1: /*
2: * Routines to support hard-linking.
3: *
4: * Copyright (C) 1996 Andrew Tridgell
5: * Copyright (C) 1996 Paul Mackerras
6: * Copyright (C) 2002 Martin Pool <mbp@samba.org>
7: * Copyright (C) 2004-2020 Wayne Davison
8: *
9: * This program is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 3 of the License, or
12: * (at your option) any later version.
13: *
14: * This program 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
17: * GNU General Public License for more details.
18: *
19: * You should have received a copy of the GNU General Public License along
20: * with this program; if not, visit the http://fsf.org website.
21: */
22:
23: #include "rsync.h"
24: #include "inums.h"
25: #include "ifuncs.h"
26:
27: extern int dry_run;
28: extern int list_only;
29: extern int am_sender;
30: extern int inc_recurse;
31: extern int do_xfers;
32: extern int alt_dest_type;
33: extern int preserve_acls;
34: extern int preserve_xattrs;
35: extern int protocol_version;
36: extern int remove_source_files;
37: extern int stdout_format_has_i;
38: extern int maybe_ATTRS_REPORT;
39: extern int unsort_ndx;
40: extern char *basis_dir[MAX_BASIS_DIRS+1];
41: extern struct file_list *cur_flist;
42:
43: #ifdef SUPPORT_HARD_LINKS
44:
45: /* Starting with protocol 30, we use a simple hashtable on the sending side
46: * for hashing the st_dev and st_ino info. The receiving side gets told
47: * (via flags and a "group index") which items are hard-linked together, so
48: * we can avoid the pool of dev+inode data. For incremental recursion mode,
49: * the receiver will use a ndx hash to remember old pathnames. */
50:
51: static void *data_when_new = "";
52:
53: static struct hashtable *dev_tbl;
54:
55: static struct hashtable *prior_hlinks;
56:
57: static struct file_list *hlink_flist;
58:
59: void init_hard_links(void)
60: {
61: if (am_sender || protocol_version < 30)
62: dev_tbl = hashtable_create(16, HT_KEY64);
63: else if (inc_recurse)
64: prior_hlinks = hashtable_create(1024, HT_KEY32);
65: }
66:
67: struct ht_int64_node *idev_find(int64 dev, int64 ino)
68: {
69: static struct ht_int64_node *dev_node = NULL;
70:
71: /* Note that some OSes have a dev == 0, so increment to avoid storing a 0. */
72: if (!dev_node || dev_node->key != dev+1) {
73: /* We keep a separate hash table of inodes for every device. */
74: dev_node = hashtable_find(dev_tbl, dev+1, data_when_new);
75: if (dev_node->data == data_when_new) {
76: dev_node->data = hashtable_create(512, HT_KEY64);
77: if (DEBUG_GTE(HLINK, 3)) {
78: rprintf(FINFO, "[%s] created hashtable for dev %s\n",
79: who_am_i(), big_num(dev));
80: }
81: }
82: }
83:
84: return hashtable_find(dev_node->data, ino, (void*)-1L);
85: }
86:
87: void idev_destroy(void)
88: {
89: int i;
90:
91: for (i = 0; i < dev_tbl->size; i++) {
92: struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
93: if (node->data)
94: hashtable_destroy(node->data);
95: }
96:
97: hashtable_destroy(dev_tbl);
98: }
99:
100: static int hlink_compare_gnum(int *int1, int *int2)
101: {
102: struct file_struct *f1 = hlink_flist->sorted[*int1];
103: struct file_struct *f2 = hlink_flist->sorted[*int2];
104: int32 gnum1 = F_HL_GNUM(f1);
105: int32 gnum2 = F_HL_GNUM(f2);
106:
107: if (gnum1 != gnum2)
108: return gnum1 > gnum2 ? 1 : -1;
109:
110: return *int1 > *int2 ? 1 : -1;
111: }
112:
113: static void match_gnums(int32 *ndx_list, int ndx_count)
114: {
115: int32 from, prev;
