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