delete.c

   1 /*
   2  * Deletion routines used in rsync.
   3  *
   4  * Copyright (C) 1996-2000 Andrew Tridgell
   5  * Copyright (C) 1996 Paul Mackerras
   6  * Copyright (C) 2002 Martin Pool <mbp@samba.org>
   7  * Copyright (C) 2003-2020 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 am_root;
  26 extern int make_backups;
  27 extern int max_delete;
  28 extern char *backup_dir;
  29 extern char *backup_suffix;
  30 extern int backup_suffix_len;
  31 extern struct stats stats;
  32
  33 int ignore_perishable = 0;
  34 int non_perishable_cnt = 0;
  35 int skipped_deletes = 0;
  36
  37 static inline int is_backup_file(char *fn)
  38 {
  39         int k = strlen(fn) - backup_suffix_len;
  40         return k > 0 && strcmp(fn+k, backup_suffix) == 0;
  41 }
  42
  43 /* The directory is about to be deleted: if DEL_RECURSE is given, delete all
  44  * its contents, otherwise just checks for content.  Returns DR_SUCCESS or
  45  * DR_NOT_EMPTY.  Note that fname must point to a MAXPATHLEN buffer!  (The
  46  * buffer is used for recursion, but returned unchanged.)
  47  */
  48 static enum delret delete_dir_contents(char *fname, uint16 flags)
  49 {
  50         struct file_list *dirlist;
  51         enum delret ret;
  52         unsigned remainder;
  53         void *save_filters;
  54         int j, dlen;
  55         char *p;
  56
  57         if (DEBUG_GTE(DEL, 3)) {
  58                 rprintf(FINFO, "delete_dir_contents(%s) flags=%d\n",
  59                         fname, flags);
  60         }
  61
  62         dlen = strlen(fname);
  63         save_filters = push_local_filters(fname, dlen);
  64
  65         non_perishable_cnt = 0;
  66         dirlist = get_dirlist(fname, dlen, 0);
  67         ret = non_perishable_cnt ? DR_NOT_EMPTY : DR_SUCCESS;
  68
  69         if (!dirlist->used)
  70                 goto done;
  71
  72         if (!(flags & DEL_RECURSE)) {
  73                 ret = DR_NOT_EMPTY;
  74                 goto done;
  75         }
  76
  77         p = fname + dlen;
  78         if (dlen != 1 || *fname != '/')
  79                 *p++ = '/';
  80         remainder = MAXPATHLEN - (p - fname);
  81
  82         /* We do our own recursion, so make delete_item() non-recursive. */
  83         flags = (flags & ~(DEL_RECURSE|DEL_MAKE_ROOM|DEL_NO_UID_WRITE))
  84               | DEL_DIR_IS_EMPTY;
  85
  86         for (j = dirlist->used; j--; ) {
  87                 struct file_struct *fp = dirlist->files[j];
  88
  89                 if (fp->flags & FLAG_MOUNT_DIR && S_ISDIR(fp->mode)) {
  90                         if (DEBUG_GTE(DEL, 1)) {
  91                                 rprintf(FINFO,
  92                                         "mount point, %s, pins parent directory\n",
  93                                         f_name(fp, NULL));
  94                         }
  95                         ret = DR_NOT_EMPTY;
  96                         continue;
  97                 }
  98
  99                 strlcpy(p, fp->basename, remainder);
 100                 if (!(fp->mode & S_IWUSR) && !am_root && fp->flags & FLAG_OWNED_BY_US)
 101                         do_chmod(fname, fp->mode | S_IWUSR);
 102                 /* Save stack by recursing to ourself directly. */
 103                 if (S_ISDIR(fp->mode)) {
 104                         if (delete_dir_contents(fname, flags | DEL_RECURSE) != DR_SUCCESS)
 105                                 ret = DR_NOT_EMPTY;
 106                 }
 107                 if (delete_item(fname, fp->mode, flags) != DR_SUCCESS)
 108                         ret = DR_NOT_EMPTY;
 109         }
 110
 111         fname[dlen] = '\0';
 112
 113   done:
 114         flist_free(dirlist);
 115         pop_local_filters(save_filters);
 116
 117         if (ret == DR_NOT_EMPTY) {
 118                 rprintf(FINFO, "cannot delete non-empty directory: %s\n",
 119                         fname);
 120         }
 121         return ret;
 122 }
 123
 124 /* Delete a file or directory.  If DEL_RECURSE is set in the flags, this will
 125  * delete recursively.
 126  *
 127  * Note that fbuf must point to a MAXPATHLEN buffer if the mode indicates it's
 128  * a directory! (The buffer is used for recursion, but returned unchanged.)
