src/lxc/storage/dir.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library 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 GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef _GNU_SOURCE
  25 #define _GNU_SOURCE 1
  26 #endif
  27 #include <stdint.h>
  28 #include <string.h>
  29
  30 #include "config.h"
  31 #include "log.h"
  32 #include "storage.h"
  33 #include "utils.h"
  34
  35 lxc_log_define(dir, lxc);
  36
  37 /* For a simple directory bind mount, we substitute the old container name and
  38  * paths for the new.
  39  */
  40 int dir_clonepaths(struct lxc_storage *orig, struct lxc_storage *new,
  41                    const char *oldname, const char *cname, const char *oldpath,
  42                    const char *lxcpath, int snap, uint64_t newsize,
  43                    struct lxc_conf *conf)
  44 {
  45         const char *src_no_prefix;
  46         int ret;
  47         size_t len;
  48
  49         if (snap) {
  50                 ERROR("Directories cannot be snapshotted");
  51                 return -1;
  52         }
  53
  54         if (!orig->dest || !orig->src)
  55                 return -1;
  56
  57         len = strlen(lxcpath) + strlen(cname) + strlen("rootfs") + 4 + 3;
  58         new->src = malloc(len);
  59         if (!new->src) {
  60                 ERROR("Failed to allocate memory");
  61                 return -1;
  62         }
  63
  64         ret = snprintf(new->src, len, "dir:%s/%s/rootfs", lxcpath, cname);
  65         if (ret < 0 || (size_t)ret >= len) {
  66                 ERROR("Failed to create string");
  67                 return -1;
  68         }
  69
  70         src_no_prefix = lxc_storage_get_path(new->src, new->type);
  71         new->dest = strdup(src_no_prefix);
  72         if (!new->dest) {
  73                 ERROR("Failed to duplicate string \"%s\"", new->src);
  74                 return -1;
  75         }
  76
  77         TRACE("Created new path \"%s\" for dir storage driver", new->dest);
  78         return 0;
  79 }
  80
  81 int dir_create(struct lxc_storage *bdev, const char *dest, const char *n,
  82                struct bdev_specs *specs)
  83 {
  84         int ret;
  85         const char *src;
  86         size_t len;
  87
  88         /* strlen("dir:") */
  89         len = 4;
  90         if (specs && specs->dir)
  91                 src = specs->dir;
  92         else
  93                 src = dest;
  94
  95         len += strlen(src) + 1;
  96         bdev->src = malloc(len);
  97         if (!bdev->src) {
  98                 ERROR("Failed to allocate memory");
  99                 return -1;
 100         }
 101
 102         ret = snprintf(bdev->src, len, "dir:%s", src);
 103         if (ret < 0 || (size_t)ret >= len) {
 104                 ERROR("Failed to create string");
 105                 return -1;
 106         }
 107
 108         bdev->dest = strdup(dest);
 109         if (!bdev->dest) {
 110                 ERROR("Failed to duplicate string \"%s\"", dest);
 111                 return -1;
 112         }
 113
 114         ret = mkdir_p(dest, 0755);
 115         if (ret < 0) {
 116                 ERROR("Failed to create directory \"%s\"", dest);
 117                 return -1;
 118         }
 119         TRACE("Created directory \"%s\"", dest);
 120
 121         return 0;
 122 }
 123
 124 int dir_destroy(struct lxc_storage *orig)
 125 {
 126         int ret;
 127         const char *src;
 128
 129         src = lxc_storage_get_path(orig->src, orig->src);
 130
 131         ret = lxc_rmdir_onedev(src, NULL);
 132         if (ret < 0) {
 133                 ERROR("Failed to delete \"%s\"", src);
 134                 return -1;
 135         }
 136
 137         return 0;
 138 }
 139
 140 bool dir_detect(const char *path)
 141 {
 142         struct stat statbuf;
 143         int ret;
 144
 145         if (!strncmp(path, "dir:", 4))
 146                 return true;
 147
 148         ret = stat(path, &statbuf);
 149         if (ret == -1 && errno == EPERM) {
 150                 SYSERROR("dir_detect: failed to look at \"%s\"", path);
 151                 return false;
 152         }
 153
 154         if (ret == 0 && S_ISDIR(statbuf.st_mode))
 155                 return true;
 156
 157         return false;
 158 }
 159
 160 int dir_mount(struct lxc_storage *bdev)
 161 {
 162         int ret;
 163         unsigned long mflags = 0, mntflags = 0, pflags = 0;
 164         char *mntdata;
 165         const char *src;
 166
 167         if (strcmp(bdev->type, "dir"))
 168                 return -22;
 169
 170         if (!bdev->src || !bdev->dest)
 171                 return -22;
 172
 173         ret = parse_mntopts(bdev->mntopts, &mntflags, &mntdata);
 174         if (ret < 0) {
 175                 ERROR("Failed to parse mount options \"%s\"", bdev->mntopts);
 176                 free(mntdata);
 177                 return -EINVAL;
 178         }
 179
 180         ret = parse_propagationopts(bdev->mntopts, &pflags);
 181         if (ret < 0) {
 182                 ERROR("Failed to parse propagation options \"%s\"", bdev->mntopts);
 183                 free(mntdata);
 184                 return -EINVAL;
 185         }
 186
 187         src = lxc_storage_get_path(bdev->src, bdev->type);
 188
 189         ret = mount(src, bdev->dest, "bind", MS_BIND | MS_REC | mntflags | pflags, mntdata);
 190         if ((0 == ret) && (mntflags & MS_RDONLY)) {
 191                 DEBUG("Remounting \"%s\" on \"%s\" readonly",
 192                       src ? src : "(none)", bdev->dest ? bdev->dest : "(none)");
 193                 mflags = add_required_remount_flags(src, bdev->dest, MS_BIND | MS_REC | mntflags | pflags | MS_REMOUNT);
 194                 ret = mount(src, bdev->dest, "bind", mflags, mntdata);
 195         }
 196
 197         if (ret < 0) {
 198                 SYSERROR("Failed to mount \"%s\" on \"%s\"", src, bdev->dest);
 199                 free(mntdata);
 200                 return -1;
 201         }
 202
 203         TRACE("Mounted \"%s\" on \"%s\"", src, bdev->dest);
 204         free(mntdata);
 205         return ret;
 206 }
 207
 208 int dir_umount(struct lxc_storage *bdev)
 209 {
 210         if (strcmp(bdev->type, "dir"))
 211                 return -22;
 212
 213         if (!bdev->src || !bdev->dest)
 214                 return -22;
 215
 216         return umount(bdev->dest);
 217 }