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                         }
 126                 }
 127                 if (gnum >= hlink_flist->ndx_start) {
 128                         file->flags |= FLAG_HLINK_FIRST;
 129                         prev = -1;
 130                 } else if (CVAL(node->data, 0) == 0) {
 131                         struct file_list *flist;
 132                         prev = IVAL(node->data, 1);
 133                         flist = flist_for_ndx(prev);
 134                         assert(flist != NULL);
 135                         file_next = flist->files[prev - flist->ndx_start];
 136                         file_next->flags &= ~FLAG_HLINK_LAST;
 137                 } else
 138                         prev = -1;
 139                 for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
 140                         file_next = hlink_flist->sorted[ndx_list[from+1]];
 141                         gnum_next = F_HL_GNUM(file_next);
 142                         if (gnum != gnum_next)
 143                                 break;
 144                         F_HL_PREV(file) = prev;
 145                         /* The linked list must use raw ndx values. */
 146 #ifdef ICONV_OPTION
 147                         if (ic_ndx)
 148                                 prev = F_NDX(file);
 149                         else
 150 #endif
 151                                 prev = ndx_list[from] + hlink_flist->ndx_start;
 152                 }
 153                 if (prev < 0 && !inc_recurse) {
 154                         file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
 155                         continue;
 156                 }
 157
 158                 file->flags |= FLAG_HLINK_LAST;
 159                 F_HL_PREV(file) = prev;
 160                 if (inc_recurse && CVAL(node->data, 0) == 0) {
 161 #ifdef ICONV_OPTION
 162                         if (ic_ndx)
 163                                 prev = F_NDX(file);
 164                         else
 165 #endif
 166                                 prev = ndx_list[from] + hlink_flist->ndx_start;
 167                         SIVAL(node->data, 1, prev);
 168                 }
 169         }
 170 }
 171
 172 /* Analyze the hard-links in the file-list by creating a list of all the
 173  * items that have hlink data, sorting them, and matching up identical
 174  * values into clusters.  These will be a single linked list from last
 175  * to first when we're done. */
 176 void match_hard_links(struct file_list *flist)
 177 {
 178         int i, ndx_count = 0;
 179         int32 *ndx_list;
 180
 181         if (!(ndx_list = new_array(int32, flist->used)))
 182                 out_of_memory("match_hard_links");
 183
 184         for (i = 0; i < flist->used; i++) {
 185                 if (F_IS_HLINKED(flist->sorted[i]))
 186                         ndx_list[ndx_count++] = i;
 187         }
 188
 189         hlink_flist = flist;
 190
 191         if (ndx_count)
 192                 match_gnums(ndx_list, ndx_count);
 193
 194         free(ndx_list);
 195         if (protocol_version < 30)
 196                 idev_destroy();
 197 }
 198
 199 static int maybe_hard_link(struct file_struct *file, int ndx,
 200                            const char *fname, int statret, statx *sxp,
 201                            const char *oldname, STRUCT_STAT *old_stp,
 202                            const char *realname, int itemizing, enum logcode code)
 203 {
 204         if (statret == 0) {
 205                 if (sxp->st.st_dev == old_stp->st_dev
 206                  && sxp->st.st_ino == old_stp->st_ino) {
 207                         if (itemizing) {
 208                                 itemize(fname, file, ndx, statret, sxp,
 209                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 210                                         0, "");
 211                         }
 212                         if (verbose > 1 && maybe_ATTRS_REPORT)
 213                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 214                         file->flags |= FLAG_HLINK_DONE;
 215                         return 0;
 216                 }
 217                 if (make_backups > 0) {
 218                         if (!make_backup(fname))
 219                                 return -1;
 220                 } else if (robust_unlink(fname)) {
 221                         rsyserr(FERROR, errno, "unlink %s failed",
 222                                 full_fname(fname));
 223                         return -1;
 224                 }
 225         }
 226
 227         if (hard_link_one(file, fname, oldname, 0)) {
 228                 if (itemizing) {
 229                         itemize(fname, file, ndx, statret, sxp,
 230                                 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 231                                 realname);
 232                 }
 233                 if (code != FNONE && verbose)
 234                         rprintf(code, "%s => %s\n", fname, realname);
 235                 return 0;
 236         }
 237         return -1;
 238 }
 239
