#ifndef BTRFS_UTIL_H
#define BTRFS_UTIL_H
+#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
+#include <sys/time.h>
#define BTRFS_UTIL_VERSION_MAJOR 1
#define BTRFS_UTIL_VERSION_MINOR 0
*/
enum btrfs_util_error btrfs_util_subvolume_id_fd(int fd, uint64_t *id_ret);
+/**
+ * btrfs_util_subvolume_path() - Get the path of the subvolume with a given ID
+ * relative to the filesystem root.
+ * @path: Path on a Btrfs filesystem.
+ * @id: ID of subvolume to set as the default. If zero is given, the subvolume
+ * ID of @path is used.
+ * @path_ret: Returned path.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_subvolume_path(const char *path, uint64_t id,
+ char **path_ret);
+
+/**
+ * btrfs_util_subvolume_path_fd() - See btrfs_util_subvolume_path().
+ */
+enum btrfs_util_error btrfs_util_subvolume_path_fd(int fd, uint64_t id,
+ char **path_ret);
+
+/**
+ * struct btrfs_util_subvolume_info - Information about a Btrfs subvolume.
+ */
+struct btrfs_util_subvolume_info {
+ /** @id: ID of this subvolume, unique across the filesystem. */
+ uint64_t id;
+
+ /**
+ * @parent_id: ID of the subvolume which contains this subvolume, or
+ * zero for the root subvolume (BTRFS_FS_TREE_OBJECTID) or orphaned
+ * subvolumes (i.e., subvolumes which have been deleted but not yet
+ * cleaned up).
+ */
+ uint64_t parent_id;
+
+ /**
+ * @dir_id: Inode number of the directory containing this subvolume in
+ * the parent subvolume, or zero for the root subvolume
+ * (BTRFS_FS_TREE_OBJECTID) or orphaned subvolumes.
+ */
+ uint64_t dir_id;
+
+ /** @flags: On-disk root item flags. */
+ uint64_t flags;
+
+ /** @uuid: UUID of this subvolume. */
+ uint8_t uuid[16];
+
+ /**
+ * @parent_uuid: UUID of the subvolume this subvolume is a snapshot of,
+ * or all zeroes if this subvolume is not a snapshot.
+ */
+ uint8_t parent_uuid[16];
+
+ /**
+ * @received_uuid: UUID of the subvolume this subvolume was received
+ * from, or all zeroes if this subvolume was not received. Note that
+ * this field, @stransid, @rtransid, @stime, and @rtime are set manually
+ * by userspace after a subvolume is received.
+ */
+ uint8_t received_uuid[16];
+
+ /** @generation: Transaction ID of the subvolume root. */
+ uint64_t generation;
+
+ /**
+ * @ctransid: Transaction ID when an inode in this subvolume was last
+ * changed.
+ */
+ uint64_t ctransid;
+
+ /** @otransid: Transaction ID when this subvolume was created. */
+ uint64_t otransid;
+
+ /**
+ * @stransid: Transaction ID of the sent subvolume this subvolume was
+ * received from, or zero if this subvolume was not received. See the
+ * note on @received_uuid.
+ */
+ uint64_t stransid;
+
+ /**
+ * @rtransid: Transaction ID when this subvolume was received, or zero
+ * if this subvolume was not received. See the note on @received_uuid.
+ */
+ uint64_t rtransid;
+
+ /** @ctime: Time when an inode in this subvolume was last changed. */
+ struct timespec ctime;
+
+ /** @otime: Time when this subvolume was created. */
+ struct timespec otime;
+
+ /**
+ * @stime: Not well-defined, usually zero unless it was set otherwise.
+ * See the note on @received_uuid.
+ */
+ struct timespec stime;
+
+ /**
+ * @rtime: Time when this subvolume was received, or zero if this
+ * subvolume was not received. See the note on @received_uuid.
+ */
+ struct timespec rtime;
+};
+
+/**
+ * btrfs_util_subvolume_info() - Get information about a subvolume.
