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