src/lxc/storage/btrfs.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef __LXC_BTRFS_H
   4 #define __LXC_BTRFS_H
   5
   6 #include <byteswap.h>
   7 #include <linux/types.h> /* __le64, __l32 ... */
   8 #include <stdbool.h>
   9 #include <stdint.h>
  10
  11 #ifndef BTRFS_SUPER_MAGIC
  12 #  define BTRFS_SUPER_MAGIC       0x9123683E
  13 #endif
  14
  15 typedef uint8_t u8;
  16 typedef uint16_t u16;
  17 typedef uint32_t u32;
  18 typedef uint64_t u64;
  19
  20 struct btrfs_ioctl_space_info {
  21         unsigned long long flags;
  22         unsigned long long total_bytes;
  23         unsigned long long used_bytes;
  24 };
  25
  26 struct btrfs_ioctl_space_args {
  27         unsigned long long space_slots;
  28         unsigned long long total_spaces;
  29         struct btrfs_ioctl_space_info spaces[];
  30 };
  31
  32 #define BTRFS_IOCTL_MAGIC 0x94
  33 #define BTRFS_IOC_SUBVOL_GETFLAGS _IOR(BTRFS_IOCTL_MAGIC, 25, unsigned long long)
  34 #define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
  35                                     struct btrfs_ioctl_space_args)
  36
  37 #define BTRFS_FSID_SIZE 16
  38 struct btrfs_ioctl_fs_info_args {
  39         unsigned long long max_id;
  40         unsigned long long num_devices;
  41         char fsid[BTRFS_FSID_SIZE];
  42         unsigned long long reserved[124];
  43 };
  44
  45 #define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
  46                 struct btrfs_ioctl_fs_info_args)
  47
  48
  49 #define BTRFS_SUBVOL_NAME_MAX 4039
  50 #define BTRFS_PATH_NAME_MAX 4087
  51
  52 struct btrfs_ioctl_vol_args {
  53         signed long long fd;
  54         char name[BTRFS_PATH_NAME_MAX + 1];
  55 };
  56
  57 #define BTRFS_IOCTL_MAGIC 0x94
  58 #define BTRFS_IOC_SUBVOL_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 24, \
  59                                    struct btrfs_ioctl_vol_args_v2)
  60 #define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
  61                                    struct btrfs_ioctl_vol_args_v2)
  62 #define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
  63                                    struct btrfs_ioctl_vol_args)
  64 #define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
  65                                    struct btrfs_ioctl_vol_args)
  66
  67 #define BTRFS_QGROUP_INHERIT_SET_LIMITS (1ULL << 0)
  68
  69 struct btrfs_ioctl_vol_args_v2 {
  70         signed long long fd;
  71         unsigned long long transid;
  72         unsigned long long flags;
  73         union {
  74                 struct {
  75                         unsigned long long size;
  76                         /*struct btrfs_qgroup_inherit *qgroup_inherit; */
  77                         void *qgroup_inherit;
  78                 };
  79                 unsigned long long unused[4];
  80         };
  81         char name[BTRFS_SUBVOL_NAME_MAX + 1];
  82 };
  83
  84 /*
  85  * root backrefs tie subvols and snapshots to the directory entries that
  86  * reference them
  87  */
  88 #define BTRFS_ROOT_BACKREF_KEY  144
  89
  90 /*
  91  * root items point to tree roots.  There are typically in the root
  92  * tree used by the super block to find all the other trees
  93  */
  94 #define BTRFS_ROOT_ITEM_KEY     132
  95
  96 /*
  97  * root refs make a fast index for listing all of the snapshots and
  98  * subvolumes referenced by a given root.  They point directly to the
  99  * directory item in the root that references the subvol
 100  */
 101 #define BTRFS_ROOT_REF_KEY      156
 102
 103 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
 104 #define BTRFS_DIR_ITEM_KEY      84
 105
 106 /*
 107  *  * this is used for both forward and backward root refs
 108  *   */
 109 struct btrfs_root_ref {
 110         __le64 dirid;
 111         __le64 sequence;
 112         __le16 name_len;
 113 } __attribute__ ((__packed__));
 114
 115 struct btrfs_disk_key {
 116         __le64 objectid;
 117         u8 type;
 118         __le64 offset;
 119 } __attribute__ ((__packed__));
 120
 121 struct btrfs_dir_item {
 122         struct btrfs_disk_key location;
 123         __le64 transid;
 124         __le16 data_len;
 125         __le16 name_len;
 126         u8 type;
 127 } __attribute__ ((__packed__));
 128
 129 #define BTRFS_IOCTL_MAGIC 0x94
 130 #define BTRFS_VOL_NAME_MAX 255
 131 #define BTRFS_PATH_NAME_MAX 4087
 132
 133 struct btrfs_ioctl_search_key {
 134         /* which root are we searching.  0 is the tree of tree roots */
 135         __u64 tree_id;
 136
 137         /* keys returned will be >= min and <= max */
 138         __u64 min_objectid;
 139         __u64 max_objectid;
 140
 141         /* keys returned will be >= min and <= max */
 142         __u64 min_offset;
 143         __u64 max_offset;
 144
 145         /* max and min transids to search for */
 146         __u64 min_transid;
 147         __u64 max_transid;
 148
 149         /* keys returned will be >= min and <= max */
 150         __u32 min_type;
 151         __u32 max_type;
 152
 153         /*
