Preparing for release of 2.6.6pre1
[rsync.git] / hlink.c
1 /*
2    Copyright (C) Andrew Tridgell 1996
3    Copyright (C) Paul Mackerras 1996
4    Copyright (C) 2002 by Martin Pool <mbp@samba.org>
5
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 2 of the License, or
9    (at your option) any later version.
10
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include "rsync.h"
22
23 extern int dry_run;
24 extern int verbose;
25 extern int make_backups;
26 extern int log_format_has_i;
27 extern struct file_list *the_file_list;
28
29 #ifdef SUPPORT_HARD_LINKS
30
31 #define SKIPPED_LINK (-1)
32 #define FINISHED_LINK (-2)
33
34 #define FPTR(i) (the_file_list->files[i])
35 #define LINKED(p1,p2) (FPTR(p1)->F_DEV == FPTR(p2)->F_DEV \
36                     && FPTR(p1)->F_INODE == FPTR(p2)->F_INODE)
37
38 static int hlink_compare(int *int1, int *int2)
39 {
40         struct file_struct *f1 = FPTR(*int1);
41         struct file_struct *f2 = FPTR(*int2);
42
43         if (f1->F_DEV != f2->F_DEV)
44                 return (int) (f1->F_DEV > f2->F_DEV ? 1 : -1);
45
46         if (f1->F_INODE != f2->F_INODE)
47                 return (int) (f1->F_INODE > f2->F_INODE ? 1 : -1);
48
49         return f_name_cmp(f1, f2);
50 }
51
52 static int *hlink_list;
53 static int hlink_count;
54
55 /* Analyze the data in the hlink_list[], remove items that aren't multiply
56  * linked, and replace the dev+inode data with the hlindex+next linked list. */
57 static void link_idev_data(void)
58 {
59         int cur, from, to, start;
60
61         alloc_pool_t hlink_pool;
62         alloc_pool_t idev_pool = the_file_list->hlink_pool;
63
64         hlink_pool = pool_create(128 * 1024, sizeof (struct hlink),
65             out_of_memory, POOL_INTERN);
66
67         for (from = to = 0; from < hlink_count; from++) {
68                 start = from;
69                 while (1) {
70                         cur = hlink_list[from];
71                         if (from == hlink_count-1
72                             || !LINKED(cur, hlink_list[from+1]))
73                                 break;
74                         pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
75                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
76                             struct hlink, 1, "hlink_list");
77
78                         FPTR(cur)->F_HLINDEX = to;
79                         FPTR(cur)->F_NEXT = hlink_list[++from];
80                 }
81                 pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
82                 if (from > start) {
83                         int head = hlink_list[start];
84                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
85                             struct hlink, 1, "hlink_list");
86
87                         FPTR(head)->flags |= FLAG_HLINK_TOL;
88                         FPTR(cur)->F_HLINDEX = to;
89                         FPTR(cur)->F_NEXT = head;
90                         FPTR(cur)->flags |= FLAG_HLINK_EOL;
91                         hlink_list[to++] = head;
92                 } else
93                         FPTR(cur)->link_u.links = NULL;
94         }
95
96         if (!to) {
97                 free(hlink_list);
98                 hlink_list = NULL;
99                 pool_destroy(hlink_pool);
100                 hlink_pool = NULL;
101         } else {
102                 hlink_count = to;
103                 hlink_list = realloc_array(hlink_list, int, hlink_count);
104                 if (!hlink_list)
105                         out_of_memory("init_hard_links");
106         }
107         the_file_list->hlink_pool = hlink_pool;
108         pool_destroy(idev_pool);
109 }
110 #endif
111
112 void init_hard_links(void)
113 {
114 #ifdef SUPPORT_HARD_LINKS
115         int i;
116
117         if (hlink_list)
118                 free(hlink_list);
119
120         if (!(hlink_list = new_array(int, the_file_list->count)))
121                 out_of_memory("init_hard_links");
122
123         hlink_count = 0;
124         for (i = 0; i < the_file_list->count; i++) {
125                 if (FPTR(i)->link_u.idev)
126                         hlink_list[hlink_count++] = i;
127         }
128
129         qsort(hlink_list, hlink_count,
130             sizeof hlink_list[0], (int (*)()) hlink_compare);
131
132         if (!hlink_count) {
133                 free(hlink_list);
134                 hlink_list = NULL;
135         } else
136                 link_idev_data();
137 #endif
138 }
139
140 #ifdef SUPPORT_HARD_LINKS
141 static int maybe_hard_link(struct file_struct *file, int ndx,
142                            char *fname, int statret, STRUCT_STAT *st,
143                            char *toname, STRUCT_STAT *to_st,
144                            int itemizing, enum logcode code)
145 {
146         if (statret == 0) {
147                 if (st->st_dev == to_st->st_dev
148                  && st->st_ino == to_st->st_ino) {
