Annotation of embedaddon/rsync/hlink.c, revision 1.1.1.1
1.1 misho 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) 2004-2009 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:
25: extern int verbose;
26: extern int dry_run;
27: extern int list_only;
28: extern int am_sender;
29: extern int inc_recurse;
30: extern int do_xfers;
31: extern int link_dest;
32: extern int preserve_acls;
33: extern int preserve_xattrs;
34: extern int make_backups;
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 struct hashtable *dev_tbl;
52:
53: static struct hashtable *prior_hlinks;
54:
55: static struct file_list *hlink_flist;
56:
57: void init_hard_links(void)
58: {
59: if (am_sender || protocol_version < 30)
60: dev_tbl = hashtable_create(16, 1);
61: else if (inc_recurse)
62: prior_hlinks = hashtable_create(1024, 0);
63: }
64:
65: struct ht_int64_node *idev_find(int64 dev, int64 ino)
66: {
67: static struct ht_int64_node *dev_node = NULL;
68: struct hashtable *tbl;
69:
70: /* Note that some OSes have a dev == 0, so increment to avoid storing a 0. */
71: if (!dev_node || dev_node->key != dev+1) {
72: /* We keep a separate hash table of inodes for every device. */
73: dev_node = hashtable_find(dev_tbl, dev+1, 1);
74: if (!(tbl = dev_node->data))
75: tbl = dev_node->data = hashtable_create(512, 1);
76: } else
77: tbl = dev_node->data;
78:
79: return hashtable_find(tbl, ino, 1);
80: }
81:
82: void idev_destroy(void)
83: {
84: int i;
85:
86: for (i = 0; i < dev_tbl->size; i++) {
87: struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
88: if (node->data)
89: hashtable_destroy(node->data);
90: }
91:
92: hashtable_destroy(dev_tbl);
93: }
94:
95: static int hlink_compare_gnum(int *int1, int *int2)
96: {
97: struct file_struct *f1 = hlink_flist->sorted[*int1];
98: struct file_struct *f2 = hlink_flist->sorted[*int2];
99: int32 gnum1 = F_HL_GNUM(f1);
100: int32 gnum2 = F_HL_GNUM(f2);
101:
102: if (gnum1 != gnum2)
103: return gnum1 > gnum2 ? 1 : -1;
104:
105: return *int1 > *int2 ? 1 : -1;
106: }
107:
108: static void match_gnums(int32 *ndx_list, int ndx_count)
109: {
110: int32 from, prev;
111: struct file_struct *file, *file_next;
112: struct ht_int32_node *node = NULL;
113: int32 gnum, gnum_next;
114:
115: qsort(ndx_list, ndx_count, sizeof ndx_list[0],
116: (int (*)()) hlink_compare_gnum);
117:
118: for (from = 0; from < ndx_count; from++) {
119: file = hlink_flist->sorted[ndx_list[from]];
120: gnum = F_HL_GNUM(file);
121: if (inc_recurse) {
122: node = hashtable_find(prior_hlinks, gnum, 1);
123: if (!node->data) {
124: if (!(node->data = new_array0(char, 5)))
125: out_of_memory("match_gnums");
126: assert(gnum >= hlink_flist->ndx_start);
127: file->flags |= FLAG_HLINK_FIRST;
128: prev = -1;
129: } else if (CVAL(node->data, 0) == 0) {
130: struct file_list *flist;
131: prev = IVAL(node->data, 1);
132: flist = flist_for_ndx(prev, NULL);
133: if (flist)
134: flist->files[prev - flist->ndx_start]->flags &= ~FLAG_HLINK_LAST;
135: else {
136: /* We skipped all prior files in this
137: * group, so mark this as a "first". */
138: file->flags |= FLAG_HLINK_FIRST;
139: prev = -1;
140: }
141: } else
142: prev = -1;
143: } else {
144: file->flags |= FLAG_HLINK_FIRST;
145: prev = -1;
146: }
147: for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
148: file_next = hlink_flist->sorted[ndx_list[from+1]];
149: gnum_next = F_HL_GNUM(file_next);
150: if (gnum != gnum_next)
151: break;
152: F_HL_PREV(file) = prev;
153: /* The linked list uses over-the-wire ndx values. */
154: if (unsort_ndx)
155: prev = F_NDX(file);
156: else
157: prev = ndx_list[from] + hlink_flist->ndx_start;
158: }
159: if (prev < 0 && !inc_recurse) {
160: /* Disable hard-link bit and set DONE so that
161: * HLINK_BUMP()-dependent values are unaffected. */
162: file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
163: file->flags |= FLAG_HLINK_DONE;
164: continue;
165: }
166:
167: file->flags |= FLAG_HLINK_LAST;
168: F_HL_PREV(file) = prev;
