+/**
+ * Store the index of the OST where stripe number \a stripe_number is stored
+ * in \a index.
+ *
+ * An error return value will result from a NULL layout, if \a
+ * stripe_number is out of range, or if \a layout was not initialized
+ * with llapi_layout_lookup_by{path,fd,fid}().
+ *
+ * \retval 0 Success
+ * \retval -1 Invalid argument, errno set to EINVAL.
+ */
+int llapi_layout_ost_index_get(const struct llapi_layout *layout,
+ uint64_t stripe_number, uint64_t *index);
+
+/**
+ * Set the OST index associated with stripe number \a stripe_number to
+ * \a ost_index.
+ * NB: This is currently supported only for \a stripe_number = 0 and
+ * other usage will return ENOTSUPP in errno. A NULL \a layout or
+ * out-of-range \a stripe_number will return EINVAL in errno.
+ *
+ * \retval 0 Success.
+ * \retval -1 Error with errno set to non-zero value.
+ */
+int llapi_layout_ost_index_set(struct llapi_layout *layout, int stripe_number,
+ uint64_t index);
+
+/******************** Pool Name ********************/
+
+/**
+ * Store up to \a pool_name_len characters of the name of the pool of
+ * OSTs associated with \a layout into the buffer pointed to by
+ * \a pool_name.
+ *
+ * The correct calling form is:
+ *
+ * llapi_layout_pool_name_get(layout, pool_name, sizeof(pool_name));
+ *
+ * A pool defines a set of OSTs from which file objects may be
+ * allocated for a file using \a layout.
+ *
+ * On success, the number of bytes stored is returned, excluding the
+ * terminating '\0' character (zero indicates that \a layout does not
+ * have an associated OST pool). On error, -1 is returned and errno is
+ * set appropriately. Possible sources of error include a NULL pointer
+ * argument or insufficient space in \a dest to store the pool name,
+ * in which cases errno will be set to EINVAL.
+ *
+ * \retval 0+ The number of bytes stored in \a dest.
+ * \retval -1 Invalid argument, errno set to EINVAL.
+ */
+int llapi_layout_pool_name_get(const struct llapi_layout *layout,
+ char *pool_name, size_t pool_name_len);
+
+/**
+ * Set the name of the pool of OSTs from which file objects will be
+ * allocated to \a pool_name.
+ *
+ * If the pool name uses "fsname.pool" notation to qualify the pool name
+ * with a filesystem name, the "fsname." portion will be silently
+ * discarded before storing the value. No validation that \a pool_name
+ * is an existing non-empty pool in filesystem \a fsname will be
+ * performed. Such validation can be performed by the application if
+ * desired using the llapi_search_ost() function. The maximum length of
+ * the stored value is defined by the constant LOV_MAXPOOLNAME.
+ *
+ * \retval 0 Success.
+ * \retval -1 Invalid argument, errno set to EINVAL.
+ */
+int llapi_layout_pool_name_set(struct llapi_layout *layout,
+ const char *pool_name);
+
+/******************** File Creation ********************/
+
+/**
+ * Open an existing file at \a path, or create it with the specified
+ * \a layout and \a mode.
+ *
+ * One access mode and zero or more file creation flags and file status
+ * flags May be bitwise-or'd in \a open_flags (see open(2)). Return an
+ * open file descriptor for the file. If \a layout is non-NULL and
+ * \a path is not on a Lustre filesystem this function will fail and set
+ * errno to ENOTTY.
+ *
+ * An already existing file may be opened with this function, but
+ * \a layout and \a mode will not be applied to it. Callers requiring a
+ * guarantee that the opened file is created with the specified
+ * \a layout and \a mode should use llapi_layout_file_create().
+ *
+ * A NULL \a layout may be specified, in which case the standard Lustre
+ * behavior for assigning layouts to newly-created files will apply.
+ *
+ * \retval 0+ An open file descriptor.
+ * \retval -1 Error with status code in errno.
+ */
+int llapi_layout_file_open(const char *path, int open_flags, mode_t mode,
+ const struct llapi_layout *layout);
+
+/**
+ * Create a new file at \a path with the specified \a layout and \a mode.
+ *
+ * One access mode and zero or more file creation flags and file status
+ * flags May be bitwise-or'd in \a open_flags (see open(2)). Return an
+ * open file descriptor for the file. If \a layout is non-NULL and
+ * \a path is not on a Lustre filesystem this function will fail and set
+ * errno to ENOTTY.
+ *
+ * The function call
+ *
+ * llapi_layout_file_create(path, open_flags, mode, layout)
+ *
+ * shall be equivalent to:
+ *
+ * llapi_layout_file_open(path, open_flags|O_CREAT|O_EXCL, mode, layout)
+ *
+ * It is an error if \a path specifies an existing file.
+ *
+ * A NULL \a layout may be specified, in which the standard Lustre
+ * behavior for assigning layouts to newly-created files will apply.
+ *
+ * \retval 0+ An open file descriptor.
+ * \retval -1 Error with status code in errno.
+ */
+int llapi_layout_file_create(const char *path, int open_flags, int mode,
+ const struct llapi_layout *layout);
+
+/** @} llapi */
+
+#endif