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 do_xfers;
  28 extern int link_dest;
  29 extern int make_backups;
  30 extern int remove_source_files;
  31 extern int stdout_format_has_i;
  32 extern char *basis_dir[];
  33 extern struct file_list *the_file_list;
  34
  35 #ifdef SUPPORT_HARD_LINKS
  36
  37 #define SKIPPED_LINK (-1)
  38 #define FINISHED_LINK (-2)
  39
  40 #define FPTR(i) (the_file_list->files[i])
  41 #define LINKED(p1,p2) (FPTR(p1)->F_DEV == FPTR(p2)->F_DEV \
  42                     && FPTR(p1)->F_INODE == FPTR(p2)->F_INODE)
  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
  49         if (f1->F_DEV != f2->F_DEV)
  50                 return (int) (f1->F_DEV > f2->F_DEV ? 1 : -1);
  51
  52         if (f1->F_INODE != f2->F_INODE)
  53                 return (int) (f1->F_INODE > f2->F_INODE ? 1 : -1);
  54
  55         return f_name_cmp(f1, f2);
  56 }
  57
  58 static int32 *hlink_list;
  59 static int32 hlink_count;
  60
  61 /* Analyze the data in the hlink_list[], remove items that aren't multiply
  62  * linked, and replace the dev+inode data with the hlindex+next linked list. */
  63 static void link_idev_data(void)
  64 {
  65         int32 cur, from, to, start;
  66
  67         alloc_pool_t hlink_pool;
  68         alloc_pool_t idev_pool = the_file_list->hlink_pool;
  69
  70         hlink_pool = pool_create(128 * 1024, sizeof (struct hlink),
  71             out_of_memory, POOL_INTERN);
  72
  73         for (from = to = 0; from < hlink_count; from++) {
  74                 start = from;
  75                 while (1) {
  76                         cur = hlink_list[from];
  77                         if (from == hlink_count-1
  78                             || !LINKED(cur, hlink_list[from+1]))
  79                                 break;
  80                         pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  81                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  82                             struct hlink, 1, "hlink_list");
  83
  84                         FPTR(cur)->F_HLINDEX = to;
  85                         FPTR(cur)->F_NEXT = hlink_list[++from];
  86                         FPTR(cur)->link_u.links->link_dest_used = 0;
  87                 }
  88                 pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  89                 if (from > start) {
  90                         int head = hlink_list[start];
  91                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  92                             struct hlink, 1, "hlink_list");
  93
  94                         FPTR(head)->flags |= FLAG_HLINK_TOL;
  95                         FPTR(cur)->F_HLINDEX = to;
  96                         FPTR(cur)->F_NEXT = head;
  97                         FPTR(cur)->flags |= FLAG_HLINK_EOL;
  98                         FPTR(cur)->link_u.links->link_dest_used = 0;
  99                         hlink_list[to++] = head;
 100                 } else
 101                         FPTR(cur)->link_u.links = NULL;
 102         }
 103
 104         if (!to) {
 105                 free(hlink_list);
 106                 hlink_list = NULL;
 107                 pool_destroy(hlink_pool);
 108                 hlink_pool = NULL;
 109         } else {
 110                 hlink_count = to;
 111                 hlink_list = realloc_array(hlink_list, int32, hlink_count);
 112                 if (!hlink_list)
 113                         out_of_memory("init_hard_links");
 114         }
 115         the_file_list->hlink_pool = hlink_pool;
 116         pool_destroy(idev_pool);
 117 }
 118 #endif
 119
 120 void init_hard_links(void)
 121 {
 122 #ifdef SUPPORT_HARD_LINKS
 123         int i;
 124
 125         if (hlink_list)
 126                 free(hlink_list);
 127
 128         if (!(hlink_list = new_array(int32, the_file_list->count)))
 129                 out_of_memory("init_hard_links");
 130
 131         hlink_count = 0;
 132         for (i = 0; i < the_file_list->count; i++) {
 133                 if (FPTR(i)->link_u.idev)
 134                         hlink_list[hlink_count++] = i;
 135         }
 136
 137         qsort(hlink_list, hlink_count,
 138             sizeof hlink_list[0], (int (*)()) hlink_compare);
 139
 140         if (!hlink_count) {
 141                 free(hlink_list);
 142                 hlink_list = NULL;
 143         } else
 144                 link_idev_data();
 145 #endif
 146 }
 147
 148 #ifdef SUPPORT_HARD_LINKS
 149 static int maybe_hard_link(struct file_struct *file, int ndx,
 150                            char *fname, int statret, STRUCT_STAT *st,
 151                            char *toname, STRUCT_STAT *to_st,
 152                            int itemizing, enum logcode code)
 153 {
 154         if (statret == 0) {
 155                 if (st->st_dev == to_st->st_dev
 156                  && st->st_ino == to_st->st_ino) {
 157                         if (itemizing) {
 158                                 itemize(file, ndx, statret, st,
 159                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 160                                         0, "");
 161                         }
 162                         return 0;
 163                 }
 164                 if (make_backups) {
 165                         if (!make_backup(fname))
 166                                 return -1;
 167                 } else if (robust_unlink(fname)) {
 168                         rsyserr(FERROR, errno, "unlink %s failed",
 169                                 full_fname(fname));
 170                         return -1;
 171                 }
 172         }
 173         return hard_link_one(file, ndx, fname, statret, st, toname,
 174                              0, itemizing, code);
 175 }
 176 #endif
 177
 178 int hard_link_check(struct file_struct *file, int ndx, char *fname,
 179                     int statret, STRUCT_STAT *st, int itemizing,
 180                     enum logcode code, int skip)
 181 {
 182 #ifdef SUPPORT_HARD_LINKS
 183         int head;
 184         if (skip && !(file->flags & FLAG_HLINK_EOL))
 185                 head = hlink_list[file->F_HLINDEX] = file->F_NEXT;
 186         else
 187                 head = hlink_list[file->F_HLINDEX];