169: if (inc_recurse && CVAL(node->data, 0) == 0) {
170: if (unsort_ndx)
171: prev = F_NDX(file);
172: else
173: prev = ndx_list[from] + hlink_flist->ndx_start;
174: SIVAL(node->data, 1, prev);
175: }
176: }
177: }
178:
179: /* Analyze the hard-links in the file-list by creating a list of all the
180: * items that have hlink data, sorting them, and matching up identical
181: * values into clusters. These will be a single linked list from last
182: * to first when we're done. */
183: void match_hard_links(struct file_list *flist)
184: {
185: if (!list_only && flist->used) {
186: int i, ndx_count = 0;
187: int32 *ndx_list;
188:
189: if (!(ndx_list = new_array(int32, flist->used)))
190: out_of_memory("match_hard_links");
191:
192: for (i = 0; i < flist->used; i++) {
193: if (F_IS_HLINKED(flist->sorted[i]))
194: ndx_list[ndx_count++] = i;
195: }
196:
197: hlink_flist = flist;
198:
199: if (ndx_count)
200: match_gnums(ndx_list, ndx_count);
201:
202: free(ndx_list);
203: }
204: if (protocol_version < 30)
205: idev_destroy();
206: }
207:
208: static int maybe_hard_link(struct file_struct *file, int ndx,
209: const char *fname, int statret, stat_x *sxp,
210: const char *oldname, STRUCT_STAT *old_stp,
211: const char *realname, int itemizing, enum logcode code)
212: {
213: if (statret == 0) {
214: if (sxp->st.st_dev == old_stp->st_dev
215: && sxp->st.st_ino == old_stp->st_ino) {
216: if (itemizing) {
217: itemize(fname, file, ndx, statret, sxp,
218: ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
219: 0, "");
220: }
221: if (verbose > 1 && maybe_ATTRS_REPORT)
222: rprintf(FCLIENT, "%s is uptodate\n", fname);
223: file->flags |= FLAG_HLINK_DONE;
224: return 0;
225: }
226: if (make_backups > 0) {
227: if (!make_backup(fname))
228: return -1;
229: } else if (robust_unlink(fname)) {
230: rsyserr(FERROR_XFER, errno, "unlink %s failed",
231: full_fname(fname));
232: return -1;
233: }
234: }
235:
236: if (hard_link_one(file, fname, oldname, 0)) {
237: if (itemizing) {
238: itemize(fname, file, ndx, statret, sxp,
239: ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
240: realname);
241: }
242: if (code != FNONE && verbose)
243: rprintf(code, "%s => %s\n", fname, realname);
244: return 0;
245: }
246: return -1;
247: }
248:
249: /* Figure out if a prior entry is still there or if we just have a
250: * cached name for it. */
251: static char *check_prior(struct file_struct *file, int gnum,
252: int *prev_ndx_p, struct file_list **flist_p)
253: {
254: struct file_struct *fp;
255: struct ht_int32_node *node;
256: int prev_ndx = F_HL_PREV(file);
257:
258: while (1) {
259: struct file_list *flist;
260: if (prev_ndx < 0
261: || (flist = flist_for_ndx(prev_ndx, NULL)) == NULL)
262: break;
263: fp = flist->files[prev_ndx - flist->ndx_start];
264: if (!(fp->flags & FLAG_SKIP_HLINK)) {
265: *prev_ndx_p = prev_ndx;
266: *flist_p = flist;
267: return NULL;
268: }
269: F_HL_PREV(file) = prev_ndx = F_HL_PREV(fp);
270: }
271:
272: if (inc_recurse
273: && (node = hashtable_find(prior_hlinks, gnum, 0)) != NULL) {
274: assert(node->data != NULL);
275: if (CVAL(node->data, 0) != 0) {
276: *prev_ndx_p = -1;
277: *flist_p = NULL;
278: return node->data;
279: }
280: /* The prior file must have been skipped. */
281: F_HL_PREV(file) = -1;
282: }
283:
284: *prev_ndx_p = -1;
285: *flist_p = NULL;
286: return NULL;
287: }
288:
289: /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not. Returns:
290: * 0 = process the file, 1 = skip the file, -1 = error occurred. */
291: int hard_link_check(struct file_struct *file, int ndx, const char *fname,
292: int statret, stat_x *sxp, int itemizing,
293: enum logcode code)
294: {
295: STRUCT_STAT prev_st;
296: char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
297: char *realname, *prev_name;
298: struct file_list *flist;
299: int gnum = inc_recurse ? F_HL_GNUM(file) : -1;
300: int prev_ndx;
301:
302: prev_name = realname = check_prior(file, gnum, &prev_ndx, &flist);
303:
304: if (!prev_name) {