116: struct file_struct *file, *file_next;
117: struct ht_int32_node *node = NULL;
118: int32 gnum, gnum_next;
119:
120: qsort(ndx_list, ndx_count, sizeof ndx_list[0], (int (*)()) hlink_compare_gnum);
121:
122: for (from = 0; from < ndx_count; from++) {
123: file = hlink_flist->sorted[ndx_list[from]];
124: gnum = F_HL_GNUM(file);
125: if (inc_recurse) {
126: node = hashtable_find(prior_hlinks, gnum, data_when_new);
127: if (node->data == data_when_new) {
128: node->data = new_array0(char, 5);
129: assert(gnum >= hlink_flist->ndx_start);
130: file->flags |= FLAG_HLINK_FIRST;
131: prev = -1;
132: } else if (CVAL(node->data, 0) == 0) {
133: struct file_list *flist;
134: prev = IVAL(node->data, 1);
135: flist = flist_for_ndx(prev, NULL);
136: if (flist)
137: flist->files[prev - flist->ndx_start]->flags &= ~FLAG_HLINK_LAST;
138: else {
139: /* We skipped all prior files in this
140: * group, so mark this as a "first". */
141: file->flags |= FLAG_HLINK_FIRST;
142: prev = -1;
143: }
144: } else
145: prev = -1;
146: } else {
147: file->flags |= FLAG_HLINK_FIRST;
148: prev = -1;
149: }
150: for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
151: file_next = hlink_flist->sorted[ndx_list[from+1]];
152: gnum_next = F_HL_GNUM(file_next);
153: if (gnum != gnum_next)
154: break;
155: F_HL_PREV(file) = prev;
156: /* The linked list uses over-the-wire ndx values. */
157: if (unsort_ndx)
158: prev = F_NDX(file);
159: else
160: prev = ndx_list[from] + hlink_flist->ndx_start;
161: }
162: if (prev < 0 && !inc_recurse) {
163: /* Disable hard-link bit and set DONE so that
164: * HLINK_BUMP()-dependent values are unaffected. */
165: file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
166: file->flags |= FLAG_HLINK_DONE;
167: continue;
168: }
169:
170: file->flags |= FLAG_HLINK_LAST;
171: F_HL_PREV(file) = prev;
172: if (inc_recurse && CVAL(node->data, 0) == 0) {
173: if (unsort_ndx)
174: prev = F_NDX(file);
175: else
176: prev = ndx_list[from] + hlink_flist->ndx_start;
177: SIVAL(node->data, 1, prev);
178: }
179: }
180: }
181:
182: /* Analyze the hard-links in the file-list by creating a list of all the
183: * items that have hlink data, sorting them, and matching up identical
184: * values into clusters. These will be a single linked list from last
185: * to first when we're done. */
186: void match_hard_links(struct file_list *flist)
187: {
188: if (!list_only && flist->used) {
189: int i, ndx_count = 0;
190: int32 *ndx_list;
191:
192: ndx_list = new_array(int32, flist->used);
193:
194: for (i = 0; i < flist->used; i++) {
195: if (F_IS_HLINKED(flist->sorted[i]))
196: ndx_list[ndx_count++] = i;
197: }
198:
199: hlink_flist = flist;
200:
201: if (ndx_count)
202: match_gnums(ndx_list, ndx_count);
203:
204: free(ndx_list);
205: }
206: if (protocol_version < 30)
207: idev_destroy();
208: }
209:
210: static int maybe_hard_link(struct file_struct *file, int ndx,
211: char *fname, int statret, stat_x *sxp,
212: const char *oldname, STRUCT_STAT *old_stp,
213: const char *realname, int itemizing, enum logcode code)
214: {
215: if (statret == 0) {
216: if (sxp->st.st_dev == old_stp->st_dev
217: && sxp->st.st_ino == old_stp->st_ino) {
218: if (itemizing) {
219: itemize(fname, file, ndx, statret, sxp,
220: ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
221: 0, "");
222: }
223: if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
224: rprintf(FCLIENT, "%s is uptodate\n", fname);
225: file->flags |= FLAG_HLINK_DONE;