 240 /* Figure out if a prior entry is still there or if we just have a
 241  * cached name for it.  Never called with a FLAG_HLINK_FIRST entry. */
 242 static char *check_prior(int prev_ndx, int gnum)
 243 {
 244         struct file_list *flist = flist_for_ndx(prev_ndx);
 245         struct ht_int32_node *node;
 246
 247         if (flist) {
 248                 hlink_flist = flist;
 249                 return NULL;
 250         }
 251
 252         node = hashtable_find(prior_hlinks, gnum, 0);
 253         assert(node != NULL && node->data);
 254         assert(CVAL(node->data, 0) != 0);
 255         return node->data;
 256 }
 257
 258 /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not.  Returns:
 259  * 0 = process the file, 1 = skip the file, -1 = error occurred. */
 260 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
 261                     int statret, statx *sxp, int itemizing,
 262                     enum logcode code)
 263 {
 264         STRUCT_STAT prev_st;
 265         char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
 266         char *realname, *prev_name;
 267         int gnum = F_HL_GNUM(file);
 268         int prev_ndx = F_HL_PREV(file);
 269
 270         prev_name = realname = check_prior(prev_ndx, gnum);
 271
 272         if (!prev_name) {
 273                 struct file_struct *prev_file = hlink_flist->files[prev_ndx - hlink_flist->ndx_start];
 274
 275                 /* Is the previous link is not complete yet? */
 276                 if (!(prev_file->flags & FLAG_HLINK_DONE)) {
 277                         /* Is the previous link being transferred? */
 278                         if (prev_file->flags & FLAG_FILE_SENT) {
 279                                 /* Add ourselves to the list of files that will be
 280                                  * updated when the transfer completes, and mark
 281                                  * ourself as waiting for the transfer. */
 282                                 F_HL_PREV(file) = F_HL_PREV(prev_file);
 283                                 F_HL_PREV(prev_file) = ndx;
 284                                 file->flags |= FLAG_FILE_SENT;
 285                                 cur_flist->in_progress++;
 286                                 return 1;
 287                         }
 288                         return 0;
 289                 }
 290
 291                 /* There is a finished file to link with! */
 292                 if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
 293                         /* The previous previous will be marked with FIRST. */
 294                         prev_ndx = F_HL_PREV(prev_file);
 295                         prev_name = realname = check_prior(prev_ndx, gnum);
 296                         /* Update our previous pointer to point to the first. */
 297                         F_HL_PREV(file) = prev_ndx;
 298                 }
 299         }
 300         if (!prev_name) {
 301                 struct file_struct *prev_file = hlink_flist->files[prev_ndx - hlink_flist->ndx_start];
 302                 int alt_dest = F_HL_PREV(prev_file); /* alternate value when DONE && FIRST */
 303
 304                 if (alt_dest >= 0 && dry_run) {
 305                         pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
 306                                  f_name(prev_file, NULL));
 307                         prev_name = namebuf;
 308                         realname = f_name(prev_file, altbuf);
 309                 } else {
 310                         prev_name = f_name(prev_file, namebuf);
 311                         realname = prev_name;
 312                 }
 313         }
 314
 315         if (link_stat(prev_name, &prev_st, 0) < 0) {
 316                 rsyserr(FERROR, errno, "stat %s failed",
 317                         full_fname(prev_name));
 318                 return -1;
 319         }
 320
 321         if (statret < 0 && basis_dir[0] != NULL) {
 322                 /* If we match an alt-dest item, we don't output this as a change. */
 323                 char cmpbuf[MAXPATHLEN];
 324                 statx alt_sx;
 325                 int j = 0;
 326 #ifdef SUPPORT_ACLS
 327                 alt_sx.acc_acl = alt_sx.def_acl = NULL;
 328 #endif
 329                 do {
 330                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 331                         if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
 332                                 continue;
 333                         if (link_dest) {
 334                                 if (prev_st.st_dev != alt_sx.st.st_dev
 335                                  || prev_st.st_ino != alt_sx.st.st_ino)
 336                                         continue;
 337                                 statret = 1;
 338                                 if (verbose < 2 || !stdout_format_has_i) {
 339                                         itemizing = 0;
 340                                         code = FNONE;
 341                                         if (verbose > 1 && maybe_ATTRS_REPORT)
 342                                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 343                                 }
