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 link_dest;
  28 extern int make_backups;
  29 extern int log_format_has_i;
  30 extern char *basis_dir[];
  31 extern struct file_list *the_file_list;
  32
  33 #ifdef SUPPORT_HARD_LINKS
  34
  35 #define SKIPPED_LINK (-1)
  36 #define FINISHED_LINK (-2)
  37
  38 #define FPTR(i) (the_file_list->files[i])
  39 #define LINKED(p1,p2) (FPTR(p1)->F_DEV == FPTR(p2)->F_DEV \
  40                     && FPTR(p1)->F_INODE == FPTR(p2)->F_INODE)
  41
  42 static int hlink_compare(int *int1, int *int2)
  43 {
  44         struct file_struct *f1 = FPTR(*int1);
  45         struct file_struct *f2 = FPTR(*int2);
  46
  47         if (f1->F_DEV != f2->F_DEV)
  48                 return (int) (f1->F_DEV > f2->F_DEV ? 1 : -1);
  49
  50         if (f1->F_INODE != f2->F_INODE)
  51                 return (int) (f1->F_INODE > f2->F_INODE ? 1 : -1);
  52
  53         return f_name_cmp(f1, f2);
  54 }
  55
  56 static int *hlink_list;
  57 static int hlink_count;
  58
  59 /* Analyze the data in the hlink_list[], remove items that aren't multiply
  60  * linked, and replace the dev+inode data with the hlindex+next linked list. */
  61 static void link_idev_data(void)
  62 {
  63         int cur, from, to, start;
  64
  65         alloc_pool_t hlink_pool;
  66         alloc_pool_t idev_pool = the_file_list->hlink_pool;
  67
  68         hlink_pool = pool_create(128 * 1024, sizeof (struct hlink),
  69             out_of_memory, POOL_INTERN);
  70
  71         for (from = to = 0; from < hlink_count; from++) {
  72                 start = from;
  73                 while (1) {
  74                         cur = hlink_list[from];
  75                         if (from == hlink_count-1
  76                             || !LINKED(cur, hlink_list[from+1]))
  77                                 break;
  78                         pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  79                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  80                             struct hlink, 1, "hlink_list");
  81
  82                         FPTR(cur)->F_HLINDEX = to;
  83                         FPTR(cur)->F_NEXT = hlink_list[++from];
  84                 }
  85                 pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  86                 if (from > start) {
  87                         int head = hlink_list[start];
  88                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  89                             struct hlink, 1, "hlink_list");
  90
  91                         FPTR(head)->flags |= FLAG_HLINK_TOL;
  92                         FPTR(cur)->F_HLINDEX = to;
  93                         FPTR(cur)->F_NEXT = head;
  94                         FPTR(cur)->flags |= FLAG_HLINK_EOL;
  95                         hlink_list[to++] = head;
  96                 } else
  97                         FPTR(cur)->link_u.links = NULL;
  98         }
  99
 100         if (!to) {
 101                 free(hlink_list);
 102                 hlink_list = NULL;
 103                 pool_destroy(hlink_pool);
 104                 hlink_pool = NULL;
 105         } else {
 106                 hlink_count = to;
 107                 hlink_list = realloc_array(hlink_list, int, hlink_count);
 108                 if (!hlink_list)
 109                         out_of_memory("init_hard_links");
 110         }
 111         the_file_list->hlink_pool = hlink_pool;
 112         pool_destroy(idev_pool);
 113 }
 114 #endif
 115
 116 void init_hard_links(void)
 117 {
 118 #ifdef SUPPORT_HARD_LINKS
 119         int i;
 120
 121         if (hlink_list)
 122                 free(hlink_list);
 123
 124         if (!(hlink_list = new_array(int, the_file_list->count)))
 125                 out_of_memory("init_hard_links");
 126
 127         hlink_count = 0;
 128         for (i = 0; i < the_file_list->count; i++) {
 129                 if (FPTR(i)->link_u.idev)
 130                         hlink_list[hlink_count++] = i;
 131         }
 132
 133         qsort(hlink_list, hlink_count,
 134             sizeof hlink_list[0], (int (*)()) hlink_compare);
 135
 136         if (!hlink_count) {
 137                 free(hlink_list);
 138                 hlink_list = NULL;
 139         } else
 140                 link_idev_data();
 141 #endif
 142 }
 143
 144 #ifdef SUPPORT_HARD_LINKS
 145 static int maybe_hard_link(struct file_struct *file, int ndx,
 146                            char *fname, int statret, STRUCT_STAT *st,
 147                            char *toname, STRUCT_STAT *to_st,
 148                            int itemizing, enum logcode code)
 149 {
 150         if (statret == 0) {
 151                 if (st->st_dev == to_st->st_dev
 152                  && st->st_ino == to_st->st_ino) {
 153                         if (itemizing) {
 154                                 itemize(file, ndx, statret, st,
 155                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 156                                         0, "");
 157                         }
 158                         return 0;
 159                 }
 160                 if (make_backups) {
 161                         if (!make_backup(fname))
 162                                 return -1;
 163                 } else if (robust_unlink(fname)) {
 164                         rsyserr(FERROR, errno, "unlink %s failed",
 165                                 full_fname(fname));
 166                         return -1;
 167                 }
 168         }
 169         return hard_link_one(file, ndx, fname, statret, st, toname,
 170                              0, itemizing, code);