305: struct file_struct *prev_file;
306:
307: if (!flist) {
308: /* The previous file was skipped, so this one is
309: * treated as if it were the first in its group. */
310: return 0;
311: }
312:
313: prev_file = flist->files[prev_ndx - flist->ndx_start];
314:
315: /* Is the previous link not complete yet? */
316: if (!(prev_file->flags & FLAG_HLINK_DONE)) {
317: /* Is the previous link being transferred? */
318: if (prev_file->flags & FLAG_FILE_SENT) {
319: /* Add ourselves to the list of files that will
320: * be updated when the transfer completes, and
321: * mark ourself as waiting for the transfer. */
322: F_HL_PREV(file) = F_HL_PREV(prev_file);
323: F_HL_PREV(prev_file) = ndx;
324: file->flags |= FLAG_FILE_SENT;
325: cur_flist->in_progress++;
326: return 1;
327: }
328: return 0;
329: }
330:
331: /* There is a finished file to link with! */
332: if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
333: /* The previous previous is FIRST when prev is not. */
334: prev_name = realname = check_prior(prev_file, gnum, &prev_ndx, &flist);
335: assert(prev_name != NULL || flist != NULL);
336: /* Update our previous pointer to point to the FIRST. */
337: F_HL_PREV(file) = prev_ndx;
338: }
339:
340: if (!prev_name) {
341: int alt_dest;
342:
343: prev_file = flist->files[prev_ndx - flist->ndx_start];
344: /* F_HL_PREV() is alt_dest value when DONE && FIRST. */
345: alt_dest = F_HL_PREV(prev_file);
346:
347: if (alt_dest >= 0 && dry_run) {
348: pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
349: f_name(prev_file, NULL));
350: prev_name = namebuf;
351: realname = f_name(prev_file, altbuf);
352: } else {
353: prev_name = f_name(prev_file, namebuf);
354: realname = prev_name;
355: }
356: }
357: }
358:
359: if (link_stat(prev_name, &prev_st, 0) < 0) {
360: if (!dry_run || errno != ENOENT) {
361: rsyserr(FERROR_XFER, errno, "stat %s failed", full_fname(prev_name));
362: return -1;
363: }
364: /* A new hard-link will get a new dev & inode, so approximate
365: * those values in dry-run mode by zeroing them. */
366: memset(&prev_st, 0, sizeof prev_st);
367: }
368:
369: if (statret < 0 && basis_dir[0] != NULL) {
370: /* If we match an alt-dest item, we don't output this as a change. */
371: char cmpbuf[MAXPATHLEN];
372: stat_x alt_sx;
373: int j = 0;
374: #ifdef SUPPORT_ACLS
375: alt_sx.acc_acl = alt_sx.def_acl = NULL;
376: #endif
377: #ifdef SUPPORT_XATTRS
378: alt_sx.xattr = NULL;
379: #endif
380: do {
381: pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
382: if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
383: continue;
384: if (link_dest) {
385: if (prev_st.st_dev != alt_sx.st.st_dev
386: || prev_st.st_ino != alt_sx.st.st_ino)
387: continue;
388: statret = 1;
389: if (stdout_format_has_i == 0
390: || (verbose < 2 && stdout_format_has_i < 2)) {
391: itemizing = 0;
392: code = FNONE;
393: if (verbose > 1 && maybe_ATTRS_REPORT)
394: rprintf(FCLIENT, "%s is uptodate\n", fname);
395: }
396: break;
397: }
398: if (!unchanged_file(cmpbuf, file, &alt_sx.st))
399: continue;
400: statret = 1;
401: if (unchanged_attrs(cmpbuf, file, &alt_sx))
402: break;
403: } while (basis_dir[++j] != NULL);
404: if (statret == 1) {
405: sxp->st = alt_sx.st;
406: #ifdef SUPPORT_ACLS
407: if (preserve_acls && !S_ISLNK(file->mode)) {
408: free_acl(sxp);
409: if (!ACL_READY(alt_sx))
410: get_acl(cmpbuf, sxp);
411: else {
412: sxp->acc_acl = alt_sx.acc_acl;
413: sxp->def_acl = alt_sx.def_acl;
414: alt_sx.acc_acl = alt_sx.def_acl = NULL;
415: }
416: }
417: #endif
418: #ifdef SUPPORT_XATTRS
419: if (preserve_xattrs) {
420: free_xattr(sxp);
421: if (!XATTR_READY(alt_sx))
422: get_xattr(cmpbuf, sxp);
423: else {
424: sxp->xattr = alt_sx.xattr;
425: alt_sx.xattr = NULL;
426: }
427: }
428: #endif
429: } else {
430: #ifdef SUPPORT_ACLS
431: if (preserve_acls)
432: free_acl(&alt_sx);
433: #endif
434: #ifdef SUPPORT_XATTRS
435: if (preserve_xattrs)
436: free_xattr(&alt_sx);
437: #endif
438: }
439: }
440:
