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) 2004-2007 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 3 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, visit the http://fsf.org website.
  21  */
  22
  23 #include "rsync.h"
  24
  25 extern int verbose;
  26 extern int dry_run;
  27 extern int am_sender;
  28 extern int inc_recurse;
  29 extern int do_xfers;
  30 extern int link_dest;
  31 extern int preserve_acls;
  32 extern int make_backups;
  33 extern int protocol_version;
  34 extern int remove_source_files;
  35 extern int stdout_format_has_i;
  36 extern int maybe_ATTRS_REPORT;
  37 extern char *basis_dir[];
  38 extern struct file_list *cur_flist;
  39 #ifdef ICONV_OPTION
  40 extern int ic_ndx;
  41 #endif
  42
  43 #ifdef SUPPORT_HARD_LINKS
  44
  45 /* Starting with protocol 30, we use a simple hashtable on the sending side
  46  * for hashing the st_dev and st_ino info.  The receiving side gets told
  47  * (via flags and a "group index") which items are hard-linked together, so
  48  * we can avoid the pool of dev+inode data.  For incremental recursion mode,
  49  * the receiver will use a ndx hash to remember old pathnames. */
  50
  51 static struct hashtable *dev_tbl;
  52
  53 static struct hashtable *prior_hlinks;
  54
  55 static struct file_list *hlink_flist;
  56
  57 void init_hard_links(void)
  58 {
  59         if (am_sender || protocol_version < 30)
  60                 dev_tbl = hashtable_create(16, SIZEOF_INT64 == 8);
  61         else if (inc_recurse)
  62                 prior_hlinks = hashtable_create(1024, 0);
  63 }
  64
  65 struct ht_int64_node *idev_find(int64 dev, int64 ino)
  66 {
  67         static struct ht_int64_node *dev_node = NULL;
  68         struct hashtable *tbl;
  69
  70         if (!dev_node || dev_node->key != dev) {
  71                 /* We keep a separate hash table of inodes for every device. */
  72                 dev_node = hashtable_find(dev_tbl, dev, 1);
  73                 if (!(tbl = dev_node->data))
  74                         tbl = dev_node->data = hashtable_create(512, SIZEOF_INT64 == 8);
  75         } else
  76                 tbl = dev_node->data;
  77
  78         return hashtable_find(tbl, ino, 1);
  79 }
  80
  81 void idev_destroy(void)
  82 {
  83         int i;
  84
  85         for (i = 0; i < dev_tbl->size; i++) {
  86                 struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
  87                 if (node->data)
  88                         hashtable_destroy(node->data);
  89         }
  90
  91         hashtable_destroy(dev_tbl);
  92 }
  93
  94 static int hlink_compare_gnum(int *int1, int *int2)
  95 {
  96         struct file_struct *f1 = hlink_flist->sorted[*int1];
  97         struct file_struct *f2 = hlink_flist->sorted[*int2];
  98         int32 gnum1 = F_HL_GNUM(f1);
  99         int32 gnum2 = F_HL_GNUM(f2);
 100
 101         if (gnum1 != gnum2)
 102                 return gnum1 > gnum2 ? 1 : -1;
 103
 104         return *int1 > *int2 ? 1 : -1;
 105 }
 106
 107 static void match_gnums(int32 *ndx_list, int ndx_count)
 108 {
 109         int32 from, prev;
 110         struct file_struct *file, *file_next;
 111         struct ht_int32_node *node = NULL;
 112         int32 gnum, gnum_next;
 113
 114         qsort(ndx_list, ndx_count, sizeof ndx_list[0],
 115              (int (*)()) hlink_compare_gnum);
 116
 117         for (from = 0; from < ndx_count; from++) {
 118                 file = hlink_flist->sorted[ndx_list[from]];
 119                 gnum = F_HL_GNUM(file);
 120                 if (inc_recurse) {
 121                         node = hashtable_find(prior_hlinks, gnum, 1);
 122                         if (!node->data) {
 123                                 node->data = new_array0(char, 5);
 124                                 assert(gnum >= hlink_flist->ndx_start);
 125                                 file->flags |= FLAG_HLINK_FIRST;
 126                                 prev = -1;
 127                         } else if (CVAL(node->data, 0) == 0) {
 128                                 struct file_list *flist;
 129                                 struct file_struct *fp;
 130                                 prev = IVAL(node->data, 1);
 131                                 flist = flist_for_ndx(prev);
 132                                 assert(flist != NULL);
 133                                 fp = flist->files[prev - flist->ndx_start];
 134                                 fp->flags &= ~FLAG_HLINK_LAST;
 135                         } else
 136                                 prev = -1;
 137                 } else {
 138                         file->flags |= FLAG_HLINK_FIRST;
 139                         prev = -1;
 140                 }
 141                 for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
 142                         file_next = hlink_flist->sorted[ndx_list[from+1]];
 143                         gnum_next = F_HL_GNUM(file_next);
