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 "config.h"
  28 #include <stdint.h>
  29 #include <sys/mount.h>
  30
  31 #include <lxc/lxccontainer.h>
  32
  33 #if IS_BIONIC
  34 #include <../include/lxcmntent.h>
  35 #else
  36 #include <mntent.h>
  37 #endif
  38
  39 #ifndef MS_DIRSYNC
  40 #define MS_DIRSYNC 128
  41 #endif
  42
  43 #ifndef MS_REC
  44 #define MS_REC 16384
  45 #endif
  46
  47 #ifndef MNT_DETACH
  48 #define MNT_DETACH 2
  49 #endif
  50
  51 #ifndef MS_SLAVE
  52 #define MS_SLAVE (1 << 19)
  53 #endif
  54
  55 #ifndef MS_RELATIME
  56 #define MS_RELATIME (1 << 21)
  57 #endif
  58
  59 #ifndef MS_STRICTATIME
  60 #define MS_STRICTATIME (1 << 24)
  61 #endif
  62
  63 #define DEFAULT_FS_SIZE 1073741824
  64 #define DEFAULT_FSTYPE "ext3"
  65
  66 #define LXC_STORAGE_INTERNAL_OVERLAY_RESTORE  (1 << 6)
  67
  68 struct lxc_storage;
  69
  70 struct lxc_storage_ops {
  71         /* detect whether path is of this bdev type */
  72         bool (*detect)(const char *path);
  73
  74         /* mount requires src and dest to be set. */
  75         int (*mount)(struct lxc_storage *bdev);
  76         int (*umount)(struct lxc_storage *bdev);
  77         int (*destroy)(struct lxc_storage *bdev);
  78         int (*create)(struct lxc_storage *bdev, const char *dest, const char *n,
  79                       struct bdev_specs *specs);
  80         /* given original mount, rename the paths for cloned container */
  81         int (*clone_paths)(struct lxc_storage *orig, struct lxc_storage *new,
  82                            const char *oldname, const char *cname,
  83                            const char *oldpath, const char *lxcpath, int snap,
  84                            uint64_t newsize, struct lxc_conf *conf);
  85         bool (*copy)(struct lxc_conf *conf, struct lxc_storage *orig,
  86                      struct lxc_storage *new, uint64_t newsize);
  87         bool (*snapshot)(struct lxc_conf *conf, struct lxc_storage *orig,
  88                          struct lxc_storage *new, uint64_t newsize);
  89         bool can_snapshot;
  90         bool can_backup;
  91 };
  92
  93 /* When lxc is mounting a rootfs, then src will be the "lxc.rootfs.path" value,
  94  * dest will be the mount dir (i.e. "<libdir>/lxc")  When clone or create is
  95  * doing so, then dest will be "<lxcpath>/<lxcname>/rootfs", since we may need
  96  * to rsync from one to the other.
  97  */
  98 struct lxc_storage {
  99         const struct lxc_storage_ops *ops;
 100         const char *type;
 101         char *src;
 102         char *dest;
 103         char *mntopts;
 104         /* Turn the following into a union if need be. */
 105         /* lofd is the open fd for the mounted loopback file. */
 106         int lofd;
 107         /* index for the connected nbd device. */
 108         int nbd_idx;
 109         int flags;
 110 };
 111
 112 extern bool storage_is_dir(struct lxc_conf *conf, const char *path);
 113 extern bool storage_can_backup(struct lxc_conf *conf);
 114
 115 /* Instantiate a lxc_storage object. The src is used to determine which blockdev
 116  * type this should be. The dst and data are optional, and will be used in case
 117  * of mount/umount.
 118  *
 119  * The source will be "dir:/var/lib/lxc/c1" or "lvm:/dev/lxc/c1". For other
 120  * backing stores, this will allow additional options. In particular,
 121  * "overlayfs:/var/lib/lxc/canonical/rootfs:/var/lib/lxc/c1/delta" will mean use
 122  * /var/lib/lxc/canonical/rootfs as lower dir, and /var/lib/lxc/c1/delta as the
 123  * upper, writeable layer.
 124  */
 125 extern struct lxc_storage *storage_init(struct lxc_conf *conf, const char *src,
 126                                         const char *dst, const char *data);
 127
 128 extern struct lxc_storage *storage_copy(struct lxc_container *c0,
 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
 139 extern int storage_destroy_wrapper(void *data);
 140 extern bool rootfs_is_blockdev(struct lxc_conf *conf);
 141 extern char *lxc_storage_get_path(char *src, const char *prefix);
 142
 143 #endif /* #define __LXC_STORAGE_H */