hlink.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1996
   3    Copyright (C) Paul Mackerras 1996
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20 #include "rsync.h"
  21
  22 extern int dry_run;
  23 extern int verbose;
  24
  25 #if SUPPORT_HARD_LINKS
  26 static int hlink_compare(struct file_struct *f1,struct file_struct *f2)
  27 {
  28   if (!S_ISREG(f1->mode) && !S_ISREG(f2->mode)) return 0;
  29   if (!S_ISREG(f1->mode)) return -1;
  30   if (!S_ISREG(f2->mode)) return 1;
  31
  32   if (f1->dev != f2->dev)
  33     return (int)(f1->dev>f2->dev?1:-1);
  34
  35   if (f1->inode != f2->inode)
  36     return (int)(f1->inode>f2->inode?1:-1);
  37
  38   return file_compare(&f1,&f2);
  39 }
  40
  41
  42 static struct file_struct *hlink_list;
  43 static int hlink_count;
  44 #endif
  45
  46 void init_hard_links(struct file_list *flist)
  47 {
  48 #if SUPPORT_HARD_LINKS
  49         int i;
  50         if (flist->count < 2) return;
  51
  52         if (hlink_list) free(hlink_list);
  53
  54         if (!(hlink_list =
  55               (struct file_struct *)malloc(sizeof(hlink_list[0])*flist->count)))
  56                 out_of_memory("init_hard_links");
  57
  58         for (i = 0; i < flist->count; i++)
  59                 memcpy(&hlink_list[i], flist->files[i], sizeof(hlink_list[0]));
  60
  61         qsort(hlink_list,flist->count,
  62               sizeof(hlink_list[0]),
  63               (int (*)())hlink_compare);
  64
  65         hlink_count=flist->count;
  66 #endif
  67 }
  68
  69 /* check if a file should be skipped because it is the same as an
  70    earlier hard link */
  71 int check_hard_link(struct file_struct *file)
  72 {
  73 #if SUPPORT_HARD_LINKS
  74   int low=0,high=hlink_count-1;
  75   int ret=0;
  76
  77   if (!hlink_list || !S_ISREG(file->mode)) return 0;
  78
  79   while (low != high) {
  80     int mid = (low+high)/2;
  81     ret = hlink_compare(&hlink_list[mid],file);
  82     if (ret == 0) {
  83             low = mid;
  84             break;
  85     }
  86     if (ret > 0)
  87       high=mid;
  88     else
  89       low=mid+1;
  90   }
  91
  92   if (hlink_compare(&hlink_list[low],file) != 0) return 0;
  93
  94   if (low > 0 &&
  95       S_ISREG(hlink_list[low-1].mode) &&
  96       file->dev == hlink_list[low-1].dev &&
  97       file->inode == hlink_list[low-1].inode)
  98     return 1;
  99 #endif
 100
 101   return 0;
 102 }
 103
 104
 105 #if SUPPORT_HARD_LINKS
 106 static void hard_link_one(int i)
 107 {
 108         STRUCT_STAT st1,st2;
 109
 110         if (link_stat(f_name(&hlink_list[i-1]),&st1) != 0) return;
 111
 112         if (link_stat(f_name(&hlink_list[i]),&st2) != 0) {
 113                 if (do_link(f_name(&hlink_list[i-1]),f_name(&hlink_list[i])) != 0) {
 114                         if (verbose > 0)
 115                                 rprintf(FINFO,"link %s => %s : %s\n",
 116                                         f_name(&hlink_list[i]),
 117                                         f_name(&hlink_list[i-1]),strerror(errno));
 118                         return;
 119                 }
 120         } else {
 121                 if (st2.st_dev == st1.st_dev && st2.st_ino == st1.st_ino) return;
 122
 123                 if (robust_unlink(f_name(&hlink_list[i])) != 0 ||
 124                     do_link(f_name(&hlink_list[i-1]),f_name(&hlink_list[i])) != 0) {
 125                         if (verbose > 0)
 126                                 rprintf(FINFO,"link %s => %s : %s\n",
 127                                         f_name(&hlink_list[i]),
 128                                         f_name(&hlink_list[i-1]),strerror(errno));
 129                         return;
 130                 }
 131         }
 132         if (verbose > 0)
 133                 rprintf(FINFO,"%s => %s\n",
 134                         f_name(&hlink_list[i]),f_name(&hlink_list[i-1]));
 135 }
 136 #endif
 137
 138 /* create any hard links in the flist */
 139 void do_hard_links(struct file_list *flist)
 140 {
 141 #if SUPPORT_HARD_LINKS
 142         int i;
 143
 144         if (!hlink_list) return;
 145
 146         for (i=1;i<hlink_count;i++) {
 147                 if (S_ISREG(hlink_list[i].mode) &&
 148                     S_ISREG(hlink_list[i-1].mode) &&
 149                     hlink_list[i].basename && hlink_list[i-1].basename &&
 150                     hlink_list[i].dev == hlink_list[i-1].dev &&
 151                     hlink_list[i].inode == hlink_list[i-1].inode) {
 152                         hard_link_one(i);
 153                 }
 154         }
 155 #endif
 156 }