 144                         if (gnum != gnum_next)
 145                                 break;
 146                         F_HL_PREV(file) = prev;
 147                         /* The linked list must use raw ndx values. */
 148 #ifdef ICONV_OPTION
 149                         if (ic_ndx)
 150                                 prev = F_NDX(file);
 151                         else
 152 #endif
 153                                 prev = ndx_list[from] + hlink_flist->ndx_start;
 154                 }
 155                 if (prev < 0 && !inc_recurse) {
 156                         /* Disable hard-link bit and set DONE so that
 157                          * HLINK_BUMP()-dependent values are unaffected. */
 158                         file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
 159                         file->flags |= FLAG_HLINK_DONE;
 160                         continue;
 161                 }
 162
 163                 file->flags |= FLAG_HLINK_LAST;
 164                 F_HL_PREV(file) = prev;
 165                 if (inc_recurse && CVAL(node->data, 0) == 0) {
 166 #ifdef ICONV_OPTION
 167                         if (ic_ndx)
 168                                 prev = F_NDX(file);
 169                         else
 170 #endif
 171                                 prev = ndx_list[from] + hlink_flist->ndx_start;
 172                         SIVAL(node->data, 1, prev);
 173                 }
 174         }
 175 }
 176
 177 /* Analyze the hard-links in the file-list by creating a list of all the
 178  * items that have hlink data, sorting them, and matching up identical
 179  * values into clusters.  These will be a single linked list from last
 180  * to first when we're done. */
 181 void match_hard_links(struct file_list *flist)
 182 {
 183         int i, ndx_count = 0;
 184         int32 *ndx_list;
 185
 186         if (!(ndx_list = new_array(int32, flist->used)))
 187                 out_of_memory("match_hard_links");
 188
 189         for (i = 0; i < flist->used; i++) {
 190                 if (F_IS_HLINKED(flist->sorted[i]))
 191                         ndx_list[ndx_count++] = i;
 192         }
 193
 194         hlink_flist = flist;
 195
 196         if (ndx_count)
 197                 match_gnums(ndx_list, ndx_count);
 198
 199         free(ndx_list);
 200         if (protocol_version < 30)
 201                 idev_destroy();
 202 }
 203
 204 static int maybe_hard_link(struct file_struct *file, int ndx,
 205                            const char *fname, int statret, statx *sxp,
 206                            const char *oldname, STRUCT_STAT *old_stp,
 207                            const char *realname, int itemizing, enum logcode code)
 208 {
 209         if (statret == 0) {
 210                 if (sxp->st.st_dev == old_stp->st_dev
 211                  && sxp->st.st_ino == old_stp->st_ino) {
 212                         if (itemizing) {
 213                                 itemize(fname, file, ndx, statret, sxp,
 214                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 215                                         0, "");
 216                         }
 217                         if (verbose > 1 && maybe_ATTRS_REPORT)
 218                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 219                         file->flags |= FLAG_HLINK_DONE;
 220                         return 0;
 221                 }
 222                 if (make_backups > 0) {
 223                         if (!make_backup(fname))
 224                                 return -1;
 225                 } else if (robust_unlink(fname)) {
 226                         rsyserr(FERROR, errno, "unlink %s failed",
 227                                 full_fname(fname));
 228                         return -1;
 229                 }
 230         }
 231
 232         if (hard_link_one(file, fname, oldname, 0)) {
 233                 if (itemizing) {
 234                         itemize(fname, file, ndx, statret, sxp,
 235                                 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 236                                 realname);
 237                 }
 238                 if (code != FNONE && verbose)
 239                         rprintf(code, "%s => %s\n", fname, realname);
 240                 return 0;
 241         }
 242         return -1;
 243 }
 244
 245 /* Figure out if a prior entry is still there or if we just have a
 246  * cached name for it.  Never called with a FLAG_HLINK_FIRST entry. */
 247 static char *check_prior(int prev_ndx, int gnum, struct file_list **flist_p)
 248 {
 249         struct file_list *flist = flist_for_ndx(prev_ndx);
 250         struct ht_int32_node *node;
 251
 252         if (flist) {
 253                 *flist_p = flist;
 254                 return NULL;
 255         }
 256
 257         node = hashtable_find(prior_hlinks, gnum, 0);
 258         assert(node != NULL && node->data);
 259         assert(CVAL(node->data, 0) != 0);
