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 flist_extra_ndx;
  32 extern int remove_source_files;
  33 extern int stdout_format_has_i;
  34 extern char *basis_dir[];
  35 extern struct file_list *the_file_list;
  36
  37 #ifdef SUPPORT_HARD_LINKS
  38
  39 #define SKIPPED_LINK (-1)
  40 #define FINISHED_LINK (-2)
  41
  42 #define FPTR(i) (the_file_list->files[i])
  43 #define LINKED(i1,i2) ((i1)->dev == (i2)->dev && (i1)->ino == (i2)->ino)
  44
  45 static int hlink_compare(int *int1, int *int2)
  46 {
  47         struct file_struct *f1 = FPTR(*int1);
  48         struct file_struct *f2 = FPTR(*int2);
  49         struct idev *i1 = F_IDEV(f1);
  50         struct idev *i2 = F_IDEV(f2);
  51
  52         if (i1->dev != i2->dev)
  53                 return i1->dev > i2->dev ? 1 : -1;
  54
  55         if (i1->ino != i2->ino)
  56                 return i1->ino > i2->ino ? 1 : -1;
  57
  58         return f_name_cmp(f1, f2);
  59 }
  60
  61 static int32 *hlink_list;
  62 static int32 hlink_count;
  63
  64 /* Analyze the data in the hlink_list[], remove items that aren't multiply
  65  * linked, and replace the dev+inode data with the hlindex+next linked list. */
  66 static void link_idev_data(void)
  67 {
  68         int32 from, to, start;
  69         struct file_struct *file, *file_next;
  70         struct idev *idev, *idev_next;
  71         struct hlist *hl;
  72
  73         alloc_pool_t hlink_pool;
  74         alloc_pool_t idev_pool = the_file_list->hlink_pool;
  75
  76         hlink_pool = pool_create(128 * 1024, sizeof (struct hlist), out_of_memory, POOL_INTERN);
  77
  78         for (from = to = 0; from < hlink_count; from++) {
  79                 start = from;
  80                 for (file = FPTR(hlink_list[from]), idev = F_IDEV(file);
  81                      from < hlink_count-1;
  82                      file = file_next, idev = idev_next)
  83                 {
  84                         file_next = FPTR(hlink_list[from+1]);
  85                         idev_next = F_IDEV(file_next);
  86                         if (!LINKED(idev, idev_next))
  87                                 break;
  88                         pool_free(idev_pool, 0, idev);
  89                         hl = pool_talloc(hlink_pool, struct hlist, 1,
  90                                          "hlink_list");
  91                         hl->hlindex = to;
  92                         hl->next = hlink_list[++from];
  93                         hl->dest_used = 0;
  94                         F_HLIST(file) = hl;
  95                 }
  96                 pool_free(idev_pool, 0, idev);
  97                 if (from > start) {
  98                         int head = hlink_list[start];
  99                         hl = pool_talloc(hlink_pool, struct hlist, 1,
 100                                          "hlink_list");
 101                         FPTR(head)->flags |= FLAG_HLINK_FIRST;
 102                         hl->hlindex = to;
 103                         hl->next = head;
 104                         hl->dest_used = 0;
 105                         hlink_list[to++] = head;
 106                         file->flags |= FLAG_HLINK_LAST;
 107                         F_HLIST(file) = hl;
 108                 } else
 109                         file->flags &= ~FLAG_HLINK_INFO;
 110         }
 111
 112         if (!to) {
 113                 free(hlink_list);
 114                 hlink_list = NULL;
 115                 pool_destroy(hlink_pool);
 116                 hlink_pool = NULL;
 117         } else {
 118                 hlink_count = to;
 119                 hlink_list = realloc_array(hlink_list, int32, hlink_count);
 120                 if (!hlink_list)
 121                         out_of_memory("init_hard_links");
 122         }
 123         the_file_list->hlink_pool = hlink_pool;
 124         pool_destroy(idev_pool);
 125 }
 126 #endif
 127
 128 void init_hard_links(void)
 129 {
 130 #ifdef SUPPORT_HARD_LINKS
 131         int i;
 132
 133         if (hlink_list)
 134                 free(hlink_list);
 135
 136         if (!(hlink_list = new_array(int32, the_file_list->count)))
 137                 out_of_memory("init_hard_links");
 138
 139         hlink_count = 0;
 140         for (i = 0; i < the_file_list->count; i++) {
 141                 if (IS_HLINKED(FPTR(i)))
 142                         hlink_list[hlink_count++] = i;
 143         }
 144
 145         qsort(hlink_list, hlink_count,
 146             sizeof hlink_list[0], (int (*)()) hlink_compare);
 147
 148         if (!hlink_count) {
 149                 free(hlink_list);
 150                 hlink_list = NULL;
 151         } else
 152                 link_idev_data();
 153 #endif
 154 }
 155
 156 #ifdef SUPPORT_HARD_LINKS
 157 static int maybe_hard_link(struct file_struct *file, int ndx,
 158                            char *fname, int statret, STRUCT_STAT *st,
 159                            char *toname, STRUCT_STAT *to_st,
 160                            int itemizing, enum logcode code)
 161 {
 162         if (statret == 0) {
 163                 if (st->st_dev == to_st->st_dev
 164                  && st->st_ino == to_st->st_ino) {
 165                         if (itemizing) {
 166                                 itemize(file, ndx, statret, st,
 167                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 168                                         0, "");
 169                         }
 170                         return 0;
 171                 }
 172                 if (make_backups) {
 173                         if (!make_backup(fname))
 174                                 return -1;
 175                 } else if (robust_unlink(fname)) {
 176                         rsyserr(FERROR, errno, "unlink %s failed",
 177                                 full_fname(fname));
 178                         return -1;
 179                 }
 180         }
 181         return hard_link_one(file, ndx, fname, statret, st, toname,
 182                              0, itemizing, code);
 183 }
 184 #endif
 185
 186 int hard_link_check(struct file_struct *file, int ndx, char *fname,
 187                     int statret, STRUCT_STAT *st, int itemizing,
 188                     enum logcode code, int skip)
 189 {
 190 #ifdef SUPPORT_HARD_LINKS
 191         int head;
 192         struct hlist *hl = F_HLIST(file);
