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                         /* Indicate that this item isn't hard-linked without
 155                          * affecting any HLINK_BUMP()-dependent values. */
 156                         file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
 157                         file->flags |= FLAG_HLINK_DONE;
 158                         continue;
 159                 }
 160
 161                 file->flags |= FLAG_HLINK_LAST;
 162                 F_HL_PREV(file) = prev;
 163                 if (inc_recurse && CVAL(node->data, 0) == 0) {
 164 #ifdef ICONV_OPTION
 165                         if (ic_ndx)
 166                                 prev = F_NDX(file);
 167                         else
 168 #endif
 169                                 prev = ndx_list[from] + hlink_flist->ndx_start;
 170                         SIVAL(node->data, 1, prev);
 171                 }
 172         }
 173 }
 174
 175 /* Analyze the hard-links in the file-list by creating a list of all the
 176  * items that have hlink data, sorting them, and matching up identical
 177  * values into clusters.  These will be a single linked list from last
 178  * to first when we're done. */
 179 void match_hard_links(struct file_list *flist)
 180 {
 181         int i, ndx_count = 0;
 182         int32 *ndx_list;
 183
 184         if (!(ndx_list = new_array(int32, flist->used)))
 185                 out_of_memory("match_hard_links");
 186
 187         for (i = 0; i < flist->used; i++) {
 188                 if (F_IS_HLINKED(flist->sorted[i]))
 189                         ndx_list[ndx_count++] = i;
 190         }
 191
 192         hlink_flist = flist;
 193
 194         if (ndx_count)
 195                 match_gnums(ndx_list, ndx_count);
 196
 197         free(ndx_list);
 198         if (protocol_version < 30)
 199                 idev_destroy();
 200 }
 201
 202 static int maybe_hard_link(struct file_struct *file, int ndx,
 203                            const char *fname, int statret, statx *sxp,
 204                            const char *oldname, STRUCT_STAT *old_stp,
 205                            const char *realname, int itemizing, enum logcode code)
 206 {
 207         if (statret == 0) {
 208                 if (sxp->st.st_dev == old_stp->st_dev
 209                  && sxp->st.st_ino == old_stp->st_ino) {
 210                         if (itemizing) {
 211                                 itemize(fname, file, ndx, statret, sxp,
 212                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 213                                         0, "");
 214                         }
 215                         if (verbose > 1 && maybe_ATTRS_REPORT)
 216                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 217                         file->flags |= FLAG_HLINK_DONE;
 218                         return 0;
 219                 }
 220                 if (make_backups > 0) {
 221                         if (!make_backup(fname))
 222                                 return -1;
 223                 } else if (robust_unlink(fname)) {
 224                         rsyserr(FERROR, errno, "unlink %s failed",
 225                                 full_fname(fname));
 226                         return -1;
 227                 }
 228         }
 229
 230         if (hard_link_one(file, fname, oldname, 0)) {
 231                 if (itemizing) {
 232                         itemize(fname, file, ndx, statret, sxp,
 233                                 ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 234                                 realname);
 235                 }
 236                 if (code != FNONE && verbose)
 237                         rprintf(code, "%s => %s\n", fname, realname);
 238                 return 0;
 239         }
 240         return -1;
 241 }
 242
 243 /* Figure out if a prior entry is still there or if we just have a
 244  * cached name for it.  Never called with a FLAG_HLINK_FIRST entry. */
 245 static char *check_prior(int prev_ndx, int gnum)
 246 {
 247         struct file_list *flist = flist_for_ndx(prev_ndx);
 248         struct ht_int32_node *node;
 249
 250         if (flist) {
 251                 hlink_flist = flist;
 252                 return NULL;
 253         }
 254
 255         node = hashtable_find(prior_hlinks, gnum, 0);
 256         assert(node != NULL && node->data);
 257         assert(CVAL(node->data, 0) != 0);
 258         return node->data;
 259 }
 260
 261 /* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not.  Returns:
 262  * 0 = process the file, 1 = skip the file, -1 = error occurred. */
 263 int hard_link_check(struct file_struct *file, int ndx, const char *fname,