 154          * how many items did userland ask for, and how many are we
 155          * returning
 156          */
 157         __u32 nr_items;
 158
 159         /* align to 64 bits */
 160         __u32 unused;
 161
 162         /* some extra for later */
 163         __u64 unused1;
 164         __u64 unused2;
 165         __u64 unused3;
 166         __u64 unused4;
 167 };
 168
 169 struct btrfs_ioctl_search_header {
 170         __u64 transid;
 171         __u64 objectid;
 172         __u64 offset;
 173         __u32 type;
 174         __u32 len;
 175 } __attribute__((may_alias));
 176
 177 #define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key))
 178 /*
 179  * the buf is an array of search headers where
 180  * each header is followed by the actual item
 181  * the type field is expanded to 32 bits for alignment
 182  */
 183 struct btrfs_ioctl_search_args {
 184         struct btrfs_ioctl_search_key key;
 185         char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
 186 };
 187
 188 #define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
 189                                    struct btrfs_ioctl_search_args)
 190 #define BTRFS_UUID_SIZE 16
 191
 192 struct btrfs_timespec {
 193         __le64 sec;
 194         __le32 nsec;
 195 } __attribute__ ((__packed__));
 196
 197 struct btrfs_inode_item {
 198         /* nfs style generation number */
 199         __le64 generation;
 200         /* transid that last touched this inode */
 201         __le64 transid;
 202         __le64 size;
 203         __le64 nbytes;
 204         __le64 block_group;
 205         __le32 nlink;
 206         __le32 uid;
 207         __le32 gid;
 208         __le32 mode;
 209         __le64 rdev;
 210         __le64 flags;
 211
 212         /* modification sequence number for NFS */
 213         __le64 sequence;
 214
 215         /*
 216          * a little future expansion, for more than this we can
 217          * just grow the inode item and version it
 218          */
 219         __le64 reserved[4];
 220         struct btrfs_timespec atime;
 221         struct btrfs_timespec ctime;
 222         struct btrfs_timespec mtime;
 223         struct btrfs_timespec otime;
 224 } __attribute__ ((__packed__));
 225
 226 struct btrfs_root_item_v0 {
 227         struct btrfs_inode_item inode;
 228         __le64 generation;
 229         __le64 root_dirid;
 230         __le64 bytenr;
 231         __le64 byte_limit;
 232         __le64 bytes_used;
 233         __le64 last_snapshot;
 234         __le64 flags;
 235         __le32 refs;
 236         struct btrfs_disk_key drop_progress;
 237         u8 drop_level;
 238         u8 level;
 239 } __attribute__ ((__packed__));
 240
 241 struct btrfs_root_item {
 242         struct btrfs_inode_item inode;
 243         __le64 generation;
 244         __le64 root_dirid;
 245         __le64 bytenr;
 246         __le64 byte_limit;
 247         __le64 bytes_used;
 248         __le64 last_snapshot;
 249         __le64 flags;
 250         __le32 refs;
 251         struct btrfs_disk_key drop_progress;
 252         u8 drop_level;
 253         u8 level;
 254
 255         /*
 256          * The following fields appear after subvol_uuids+subvol_times
 257          * were introduced.
 258          */
 259
 260         /*
 261          * This generation number is used to test if the new fields are valid
 262          * and up to date while reading the root item. Every time the root item
 263          * is written out, the "generation" field is copied into this field. If
 264          * anyone ever mounted the fs with an older kernel, we will have
 265          * mismatching generation values here and thus must invalidate the
 266          * new fields. See btrfs_update_root and btrfs_find_last_root for
 267          * details.
 268          * the offset of generation_v2 is also used as the start for the memset
 269          * when invalidating the fields.
 270          */
 271         __le64 generation_v2;
 272         u8 uuid[BTRFS_UUID_SIZE];
 273         u8 parent_uuid[BTRFS_UUID_SIZE];
 274         u8 received_uuid[BTRFS_UUID_SIZE];
 275         __le64 ctransid; /* updated when an inode changes */
 276         __le64 otransid; /* trans when created */
 277         __le64 stransid; /* trans when sent. non-zero for received subvol */
 278         __le64 rtransid; /* trans when received. non-zero for received subvol */
 279         struct btrfs_timespec ctime;
 280         struct btrfs_timespec otime;
 281         struct btrfs_timespec stime;
 282         struct btrfs_timespec rtime;
 283         __le64 reserved[8]; /* for future */
 284 } __attribute__ ((__packed__));
 285
 286 #define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
 287                                    struct btrfs_ioctl_ino_lookup_args)
 288
 289 #define BTRFS_INO_LOOKUP_PATH_MAX 4080
 290 struct btrfs_ioctl_ino_lookup_args {
 291         __u64 treeid;
 292         __u64 objectid;
 293         char name[BTRFS_INO_LOOKUP_PATH_MAX];
 294 };
 295
 296 /*
 297  * All files have objectids in this range.
