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
 126 void init_hard_links(void)
 127 {
 128         int i;
 129
 130         if (hlink_list)
 131                 free(hlink_list);
 132
 133         if (!(hlink_list = new_array(int32, the_file_list->count)))
 134                 out_of_memory("init_hard_links");
 135
 136         hlink_count = 0;
 137         for (i = 0; i < the_file_list->count; i++) {
 138                 if (F_IS_HLINKED(FPTR(i)))
 139                         hlink_list[hlink_count++] = i;
 140         }
 141
 142         qsort(hlink_list, hlink_count,
 143             sizeof hlink_list[0], (int (*)()) hlink_compare);
 144
 145         if (!hlink_count) {
 146                 free(hlink_list);
 147                 hlink_list = NULL;
 148         } else
 149                 link_idev_data();
 150 }
 151
 152 static int maybe_hard_link(struct file_struct *file, int ndx,
 153                            const char *fname, int statret, STRUCT_STAT *stp,
 154                            const char *toname, STRUCT_STAT *to_stp,
 155                            int itemizing, enum logcode code)
 156 {
 157         if (statret == 0) {
 158                 if (stp->st_dev == to_stp->st_dev
 159                  && stp->st_ino == to_stp->st_ino) {
 160                         if (itemizing) {
 161                                 itemize(file, ndx, statret, stp,
 162                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 163                                         0, "");
 164                         }
 165                         return 0;
 166                 }
 167                 if (make_backups) {
 168                         if (!make_backup(fname))
 169                                 return -1;
 170                 } else if (robust_unlink(fname)) {
 171                         rsyserr(FERROR, errno, "unlink %s failed",
 172                                 full_fname(fname));
 173                         return -1;
 174                 }
 175         }
 176         return hard_link_one(file, ndx, fname, statret, stp, toname,
 177                              0, itemizing, code);
 178 }
 179
 180 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
 181                     int statret, STRUCT_STAT *stp, int itemizing,
 182                     enum logcode code, int skip)
 183 {
 184         int head;
 185         struct hlist *hl = F_HLIST(file);
 186
 187         if (skip && !(file->flags & FLAG_HLINK_LAST))
 188                 head = hlink_list[hl->hlindex] = hl->next;
 189         else
 190                 head = hlink_list[hl->hlindex];
 191         if (ndx != head) {
 192                 struct file_struct *head_file = FPTR(head);
 193                 struct hlist *hf_hl = F_HLIST(head_file);
 194                 if (!stdout_format_has_i && verbose > 1) {
 195                         rprintf(FINFO, "\"%s\" is a hard link\n",
 196                                 f_name(file, NULL));
 197                 }
 198                 if (hf_hl->hlindex == FINISHED_LINK) {
 199                         STRUCT_STAT st2, st3;
 200                         char toname[MAXPATHLEN];
 201                         int ldu = hf_hl->dest_used;
 202                         if (ldu) {
 203                                 pathjoin(toname, MAXPATHLEN, basis_dir[ldu-1],
 204                                          f_name(head_file, NULL));
 205                         } else
 206                                 f_name(head_file, toname);
 207                         if (link_stat(toname, &st2, 0) < 0) {
 208                                 rsyserr(FERROR, errno, "stat %s failed",
 209                                         full_fname(toname));
 210                                 return -1;
 211                         }
 212                         if (statret < 0 && basis_dir[0] != NULL) {
 213                                 char cmpbuf[MAXPATHLEN];
 214                                 int j = 0;
 215                                 do {
 216                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 217                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 218                                                 continue;
 219                                         if (link_dest) {
 220                                                 if (st2.st_dev != st3.st_dev
 221                                                  || st2.st_ino != st3.st_ino)
 222                                                         continue;
 223                                                 statret = 1;
 224                                                 stp = &st3;
 225                                                 if (verbose < 2 || !stdout_format_has_i) {
 226                                                         itemizing = 0;
 227                                                         code = FNONE;
 228                                                 }
 229                                                 break;
 230                                         }
 231                                         if (!unchanged_file(cmpbuf, file, &st3))
 232                                                 continue;
 233                                         statret = 1;
 234                                         stp = &st3;
 235                                         if (unchanged_attrs(file, &st3))
 236                                                 break;
 237                                 } while (basis_dir[++j] != NULL);
 238                         }
 239                         maybe_hard_link(file, ndx, fname, statret, stp,
 240                                         toname, &st2, itemizing, code);
 241                         if (remove_source_files == 1 && do_xfers)
 242                                 send_msg_int(MSG_SUCCESS, ndx);
 243                         hl->hlindex = FINISHED_LINK;
 244                 } else
 245                         hl->hlindex = SKIPPED_LINK;
 246                 return 1;
 247         }
 248         return 0;
 249 }
 250
 251 int hard_link_one(struct file_struct *file, int ndx, const char *fname,
 252                   int statret, STRUCT_STAT *stp, const char *toname, int terse,
 253                   int itemizing, enum logcode code)
 254 {
 255         if (do_link(toname, fname)) {
 256                 if (terse) {
 257                         if (!verbose)
 258                                 return -1;
 259                         code = FINFO;
 260                 } else
 261                         code = FERROR;
 262                 rsyserr(code, errno, "link %s => %s failed",
 263                         full_fname(fname), toname);
 264                 return -1;
 265         }
 266
 267         if (itemizing) {
 268                 itemize(file, ndx, statret, stp,
 269                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 270                         terse ? "" : toname);
 271         }
 272         if (code != FNONE && verbose && !terse)
 273                 rprintf(code, "%s => %s\n", fname, toname);
 274         return 0;
 275 }
 276
 277 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 278                        enum logcode code, int dest_used)
 279 {
 280         char hlink1[MAXPATHLEN];
 281         char *hlink2;
 282         STRUCT_STAT st1, st2;
 283         int statret, ndx = master;
 284         struct hlist *hl = F_HLIST(file);
 285
 286         hl->hlindex = FINISHED_LINK;
 287         if (dry_run)
 288                 hl->dest_used = dest_used + 1;
 289         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 290                 return;
 291         if (!(file->flags & FLAG_HLINK_FIRST)) {
 292                 while (!(file->flags & FLAG_HLINK_LAST)) {
 293                         ndx = hl->next;
 294                         file = FPTR(ndx);
 295                         hl = F_HLIST(file);
 296                 }
 297         }
 298         do {
 299                 ndx = hl->next;
 300                 file = FPTR(ndx);
 301                 hl = F_HLIST(file);
 302                 if (hl->hlindex != SKIPPED_LINK)
 303                         continue;
 304                 hlink2 = f_name(file, NULL);
 305                 statret = link_stat(hlink2, &st2, 0);
 306                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 307                                 hlink1, &st1, itemizing, code);
 308                 if (remove_source_files == 1 && do_xfers)
 309                         send_msg_int(MSG_SUCCESS, ndx);
 310                 hl->hlindex = FINISHED_LINK;
 311         } while (!(file->flags & FLAG_HLINK_LAST));
 312 }
 313 #endif