hlink.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1996
   3    Copyright (C) Paul Mackerras 1996
   4    Copyright (C) 2002 by Martin Pool <mbp@samba.org>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "rsync.h"
  22
  23 extern int dry_run;
  24 extern int verbose;
  25 extern int link_dest;
  26 extern int make_backups;
  27 extern int log_format_has_i;
  28 extern char *basis_dir[];
  29 extern struct file_list *the_file_list;
  30
  31 #ifdef SUPPORT_HARD_LINKS
  32
  33 #define SKIPPED_LINK (-1)
  34 #define FINISHED_LINK (-2)
  35
  36 #define FPTR(i) (the_file_list->files[i])
  37 #define LINKED(p1,p2) (FPTR(p1)->F_DEV == FPTR(p2)->F_DEV \
  38                     && FPTR(p1)->F_INODE == FPTR(p2)->F_INODE)
  39
  40 static int hlink_compare(int *int1, int *int2)
  41 {
  42         struct file_struct *f1 = FPTR(*int1);
  43         struct file_struct *f2 = FPTR(*int2);
  44
  45         if (f1->F_DEV != f2->F_DEV)
  46                 return (int) (f1->F_DEV > f2->F_DEV ? 1 : -1);
  47
  48         if (f1->F_INODE != f2->F_INODE)
  49                 return (int) (f1->F_INODE > f2->F_INODE ? 1 : -1);
  50
  51         return f_name_cmp(f1, f2);
  52 }
  53
  54 static int *hlink_list;
  55 static int hlink_count;
  56
  57 /* Analyze the data in the hlink_list[], remove items that aren't multiply
  58  * linked, and replace the dev+inode data with the hlindex+next linked list. */
  59 static void link_idev_data(void)
  60 {
  61         int cur, from, to, start;
  62
  63         alloc_pool_t hlink_pool;
  64         alloc_pool_t idev_pool = the_file_list->hlink_pool;
  65
  66         hlink_pool = pool_create(128 * 1024, sizeof (struct hlink),
  67             out_of_memory, POOL_INTERN);
  68
  69         for (from = to = 0; from < hlink_count; from++) {
  70                 start = from;
  71                 while (1) {
  72                         cur = hlink_list[from];
  73                         if (from == hlink_count-1
  74                             || !LINKED(cur, hlink_list[from+1]))
  75                                 break;
  76                         pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  77                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  78                             struct hlink, 1, "hlink_list");
  79
  80                         FPTR(cur)->F_HLINDEX = to;
  81                         FPTR(cur)->F_NEXT = hlink_list[++from];
  82                 }
  83                 pool_free(idev_pool, 0, FPTR(cur)->link_u.idev);
  84                 if (from > start) {
  85                         int head = hlink_list[start];
  86                         FPTR(cur)->link_u.links = pool_talloc(hlink_pool,
  87                             struct hlink, 1, "hlink_list");
  88
  89                         FPTR(head)->flags |= FLAG_HLINK_TOL;
  90                         FPTR(cur)->F_HLINDEX = to;
  91                         FPTR(cur)->F_NEXT = head;
  92                         FPTR(cur)->flags |= FLAG_HLINK_EOL;
  93                         hlink_list[to++] = head;
  94                 } else
  95                         FPTR(cur)->link_u.links = NULL;
  96         }
  97
  98         if (!to) {
  99                 free(hlink_list);
 100                 hlink_list = NULL;
 101                 pool_destroy(hlink_pool);
 102                 hlink_pool = NULL;
 103         } else {
 104                 hlink_count = to;
 105                 hlink_list = realloc_array(hlink_list, int, hlink_count);
 106                 if (!hlink_list)
 107                         out_of_memory("init_hard_links");
 108         }
 109         the_file_list->hlink_pool = hlink_pool;
 110         pool_destroy(idev_pool);
 111 }
 112 #endif
 113
 114 void init_hard_links(void)
 115 {
 116 #ifdef SUPPORT_HARD_LINKS
 117         int i;
 118
 119         if (hlink_list)
 120                 free(hlink_list);
 121
 122         if (!(hlink_list = new_array(int, the_file_list->count)))
 123                 out_of_memory("init_hard_links");
 124
 125         hlink_count = 0;
 126         for (i = 0; i < the_file_list->count; i++) {
 127                 if (FPTR(i)->link_u.idev)
 128                         hlink_list[hlink_count++] = i;
 129         }
 130
 131         qsort(hlink_list, hlink_count,
 132             sizeof hlink_list[0], (int (*)()) hlink_compare);
 133
 134         if (!hlink_count) {
 135                 free(hlink_list);
 136                 hlink_list = NULL;
 137         } else
 138                 link_idev_data();
 139 #endif
 140 }
 141
 142 #ifdef SUPPORT_HARD_LINKS
 143 static int maybe_hard_link(struct file_struct *file, int ndx,
 144                            char *fname, int statret, STRUCT_STAT *st,
 145                            char *toname, STRUCT_STAT *to_st,
 146                            int itemizing, enum logcode code)
 147 {
 148         if (statret == 0) {
 149                 if (st->st_dev == to_st->st_dev
 150                  && st->st_ino == to_st->st_ino) {
 151                         if (itemizing) {
 152                                 itemize(file, ndx, statret, st,
 153                                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
 154                                         0, "");
 155                         }
 156                         return 0;
 157                 }
 158                 if (make_backups) {
 159                         if (!make_backup(fname))
 160                                 return -1;
 161                 } else if (robust_unlink(fname)) {
 162                         rsyserr(FERROR, errno, "unlink %s failed",
 163                                 full_fname(fname));
 164                         return -1;
 165                 }
 166         }