 298  */
 299 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
 300 #define BTRFS_LAST_FREE_OBJECTID -256ULL
 301 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
 302
 303 /*
 304  * The followings are macro for correctly getting member of
 305  * structures in both low and big endian platforms as per
 306  * btrfs-progs
 307  */
 308 #ifdef __CHECKER__
 309 #define __force    __attribute__((force))
 310 #else
 311 #define __force
 312 #endif
 313
 314 #if __BYTE_ORDER == __BIG_ENDIAN
 315 #define cpu_to_le64(x) ((__force __le64)(u64)(bswap_64(x)))
 316 #define le64_to_cpu(x) ((__force u64)(__le64)(bswap_64(x)))
 317 #define cpu_to_le32(x) ((__force __le32)(u32)(bswap_32(x)))
 318 #define le32_to_cpu(x) ((__force u32)(__le32)(bswap_32(x)))
 319 #define cpu_to_le16(x) ((__force __le16)(u16)(bswap_16(x)))
 320 #define le16_to_cpu(x) ((__force u16)(__le16)(bswap_16(x)))
 321 #else
 322 #define cpu_to_le64(x) ((__force __le64)(u64)(x))
 323 #define le64_to_cpu(x) ((__force u64)(__le64)(x))
 324 #define cpu_to_le32(x) ((__force __le32)(u32)(x))
 325 #define le32_to_cpu(x) ((__force u32)(__le32)(x))
 326 #define cpu_to_le16(x) ((__force __le16)(u16)(x))
 327 #define le16_to_cpu(x) ((__force u16)(__le16)(x))
 328 #endif
 329
 330 #define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)              \
 331 static inline u##bits btrfs_##name(type *s)                             \
 332 {                                                                       \
 333         return le##bits##_to_cpu(s->member);                            \
 334 }                                                                       \
 335 static inline void btrfs_set_##name(type *s, u##bits val)               \
 336 {                                                                       \
 337         s->member = cpu_to_le##bits(val);                               \
 338 }
 339
 340 /* defined as btrfs_stack_root_ref_dirid */
 341 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_dirid, struct btrfs_root_ref, dirid, 64);
 342 /* defined as btrfs_stack_root_ref_sequence */
 343 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_sequence, struct btrfs_root_ref, sequence, 64);
 344 /* defined as btrfs_stack_root_ref_name_len */
 345 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_name_len, struct btrfs_root_ref, name_len, 16);
 346
 347 struct lxc_storage;
 348
 349 struct bdev_specs;
 350
 351 struct lxc_conf;
 352
 353 struct mytree_node {
 354         u64 objid;
 355         u64 parentid;
 356         char *name;
 357         char *dirname;
 358 };
 359
 360 struct my_btrfs_tree {
 361         struct mytree_node *nodes;
 362         int num;
 363 };
 364
 365 extern int btrfs_clonepaths(struct lxc_storage *orig, struct lxc_storage *new,
 366                             const char *oldname, const char *cname,
 367                             const char *oldpath, const char *lxcpath, int snap,
 368                             uint64_t newsize, struct lxc_conf *conf);
 369 extern int btrfs_create(struct lxc_storage *bdev, const char *dest,
 370                         const char *n, struct bdev_specs *specs);
 371 extern int btrfs_destroy(struct lxc_storage *orig);
 372 extern bool btrfs_detect(const char *path);
 373 extern int btrfs_mount(struct lxc_storage *bdev);
 374 extern int btrfs_umount(struct lxc_storage *bdev);
 375
 376 extern char *get_btrfs_subvol_path(int fd, u64 dir_id, u64 objid, char *name,
 377                                    u16 name_len);
 378 extern int btrfs_list_get_path_rootid(int fd, u64 *treeid);
 379 extern bool is_btrfs_fs(const char *path);
 380 extern int is_btrfs_subvol(const char *path);
 381 extern bool btrfs_try_remove_subvol(const char *path);
 382 extern int btrfs_same_fs(const char *orig, const char *new);
 383 extern int btrfs_snapshot(const char *orig, const char *new);
 384 extern int btrfs_snapshot_wrapper(void *data);
 385 extern bool btrfs_create_clone(struct lxc_conf *conf, struct lxc_storage *orig,
 386                                struct lxc_storage *new, uint64_t newsize);
 387 extern bool btrfs_create_snapshot(struct lxc_conf *conf,
 388                                   struct lxc_storage *orig,
 389                                   struct lxc_storage *new, uint64_t newsize);
 390
 391 #endif /* __LXC_BTRFS_H */