 193
 194         if (skip && !(file->flags & FLAG_HLINK_LAST))
 195                 head = hlink_list[hl->hlindex] = hl->next;
 196         else
 197                 head = hlink_list[hl->hlindex];
 198         if (ndx != head) {
 199                 struct file_struct *head_file = FPTR(head);
 200                 struct hlist *hf_hl = F_HLIST(head_file);
 201                 if (!stdout_format_has_i && verbose > 1) {
 202                         rprintf(FINFO, "\"%s\" is a hard link\n",
 203                                 f_name(file, NULL));
 204                 }
 205                 if (hf_hl->hlindex == FINISHED_LINK) {
 206                         STRUCT_STAT st2, st3;
 207                         char toname[MAXPATHLEN];
 208                         int ldu = hf_hl->dest_used;
 209                         if (ldu) {
 210                                 pathjoin(toname, MAXPATHLEN, basis_dir[ldu-1],
 211                                          f_name(head_file, NULL));
 212                         } else
 213                                 f_name(head_file, toname);
 214                         if (link_stat(toname, &st2, 0) < 0) {
 215                                 rsyserr(FERROR, errno, "stat %s failed",
 216                                         full_fname(toname));
 217                                 return -1;
 218                         }
 219                         if (statret < 0 && basis_dir[0] != NULL) {
 220                                 char cmpbuf[MAXPATHLEN];
 221                                 int j = 0;
 222                                 do {
 223                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 224                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 225                                                 continue;
 226                                         if (link_dest) {
 227                                                 if (st2.st_dev != st3.st_dev
 228                                                  || st2.st_ino != st3.st_ino)
 229                                                         continue;
 230                                                 statret = 1;
 231                                                 st = &st3;
 232                                                 if (verbose < 2 || !stdout_format_has_i) {
 233                                                         itemizing = 0;
 234                                                         code = FNONE;
 235                                                 }
 236                                                 break;
 237                                         }
 238                                         if (!unchanged_file(cmpbuf, file, &st3))
 239                                                 continue;
 240                                         statret = 1;
 241                                         st = &st3;
 242                                         if (unchanged_attrs(file, &st3))
 243                                                 break;
 244                                 } while (basis_dir[++j] != NULL);
 245                         }
 246                         maybe_hard_link(file, ndx, fname, statret, st,
 247                                         toname, &st2, itemizing, code);
 248                         if (remove_source_files == 1 && do_xfers)
 249                                 send_msg_int(MSG_SUCCESS, ndx);
 250                         hl->hlindex = FINISHED_LINK;
 251                 } else
 252                         hl->hlindex = SKIPPED_LINK;
 253                 return 1;
 254         }
 255 #endif
 256         return 0;
 257 }
 258
 259 #ifdef SUPPORT_HARD_LINKS
 260 int hard_link_one(struct file_struct *file, int ndx, char *fname,
 261                   int statret, STRUCT_STAT *st, char *toname, int terse,
 262                   int itemizing, enum logcode code)
 263 {
 264         if (do_link(toname, fname)) {
 265                 if (terse) {
 266                         if (!verbose)
 267                                 return -1;
 268                         code = FINFO;
 269                 } else
 270                         code = FERROR;
 271                 rsyserr(code, errno, "link %s => %s failed",
 272                         full_fname(fname), toname);
 273                 return -1;
 274         }
 275
 276         if (itemizing) {
 277                 itemize(file, ndx, statret, st,
 278                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 279                         terse ? "" : toname);
 280         }
 281         if (code != FNONE && verbose && !terse)
 282                 rprintf(code, "%s => %s\n", fname, toname);
 283         return 0;
 284 }
 285 #endif
 286
 287
 288 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 289                        enum logcode code, int dest_used)
 290 {
 291 #ifdef SUPPORT_HARD_LINKS
 292         char hlink1[MAXPATHLEN];
 293         char *hlink2;
 294         STRUCT_STAT st1, st2;
 295         int statret, ndx = master;
 296         struct hlist *hl = F_HLIST(file);
 297
 298         hl->hlindex = FINISHED_LINK;
 299         if (dry_run)
 300                 hl->dest_used = dest_used + 1;
 301         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 302                 return;
 303         if (!(file->flags & FLAG_HLINK_FIRST)) {
 304                 while (!(file->flags & FLAG_HLINK_LAST)) {
 305                         ndx = hl->next;
 306                         file = FPTR(ndx);
 307                         hl = F_HLIST(file);
 308                 }
 309         }
 310         do {
 311                 ndx = hl->next;
 312                 file = FPTR(ndx);
 313                 hl = F_HLIST(file);
 314                 if (hl->hlindex != SKIPPED_LINK)
 315                         continue;
 316                 hlink2 = f_name(file, NULL);
 317                 statret = link_stat(hlink2, &st2, 0);
 318                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 319                                 hlink1, &st1, itemizing, code);
 320                 if (remove_source_files == 1 && do_xfers)
 321                         send_msg_int(MSG_SUCCESS, ndx);
 322                 hl->hlindex = FINISHED_LINK;
 323         } while (!(file->flags & FLAG_HLINK_LAST));
 324 #endif
 325 }