 167         return hard_link_one(file, ndx, fname, statret, st, toname,
 168                              0, itemizing, code);
 169 }
 170 #endif
 171
 172 int hard_link_check(struct file_struct *file, int ndx, char *fname,
 173                     int statret, STRUCT_STAT *st, int itemizing,
 174                     enum logcode code, int skip)
 175 {
 176 #ifdef SUPPORT_HARD_LINKS
 177         int head;
 178         if (skip && !(file->flags & FLAG_HLINK_EOL))
 179                 head = hlink_list[file->F_HLINDEX] = file->F_NEXT;
 180         else
 181                 head = hlink_list[file->F_HLINDEX];
 182         if (ndx != head) {
 183                 struct file_struct *head_file = FPTR(head);
 184                 if (!log_format_has_i && verbose > 1) {
 185                         rprintf(FINFO, "\"%s\" is a hard link\n",
 186                                 f_name(file, NULL));
 187                 }
 188                 if (head_file->F_HLINDEX == FINISHED_LINK) {
 189                         STRUCT_STAT st2, st3;
 190                         char *toname = f_name(head_file, NULL);
 191                         if (link_stat(toname, &st2, 0) < 0) {
 192                                 rsyserr(FERROR, errno, "stat %s failed",
 193                                         full_fname(toname));
 194                                 return -1;
 195                         }
 196                         if (statret < 0 && basis_dir[0] != NULL) {
 197                                 char cmpbuf[MAXPATHLEN];
 198                                 int j = 0;
 199                                 do {
 200                                         pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
 201                                         if (link_stat(cmpbuf, &st3, 0) < 0)
 202                                                 continue;
 203                                         if (link_dest) {
 204                                                 if (st2.st_dev != st3.st_dev
 205                                                  || st2.st_ino != st3.st_ino)
 206                                                         continue;
 207                                                 statret = 1;
 208                                                 st = &st3;
 209                                                 if (verbose < 2 || !log_format_has_i)
 210                                                         itemizing = code = 0;
 211                                                 break;
 212                                         }
 213                                         if (!unchanged_file(cmpbuf, file, &st3))
 214                                                 continue;
 215                                         statret = 1;
 216                                         st = &st3;
 217                                         if (unchanged_attrs(file, &st3))
 218                                                 break;
 219                                 } while (basis_dir[++j] != NULL);
 220                         }
 221                         maybe_hard_link(file, ndx, fname, statret, st,
 222                                         toname, &st2, itemizing, code);
 223                         file->F_HLINDEX = FINISHED_LINK;
 224                 } else
 225                         file->F_HLINDEX = SKIPPED_LINK;
 226                 return 1;
 227         }
 228 #endif
 229         return 0;
 230 }
 231
 232 #ifdef SUPPORT_HARD_LINKS
 233 int hard_link_one(struct file_struct *file, int ndx, char *fname,
 234                   int statret, STRUCT_STAT *st, char *toname, int terse,
 235                   int itemizing, enum logcode code)
 236 {
 237         if (do_link(toname, fname)) {
 238                 if (terse) {
 239                         if (!verbose)
 240                                 return -1;
 241                         code = FINFO;
 242                 } else
 243                         code = FERROR;
 244                 rsyserr(code, errno, "link %s => %s failed",
 245                         full_fname(fname), toname);
 246                 return -1;
 247         }
 248
 249         if (itemizing) {
 250                 itemize(file, ndx, statret, st,
 251                         ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
 252                         terse ? "" : toname);
 253         }
 254         if (code && verbose && !terse)
 255                 rprintf(code, "%s => %s\n", fname, toname);
 256         return 0;
 257 }
 258 #endif
 259
 260
 261 void hard_link_cluster(struct file_struct *file, int master, int itemizing,
 262                        enum logcode code)
 263 {
 264 #ifdef SUPPORT_HARD_LINKS
 265         char hlink1[MAXPATHLEN];
 266         char *hlink2;
 267         STRUCT_STAT st1, st2;
 268         int statret, ndx = master;
 269
 270         file->F_HLINDEX = FINISHED_LINK;
 271         if (link_stat(f_name(file, hlink1), &st1, 0) < 0)
 272                 return;
 273         if (!(file->flags & FLAG_HLINK_TOL)) {
 274                 while (!(file->flags & FLAG_HLINK_EOL)) {
 275                         ndx = file->F_NEXT;
 276                         file = FPTR(ndx);
 277                 }
 278         }
 279         do {
 280                 ndx = file->F_NEXT;
 281                 file = FPTR(ndx);
 282                 if (file->F_HLINDEX != SKIPPED_LINK)
 283                         continue;
 284                 hlink2 = f_name(file, NULL);
 285                 statret = link_stat(hlink2, &st2, 0);
 286                 maybe_hard_link(file, ndx, hlink2, statret, &st2,
 287                                 hlink1, &st1, itemizing, code);
 288                 file->F_HLINDEX = FINISHED_LINK;
 289         } while (!(file->flags & FLAG_HLINK_EOL));
 290 #endif
 291 }