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) 2004-2007 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 version 3 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, visit the http://fsf.org website.
28 extern int preserve_acls;
29 extern int make_backups;
30 extern int protocol_version;
31 extern int remove_source_files;
32 extern int stdout_format_has_i;
33 extern int maybe_ATTRS_REPORT;
34 extern char *basis_dir[];
35 extern struct file_list *cur_flist;
40 #ifdef SUPPORT_HARD_LINKS
42 #define HASH_LOAD_LIMIT(size) ((size)*3/4)
47 struct idev_node *buckets;
50 static struct idev_node *ihash_node(struct ihash_table *tbl, int64 key);
52 /* Starting with protocol 30, we use a simple hashtable on the sending side
53 * for hashing the st_dev and st_ino info. The receiving side gets told
54 * (via flags and a "group index") which items are hard-linked together, so
55 * we can avoid the pool of dev+inode data. */
57 static struct ihash_table *ihash_create(int size)
59 struct ihash_table *tbl;
61 /* Pick a power of 2 that can hold the requested size. */
62 if (size & (size-1) || size < 16) {
69 if (!(tbl = new(struct ihash_table))
70 || !(tbl->buckets = new_array(struct idev_node, size)))
71 out_of_memory("ihash_create");
72 memset(tbl->buckets, 0, size * sizeof tbl->buckets[0]);
79 static void ihash_destroy(struct ihash_table *tbl)
85 void init_hard_links(void)
87 dev_tbl = ihash_create(16);
90 static void expand_ihash(struct ihash_table *tbl)
92 struct idev_node *old_buckets = tbl->buckets;
93 int size = tbl->size * 2;
96 if (!(tbl->buckets = new_array(struct idev_node, size)))
97 out_of_memory("ihash_create");
98 memset(tbl->buckets, 0, size * sizeof (struct idev_node));
102 for (i = size / 2; i-- > 0; ) {
103 int64 key = old_buckets[i].key;
106 ihash_node(tbl, key)->data = old_buckets[i].data;
112 /* This returns the node for the indicated key, either newly created,
113 * or already existing. */
114 static struct idev_node *ihash_node(struct ihash_table *tbl, int64 key)
118 if (tbl->entries > HASH_LOAD_LIMIT(tbl->size))
122 /* Based on Jenkins One-at-a-time hash. */
124 uchar *keyp = (uchar*)&key;
127 for (bkt = 0, i = 0; i < SIZEOF_INT64; i++) {
137 #define rot(x,k) (((x)<<(k)) ^ ((x)>>(32-(k))))
138 /* Based on Jenkins hashword() from lookup3.c. */
142 /* Set up the internal state */
143 a = b = c = 0xdeadbeef + (8 << 2);
145 b += (uint32)(key >> 32);
147 c ^= b; c -= rot(b, 14);
148 a ^= c; a -= rot(c, 11);
149 b ^= a; b -= rot(a, 25);
150 c ^= b; c -= rot(b, 16);
151 a ^= c; a -= rot(c, 4);
152 b ^= a; b -= rot(a, 14);
153 c ^= b; c -= rot(b, 24);
158 /* If it already exists, return it. */
160 bkt &= tbl->size - 1;
161 if (tbl->buckets[bkt].key == key)
162 return &tbl->buckets[bkt];
163 if (tbl->buckets[bkt].key == 0)
168 /* Otherwise, take over this empty spot and then return it. */
169 tbl->buckets[bkt].key = key;
171 return &tbl->buckets[bkt];
174 struct idev_node *idev_node(int64 dev, int64 ino)
176 static struct idev_node *dev_node = NULL;
177 struct ihash_table *tbl;
179 if (!dev_node || dev_node->key != dev) {
180 /* We keep a separate hash table of inodes for every device. */
181 dev_node = ihash_node(dev_tbl, dev);
182 if (!(tbl = dev_node->data))
183 tbl = dev_node->data = ihash_create(512);
185 tbl = dev_node->data;
187 return ihash_node(tbl, ino);
190 void idev_destroy(void)
194 for (i = 0; i < dev_tbl->size; i++) {