149                         if (itemizing) {
150                                 itemize(file, ndx, statret, st,
151                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
152                                         0, "");
153                         }
154                         return 0;
155                 }
156                 if (make_backups) {
157                         if (!make_backup(fname))
158                                 return -1;
159                 } else if (robust_unlink(fname)) {
160                         rsyserr(FERROR, errno, "unlink %s failed",
161                                 full_fname(fname));
162                         return -1;
163                 }
164         }
165         return hard_link_one(file, ndx, fname, statret, st, toname,
166                              0, itemizing, code);
167 }
168 #endif
169
170 int hard_link_check(struct file_struct *file, int ndx, char *fname,
171                     int statret, STRUCT_STAT *st, int itemizing,
172                     enum logcode code, int skip)
173 {
174 #ifdef SUPPORT_HARD_LINKS
175         int head;
176         if (!file->link_u.links)
177                 return 0;
178         if (skip && !(file->flags & FLAG_HLINK_EOL))
179                 head = hlink_list[file->F_HLINDEX] = file->F_NEXT;
180         else
181                 head = hlink_list[file->F_HLINDEX];
182         if (ndx != head) {
183                 struct file_struct *head_file = FPTR(head);
184                 if (!log_format_has_i && verbose > 1) {
185                         rprintf(FINFO, "\"%s\" is a hard link\n",
186                                 safe_fname(f_name(file)));
187                 }
188                 if (head_file->F_HLINDEX == FINISHED_LINK) {
189                         STRUCT_STAT st2;
190                         char *toname = f_name(head_file);
191                         if (link_stat(toname, &st2, 0) < 0) {
192                                 rsyserr(FERROR, errno, "stat %s failed",
193                                         full_fname(toname));
194                                 return -1;
195                         }
196                         maybe_hard_link(file, ndx, fname, statret, st,
197                                         toname, &st2, itemizing, code);
198                         file->F_HLINDEX = FINISHED_LINK;
199                 } else
200                         file->F_HLINDEX = SKIPPED_LINK;
201                 return 1;
202         }
203 #endif
204         return 0;
205 }
206
207 #ifdef SUPPORT_HARD_LINKS
208 int hard_link_one(struct file_struct *file, int ndx, char *fname,
209                   int statret, STRUCT_STAT *st, char *toname, int terse,
210                   int itemizing, enum logcode code)
211 {
212         if (do_link(toname, fname)) {
213                 if (terse) {
214                         if (!verbose)
215                                 return -1;
216                         code = FINFO;
217                 } else
218                         code = FERROR;
219                 rsyserr(code, errno, "link %s => %s failed",
220                         full_fname(fname), safe_fname(toname));
221                 return -1;
222         }
223
224         if (itemizing) {
225                 itemize(file, ndx, statret, st,
226                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
227                         terse ? "" : toname);
228         }
229         if (code && verbose && !terse) {
230                 rprintf(code, "%s => %s\n",
231                         safe_fname(fname), safe_fname(toname));
232         }
233         return 0;
234 }
235 #endif
236
237
238 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
239                        enum logcode code)
240 {
241 #ifdef SUPPORT_HARD_LINKS
242         char hlink1[MAXPATHLEN];
243         char *hlink2;
244         STRUCT_STAT st1, st2;
245         int statret, ndx = master;
246
247         file->F_HLINDEX = FINISHED_LINK;
248         if (link_stat(f_name_to(file, hlink1), &st1, 0) < 0)
249                 return;
250         if (!(file->flags & FLAG_HLINK_TOL)) {
251                 while (!(file->flags & FLAG_HLINK_EOL)) {
252                         ndx = file->F_NEXT;
253                         file = FPTR(ndx);
254                 }
255         }
256         do {
257                 ndx = file->F_NEXT;
258                 file = FPTR(ndx);
259                 if (file->F_HLINDEX != SKIPPED_LINK)
260                         continue;
261                 hlink2 = f_name(file);
262                 statret = link_stat(hlink2, &st2, 0);
263                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
264                                 hlink1, &st1, itemizing, code);
265                 file->F_HLINDEX = FINISHED_LINK;
266         } while (!(file->flags & FLAG_HLINK_EOL));
267 #endif
268 }