 171 }
 172 #endif
 173
 174 int hard_link_check(struct file_struct *file, int ndx, char *fname,
 175                     int statret, STRUCT_STAT *st, int itemizing,
 176                     enum logcode code, int skip)
 177 {
 178 #ifdef SUPPORT_HARD_LINKS
 179         int head;
 180         if (skip && !(file->flags & FLAG_HLINK_EOL))
 181                 head = hlink_list[file->F_HLINDEX] = file->F_NEXT;
 182         else
 183                 head = hlink_list[file->F_HLINDEX];
 184         if (ndx != head) {
 185                 struct file_struct *head_file = FPTR(head);
 186                 if (!log_format_has_i && verbose > 1) {
 187                         rprintf(FINFO, "\"%s\" is a hard link\n",
 188                                 f_name(file, NULL));
 189                 }
 190                 if (head_file->F_HLINDEX == FINISHED_LINK) {
 191                         STRUCT_STAT st2, st3;
 192                         char *toname = f_name(head_file, NULL);
 193                         if (link_stat(toname, &st2, 0) < 0) {
 194                                 rsyserr(FERROR, errno, "stat %s failed",
 195                                         full_fname(toname));
 196                                 return -1;
 197                         }
 198                         if (statret < 0 && basis_dir[0] != NULL) {
 199                                 char cmpbuf[MAXPATHLEN];
 200                                 int j = 0;
 201                                 do {
 202                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 203                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 204                                                 continue;
 205                                         if (link_dest) {
 206                                                 if (st2.st_dev != st3.st_dev
 207                                                  || st2.st_ino != st3.st_ino)
 208                                                         continue;
 209                                                 statret = 1;
 210                                                 st = &st3;
 211                                                 if (verbose < 2 || !log_format_has_i)
 212                                                         itemizing = code = 0;
 213                                                 break;
 214                                         }
 215                                         if (!unchanged_file(cmpbuf, file, &st3))
 216                                                 continue;
 217                                         statret = 1;
 218                                         st = &st3;
 219                                         if (unchanged_attrs(file, &st3))
 220                                                 break;
 221                                 } while (basis_dir[++j] != NULL);
 222                         }
 223                         maybe_hard_link(file, ndx, fname, statret, st,
 224                                         toname, &st2, itemizing, code);
 225                         file->F_HLINDEX = FINISHED_LINK;
 226                 } else
 227                         file->F_HLINDEX = SKIPPED_LINK;
 228                 return 1;
 229         }
 230 #endif
 231         return 0;
 232 }
 233
 234 #ifdef SUPPORT_HARD_LINKS
 235 int hard_link_one(struct file_struct *file, int ndx, char *fname,
 236                   int statret, STRUCT_STAT *st, char *toname, int terse,
 237                   int itemizing, enum logcode code)
 238 {
 239         if (do_link(toname, fname)) {
 240                 if (terse) {
 241                         if (!verbose)
 242                                 return -1;
 243                         code = FINFO;
 244                 } else
 245                         code = FERROR;
 246                 rsyserr(code, errno, "link %s => %s failed",
 247                         full_fname(fname), toname);
 248                 return -1;
 249         }
 250
 251         if (itemizing) {
 252                 itemize(file, ndx, statret, st,
 253                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 254                         terse ? "" : toname);
 255         }
 256         if (code && verbose && !terse)
 257                 rprintf(code, "%s => %s\n", fname, toname);
 258         return 0;
 259 }
 260 #endif
 261
 262
 263 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 264                        enum logcode code)
 265 {
 266 #ifdef SUPPORT_HARD_LINKS
 267         char hlink1[MAXPATHLEN];
 268         char *hlink2;
 269         STRUCT_STAT st1, st2;
 270         int statret, ndx = master;
 271
 272         file->F_HLINDEX = FINISHED_LINK;
 273         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 274                 return;
 275         if (!(file->flags & FLAG_HLINK_TOL)) {
 276                 while (!(file->flags & FLAG_HLINK_EOL)) {
 277                         ndx = file->F_NEXT;
 278                         file = FPTR(ndx);
 279                 }
 280         }
 281         do {
 282                 ndx = file->F_NEXT;
 283                 file = FPTR(ndx);
 284                 if (file->F_HLINDEX != SKIPPED_LINK)
 285                         continue;
 286                 hlink2 = f_name(file, NULL);
 287                 statret = link_stat(hlink2, &st2, 0);
 288                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 289                                 hlink1, &st1, itemizing, code);
 290                 file->F_HLINDEX = FINISHED_LINK;
 291         } while (!(file->flags & FLAG_HLINK_EOL));
 292 #endif
 293 }