+ * @path: Path in a Btrfs filesystem. This may be any path in the filesystem; it
+ * does not have to refer to a subvolume unless @id is zero.
+ * @id: ID of subvolume to get information about. If zero is given, the
+ * subvolume ID of @path is used.
+ * @subvol: Returned subvolume information. This can be %NULL if you just want
+ * to check whether the subvolume exists; %BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND
+ * will be returned if it does not.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_subvolume_info(const char *path, uint64_t id,
+ struct btrfs_util_subvolume_info *subvol);
+
+/**
+ * btrfs_util_subvolume_info_fd() - See btrfs_util_subvolume_info().
+ */
+enum btrfs_util_error btrfs_util_subvolume_info_fd(int fd, uint64_t id,
+ struct btrfs_util_subvolume_info *subvol);
+
+/**
+ * btrfs_util_get_subvolume_read_only() - Get whether a subvolume is read-only.
+ * @path: Subvolume path.
+ * @ret: Returned read-only flag.
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_get_subvolume_read_only(const char *path,
+ bool *ret);
+
+/**
+ * btrfs_util_get_subvolume_read_only_fd() - See
+ * btrfs_util_get_subvolume_read_only().
+ */
+enum btrfs_util_error btrfs_util_get_subvolume_read_only_fd(int fd, bool *ret);
+
+/**
+ * btrfs_util_set_subvolume_read_only() - Set whether a subvolume is read-only.
+ * @path: Subvolume path.
+ * @read_only: New value of read-only flag.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_set_subvolume_read_only(const char *path,
+ bool read_only);
+
+/**
+ * btrfs_util_set_subvolume_read_only_fd() - See
+ * btrfs_util_set_subvolume_read_only().
+ */
+enum btrfs_util_error btrfs_util_set_subvolume_read_only_fd(int fd,
+ bool read_only);
+
+/**
+ * btrfs_util_get_default_subvolume() - Get the default subvolume for a
+ * filesystem.
+ * @path: Path on a Btrfs filesystem.
+ * @id_ret: Returned subvolume ID.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_get_default_subvolume(const char *path,
+ uint64_t *id_ret);
+
+/**
+ * btrfs_util_get_default_subvolume_fd() - See
+ * btrfs_util_get_default_subvolume().
+ */
+enum btrfs_util_error btrfs_util_get_default_subvolume_fd(int fd,
+ uint64_t *id_ret);
+
+/**
+ * btrfs_util_set_default_subvolume() - Set the default subvolume for a
+ * filesystem.
+ * @path: Path in a Btrfs filesystem. This may be any path in the filesystem; it
+ * does not have to refer to a subvolume unless @id is zero.
+ * @id: ID of subvolume to set as the default. If zero is given, the subvolume
+ * ID of @path is used.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_set_default_subvolume(const char *path,
+ uint64_t id);
+
+/**
+ * btrfs_util_set_default_subvolume_fd() - See
+ * btrfs_util_set_default_subvolume().
+ */
+enum btrfs_util_error btrfs_util_set_default_subvolume_fd(int fd, uint64_t id);
+
struct btrfs_util_qgroup_inherit;
/**
+ * btrfs_util_create_subvolume() - Create a new subvolume.
+ * @path: Where to create the subvolume.
+ * @flags: Must be zero.
+ * @async_transid: If not NULL, create the subvolume asynchronously (i.e.,
+ * without waiting for it to commit it to disk) and return the transaction ID
+ * that it was created in. This transaction ID can be waited on with
+ * btrfs_util_wait_sync().
+ * @qgroup_inherit: Qgroups to inherit from, or NULL.
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_create_subvolume(const char *path, int flags,
+ uint64_t *async_transid,
+ struct btrfs_util_qgroup_inherit *qgroup_inherit);
+
+/**
+ * btrfs_util_create_subvolume_fd() - Create a new subvolume given its parent
+ * and name.
+ * @parent_fd: File descriptor of the parent directory where the subvolume
+ * should be created.