 129  */
 130 enum delret delete_item(char *fbuf, uint16 mode, uint16 flags)
 131 {
 132         enum delret ret;
 133         char *what;
 134         int ok;
 135
 136         if (DEBUG_GTE(DEL, 2)) {
 137                 rprintf(FINFO, "delete_item(%s) mode=%o flags=%d\n",
 138                         fbuf, (int)mode, (int)flags);
 139         }
 140
 141         if (flags & DEL_NO_UID_WRITE)
 142                 do_chmod(fbuf, mode | S_IWUSR);
 143
 144         if (S_ISDIR(mode) && !(flags & DEL_DIR_IS_EMPTY)) {
 145                 /* This only happens on the first call to delete_item() since
 146                  * delete_dir_contents() always calls us w/DEL_DIR_IS_EMPTY. */
 147                 ignore_perishable = 1;
 148                 /* If DEL_RECURSE is not set, this just reports emptiness. */
 149                 ret = delete_dir_contents(fbuf, flags);
 150                 ignore_perishable = 0;
 151                 if (ret == DR_NOT_EMPTY || ret == DR_AT_LIMIT)
 152                         goto check_ret;
 153                 /* OK: try to delete the directory. */
 154         }
 155
 156         if (!(flags & DEL_MAKE_ROOM) && max_delete >= 0 && stats.deleted_files >= max_delete) {
 157                 skipped_deletes++;
 158                 return DR_AT_LIMIT;
 159         }
 160
 161         if (S_ISDIR(mode)) {
 162                 what = "rmdir";
 163                 ok = do_rmdir(fbuf) == 0;
 164         } else {
 165                 if (make_backups > 0 && !(flags & DEL_FOR_BACKUP) && (backup_dir || !is_backup_file(fbuf))) {
 166                         what = "make_backup";
 167                         ok = make_backup(fbuf, True);
 168                         if (ok == 2) {
 169                                 what = "unlink";
 170                                 ok = robust_unlink(fbuf) == 0;
 171                         }
 172                 } else {
 173                         what = "unlink";
 174                         ok = robust_unlink(fbuf) == 0;
 175                 }
 176         }
 177
 178         if (ok) {
 179                 if (!(flags & DEL_MAKE_ROOM)) {
 180                         log_delete(fbuf, mode);
 181                         stats.deleted_files++;
 182                         if (S_ISREG(mode)) {
 183                                 /* Nothing more to count */
 184                         } else if (S_ISDIR(mode))
 185                                 stats.deleted_dirs++;
 186 #ifdef SUPPORT_LINKS
 187                         else if (S_ISLNK(mode))
 188                                 stats.deleted_symlinks++;
 189 #endif
 190                         else if (IS_DEVICE(mode))
 191                                 stats.deleted_symlinks++;
 192                         else
 193                                 stats.deleted_specials++;
 194                 }
 195                 ret = DR_SUCCESS;
 196         } else {
 197                 if (S_ISDIR(mode) && errno == ENOTEMPTY) {
 198                         rprintf(FINFO, "cannot delete non-empty directory: %s\n",
 199                                 fbuf);
 200                         ret = DR_NOT_EMPTY;
 201                 } else if (errno != ENOENT) {
 202                         rsyserr(FERROR_XFER, errno, "delete_file: %s(%s) failed",
 203                                 what, fbuf);
 204                         ret = DR_FAILURE;
 205                 } else
 206                         ret = DR_SUCCESS;
 207         }
 208
 209   check_ret:
 210         if (ret != DR_SUCCESS && flags & DEL_MAKE_ROOM) {
 211                 const char *desc;
 212                 switch (flags & DEL_MAKE_ROOM) {
 213                 case DEL_FOR_FILE: desc = "regular file"; break;
 214                 case DEL_FOR_DIR: desc = "directory"; break;
 215                 case DEL_FOR_SYMLINK: desc = "symlink"; break;
 216                 case DEL_FOR_DEVICE: desc = "device file"; break;
 217                 case DEL_FOR_SPECIAL: desc = "special file"; break;
 218                 default: exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE */
 219                 }
 220                 rprintf(FERROR_XFER, "could not make way for %s %s: %s\n",
 221                         flags & DEL_FOR_BACKUP ? "backup" : "new",
 222                         desc, fbuf);
 223         }
 224         return ret;
 225 }
 226
 227 uint16 get_del_for_flag(uint16 mode)
 228 {
 229         if (S_ISREG(mode))
 230                 return DEL_FOR_FILE;
 231         if (S_ISDIR(mode))
 232                 return DEL_FOR_DIR;
 233         if (S_ISLNK(mode))
 234                 return DEL_FOR_SYMLINK;
 235         if (IS_DEVICE(mode))
 236                 return DEL_FOR_DEVICE;
 237         if (IS_SPECIAL(mode))
 238                 return DEL_FOR_SPECIAL;
 239         exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE */
 240 }