 264                     int statret, statx *sxp, int itemizing,
 265                     enum logcode code)
 266 {
 267         STRUCT_STAT prev_st;
 268         char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
 269         char *realname, *prev_name;
 270         int gnum = F_HL_GNUM(file);
 271         int prev_ndx = F_HL_PREV(file);
 272
 273         prev_name = realname = check_prior(prev_ndx, gnum);
 274
 275         if (!prev_name) {
 276                 struct file_struct *prev_file = hlink_flist->files[prev_ndx - hlink_flist->ndx_start];
 277
 278                 /* Is the previous link is not complete yet? */
 279                 if (!(prev_file->flags & FLAG_HLINK_DONE)) {
 280                         /* Is the previous link being transferred? */
 281                         if (prev_file->flags & FLAG_FILE_SENT) {
 282                                 /* Add ourselves to the list of files that will be
 283                                  * updated when the transfer completes, and mark
 284                                  * ourself as waiting for the transfer. */
 285                                 F_HL_PREV(file) = F_HL_PREV(prev_file);
 286                                 F_HL_PREV(prev_file) = ndx;
 287                                 file->flags |= FLAG_FILE_SENT;
 288                                 cur_flist->in_progress++;
 289                                 return 1;
 290                         }
 291                         return 0;
 292                 }
 293
 294                 /* There is a finished file to link with! */
 295                 if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
 296                         /* The previous previous will be marked with FIRST. */
 297                         prev_ndx = F_HL_PREV(prev_file);
 298                         prev_name = realname = check_prior(prev_ndx, gnum);
 299                         /* Update our previous pointer to point to the first. */
 300                         F_HL_PREV(file) = prev_ndx;
 301                 }
 302         }
 303         if (!prev_name) {
 304                 struct file_struct *prev_file = hlink_flist->files[prev_ndx - hlink_flist->ndx_start];
 305                 int alt_dest = F_HL_PREV(prev_file); /* alternate value when DONE && FIRST */
 306
 307                 if (alt_dest >= 0 && dry_run) {
 308                         pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
 309                                  f_name(prev_file, NULL));
 310                         prev_name = namebuf;
 311                         realname = f_name(prev_file, altbuf);
 312                 } else {
 313                         prev_name = f_name(prev_file, namebuf);
 314                         realname = prev_name;
 315                 }
 316         }
 317
 318         if (link_stat(prev_name, &prev_st, 0) < 0) {
 319                 rsyserr(FERROR, errno, "stat %s failed",
 320                         full_fname(prev_name));
 321                 return -1;
 322         }
 323
 324         if (statret < 0 && basis_dir[0] != NULL) {
 325                 /* If we match an alt-dest item, we don't output this as a change. */
 326                 char cmpbuf[MAXPATHLEN];
 327                 statx alt_sx;
 328                 int j = 0;
 329 #ifdef SUPPORT_ACLS
 330                 alt_sx.acc_acl = alt_sx.def_acl = NULL;
 331 #endif
 332                 do {
 333                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 334                         if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
 335                                 continue;
 336                         if (link_dest) {
 337                                 if (prev_st.st_dev != alt_sx.st.st_dev
 338                                  || prev_st.st_ino != alt_sx.st.st_ino)
 339                                         continue;
 340                                 statret = 1;
 341                                 if (verbose < 2 || !stdout_format_has_i) {
 342                                         itemizing = 0;
 343                                         code = FNONE;
 344                                         if (verbose > 1 && maybe_ATTRS_REPORT)
 345                                                 rprintf(FCLIENT, "%s is uptodate\n", fname);
 346                                 }
 347                                 break;
 348                         }
 349                         if (!unchanged_file(cmpbuf, file, &alt_sx.st))
 350                                 continue;
 351                         statret = 1;
 352                         if (unchanged_attrs(cmpbuf, file, &alt_sx))
 353                                 break;