226: return 0;
227: }
228: }
229:
230: if (atomic_create(file, fname, NULL, oldname, MAKEDEV(0, 0), sxp, statret == 0 ? DEL_FOR_FILE : 0)) {
231: if (itemizing) {
232: itemize(fname, file, ndx, statret, sxp,
233: ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
234: realname);
235: }
236: if (code != FNONE && INFO_GTE(NAME, 1))
237: rprintf(code, "%s => %s\n", fname, realname);
238: return 0;
239: }
240:
241: return -1;
242: }
243:
244: /* Figure out if a prior entry is still there or if we just have a
245: * cached name for it. */
246: static char *check_prior(struct file_struct *file, int gnum,
247: int *prev_ndx_p, struct file_list **flist_p)
248: {
249: struct file_struct *fp;
250: struct ht_int32_node *node;
251: int prev_ndx = F_HL_PREV(file);
252:
253: while (1) {
254: struct file_list *flist;
255: if (prev_ndx < 0
256: || (flist = flist_for_ndx(prev_ndx, NULL)) == NULL)
257: break;
258: fp = flist->files[prev_ndx - flist->ndx_start];
259: if (!(fp->flags & FLAG_SKIP_HLINK)) {
260: *prev_ndx_p = prev_ndx;
261: *flist_p = flist;
262: return NULL;
263: }
264: F_HL_PREV(file) = prev_ndx = F_HL_PREV(fp);
265: }
266:
267: if (inc_recurse
268: && (node = hashtable_find(prior_hlinks, gnum, NULL)) != NULL) {
269: assert(node->data != NULL);
270: if (CVAL(node->data, 0) != 0) {
271: *prev_ndx_p = -1;
272: *flist_p = NULL;
273: return node->data;
274: }
275: /* The prior file must have been skipped. */
276: F_HL_PREV(file) = -1;
277: }
278:
279: *prev_ndx_p = -1;
280: *flist_p = NULL;
281: return NULL;
282: }
283:
284: /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not. Returns:
285: * 0 = process the file, 1 = skip the file, -1 = error occurred. */
286: int hard_link_check(struct file_struct *file, int ndx, char *fname,
287: int statret, stat_x *sxp, int itemizing,
288: enum logcode code)
289: {
290: STRUCT_STAT prev_st;
291: char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
292: char *realname, *prev_name;
293: struct file_list *flist;
294: int gnum = inc_recurse ? F_HL_GNUM(file) : -1;
295: int prev_ndx;
296:
297: prev_name = realname = check_prior(file, gnum, &prev_ndx, &flist);
298:
299: if (!prev_name) {
300: struct file_struct *prev_file;
301:
302: if (!flist) {
303: /* The previous file was skipped, so this one is
304: * treated as if it were the first in its group. */
305: if (DEBUG_GTE(HLINK, 2)) {
306: rprintf(FINFO, "hlink for %d (%s,%d): virtual first\n",
307: ndx, f_name(file, NULL), gnum);
308: }
309: return 0;
310: }
311:
312: prev_file = flist->files[prev_ndx - flist->ndx_start];
313:
314: /* Is the previous link not complete yet? */
315: if (!(prev_file->flags & FLAG_HLINK_DONE)) {
316: /* Is the previous link being transferred? */
317: if (prev_file->flags & FLAG_FILE_SENT) {
318: /* Add ourselves to the list of files that will
319: * be updated when the transfer completes, and
320: * mark ourself as waiting for the transfer. */
321: F_HL_PREV(file) = F_HL_PREV(prev_file);
322: F_HL_PREV(prev_file) = ndx;
323: file->flags |= FLAG_FILE_SENT;
324: cur_flist->in_progress++;
325: if (DEBUG_GTE(HLINK, 2)) {
326: rprintf(FINFO, "hlink for %d (%s,%d): waiting for %d\n",
327: ndx, f_name(file, NULL), gnum, F_HL_PREV(file));
328: }
329: return 1;
330: }
331: if (DEBUG_GTE(HLINK, 2)) {
332: rprintf(FINFO, "hlink for %d (%s,%d): looking for a leader\n",
333: ndx, f_name(file, NULL), gnum);
334: }
335: return 0;
336: }
337:
338: /* There is a finished file to link with! */