195 if (dev_tbl->buckets[i].data)
196 ihash_destroy(dev_tbl->buckets[i].data);
199 ihash_destroy(dev_tbl);
202 static int hlink_compare_gnum(int *int1, int *int2)
204 struct file_struct *f1 = cur_flist->sorted[*int1];
205 struct file_struct *f2 = cur_flist->sorted[*int2];
206 int32 gnum1 = F_HL_GNUM(f1);
207 int32 gnum2 = F_HL_GNUM(f2);
210 return gnum1 > gnum2 ? 1 : -1;
212 return *int1 > *int2 ? 1 : -1;
215 static void match_gnums(int32 *ndx_list, int ndx_count)
218 struct file_struct *file, *file_next;
219 int32 gnum, gnum_next;
221 qsort(ndx_list, ndx_count, sizeof ndx_list[0],
222 (int (*)()) hlink_compare_gnum);
224 for (from = 0; from < ndx_count; from++) {
225 for (file = cur_flist->sorted[ndx_list[from]], gnum = F_HL_GNUM(file), prev = -1;
227 file = file_next, gnum = gnum_next, from++) /*SHARED ITERATOR*/
229 file_next = cur_flist->sorted[ndx_list[from+1]];
230 gnum_next = F_HL_GNUM(file_next);
231 if (gnum != gnum_next)
234 file->flags |= FLAG_HLINK_FIRST;
235 F_HL_PREV(file) = prev;
236 /* The linked list must use raw ndx values. */
242 prev = ndx_list[from];
245 file->flags &= ~FLAG_HLINKED;
247 file->flags |= FLAG_HLINK_LAST;
248 F_HL_PREV(file) = prev;
253 /* Analyze the hard-links in the file-list by creating a list of all the
254 * items that have hlink data, sorting them, and matching up identical
255 * values into clusters. These will be a single linked list from last
256 * to first when we're done. */
257 void match_hard_links(void)
259 int i, ndx_count = 0;
262 if (!(ndx_list = new_array(int32, cur_flist->used)))
263 out_of_memory("match_hard_links");
265 for (i = 0; i < cur_flist->used; i++) {
266 if (F_IS_HLINKED(cur_flist->sorted[i]))
267 ndx_list[ndx_count++] = i;
271 match_gnums(ndx_list, ndx_count);
274 if (protocol_version < 30)
278 static int maybe_hard_link(struct file_struct *file, int ndx,
279 const char *fname, int statret, statx *sxp,
280 const char *oldname, STRUCT_STAT *old_stp,
281 const char *realname, int itemizing, enum logcode code)
284 if (sxp->st.st_dev == old_stp->st_dev
285 && sxp->st.st_ino == old_stp->st_ino) {
287 itemize(fname, file, ndx, statret, sxp,
288 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
291 if (verbose > 1 && maybe_ATTRS_REPORT)
292 rprintf(FCLIENT, "%s is uptodate\n", fname);
293 file->flags |= FLAG_HLINK_DONE;
296 if (make_backups > 0) {
297 if (!make_backup(fname))
299 } else if (robust_unlink(fname)) {
300 rsyserr(FERROR, errno, "unlink %s failed",
306 if (hard_link_one(file, fname, oldname, 0)) {
308 itemize(fname, file, ndx, statret, sxp,
309 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
312 if (code != FNONE && verbose)
313 rprintf(code, "%s => %s\n", fname, realname);
319 /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not. Returns:
320 * 0 = process the file, 1 = skip the file, -1 = error occurred. */
321 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
322 int statret, statx *sxp, int itemizing,
326 char prev_name[MAXPATHLEN], altbuf[MAXPATHLEN], *realname;
327 int alt_dest, prev_ndx = F_HL_PREV(file);
328 struct file_struct *prev_file = cur_flist->files[prev_ndx];
330 /* Is the previous link is not complete yet? */
331 if (!(prev_file->flags & FLAG_HLINK_DONE)) {
332 /* Is the previous link being transferred? */
333 if (prev_file->flags & FLAG_FILE_SENT) {
334 /* Add ourselves to the list of files that will be
