name) {
			int alt_dest;

			assert(flist != NULL);
			prev_file = flist->files[prev_ndx - flist->ndx_start];
			/* F_HL_PREV() is alt_dest value when DONE && FIRST. */
			alt_dest = F_HL_PREV(prev_file);
			if (DEBUG_GTE(HLINK, 2)) {
				rprintf(FINFO, "hlink for %d (%s,%d): found flist match (alt %d)\n",
					ndx, f_name(file, NULL), gnum, alt_dest);
			}

			if (alt_dest >= 0 && dry_run) {
				pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
					 f_name(prev_file, NULL));
				prev_name = namebuf;
				realname = f_name(prev_file, altbuf);
			} else {
				prev_name = f_name(prev_file, namebuf);
				realname = prev_name;
			}
		}
	}

	if (DEBUG_GTE(HLINK, 2)) {
		rprintf(FINFO, "hlink for %d (%s,%d): leader is %d (%s)\n",
			ndx, f_name(file, NULL), gnum, prev_ndx, prev_name);
	}

	if (link_stat(prev_name, &prev_st, 0) < 0) {
		rsyserr(FERROR_XFER, errno, "stat %s failed",
			full_fname(prev_name));
		return -1;
	}

	if (statret < 0 && basis_dir[0] != NULL) {
		/* If we match an alt-dest item, we don't output this as a change. */
		char cmpbuf[MAXPATHLEN];
		stat_x alt_sx;
		int j = 0;
#ifdef SUPPORT_ACLS
		alt_sx.acc_acl = alt_sx.def_acl = NULL;
#endif
		do {
			pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
			if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
				continue;
			if (link_dest) {
				if (prev_st.st_dev != alt_sx.st.st_dev
				 || prev_st.st_ino != alt_sx.st.st_ino)
					continue;
				statret = 1;
				if (stdout_format_has_i == 0
				 || (!INFO_GTE(NAME, 2) && stdout_format_has_i < 2)) {
					itemizing = 0;
					code = FNONE;
					if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
						rprintf(FCLIENT, "%s is uptodate\n", fname);
				}
				break;
			}
			if (!unchanged_file(cmpbuf, file, &alt_sx.st))
				continue;
			statret = 1;
			if (unchanged_attrs(cmpbuf, file, &alt_sx))
				break;
		} while (basis_dir[++j] != NULL);
		if (statret == 1) {
			sxp->st = alt_sx.st;
#ifdef SUPPORT_ACLS
			if (preserve_acls && !S_ISLNK(file->mode)) {
				if (!ACL_READY(*sxp))
					get_acl(cmpbuf, sxp);
				else {
					sxp->acc_acl = alt_sx.acc_acl;
					sxp->def_acl = alt_sx.def_acl;
				}
			}
#endif
		}
#ifdef SUPPORT_ACLS
		else if (preserve_acls)
			free_acl(&alt_sx);
#endif
	}

	if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
			    realname, itemizing, code) < 0)
		return -1;

	if (remove_source_files == 1 && do_xfers)
		send_msg_int(MSG_SUCCESS, ndx);

	return 1;
}

int hard_link_one(struct file_struct *file, const char *fname,
		  const char *oldname, int terse)
{
	if (do_link(oldname, fname) < 0) {
		enum logcode code;
		if (terse) {
			if (!INFO_GTE(NAME, 1))
				return 0;
			code = FINFO;
		} else
			code = FERROR_XFER;
		rsyserr(code, errno, "link %s => %s failed",
			full_fname(fname), oldname);
		return 0;
	}

	file->flags |= FLAG_HLINK_DONE;

	return 1;
}

void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
		      STRUCT_STAT *stp, int itemizing, enum logcode code,
		      int alt_dest)
{
	stat_x prev_sx;
	STRUCT_STAT st;
	char prev_name[MAXPATHLEN], alt_name[MAXPATHLEN];
	const char *our_name;
	struct file_list *flist;
	int prev_statret, ndx, prev_ndx = F_HL_PREV(file);

	if (stp == NULL && prev_ndx >= 0) {
		if (link_stat(fname, &st, 0) < 0) {
			rsyserr(FERROR_XFER, errno, "stat %s failed",
				full_fname(fname));
			return;
		}
		stp = &st;
	}

	/* FIRST combined with DONE means we were the first to get done. */
	file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
	F_HL_PREV(file) = alt_dest;
	if (alt_dest >= 0 && dry_run) {
		pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
			 f_name(file, NULL));
		our_name = alt_name;
	} else
		our_name = fname;

#ifdef SUPPORT_ACLS
	prev_sx.acc_acl = prev_sx.def_acl = NULL;
#endif

	while ((ndx = prev_ndx) >= 0) {
		int val;
		flist = flist_for_ndx(ndx, "finish_hard_link");
		file = flist->files[ndx - flist->ndx_start];
		file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
		prev_ndx = F_HL_PREV(file);
		F_HL_PREV(file) = fin_ndx;
		prev_statret = link_stat(f_name(file, prev_name), &prev_sx.st, 0);
		val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
				      our_name, stp, fname, itemizing, code);
		flist->in_progress--;
#ifdef SUPPORT_ACLS
		if (preserve_acls)
			free_acl(&prev_sx);
#endif
		if (val < 0)
			continue;
		if (remove_source_files == 1 && do_xfers)
			send_msg_int(MSG_SUCCESS, ndx);
	}

	if (inc_recurse) {
		int gnum = F_HL_GNUM(file);
		struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
		assert(node != NULL && node->data != NULL);
		assert(CVAL(node->data, 0) == 0);
		free(node->data);
		if (!(node->data = strdup(our_name)))
			out_of_memory("finish_hard_link");
	}
}

int skip_hard_link(struct file_struct *file, struct file_list **flist_p)
{
	struct file_list *flist;
	int prev_ndx;

	file->flags |= FLAG_SKIP_HLINK;
	if (!(file->flags & FLAG_HLINK_LAST))
		return -1;

	check_prior(file, F_HL_GNUM(file), &prev_ndx, &flist);
	if (prev_ndx >= 0) {
		file = flist->files[prev_ndx - flist->ndx_start];
		if (file->flags & (FLAG_HLINK_DONE|FLAG_FILE_SENT))
			return -1;
		file->flags |= FLAG_HLINK_LAST;
		*flist_p = flist;
	}

	return prev_ndx;
}
#endif