src/lxc/storage/storage.h

   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 __LXC_STORAGE_H
  25 #define __LXC_STORAGE_H
  26
  27 #include <stdint.h>
  28 #include <sys/mount.h>
  29
  30 #include <lxc/lxccontainer.h>
  31
  32 #if IS_BIONIC
  33 #include <../include/lxcmntent.h>
  34 #else
  35 #include <mntent.h>
  36 #endif
  37
  38 #ifndef MS_DIRSYNC
  39 #define MS_DIRSYNC 128
  40 #endif
  41
  42 #ifndef MS_REC
  43 #define MS_REC 16384
  44 #endif
  45
  46 #ifndef MNT_DETACH
  47 #define MNT_DETACH 2
  48 #endif
  49
  50 #ifndef MS_SLAVE
  51 #define MS_SLAVE (1 << 19)
  52 #endif
  53
  54 #ifndef MS_RELATIME
  55 #define MS_RELATIME (1 << 21)
  56 #endif
  57
  58 #ifndef MS_STRICTATIME
  59 #define MS_STRICTATIME (1 << 24)
  60 #endif
  61
  62 #define DEFAULT_FS_SIZE 1073741824
  63 #define DEFAULT_FSTYPE "ext4"
  64
  65 #define LXC_STORAGE_INTERNAL_OVERLAY_RESTORE  (1 << 6)
  66
  67 struct lxc_storage;
  68
  69 struct lxc_storage_ops {
  70         /* detect whether path is of this bdev type */
  71         bool (*detect)(const char *path);
  72
  73         /* mount requires src and dest to be set. */
  74         int (*mount)(struct lxc_storage *bdev);
  75         int (*umount)(struct lxc_storage *bdev);
  76         int (*destroy)(struct lxc_storage *bdev);
  77         int (*create)(struct lxc_storage *bdev, const char *dest, const char *n,
  78                       struct bdev_specs *specs);
  79         /* given original mount, rename the paths for cloned container */
  80         int (*clone_paths)(struct lxc_storage *orig, struct lxc_storage *new,
  81                            const char *oldname, const char *cname,
  82                            const char *oldpath, const char *lxcpath, int snap,
  83                            uint64_t newsize, struct lxc_conf *conf);
  84         bool (*copy)(struct lxc_conf *conf, struct lxc_storage *orig,
  85                      struct lxc_storage *new, uint64_t newsize);
  86         bool (*snapshot)(struct lxc_conf *conf, struct lxc_storage *orig,
  87                          struct lxc_storage *new, uint64_t newsize);
  88         bool can_snapshot;
  89         bool can_backup;
  90 };
  91
  92 /* When lxc is mounting a rootfs, then src will be the "lxc.rootfs.path" value,
  93  * dest will be the mount dir (i.e. "<libdir>/lxc")  When clone or create is
  94  * doing so, then dest will be "<lxcpath>/<lxcname>/rootfs", since we may need
  95  * to rsync from one to the other.
  96  */
  97 struct lxc_storage {
  98         const struct lxc_storage_ops *ops;
  99         const char *type;
 100         char *src;
 101         char *dest;
 102         char *mntopts;
 103         /* Turn the following into a union if need be. */
 104         /* lofd is the open fd for the mounted loopback file. */
 105         int lofd;
 106         /* index for the connected nbd device. */
 107         int nbd_idx;
 108         int flags;
 109 };
 110
 111 /**
 112  * storage_is_dir : Check whether the roots is a directory. This function will
 113  *                  trust the config file. If the config file key
 114  *                  lxc.rootfs.path is set to <storage type>:<container path>
 115  *                  the confile parser will have split this into <storage type>
 116  *                  and <container path> and set the <bdev_type> member in the
 117  *                  lxc_rootfs struct to <storage type> and the <path> member
 118  *                  will be set to a clean <container path> without the <storage
 119  *                  type> prefix. This is the new, clean way of handling storage
 120  *                  type specifications.  If the <storage type> prefix is not
 121  *                  detected liblxc will try to detect the storage type.
 122  */
 123 extern bool storage_is_dir(struct lxc_conf *conf);
 124 extern bool storage_can_backup(struct lxc_conf *conf);
 125
 126 extern struct lxc_storage *storage_init(struct lxc_conf *conf);
 127
 128 extern struct lxc_storage *storage_copy(struct lxc_container *c,
 129                                         const char *cname, const char *lxcpath,
 130                                         const char *bdevtype, int flags,
 131                                         const char *bdevdata, uint64_t newsize,
 132                                         bool *needs_rdep);
 133 extern struct lxc_storage *storage_create(const char *dest, const char *type,
 134                                           const char *cname,
 135                                           struct bdev_specs *specs);
 136 extern void storage_put(struct lxc_storage *bdev);
 137 extern bool storage_destroy(struct lxc_conf *conf);
 138 extern bool rootfs_is_blockdev(struct lxc_conf *conf);
 139 extern const char *lxc_storage_get_path(char *src, const char *prefix);
 140
 141 #endif /* #define __LXC_STORAGE_H */