339: if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
340: /* The previous previous is FIRST when prev is not. */
341: prev_name = realname = check_prior(prev_file, gnum, &prev_ndx, &flist);
342: /* Update our previous pointer to point to the FIRST. */
343: F_HL_PREV(file) = prev_ndx;
344: }
345:
346: if (!prev_name) {
347: int alt_dest;
348:
349: assert(flist != NULL);
350: prev_file = flist->files[prev_ndx - flist->ndx_start];
351: /* F_HL_PREV() is alt_dest value when DONE && FIRST. */
352: alt_dest = F_HL_PREV(prev_file);
353: if (DEBUG_GTE(HLINK, 2)) {
354: rprintf(FINFO, "hlink for %d (%s,%d): found flist match (alt %d)\n",
355: ndx, f_name(file, NULL), gnum, alt_dest);
356: }
357:
358: if (alt_dest >= 0 && dry_run) {
359: pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
360: f_name(prev_file, NULL));
361: prev_name = namebuf;
362: realname = f_name(prev_file, altbuf);
363: } else {
364: prev_name = f_name(prev_file, namebuf);
365: realname = prev_name;
366: }
367: }
368: }
369:
370: if (DEBUG_GTE(HLINK, 2)) {
371: rprintf(FINFO, "hlink for %d (%s,%d): leader is %d (%s)\n",
372: ndx, f_name(file, NULL), gnum, prev_ndx, prev_name);
373: }
374:
375: if (link_stat(prev_name, &prev_st, 0) < 0) {
376: if (!dry_run || errno != ENOENT) {
377: rsyserr(FERROR_XFER, errno, "stat %s failed", full_fname(prev_name));
378: return -1;
379: }
380: /* A new hard-link will get a new dev & inode, so approximate
381: * those values in dry-run mode by zeroing them. */
382: memset(&prev_st, 0, sizeof prev_st);
383: }
384:
385: if (statret < 0 && basis_dir[0] != NULL) {
386: /* If we match an alt-dest item, we don't output this as a change. */
387: char cmpbuf[MAXPATHLEN];
388: stat_x alt_sx;
389: int j = 0;
390: init_stat_x(&alt_sx);
391: do {
392: pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
393: if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
394: continue;
395: if (alt_dest_type == LINK_DEST) {
396: if (prev_st.st_dev != alt_sx.st.st_dev
397: || prev_st.st_ino != alt_sx.st.st_ino)
398: continue;
399: statret = 1;
400: if (stdout_format_has_i == 0
401: || (!INFO_GTE(NAME, 2) && stdout_format_has_i < 2)) {
402: itemizing = 0;
403: code = FNONE;
404: if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
405: rprintf(FCLIENT, "%s is uptodate\n", fname);
406: }
407: break;
408: }
409: if (!unchanged_file(cmpbuf, file, &alt_sx.st, j+1))
410: continue;
411: statret = 1;
412: if (unchanged_attrs(cmpbuf, file, &alt_sx))
413: break;
414: } while (basis_dir[++j] != NULL);
415: if (statret == 1) {
416: sxp->st = alt_sx.st;
417: #ifdef SUPPORT_ACLS
418: if (preserve_acls && !S_ISLNK(file->mode)) {
419: free_acl(sxp);
420: if (!ACL_READY(alt_sx))
421: get_acl(cmpbuf, sxp);
422: else {
423: sxp->acc_acl = alt_sx.acc_acl;
424: sxp->def_acl = alt_sx.def_acl;
425: alt_sx.acc_acl = alt_sx.def_acl = NULL;
426: }
427: }
428: #endif
429: #ifdef SUPPORT_XATTRS
430: if (preserve_xattrs) {
431: free_xattr(sxp);
432: if (!XATTR_READY(alt_sx))
433: get_xattr(cmpbuf, sxp);
434: else {
435: sxp->xattr = alt_sx.xattr;
436: alt_sx.xattr = NULL;
437: }
438: }
439: #endif
440: } else
441: free_stat_x(&alt_sx);
442: }
443:
444: if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
445: realname, itemizing, code) < 0)
446: return -1;
447:
448: if (remove_source_files == 1 && do_xfers)
449: send_msg_int(MSG_SUCCESS, ndx);
450:
451: return 1;
452: }
453:
