hlink.c

   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, 2005, 2006 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 2 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, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
  22  */
  23
  24 #include "rsync.h"
  25
  26 extern int verbose;
  27 extern int dry_run;
  28 extern int do_xfers;
  29 extern int link_dest;
  30 extern int make_backups;
  31 extern int remove_source_files;
  32 extern int stdout_format_has_i;
  33 extern char *basis_dir[];
  34 extern struct file_list *the_file_list;
  35
  36 #ifdef SUPPORT_HARD_LINKS
  37
  38 #define SKIPPED_LINK (-1)
  39 #define FINISHED_LINK (-2)
  40
  41 #define FPTR(i) (the_file_list->files[i])
  42 #define LINKED(i1,i2) ((i1)->dev == (i2)->dev && (i1)->ino == (i2)->ino)
  43
  44 static int hlink_compare(int *int1, int *int2)
  45 {
  46         struct file_struct *f1 = FPTR(*int1);
  47         struct file_struct *f2 = FPTR(*int2);
  48         struct idev *i1 = F_IDEV(f1);
  49         struct idev *i2 = F_IDEV(f2);
  50
  51         if (i1->dev != i2->dev)
  52                 return i1->dev > i2->dev ? 1 : -1;
  53
  54         if (i1->ino != i2->ino)
  55                 return i1->ino > i2->ino ? 1 : -1;
  56
  57         return f_name_cmp(f1, f2);
  58 }
  59
  60 static int32 *hlink_list;
  61 static int32 hlink_count;
  62
  63 /* Analyze the data in the hlink_list[], remove items that aren't multiply
  64  * linked, and replace the dev+inode data with the hlindex+next linked list. */
  65 static void link_idev_data(void)
  66 {
  67         int32 from, to, start;
  68         struct file_struct *file, *file_next;
  69         struct idev *idev, *idev_next;
  70         struct hlist *hl;
  71
  72         alloc_pool_t hlink_pool;
  73         alloc_pool_t idev_pool = the_file_list->hlink_pool;
  74
  75         hlink_pool = pool_create(128 * 1024, sizeof (struct hlist), out_of_memory, POOL_INTERN);
  76
  77         for (from = to = 0; from < hlink_count; from++) {
  78                 start = from;
  79                 for (file = FPTR(hlink_list[from]), idev = F_IDEV(file);
  80                      from < hlink_count-1;
  81                      file = file_next, idev = idev_next)
  82                 {
  83                         file_next = FPTR(hlink_list[from+1]);
  84                         idev_next = F_IDEV(file_next);
  85                         if (!LINKED(idev, idev_next))
  86                                 break;
  87                         pool_free(idev_pool, 0, idev);
  88                         hl = pool_talloc(hlink_pool, struct hlist, 1,
  89                                          "hlink_list");
  90                         hl->hlindex = to;
  91                         hl->next = hlink_list[++from];
  92                         hl->dest_used = 0;
  93                         F_HLIST(file) = hl;
  94                 }
  95                 pool_free(idev_pool, 0, idev);
  96                 if (from > start) {
  97                         int head = hlink_list[start];
  98                         hl = pool_talloc(hlink_pool, struct hlist, 1,
  99                                          "hlink_list");
 100                         FPTR(head)->flags |= FLAG_HLINK_FIRST;
 101                         hl->hlindex = to;
 102                         hl->next = head;
 103                         hl->dest_used = 0;
 104                         hlink_list[to++] = head;
 105                         file->flags |= FLAG_HLINK_LAST;
 106                         F_HLIST(file) = hl;
 107                 } else
 108                         file->flags &= ~FLAG_HLINKED;
 109         }
 110
 111         if (!to) {
 112                 free(hlink_list);
 113                 hlink_list = NULL;
 114                 pool_destroy(hlink_pool);
 115                 hlink_pool = NULL;
 116         } else {
 117                 hlink_count = to;
 118                 hlink_list = realloc_array(hlink_list, int32, hlink_count);
 119                 if (!hlink_list)
 120                         out_of_memory("init_hard_links");
 121         }
 122         the_file_list->hlink_pool = hlink_pool;
 123         pool_destroy(idev_pool);
 124 }
 125 #endif
 126
 127 void init_hard_links(void)
 128 {
 129 #ifdef SUPPORT_HARD_LINKS
 130         int i;
 131
 132         if (hlink_list)