 188         if (ndx != head) {
 189                 struct file_struct *head_file = FPTR(head);
 190                 if (!stdout_format_has_i && verbose > 1) {
 191                         rprintf(FINFO, "\"%s\" is a hard link\n",
 192                                 f_name(file, NULL));
 193                 }
 194                 if (head_file->F_HLINDEX == FINISHED_LINK) {
 195                         STRUCT_STAT st2, st3;
 196                         char toname[MAXPATHLEN];
 197                         int ldu = head_file->link_u.links->link_dest_used;
 198                         if (ldu) {
 199                                 pathjoin(toname, MAXPATHLEN, basis_dir[ldu-1],
 200                                          f_name(head_file, NULL));
 201                         } else
 202                                 f_name(head_file, toname);
 203                         if (link_stat(toname, &st2, 0) < 0) {
 204                                 rsyserr(FERROR, errno, "stat %s failed",
 205                                         full_fname(toname));
 206                                 return -1;
 207                         }
 208                         if (statret < 0 && basis_dir[0] != NULL) {
 209                                 char cmpbuf[MAXPATHLEN];
 210                                 int j = 0;
 211                                 do {
 212                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 213                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 214                                                 continue;
 215                                         if (link_dest) {
 216                                                 if (st2.st_dev != st3.st_dev
 217                                                  || st2.st_ino != st3.st_ino)
 218                                                         continue;
 219                                                 statret = 1;
 220                                                 st = &st3;
 221                                                 if (verbose < 2 || !stdout_format_has_i) {
 222                                                         itemizing = 0;
 223                                                         code = FNONE;
 224                                                 }
 225                                                 break;
 226                                         }
 227                                         if (!unchanged_file(cmpbuf, file, &st3))
 228                                                 continue;
 229                                         statret = 1;
 230                                         st = &st3;
 231                                         if (unchanged_attrs(file, &st3))
 232                                                 break;
 233                                 } while (basis_dir[++j] != NULL);
 234                         }
 235                         maybe_hard_link(file, ndx, fname, statret, st,
 236                                         toname, &st2, itemizing, code);
 237                         if (remove_source_files == 1 && do_xfers) {
 238                                 char numbuf[4];
 239                                 SIVAL(numbuf, 0, ndx);
 240                                 send_msg(MSG_SUCCESS, numbuf, 4);
 241                         }
 242                         file->F_HLINDEX = FINISHED_LINK;
 243                 } else
 244                         file->F_HLINDEX = SKIPPED_LINK;
 245                 return 1;
 246         }
 247 #endif
 248         return 0;
 249 }
 250
 251 #ifdef SUPPORT_HARD_LINKS
 252 int hard_link_one(struct file_struct *file, int ndx, char *fname,
 253                   int statret, STRUCT_STAT *st, char *toname, int terse,
 254                   int itemizing, enum logcode code)
 255 {
 256         if (do_link(toname, fname)) {
 257                 if (terse) {
 258                         if (!verbose)
 259                                 return -1;
 260                         code = FINFO;
 261                 } else
 262                         code = FERROR;
 263                 rsyserr(code, errno, "link %s => %s failed",
 264                         full_fname(fname), toname);
 265                 return -1;
 266         }
 267
 268         if (itemizing) {
 269                 itemize(file, ndx, statret, st,
 270                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 271                         terse ? "" : toname);
 272         }
 273         if (code != FNONE && verbose && !terse)
 274                 rprintf(code, "%s => %s\n", fname, toname);
 275         return 0;
 276 }
 277 #endif
 278
 279
 280 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 281                        enum logcode code)
 282 {
 283 #ifdef SUPPORT_HARD_LINKS
 284         char hlink1[MAXPATHLEN];
 285         char *hlink2;
 286         STRUCT_STAT st1, st2;
 287         int statret, ndx = master;
 288
 289         file->F_HLINDEX = FINISHED_LINK;
 290         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 291                 return;
 292         if (!(file->flags & FLAG_HLINK_TOL)) {
 293                 while (!(file->flags & FLAG_HLINK_EOL)) {
 294                         ndx = file->F_NEXT;
 295                         file = FPTR(ndx);
 296                 }
 297         }
 298         do {
 299                 ndx = file->F_NEXT;
 300                 file = FPTR(ndx);
 301                 if (file->F_HLINDEX != SKIPPED_LINK)
 302                         continue;
 303                 hlink2 = f_name(file, NULL);
 304                 statret = link_stat(hlink2, &st2, 0);
 305                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 306                                 hlink1, &st1, itemizing, code);
 307                 if (remove_source_files == 1 && do_xfers) {
 308                         char numbuf[4];
 309                         SIVAL(numbuf, 0, ndx);
 310                         send_msg(MSG_SUCCESS, numbuf, 4);
 311                 }
 312                 file->F_HLINDEX = FINISHED_LINK;
 313         } while (!(file->flags & FLAG_HLINK_EOL));
 314 #endif
 315 }