src/import/aufs-util.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <ftw.h>
  21
  22 #include "aufs-util.h"
  23 #include "rm-rf.h"
  24 #include "string-util.h"
  25 #include "util.h"
  26
  27 static int nftw_cb(
  28                 const char *fpath,
  29                 const struct stat *sb,
  30                 int flag,
  31                 struct FTW *ftwbuf) {
  32
  33         const char *fn, *original;
  34         char *p;
  35         int r;
  36
  37         fn = fpath + ftwbuf->base;
  38
  39         /* We remove all whiteout files, and all whiteouts */
  40
  41         original = startswith(fn, ".wh.");
  42         if (!original)
  43                 return FTW_CONTINUE;
  44
  45         log_debug("Removing whiteout indicator %s.", fpath);
  46         r = rm_rf(fpath, REMOVE_ROOT|REMOVE_PHYSICAL);
  47         if (r < 0)
  48                 return FTW_STOP;
  49
  50         if (!startswith(fn, ".wh..wh.")) {
  51
  52                 p = alloca(ftwbuf->base + strlen(original));
  53                 strcpy(mempcpy(p, fpath, ftwbuf->base), original);
  54
  55                 log_debug("Removing deleted file %s.", p);
  56                 r = rm_rf(p, REMOVE_ROOT|REMOVE_PHYSICAL);
  57                 if (r < 0)
  58                         return FTW_STOP;
  59         }
  60
  61         return FTW_CONTINUE;
  62 }
  63
  64 int aufs_resolve(const char *path) {
  65         int r;
  66
  67         errno = 0;
  68         r = nftw(path, nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
  69         if (r == FTW_STOP)
  70                 return errno > 0 ? -errno : -EIO;
  71
  72         return 0;
  73 }