 260         return node->data;
 261 }
 262
 263 /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not.  Returns:
 264  * 0 = process the file, 1 = skip the file, -1 = error occurred. */
 265 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
 266                     int statret, statx *sxp, int itemizing,
 267                     enum logcode code)
 268 {
 269         STRUCT_STAT prev_st;
 270         char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
 271         char *realname, *prev_name;
 272         struct file_list *flist;
 273         int gnum = inc_recurse ? F_HL_GNUM(file) : -1;
 274         int prev_ndx = F_HL_PREV(file);
 275
 276         prev_name = realname = check_prior(prev_ndx, gnum, &flist);
 277
 278         if (!prev_name) {
 279                 struct file_struct *prev_file = flist->files[prev_ndx - flist->ndx_start];
 280
 281                 /* Is the previous link is not complete yet? */
 282                 if (!(prev_file->flags & FLAG_HLINK_DONE)) {
 283                         /* Is the previous link being transferred? */
 284                         if (prev_file->flags & FLAG_FILE_SENT) {
 285                                 /* Add ourselves to the list of files that will be
 286                                  * updated when the transfer completes, and mark
 287                                  * ourself as waiting for the transfer. */
 288                                 F_HL_PREV(file) = F_HL_PREV(prev_file);
 289                                 F_HL_PREV(prev_file) = ndx;
 290                                 file->flags |= FLAG_FILE_SENT;
 291                                 cur_flist->in_progress++;
 292                                 return 1;
 293                         }
 294                         return 0;
 295                 }
 296
 297                 /* There is a finished file to link with! */
 298                 if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
 299                         /* The previous previous is FIRST when prev is not. */
 300                         prev_ndx = F_HL_PREV(prev_file);
 301                         prev_name = realname = check_prior(prev_ndx, gnum, &flist);
 302                         /* Update our previous pointer to point to the FIRST. */
 303                         F_HL_PREV(file) = prev_ndx;
 304                 }
 305
 306                 if (!prev_name) {
 307                         int alt_dest;
 308
 309                         prev_file = flist->files[prev_ndx - flist->ndx_start];
 310                         /* F_HL_PREV() is alt_dest value when DONE && FIRST. */
 311                         alt_dest = F_HL_PREV(prev_file);
 312
 313                         if (alt_dest >= 0 && dry_run) {
 314                                 pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
 315                                          f_name(prev_file, NULL));
 316                                 prev_name = namebuf;
 317                                 realname = f_name(prev_file, altbuf);
 318                         } else {
 319                                 prev_name = f_name(prev_file, namebuf);
 320                                 realname = prev_name;
 321                         }
 322                 }
 323         }
 324
 325         if (link_stat(prev_name, &prev_st, 0) < 0) {
 326                 rsyserr(FERROR, errno, "stat %s failed",
 327                         full_fname(prev_name));
 328                 return -1;
 329         }
 330
 331         if (statret < 0 && basis_dir[0] != NULL) {
 332                 /* If we match an alt-dest item, we don't output this as a change. */
 333                 char cmpbuf[MAXPATHLEN];
 334                 statx alt_sx;
 335                 int j = 0;
 336 #ifdef SUPPORT_ACLS
 337                 alt_sx.acc_acl = alt_sx.def_acl = NULL;
 338 #endif
 339                 do {
 340                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 341                         if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
 342                                 continue;
 343                         if (link_dest) {
 344                                 if (prev_st.st_dev != alt_sx.st.st_dev
 345                                  || prev_st.st_ino != alt_sx.st.st_ino)
 346                                         continue;
 347                                 statret = 1;
 348                                 if (verbose < 2 || !stdout_format_has_i) {
 349                                         itemizing = 0;
 350                                         code = FNONE;
 351                                         if (verbose > 1 && maybe_ATTRS_REPORT)
 352                                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 353                                 }
 354                                 break;
 355                         }
 356                         if (!unchanged_file(cmpbuf, file, &alt_sx.st))