454: int hard_link_one(struct file_struct *file, const char *fname,
455: const char *oldname, int terse)
456: {
457: if (do_link(oldname, fname) < 0) {
458: enum logcode code;
459: if (terse) {
460: if (!INFO_GTE(NAME, 1))
461: return 0;
462: code = FINFO;
463: } else
464: code = FERROR_XFER;
465: rsyserr(code, errno, "link %s => %s failed",
466: full_fname(fname), oldname);
467: return 0;
468: }
469:
470: file->flags |= FLAG_HLINK_DONE;
471:
472: return 1;
473: }
474:
475: void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
476: STRUCT_STAT *stp, int itemizing, enum logcode code,
477: int alt_dest)
478: {
479: stat_x prev_sx;
480: STRUCT_STAT st;
481: char prev_name[MAXPATHLEN], alt_name[MAXPATHLEN];
482: const char *our_name;
483: struct file_list *flist;
484: int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
485:
486: if (stp == NULL && prev_ndx >= 0) {
487: if (link_stat(fname, &st, 0) < 0 && !dry_run) {
488: rsyserr(FERROR_XFER, errno, "stat %s failed",
489: full_fname(fname));
490: return;
491: }
492: stp = &st;
493: }
494:
495: /* FIRST combined with DONE means we were the first to get done. */
496: file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
497: F_HL_PREV(file) = alt_dest;
498: if (alt_dest >= 0 && dry_run) {
499: pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
500: f_name(file, NULL));
501: our_name = alt_name;
502: } else
503: our_name = fname;
504:
505: init_stat_x(&prev_sx);
506:
507: while ((ndx = prev_ndx) >= 0) {
508: int val;
509: flist = flist_for_ndx(ndx, "finish_hard_link");
510: file = flist->files[ndx - flist->ndx_start];
511: file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
512: prev_ndx = F_HL_PREV(file);
513: F_HL_PREV(file) = fin_ndx;
514: prev_statret = link_stat(f_name(file, prev_name), &prev_sx.st, 0);
515: val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
516: our_name, stp, fname, itemizing, code);
517: flist->in_progress--;
518: free_stat_x(&prev_sx);
519: if (val < 0)
520: continue;
521: if (remove_source_files == 1 && do_xfers)
522: send_msg_int(MSG_SUCCESS, ndx);
523: }
524:
525: if (inc_recurse) {
526: int gnum = F_HL_GNUM(file);
527: struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, NULL);
528: if (node == NULL) {
529: rprintf(FERROR, "Unable to find a hlink node for %d (%s)\n", gnum, f_name(file, prev_name));
530: exit_cleanup(RERR_MESSAGEIO);
531: }
532: if (node->data == NULL) {
533: rprintf(FERROR, "Hlink node data for %d is NULL (%s)\n", gnum, f_name(file, prev_name));
534: exit_cleanup(RERR_MESSAGEIO);
535: }
536: if (CVAL(node->data, 0) != 0) {
537: rprintf(FERROR, "Hlink node data for %d already has path=%s (%s)\n",
538: gnum, (char*)node->data, f_name(file, prev_name));
539: exit_cleanup(RERR_MESSAGEIO);
540: }
541: free(node->data);
542: node->data = strdup(our_name);
543: }
544: }
545:
546: int skip_hard_link(struct file_struct *file, struct file_list **flist_p)
547: {
548: struct file_list *flist;
549: int prev_ndx;
550:
551: file->flags |= FLAG_SKIP_HLINK;
552: if (!(file->flags & FLAG_HLINK_LAST))
553: return -1;
554:
555: check_prior(file, F_HL_GNUM(file), &prev_ndx, &flist);
556: if (prev_ndx >= 0) {
557: file = flist->files[prev_ndx - flist->ndx_start];
558: if (file->flags & (FLAG_HLINK_DONE|FLAG_FILE_SENT))
559: return -1;
560: file->flags |= FLAG_HLINK_LAST;
561: *flist_p = flist;
562: }
563:
564: return prev_ndx;
565: }
566: #endif
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