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 2 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, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
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;
37 #ifdef SUPPORT_HARD_LINKS
39 #define HASH_LOAD_LIMIT(size) ((size)*3/4)
40 #define FPTR(i) (cur_flist->files[i])
45 struct idev_node *buckets;
48 static struct idev_node *ihash_node(struct ihash_table *tbl, int64 key);
50 /* Starting with protocol 30, we use a simple hashtable on the sending side
51 * for hashing the st_dev and st_ino info. The receiving side gets told
52 * (via flags and a "group index") which items are hard-linked together, so
53 * we can avoid the pool of dev+inode data. */
55 static struct ihash_table *ihash_create(int size)
57 struct ihash_table *tbl;
59 /* Pick a power of 2 that can hold the requested size. */
60 if (size & (size-1) || size < 16) {
67 if (!(tbl = new(struct ihash_table))
68 || !(tbl->buckets = new_array(struct idev_node, size)))
69 out_of_memory("ihash_create");
70 memset(tbl->buckets, 0, size * sizeof tbl->buckets[0]);
77 static void ihash_destroy(struct ihash_table *tbl)
83 void init_hard_links(void)
85 dev_tbl = ihash_create(16);
88 static void expand_ihash(struct ihash_table *tbl)
90 struct idev_node *old_buckets = tbl->buckets;
91 int size = tbl->size * 2;
94 if (!(tbl->buckets = new_array(struct idev_node, size)))
95 out_of_memory("ihash_create");
96 memset(tbl->buckets, 0, size * sizeof (struct idev_node));
100 for (i = size / 2; i-- > 0; ) {
101 int64 key = old_buckets[i].key;
104 ihash_node(tbl, key)->data = old_buckets[i].data;
110 /* This returns the node for the indicated key, either newly created,
111 * or already existing. */
112 static struct idev_node *ihash_node(struct ihash_table *tbl, int64 key)
116 if (tbl->entries > HASH_LOAD_LIMIT(tbl->size))
120 /* Based on Jenkins One-at-a-time hash. */
122 uchar *keyp = (uchar*)&key;
125 for (bkt = 0, i = 0; i < SIZEOF_INT64; i++) {
135 #define rot(x,k) (((x)<<(k)) ^ ((x)>>(32-(k))))
136 /* Based on Jenkins hashword() from lookup3.c. */
140 /* Set up the internal state */
141 a = b = c = 0xdeadbeef + (8 << 2);
143 b += (uint32)(key >> 32);
145 c ^= b; c -= rot(b, 14);
146 a ^= c; a -= rot(c, 11);
147 b ^= a; b -= rot(a, 25);
148 c ^= b; c -= rot(b, 16);
149 a ^= c; a -= rot(c, 4);
150 b ^= a; b -= rot(a, 14);
151 c ^= b; c -= rot(b, 24);
156 /* If it already exists, return it. */
158 bkt &= tbl->size - 1;
159 if (tbl->buckets[bkt].key == key)
160 return &tbl->buckets[bkt];
161 if (tbl->buckets[bkt].key == 0)
166 /* Otherwise, take over this empty spot and then return it. */
167 tbl->buckets[bkt].key = key;
169 return &tbl->buckets[bkt];
172 struct idev_node *idev_node(int64 dev, int64 ino)
174 static struct idev_node *dev_node = NULL;
175 struct ihash_table *tbl;
177 if (!dev_node || dev_node->key != dev) {
178 /* We keep a separate hash table of inodes for every device. */
179 dev_node = ihash_node(dev_tbl, dev);
180 if (!(tbl = dev_node->data))
181 tbl = dev_node->data = ihash_create(512);
183 tbl = dev_node->data;
185 return ihash_node(tbl, ino);
188 void idev_destroy(void)
192 for (i = 0; i < dev_tbl->size; i++) {
193 if (dev_tbl->buckets[i].data)
194 ihash_destroy(dev_tbl->buckets[i].data);
197 ihash_destroy(dev_tbl);
200 static int hlink_compare_gnum(int *int1, int *int2)
202 struct file_struct *f1 = FPTR(*int1);
203 struct file_struct *f2 = FPTR(*int2);
204 int32 gnum1 = F_HL_GNUM(f1);
205 int32 gnum2 = F_HL_GNUM(f2);
208 return gnum1 > gnum2 ? 1 : -1;
210 return *int1 > *int2 ? 1 : -1;
213 static void match_gnums(int32 *ndx_list, int ndx_count)
216 struct file_struct *file, *file_next;
217 int32 gnum, gnum_next;
219 qsort(ndx_list, ndx_count, sizeof ndx_list[0],
220 (int (*)()) hlink_compare_gnum);
222 for (from = 0; from < ndx_count; from++) {
223 for (file = FPTR(ndx_list[from]), gnum = F_HL_GNUM(file), prev = -1;
225 file = file_next, gnum = gnum_next, prev = ndx_list[from++])
227 file_next = FPTR(ndx_list[from+1]);
228 gnum_next = F_HL_GNUM(file_next);
229 if (gnum != gnum_next)
232 file->flags |= FLAG_HLINK_FIRST;
233 F_HL_PREV(file) = prev;
236 file->flags &= ~FLAG_HLINKED;
238 file->flags |= FLAG_HLINK_LAST;
239 F_HL_PREV(file) = prev;
244 /* Analyze the hard-links in the file-list by creating a list of all the
245 * items that have hlink data, sorting them, and matching up identical
246 * values into clusters. These will be a single linked list from last
247 * to first when we're done. */
248 void match_hard_links(void)
250 int i, ndx_count = 0;
253 if (!(ndx_list = new_array(int32, cur_flist->count)))
254 out_of_memory("match_hard_links");
256 for (i = 0; i < cur_flist->count; i++) {
257 if (F_IS_HLINKED(FPTR(i)))