335 * updated when the transfer completes, and mark
336 * ourself as waiting for the transfer. */
337 F_HL_PREV(file) = F_HL_PREV(prev_file);
338 F_HL_PREV(prev_file) = ndx;
339 file->flags |= FLAG_FILE_SENT;
345 /* There is a finished file to link with! */
346 if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
347 /* The previous previous will be marked with FIRST. */
348 prev_ndx = F_HL_PREV(prev_file);
349 prev_file = cur_flist->files[prev_ndx];
350 /* Update our previous pointer to point to the first. */
351 F_HL_PREV(file) = prev_ndx;
353 alt_dest = F_HL_PREV(prev_file); /* alternate value when DONE && FIRST */
354 if (alt_dest >= 0 && dry_run) {
355 pathjoin(prev_name, MAXPATHLEN, basis_dir[alt_dest],
356 f_name(prev_file, NULL));
357 f_name(prev_file, altbuf);
360 f_name(prev_file, prev_name);
361 realname = prev_name;
364 if (link_stat(prev_name, &prev_st, 0) < 0) {
365 rsyserr(FERROR, errno, "stat %s failed",
366 full_fname(prev_name));
370 if (statret < 0 && basis_dir[0] != NULL) {
371 /* If we match an alt-dest item, we don't output this as a change. */
372 char cmpbuf[MAXPATHLEN];
376 alt_sx.acc_acl = alt_sx.def_acl = NULL;
379 pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
380 if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
383 if (prev_st.st_dev != alt_sx.st.st_dev
384 || prev_st.st_ino != alt_sx.st.st_ino)
387 if (verbose < 2 || !stdout_format_has_i) {
390 if (verbose > 1 && maybe_ATTRS_REPORT)
391 rprintf(FCLIENT, "%s is uptodate\n", fname);
395 if (!unchanged_file(cmpbuf, file, &alt_sx.st))
398 if (unchanged_attrs(cmpbuf, file, &alt_sx))
400 } while (basis_dir[++j] != NULL);
404 if (preserve_acls && !S_ISLNK(file->mode)) {
405 if (!ACL_READY(*sxp))
406 get_acl(cmpbuf, sxp);
408 sxp->acc_acl = alt_sx.acc_acl;
409 sxp->def_acl = alt_sx.def_acl;
415 else if (preserve_acls)
420 if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
421 realname, itemizing, code) < 0)
424 if (remove_source_files == 1 && do_xfers)
425 send_msg_int(MSG_SUCCESS, ndx);
430 int hard_link_one(struct file_struct *file, const char *fname,
431 const char *oldname, int terse)
433 if (do_link(oldname, fname) < 0) {
441 rsyserr(code, errno, "link %s => %s failed",
442 full_fname(fname), oldname);
446 file->flags |= FLAG_HLINK_DONE;
451 void finish_hard_link(struct file_struct *file, const char *fname,
452 STRUCT_STAT *stp, int itemizing, enum logcode code,
457 char alt_name[MAXPATHLEN], *prev_name;
458 const char *our_name;
459 int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
461 if (stp == NULL && prev_ndx >= 0) {
462 if (link_stat(fname, &st, 0) < 0) {
463 rsyserr(FERROR, errno, "stat %s failed",
470 /* FIRST combined with DONE means we were the first to get done. */
471 file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
472 F_HL_PREV(file) = alt_dest;
473 if (alt_dest >= 0 && dry_run) {
474 pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
481 prev_sx.acc_acl = prev_sx.def_acl = NULL;
484 while ((ndx = prev_ndx) >= 0) {
486 file = cur_flist->files[ndx];
487 file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
488 prev_ndx = F_HL_PREV(file);
489 prev_name = f_name(file, NULL);
490 prev_statret = link_stat(prev_name, &prev_sx.st, 0);
491 val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
492 our_name, stp, fname, itemizing, code);
499 if (remove_source_files == 1 && do_xfers)
500 send_msg_int(MSG_SUCCESS, ndx);