* This number should be one less than the total number of parts in the
* split WIM. Set to 0 if the WIM is a standalone WIM.
* @param staging_dir
- * Currently ignored, but may provide a way to specify the staging
- * directory in the future. Set to @c NULL.
+ * If non-NULL, the name of a directory in which the staging directory will
+ * be created. Ignored if ::WIMLIB_MOUNT_FLAG_READWRITE is not specified
+ * in @a mount_flags. If left @c NULL, the staging directory is created in
+ * the same directory as the WIM file that @a wim was originally read from.
*
* @return 0 on success; nonzero on error.
+ * @retval ::WIMLIB_ERR_ALREADY_LOCKED
+ * A read-write mount was requested, but an an exclusive advisory lock on
+ * the on-disk WIM file could not be acquired because another thread or
+ * process has mounted an image from the WIM read-write or is currently
+ * modifying the WIM in-place.
* @retval ::WIMLIB_ERR_DECOMPRESSION
* Could not decompress the metadata resource for @a image in @a wim.
* @retval ::WIMLIB_ERR_FUSE
* @return 0 on success; nonzero on error. This function may return any value
* returned by wimlib_write() as well as the following error codes:
* @retval ::WIMLIB_ERR_ALREADY_LOCKED
- * The append-only overwrite mode was going to be used, but an exclusive
- * advisory lock on the on-disk WIM file could not be acquired, probably
- * because another thread or process was calling wimlib_overwrite() on the
- * same underlying on-disk file at the same time.
+ * The WIM was going to be modifien in-place (with no temporary file), but
+ * an exclusive advisory lock on the on-disk WIM file could not be acquired
+ * because another thread or process has mounted an image from the WIM
+ * read-write or is currently modifying the WIM in-place.
* @retval ::WIMLIB_ERR_NO_FILENAME
* @a wim corresponds to a WIM created with wimlib_create_new_wim() rather
* than a WIM read with wimlib_open_wim().