 354                 } while (basis_dir[++j] != NULL);
 355                 if (statret == 1) {
 356                         sxp->st = alt_sx.st;
 357 #ifdef SUPPORT_ACLS
 358                         if (preserve_acls && !S_ISLNK(file->mode)) {
 359                                 if (!ACL_READY(*sxp))
 360                                         get_acl(cmpbuf, sxp);
 361                                 else {
 362                                         sxp->acc_acl = alt_sx.acc_acl;
 363                                         sxp->def_acl = alt_sx.def_acl;
 364                                 }
 365                         }
 366 #endif
 367                 }
 368 #ifdef SUPPORT_ACLS
 369                 else if (preserve_acls)
 370                         free_acl(&alt_sx);
 371 #endif
 372         }
 373
 374         if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
 375                             realname, itemizing, code) < 0)
 376                 return -1;
 377
 378         if (remove_source_files == 1 && do_xfers)
 379                 send_msg_int(MSG_SUCCESS, ndx);
 380
 381         return 1;
 382 }
 383
 384 int hard_link_one(struct file_struct *file, const char *fname,
 385                   const char *oldname, int terse)
 386 {
 387         if (do_link(oldname, fname) < 0) {
 388                 enum logcode code;
 389                 if (terse) {
 390                         if (!verbose)
 391                                 return -1;
 392                         code = FINFO;
 393                 } else
 394                         code = FERROR;
 395                 rsyserr(code, errno, "link %s => %s failed",
 396                         full_fname(fname), oldname);
 397                 return 0;
 398         }
 399
 400         file->flags |= FLAG_HLINK_DONE;
 401
 402         return 1;
 403 }
 404
 405 void finish_hard_link(struct file_struct *file, const char *fname,
 406                       STRUCT_STAT *stp, int itemizing, enum logcode code,
 407                       int alt_dest)
 408 {
 409         statx prev_sx;
 410         STRUCT_STAT st;
 411         char alt_name[MAXPATHLEN], *prev_name;
 412         const char *our_name;
 413         struct file_list *flist;
 414         int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
 415
 416         if (stp == NULL && prev_ndx >= 0) {
 417                 if (link_stat(fname, &st, 0) < 0) {
 418                         rsyserr(FERROR, errno, "stat %s failed",
 419                                 full_fname(fname));
 420                         return;
 421                 }
 422                 stp = &st;
 423         }
 424
 425         /* FIRST combined with DONE means we were the first to get done. */
 426         file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
 427         F_HL_PREV(file) = alt_dest;
 428         if (alt_dest >= 0 && dry_run) {
 429                 pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
 430                          f_name(file, NULL));
 431                 our_name = alt_name;
 432         } else
 433                 our_name = fname;
 434
 435 #ifdef SUPPORT_ACLS
 436         prev_sx.acc_acl = prev_sx.def_acl = NULL;
 437 #endif
 438
 439         while ((ndx = prev_ndx) >= 0) {
 440                 int val;
 441                 flist = flist_for_ndx(ndx);
 442                 assert(flist != NULL);
 443                 file = flist->files[ndx - flist->ndx_start];
 444                 file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
 445                 prev_ndx = F_HL_PREV(file);
 446                 prev_name = f_name(file, NULL);
 447                 prev_statret = link_stat(prev_name, &prev_sx.st, 0);
 448                 val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
 449                                       our_name, stp, fname, itemizing, code);
 450                 flist->in_progress--;
 451 #ifdef SUPPORT_ACLS
 452                 if (preserve_acls)
 453                         free_acl(&prev_sx);
 454 #endif
 455                 if (val < 0)
 456                         continue;
 457                 if (remove_source_files == 1 && do_xfers)
 458                         send_msg_int(MSG_SUCCESS, ndx);
 459         }
 460
 461         if (inc_recurse) {
 462                 int gnum = F_HL_GNUM(file);
 463                 struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
 464                 assert(node != NULL && node->data != NULL);
 465                 assert(CVAL(node->data, 0) == 0);
 466                 free(node->data);
 467                 if (!(node->data = strdup(our_name)))
 468                         out_of_memory("finish_hard_link");
 469         }
 470 }
 471 #endif