 344                                 break;
 345                         }
 346                         if (!unchanged_file(cmpbuf, file, &alt_sx.st))
 347                                 continue;
 348                         statret = 1;
 349                         if (unchanged_attrs(cmpbuf, file, &alt_sx))
 350                                 break;
 351                 } while (basis_dir[++j] != NULL);
 352                 if (statret == 1) {
 353                         sxp->st = alt_sx.st;
 354 #ifdef SUPPORT_ACLS
 355                         if (preserve_acls && !S_ISLNK(file->mode)) {
 356                                 if (!ACL_READY(*sxp))
 357                                         get_acl(cmpbuf, sxp);
 358                                 else {
 359                                         sxp->acc_acl = alt_sx.acc_acl;
 360                                         sxp->def_acl = alt_sx.def_acl;
 361                                 }
 362                         }
 363 #endif
 364                 }
 365 #ifdef SUPPORT_ACLS
 366                 else if (preserve_acls)
 367                         free_acl(&alt_sx);
 368 #endif
 369         }
 370
 371         if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
 372                             realname, itemizing, code) < 0)
 373                 return -1;
 374
 375         if (remove_source_files == 1 && do_xfers)
 376                 send_msg_int(MSG_SUCCESS, ndx);
 377
 378         return 1;
 379 }
 380
 381 int hard_link_one(struct file_struct *file, const char *fname,
 382                   const char *oldname, int terse)
 383 {
 384         if (do_link(oldname, fname) < 0) {
 385                 enum logcode code;
 386                 if (terse) {
 387                         if (!verbose)
 388                                 return -1;
 389                         code = FINFO;
 390                 } else
 391                         code = FERROR;
 392                 rsyserr(code, errno, "link %s => %s failed",
 393                         full_fname(fname), oldname);
 394                 return 0;
 395         }
 396
 397         file->flags |= FLAG_HLINK_DONE;
 398
 399         return 1;
 400 }
 401
 402 void finish_hard_link(struct file_struct *file, const char *fname,
 403                       STRUCT_STAT *stp, int itemizing, enum logcode code,
 404                       int alt_dest)
 405 {
 406         statx prev_sx;
 407         STRUCT_STAT st;
 408         char alt_name[MAXPATHLEN], *prev_name;
 409         const char *our_name;
 410         struct file_list *flist;
 411         int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
 412
 413         if (stp == NULL && prev_ndx >= 0) {
 414                 if (link_stat(fname, &st, 0) < 0) {
 415                         rsyserr(FERROR, errno, "stat %s failed",
 416                                 full_fname(fname));
 417                         return;
 418                 }
 419                 stp = &st;
 420         }
 421
 422         /* FIRST combined with DONE means we were the first to get done. */
 423         file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
 424         F_HL_PREV(file) = alt_dest;
 425         if (alt_dest >= 0 && dry_run) {
 426                 pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
 427                          f_name(file, NULL));
 428                 our_name = alt_name;
 429         } else
 430                 our_name = fname;
 431
 432 #ifdef SUPPORT_ACLS
 433         prev_sx.acc_acl = prev_sx.def_acl = NULL;
 434 #endif
 435
 436         while ((ndx = prev_ndx) >= 0) {
 437                 int val;
 438                 flist = flist_for_ndx(ndx);
 439                 assert(flist != NULL);
 440                 file = flist->files[ndx - flist->ndx_start];
 441                 file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
 442                 prev_ndx = F_HL_PREV(file);
 443                 prev_name = f_name(file, NULL);
 444                 prev_statret = link_stat(prev_name, &prev_sx.st, 0);
 445                 val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
 446                                       our_name, stp, fname, itemizing, code);
 447                 flist->in_progress--;
 448 #ifdef SUPPORT_ACLS
 449                 if (preserve_acls)
 450                         free_acl(&prev_sx);
 451 #endif
 452                 if (val < 0)
 453                         continue;
 454                 if (remove_source_files == 1 && do_xfers)
 455                         send_msg_int(MSG_SUCCESS, ndx);
 456         }
 457
 458         if (inc_recurse) {
 459                 int gnum = F_HL_GNUM(file);
 460                 struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
 461                 assert(node != NULL && node->data != NULL);
 462                 assert(CVAL(node->data, 0) == 0);
 463                 free(node->data);
 464                 if (!(node->data = strdup(our_name)))
 465                         out_of_memory("finish_hard_link");
 466         }
 467 }
 468 #endif