 133                 free(hlink_list);
 134
 135         if (!(hlink_list = new_array(int32, the_file_list->count)))
 136                 out_of_memory("init_hard_links");
 137
 138         hlink_count = 0;
 139         for (i = 0; i < the_file_list->count; i++) {
 140                 if (F_IS_HLINKED(FPTR(i)))
 141                         hlink_list[hlink_count++] = i;
 142         }
 143
 144         qsort(hlink_list, hlink_count,
 145             sizeof hlink_list[0], (int (*)()) hlink_compare);
 146
 147         if (!hlink_count) {
 148                 free(hlink_list);
 149                 hlink_list = NULL;
 150         } else
 151                 link_idev_data();
 152 #endif
 153 }
 154
 155 #ifdef SUPPORT_HARD_LINKS
 156 static int maybe_hard_link(struct file_struct *file, int ndx,
 157                            char *fname, int statret, STRUCT_STAT *st,
 158                            char *toname, STRUCT_STAT *to_st,
 159                            int itemizing, enum logcode code)
 160 {
 161         if (statret == 0) {
 162                 if (st->st_dev == to_st->st_dev
 163                  && st->st_ino == to_st->st_ino) {
 164                         if (itemizing) {
 165                                 itemize(file, ndx, statret, st,
 166                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 167                                         0, "");
 168                         }
 169                         return 0;
 170                 }
 171                 if (make_backups) {
 172                         if (!make_backup(fname))
 173                                 return -1;
 174                 } else if (robust_unlink(fname)) {
 175                         rsyserr(FERROR, errno, "unlink %s failed",
 176                                 full_fname(fname));
 177                         return -1;
 178                 }
 179         }
 180         return hard_link_one(file, ndx, fname, statret, st, toname,
 181                              0, itemizing, code);
 182 }
 183 #endif
 184
 185 int hard_link_check(struct file_struct *file, int ndx, char *fname,
 186                     int statret, STRUCT_STAT *st, int itemizing,
 187                     enum logcode code, int skip)
 188 {
 189 #ifdef SUPPORT_HARD_LINKS
 190         int head;
 191         struct hlist *hl = F_HLIST(file);
 192
 193         if (skip && !(file->flags & FLAG_HLINK_LAST))
 194                 head = hlink_list[hl->hlindex] = hl->next;
 195         else
 196                 head = hlink_list[hl->hlindex];
 197         if (ndx != head) {
 198                 struct file_struct *head_file = FPTR(head);
 199                 struct hlist *hf_hl = F_HLIST(head_file);
 200                 if (!stdout_format_has_i && verbose > 1) {
 201                         rprintf(FINFO, "\"%s\" is a hard link\n",
 202                                 f_name(file, NULL));
 203                 }
 204                 if (hf_hl->hlindex == FINISHED_LINK) {
 205                         STRUCT_STAT st2, st3;
 206                         char toname[MAXPATHLEN];
 207                         int ldu = hf_hl->dest_used;
 208                         if (ldu) {
 209                                 pathjoin(toname, MAXPATHLEN, basis_dir[ldu-1],
 210                                          f_name(head_file, NULL));
 211                         } else
 212                                 f_name(head_file, toname);
 213                         if (link_stat(toname, &st2, 0) < 0) {
 214                                 rsyserr(FERROR, errno, "stat %s failed",
 215                                         full_fname(toname));
 216                                 return -1;
 217                         }
 218                         if (statret < 0 && basis_dir[0] != NULL) {
 219                                 char cmpbuf[MAXPATHLEN];
 220                                 int j = 0;
 221                                 do {
 222                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 223                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 224                                                 continue;
 225                                         if (link_dest) {
 226                                                 if (st2.st_dev != st3.st_dev