+ * @name: Name of the subvolume to create.
+ * @flags: See btrfs_util_create_subvolume().
+ * @async_transid: See btrfs_util_create_subvolume().
+ * @qgroup_inherit: See btrfs_util_create_subvolume().
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
+ const char *name,
+ int flags,
+ uint64_t *async_transid,
+ struct btrfs_util_qgroup_inherit *qgroup_inherit);
+
+struct btrfs_util_subvolume_iterator;
+
+/**
+ * BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER - Iterate post-order. The default
+ * behavior is pre-order, e.g., foo will be yielded before foo/bar. If this flag
+ * is specified, foo/bar will be yielded before foo.
+ */
+#define BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER (1 << 0)
+#define BTRFS_UTIL_SUBVOLUME_ITERATOR_MASK ((1 << 1) - 1)
+
+/**
+ * btrfs_util_create_subvolume_iterator() - Create an iterator over subvolumes
+ * in a Btrfs filesystem.
+ * @path: Path in a Btrfs filesystem. This may be any path in the filesystem; it
+ * does not have to refer to a subvolume unless @top is zero.
+ * @top: List subvolumes beneath (but not including) the subvolume with this ID.
+ * If zero is given, the subvolume ID of @path is used. To list all subvolumes,
+ * pass %BTRFS_FS_TREE_OBJECTID (i.e., 5). The returned paths are relative to
+ * the subvolume with this ID.
+ * @flags: Bitmask of BTRFS_UTIL_SUBVOLUME_ITERATOR_* flags.
+ * @ret: Returned iterator.
+ *
+ * The returned iterator must be freed with
+ * btrfs_util_destroy_subvolume_iterator().
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_create_subvolume_iterator(const char *path,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret);
+
+/**
+ * btrfs_util_create_subvolume_iterator_fd() - See
+ * btrfs_util_create_subvolume_iterator().
+ */
+enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret);
+
+/**
+ * btrfs_util_destroy_subvolume_iterator() - Destroy a subvolume iterator
+ * previously created by btrfs_util_create_subvolume_iterator().
+ * @iter: Iterator to destroy.
+ */
+void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter);
+
+/**
+ * btrfs_util_subvolume_iterator_fd() - Get the file descriptor associated with
+ * a subvolume iterator.
+ * @iter: Iterator to get.
+ *
+ * This can be used to get the file descriptor opened by
+ * btrfs_util_create_subvolume_iterator() in order to use it for other
+ * functions.
+ *
+ * Return: File descriptor.
+ */
+int btrfs_util_subvolume_iterator_fd(const struct btrfs_util_subvolume_iterator *iter);
+
+/**
+ * btrfs_util_subvolume_iterator_next() - Get the next subvolume from a
+ * subvolume iterator.
+ * @iter: Subvolume iterator.
+ * @path_ret: Returned subvolume path, relative to the subvolume ID used to
+ * create the iterator. May be %NULL.
+ * Must be freed with free().
+ * @id_ret: Returned subvolume ID. May be %NULL.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, %BTRFS_UTIL_ERROR_STOP_ITERATION if there
+ * are no more subvolumes, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ uint64_t *id_ret);
+
+/**
+ * btrfs_util_subvolume_iterator_next_info() - Get information about the next
+ * subvolume for a subvolume iterator.
+ * @iter: Subvolume iterator.
+ * @path_ret: See btrfs_util_subvolume_iterator_next().
+ * @subvol: Returned subvolume information.
+ *
+ * This convenience function basically combines
+ * btrfs_util_subvolume_iterator_next() and btrfs_util_subvolume_info().
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: See btrfs_util_subvolume_iterator_next().
+ */
+enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ struct btrfs_util_subvolume_info *subvol);
+
+/**
* btrfs_util_create_qgroup_inherit() - Create a qgroup inheritance specifier
* for btrfs_util_create_subvolume() or btrfs_util_create_snapshot().
* @flags: Must be zero.