2 * Routines to support hard-linking.
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
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.
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.
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.
30 extern int inc_recurse;
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;
43 #ifdef SUPPORT_HARD_LINKS
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. */
51 static void *data_when_new = "";
53 static struct hashtable *dev_tbl;
55 static struct hashtable *prior_hlinks;
57 static struct file_list *hlink_flist;
59 void init_hard_links(void)
61 if (am_sender || protocol_version < 30)
62 dev_tbl = hashtable_create(16, HT_KEY64);
64 prior_hlinks = hashtable_create(1024, HT_KEY32);
67 struct ht_int64_node *idev_find(int64 dev, int64 ino)
69 static struct ht_int64_node *dev_node = NULL;
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));
84 return hashtable_find(dev_node->data, ino, (void*)-1L);
87 void idev_destroy(void)
91 for (i = 0; i < dev_tbl->size; i++) {
92 struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
94 hashtable_destroy(node->data);
97 hashtable_destroy(dev_tbl);
100 static int hlink_compare_gnum(int *int1, int *int2)
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);
108 return gnum1 > gnum2 ? 1 : -1;
110 return *int1 > *int2 ? 1 : -1;
113 static void match_gnums(int32 *ndx_list, int ndx_count)
116 struct file_struct *file, *file_next;
117 struct ht_int32_node *node = NULL;
118 int32 gnum, gnum_next;
120 qsort(ndx_list, ndx_count, sizeof ndx_list[0], (int (*)()) hlink_compare_gnum);
122 for (from = 0; from < ndx_count; from++) {
123 file = hlink_flist->sorted[ndx_list[from]];
124 gnum = F_HL_GNUM(file);
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;
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);
137 flist->files[prev - flist->ndx_start]->flags &= ~FLAG_HLINK_LAST;
139 /* We skipped all prior files in this
140 * group, so mark this as a "first". */
141 file->flags |= FLAG_HLINK_FIRST;
147 file->flags |= FLAG_HLINK_FIRST;
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)
155 F_HL_PREV(file) = prev;
156 /* The linked list uses over-the-wire ndx values. */
160 prev = ndx_list[from] + hlink_flist->ndx_start;
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;
170 file->flags |= FLAG_HLINK_LAST;
171 F_HL_PREV(file) = prev;
172 if (inc_recurse && CVAL(node->data, 0) == 0) {
176 prev = ndx_list[from] + hlink_flist->ndx_start;
177 SIVAL(node->data, 1, prev);
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)
188 if (!list_only && flist->used) {
189 int i, ndx_count = 0;
192 ndx_list = new_array(int32, flist->used);
194 for (i = 0; i < flist->used; i++) {
195 if (F_IS_HLINKED(flist->sorted[i]))
196 ndx_list[ndx_count++] = i;
202 match_gnums(ndx_list, ndx_count);
206 if (protocol_version < 30)
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)
216 if (sxp->st.st_dev == old_stp->st_dev
217 && sxp->st.st_ino == old_stp->st_ino) {
219 itemize(fname, file, ndx, statret, sxp,
220 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
223 if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
224 rprintf(FCLIENT, "%s is uptodate\n", fname);
225 file->flags |= FLAG_HLINK_DONE;
230 if (atomic_create(file, fname, NULL, oldname, MAKEDEV(0, 0), sxp, statret == 0 ? DEL_FOR_FILE : 0)) {
232 itemize(fname, file, ndx, statret, sxp,
233 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
236 if (code != FNONE && INFO_GTE(NAME, 1))
237 rprintf(code, "%s => %s\n", fname, realname);
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)
249 struct file_struct *fp;
250 struct ht_int32_node *node;
251 int prev_ndx = F_HL_PREV(file);
254 struct file_list *flist;
256 || (flist = flist_for_ndx(prev_ndx, NULL)) == NULL)
258 fp = flist->files[prev_ndx - flist->ndx_start];
259 if (!(fp->flags & FLAG_SKIP_HLINK)) {
260 *prev_ndx_p = prev_ndx;
264 F_HL_PREV(file) = prev_ndx = F_HL_PREV(fp);
268 && (node = hashtable_find(prior_hlinks, gnum, NULL)) != NULL) {
269 assert(node->data != NULL);
270 if (CVAL(node->data, 0) != 0) {
275 /* The prior file must have been skipped. */
276 F_HL_PREV(file) = -1;
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,
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;
297 prev_name = realname = check_prior(file, gnum, &prev_ndx, &flist);
300 struct file_struct *prev_file;
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);
312 prev_file = flist->files[prev_ndx - flist->ndx_start];
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));
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);
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;
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);
358 if (alt_dest >= 0 && dry_run) {
359 pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
360 f_name(prev_file, NULL));
362 realname = f_name(prev_file, altbuf);
364 prev_name = f_name(prev_file, namebuf);
365 realname = prev_name;
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);
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));
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);
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];
390 init_stat_x(&alt_sx);
392 pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
393 if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
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)
400 if (stdout_format_has_i == 0
401 || (!INFO_GTE(NAME, 2) && stdout_format_has_i < 2)) {
404 if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
405 rprintf(FCLIENT, "%s is uptodate\n", fname);
409 if (!quick_check_ok(FT_REG, cmpbuf, file, &alt_sx.st))
412 if (unchanged_attrs(cmpbuf, file, &alt_sx))
414 } while (basis_dir[++j] != NULL);
418 if (preserve_acls && !S_ISLNK(file->mode)) {
420 if (!ACL_READY(alt_sx))
421 get_acl(cmpbuf, sxp);
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;
429 #ifdef SUPPORT_XATTRS
430 if (preserve_xattrs) {
432 if (!XATTR_READY(alt_sx))
433 get_xattr(cmpbuf, sxp);
435 sxp->xattr = alt_sx.xattr;
441 free_stat_x(&alt_sx);
444 if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
445 realname, itemizing, code) < 0)
448 if (remove_source_files == 1 && do_xfers)
449 send_msg_success(fname, ndx);
454 int hard_link_one(struct file_struct *file, const char *fname,
455 const char *oldname, int terse)
457 if (do_link(oldname, fname) < 0) {
460 if (!INFO_GTE(NAME, 1))
465 rsyserr(code, errno, "link %s => %s failed",
466 full_fname(fname), oldname);
470 file->flags |= FLAG_HLINK_DONE;
475 void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
476 STRUCT_STAT *stp, int itemizing, enum logcode code,
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);
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",
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],
505 init_stat_x(&prev_sx);
507 while ((ndx = prev_ndx) >= 0) {
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);
521 if (remove_source_files == 1 && do_xfers)
522 send_msg_success(fname, ndx);
526 int gnum = F_HL_GNUM(file);
527 struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 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);
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);
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);
542 node->data = strdup(our_name);
546 int skip_hard_link(struct file_struct *file, struct file_list **flist_p)
548 struct file_list *flist;
551 file->flags |= FLAG_SKIP_HLINK;
552 if (!(file->flags & FLAG_HLINK_LAST))
555 check_prior(file, F_HL_GNUM(file), &prev_ndx, &flist);
557 file = flist->files[prev_ndx - flist->ndx_start];
558 if (file->flags & (FLAG_HLINK_DONE|FLAG_FILE_SENT))
560 file->flags |= FLAG_HLINK_LAST;