 227                                                  || st2.st_ino != st3.st_ino)
 228                                                         continue;
 229                                                 statret = 1;
 230                                                 st = &st3;
 231                                                 if (verbose < 2 || !stdout_format_has_i) {
 232                                                         itemizing = 0;
 233                                                         code = FNONE;
 234                                                 }
 235                                                 break;
 236                                         }
 237                                         if (!unchanged_file(cmpbuf, file, &st3))
 238                                                 continue;
 239                                         statret = 1;
 240                                         st = &st3;
 241                                         if (unchanged_attrs(file, &st3))
 242                                                 break;
 243                                 } while (basis_dir[++j] != NULL);
 244                         }
 245                         maybe_hard_link(file, ndx, fname, statret, st,
 246                                         toname, &st2, itemizing, code);
 247                         if (remove_source_files == 1 && do_xfers)
 248                                 send_msg_int(MSG_SUCCESS, ndx);
 249                         hl->hlindex = FINISHED_LINK;
 250                 } else
 251                         hl->hlindex = SKIPPED_LINK;
 252                 return 1;
 253         }
 254 #endif
 255         return 0;
 256 }
 257
 258 #ifdef SUPPORT_HARD_LINKS
 259 int hard_link_one(struct file_struct *file, int ndx, char *fname,
 260                   int statret, STRUCT_STAT *st, char *toname, int terse,
 261                   int itemizing, enum logcode code)
 262 {
 263         if (do_link(toname, fname)) {
 264                 if (terse) {
 265                         if (!verbose)
 266                                 return -1;
 267                         code = FINFO;
 268                 } else
 269                         code = FERROR;
 270                 rsyserr(code, errno, "link %s => %s failed",
 271                         full_fname(fname), toname);
 272                 return -1;
 273         }
 274
 275         if (itemizing) {
 276                 itemize(file, ndx, statret, st,
 277                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 278                         terse ? "" : toname);
 279         }
 280         if (code != FNONE && verbose && !terse)
 281                 rprintf(code, "%s => %s\n", fname, toname);
 282         return 0;
 283 }
 284 #endif
 285
 286
 287 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 288                        enum logcode code, int dest_used)
 289 {
 290 #ifdef SUPPORT_HARD_LINKS
 291         char hlink1[MAXPATHLEN];
 292         char *hlink2;
 293         STRUCT_STAT st1, st2;
 294         int statret, ndx = master;
 295         struct hlist *hl = F_HLIST(file);
 296
 297         hl->hlindex = FINISHED_LINK;
 298         if (dry_run)
 299                 hl->dest_used = dest_used + 1;
 300         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 301                 return;
 302         if (!(file->flags & FLAG_HLINK_FIRST)) {
 303                 while (!(file->flags & FLAG_HLINK_LAST)) {
 304                         ndx = hl->next;
 305                         file = FPTR(ndx);
 306                         hl = F_HLIST(file);
 307                 }
 308         }
 309         do {
 310                 ndx = hl->next;
 311                 file = FPTR(ndx);
 312                 hl = F_HLIST(file);
 313                 if (hl->hlindex != SKIPPED_LINK)
 314                         continue;
 315                 hlink2 = f_name(file, NULL);
 316                 statret = link_stat(hlink2, &st2, 0);
 317                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 318                                 hlink1, &st1, itemizing, code);
 319                 if (remove_source_files == 1 && do_xfers)
 320                         send_msg_int(MSG_SUCCESS, ndx);
 321                 hl->hlindex = FINISHED_LINK;
 322         } while (!(file->flags & FLAG_HLINK_LAST));
 323 #endif
 324 }