 357                                 continue;
 358                         statret = 1;
 359                         if (unchanged_attrs(cmpbuf, file, &alt_sx))
 360                                 break;
 361                 } while (basis_dir[++j] != NULL);
 362                 if (statret == 1) {
 363                         sxp->st = alt_sx.st;
 364 #ifdef SUPPORT_ACLS
 365                         if (preserve_acls && !S_ISLNK(file->mode)) {
 366                                 if (!ACL_READY(*sxp))
 367                                         get_acl(cmpbuf, sxp);
 368                                 else {
 369                                         sxp->acc_acl = alt_sx.acc_acl;
 370                                         sxp->def_acl = alt_sx.def_acl;
 371                                 }
 372                         }
 373 #endif
 374                 }
 375 #ifdef SUPPORT_ACLS
 376                 else if (preserve_acls)
 377                         free_acl(&alt_sx);
 378 #endif
 379         }
 380
 381         if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
 382                             realname, itemizing, code) < 0)
 383                 return -1;
 384
 385         if (remove_source_files == 1 && do_xfers)
 386                 send_msg_int(MSG_SUCCESS, ndx);
 387
 388         return 1;
 389 }
 390
 391 int hard_link_one(struct file_struct *file, const char *fname,
 392                   const char *oldname, int terse)
 393 {
 394         if (do_link(oldname, fname) < 0) {
 395                 enum logcode code;
 396                 if (terse) {
 397                         if (!verbose)
 398                                 return -1;
 399                         code = FINFO;
 400                 } else
 401                         code = FERROR;
 402                 rsyserr(code, errno, "link %s => %s failed",
 403                         full_fname(fname), oldname);
 404                 return 0;
 405         }
 406
 407         file->flags |= FLAG_HLINK_DONE;
 408
 409         return 1;
 410 }
 411
 412 void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
 413                       STRUCT_STAT *stp, int itemizing, enum logcode code,
 414                       int alt_dest)
 415 {
 416         statx prev_sx;
 417         STRUCT_STAT st;
 418         char alt_name[MAXPATHLEN], *prev_name;
 419         const char *our_name;
 420         struct file_list *flist;
 421         int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
 422
 423         if (stp == NULL && prev_ndx >= 0) {
 424                 if (link_stat(fname, &st, 0) < 0) {
 425                         rsyserr(FERROR, errno, "stat %s failed",
 426                                 full_fname(fname));
 427                         return;
 428                 }
 429                 stp = &st;
 430         }
 431
 432         /* FIRST combined with DONE means we were the first to get done. */
 433         file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
 434         F_HL_PREV(file) = alt_dest;
 435         if (alt_dest >= 0 && dry_run) {
 436                 pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
 437                          f_name(file, NULL));
 438                 our_name = alt_name;
 439         } else
 440                 our_name = fname;
 441
 442 #ifdef SUPPORT_ACLS
 443         prev_sx.acc_acl = prev_sx.def_acl = NULL;
 444 #endif
 445
 446         while ((ndx = prev_ndx) >= 0) {
 447                 int val;
 448                 flist = flist_for_ndx(ndx);
 449                 assert(flist != NULL);
 450                 file = flist->files[ndx - flist->ndx_start];
 451                 file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
 452                 prev_ndx = F_HL_PREV(file);
 453                 F_HL_PREV(file) = fin_ndx;
 454                 prev_name = f_name(file, NULL);
 455                 prev_statret = link_stat(prev_name, &prev_sx.st, 0);
 456                 val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
 457                                       our_name, stp, fname, itemizing, code);
 458                 flist->in_progress--;
 459 #ifdef SUPPORT_ACLS
 460                 if (preserve_acls)
 461                         free_acl(&prev_sx);
 462 #endif
 463                 if (val < 0)
 464                         continue;
 465                 if (remove_source_files == 1 && do_xfers)
 466                         send_msg_int(MSG_SUCCESS, ndx);
 467         }
 468
 469         if (inc_recurse) {
 470                 int gnum = F_HL_GNUM(file);
 471                 struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
 472                 assert(node != NULL && node->data != NULL);
 473                 assert(CVAL(node->data, 0) == 0);
 474                 free(node->data);
 475                 if (!(node->data = strdup(our_name)))
 476                         out_of_memory("finish_hard_link");
 477         }
 478 }
 479 #endif