258 ndx_list[ndx_count++] = i;
262 match_gnums(ndx_list, ndx_count);
265 if (protocol_version < 30)
269 static int maybe_hard_link(struct file_struct *file, int ndx,
270 const char *fname, int statret, STRUCT_STAT *stp,
271 const char *oldname, STRUCT_STAT *old_stp,
272 const char *realname, int itemizing, enum logcode code)
275 if (stp->st_dev == old_stp->st_dev
276 && stp->st_ino == old_stp->st_ino) {
278 itemize(file, ndx, statret, stp,
279 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
282 if (verbose > 1 && maybe_ATTRS_REPORT)
283 rprintf(FCLIENT, "%s is uptodate\n", fname);
284 file->flags |= FLAG_HLINK_DONE;
287 if (make_backups > 0) {
288 if (!make_backup(fname))
290 } else if (robust_unlink(fname)) {
291 rsyserr(FERROR, errno, "unlink %s failed",
297 if (hard_link_one(file, fname, oldname, 0)) {
299 itemize(file, ndx, statret, stp,
300 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
303 if (code != FNONE && verbose)
304 rprintf(code, "%s => %s\n", fname, realname);
310 /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not. Returns:
311 * 0 = process the file, 1 = skip the file, -1 = error occurred. */
312 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
313 int statret, STRUCT_STAT *stp, int itemizing,
317 char prev_name[MAXPATHLEN], altbuf[MAXPATHLEN], *realname;
318 int alt_dest, prev_ndx = F_HL_PREV(file);
319 struct file_struct *prev_file = FPTR(prev_ndx);
321 /* Is the previous link is not complete yet? */
322 if (!(prev_file->flags & FLAG_HLINK_DONE)) {
323 /* Is the previous link being transferred? */
324 if (prev_file->flags & FLAG_FILE_SENT) {
325 /* Add ourselves to the list of files that will be
326 * updated when the transfer completes, and mark
327 * ourself as waiting for the transfer. */
328 F_HL_PREV(file) = F_HL_PREV(prev_file);
329 F_HL_PREV(prev_file) = ndx;
330 file->flags |= FLAG_FILE_SENT;
336 /* There is a finished file to link with! */
337 if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
338 /* The previous previous will be marked with FIRST. */
339 prev_ndx = F_HL_PREV(prev_file);
340 prev_file = FPTR(prev_ndx);
341 /* Update our previous pointer to point to the first. */
342 F_HL_PREV(file) = prev_ndx;
344 alt_dest = F_HL_PREV(prev_file); /* alternate value when DONE && FIRST */
345 if (alt_dest >= 0 && dry_run) {
346 pathjoin(prev_name, MAXPATHLEN, basis_dir[alt_dest],
347 f_name(prev_file, NULL));
348 f_name(prev_file, altbuf);
351 f_name(prev_file, prev_name);
352 realname = prev_name;
355 if (link_stat(prev_name, &prev_st, 0) < 0) {
356 rsyserr(FERROR, errno, "stat %s failed",
357 full_fname(prev_name));
361 if (statret < 0 && basis_dir[0] != NULL) {
362 /* If we match an alt-dest item, we don't output this as a change. */
363 char cmpbuf[MAXPATHLEN];
367 pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
368 if (link_stat(cmpbuf, &alt_st, 0) < 0)
371 if (prev_st.st_dev != alt_st.st_dev
372 || prev_st.st_ino != alt_st.st_ino)
376 if (verbose < 2 || !stdout_format_has_i) {
379 if (verbose > 1 && maybe_ATTRS_REPORT)
380 rprintf(FCLIENT, "%s is uptodate\n", fname);
384 if (!unchanged_file(cmpbuf, file, &alt_st))
388 if (unchanged_attrs(file, &alt_st))
390 } while (basis_dir[++j] != NULL);
393 if (maybe_hard_link(file, ndx, fname, statret, stp, prev_name, &prev_st,
394 realname, itemizing, code) < 0)
397 if (remove_source_files == 1 && do_xfers)
398 send_msg_int(MSG_SUCCESS, ndx);
403 int hard_link_one(struct file_struct *file, const char *fname,
404 const char *oldname, int terse)
406 if (do_link(oldname, fname) < 0) {
414 rsyserr(code, errno, "link %s => %s failed",
415 full_fname(fname), oldname);
419 file->flags |= FLAG_HLINK_DONE;
424 void finish_hard_link(struct file_struct *file, const char *fname,
425 STRUCT_STAT *stp, int itemizing, enum logcode code,
428 STRUCT_STAT st, prev_st;
429 char alt_name[MAXPATHLEN], *prev_name;
430 const char *our_name;
431 int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
433 if (stp == NULL && prev_ndx >= 0) {
434 if (link_stat(fname, &st, 0) < 0) {
435 rsyserr(FERROR, errno, "stat %s failed",
442 /* FIRST combined with DONE means we were the first to get done. */
443 file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
444 F_HL_PREV(file) = alt_dest;
445 if (alt_dest >= 0 && dry_run) {
446 pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
452 while ((ndx = prev_ndx) >= 0) {
454 file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
455 prev_ndx = F_HL_PREV(file);
456 prev_name = f_name(file, NULL);
457 prev_statret = link_stat(prev_name, &prev_st, 0);
458 if (maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_st,
459 our_name, stp, fname, itemizing, code) < 0)
461 if (remove_source_files == 1 && do_xfers)
462 send_msg_int(MSG_SUCCESS, ndx);