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