441: if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
442: realname, itemizing, code) < 0)
443: return -1;
444:
445: if (remove_source_files == 1 && do_xfers)
446: send_msg_int(MSG_SUCCESS, ndx);
447:
448: return 1;
449: }
450:
451: int hard_link_one(struct file_struct *file, const char *fname,
452: const char *oldname, int terse)
453: {
454: if (do_link(oldname, fname) < 0) {
455: enum logcode code;
456: if (terse) {
457: if (!verbose)
458: return 0;
459: code = FINFO;
460: } else
461: code = FERROR_XFER;
462: rsyserr(code, errno, "link %s => %s failed",
463: full_fname(fname), oldname);
464: return 0;
465: }
466:
467: file->flags |= FLAG_HLINK_DONE;
468:
469: return 1;
470: }
471:
472: void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
473: STRUCT_STAT *stp, int itemizing, enum logcode code,
474: int alt_dest)
475: {
476: stat_x prev_sx;
477: STRUCT_STAT st;
478: char prev_name[MAXPATHLEN], alt_name[MAXPATHLEN];
479: const char *our_name;
480: struct file_list *flist;
481: int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
482:
483: if (stp == NULL && prev_ndx >= 0) {
484: if (link_stat(fname, &st, 0) < 0) {
485: rsyserr(FERROR_XFER, errno, "stat %s failed",
486: full_fname(fname));
487: return;
488: }
489: stp = &st;
490: }
491:
492: /* FIRST combined with DONE means we were the first to get done. */
493: file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
494: F_HL_PREV(file) = alt_dest;
495: if (alt_dest >= 0 && dry_run) {
496: pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
497: f_name(file, NULL));
498: our_name = alt_name;
499: } else
500: our_name = fname;
501:
502: #ifdef SUPPORT_ACLS
503: prev_sx.acc_acl = prev_sx.def_acl = NULL;
504: #endif
505: #ifdef SUPPORT_XATTRS
506: prev_sx.xattr = NULL;
507: #endif
508:
509: while ((ndx = prev_ndx) >= 0) {
510: int val;
511: flist = flist_for_ndx(ndx, "finish_hard_link");
512: file = flist->files[ndx - flist->ndx_start];
513: file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
514: prev_ndx = F_HL_PREV(file);
515: F_HL_PREV(file) = fin_ndx;
516: prev_statret = link_stat(f_name(file, prev_name), &prev_sx.st, 0);
517: val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
518: our_name, stp, fname, itemizing, code);
519: flist->in_progress--;
520: #ifdef SUPPORT_ACLS
521: if (preserve_acls)
522: free_acl(&prev_sx);
523: #endif
524: #ifdef SUPPORT_XATTRS
525: if (preserve_xattrs)
526: free_xattr(&prev_sx);
527: #endif
528: if (val < 0)
529: continue;
530: if (remove_source_files == 1 && do_xfers)
531: send_msg_int(MSG_SUCCESS, ndx);
532: }
533:
534: if (inc_recurse) {
535: int gnum = F_HL_GNUM(file);
536: struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
537: if (node == NULL) {
538: rprintf(FERROR, "Unable to find a hlink node for %d (%s)\n", gnum, f_name(file, prev_name));
539: exit_cleanup(RERR_MESSAGEIO);
540: }
541: if (node->data == NULL) {
542: rprintf(FERROR, "Hlink node data for %d is NULL (%s)\n", gnum, f_name(file, prev_name));
543: exit_cleanup(RERR_MESSAGEIO);
544: }
545: if (CVAL(node->data, 0) != 0) {
546: rprintf(FERROR, "Hlink node data for %d already has path=%s (%s)\n",
547: gnum, (char*)node->data, f_name(file, prev_name));
548: exit_cleanup(RERR_MESSAGEIO);
549: }
550: free(node->data);
551: if (!(node->data = strdup(our_name)))
552: out_of_memory("finish_hard_link");
553: }
554: }
555:
556: int skip_hard_link(struct file_struct *file, struct file_list **flist_p)
557: {
558: struct file_list *flist;
559: int prev_ndx;
560:
561: file->flags |= FLAG_SKIP_HLINK;
562: if (!(file->flags & FLAG_HLINK_LAST))
563: return -1;
564:
565: check_prior(file, F_HL_GNUM(file), &prev_ndx, &flist);
566: if (prev_ndx >= 0) {
567: file = flist->files[prev_ndx - flist->ndx_start];
568: if (file->flags & (FLAG_HLINK_DONE|FLAG_FILE_SENT))
569: return -1;
570: file->flags |= FLAG_HLINK_LAST;
571: *flist_p = flist;
572: }
573:
574: return prev_ndx;
575: }
576: #endif
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