| ================================== |
| libfuse API Changes (3.0 to 3.19) |
| ================================== |
| |
| This document describes API changes between FUSE_USE_VERSION values. |
| Set FUSE_USE_VERSION before including fuse.h or fuse_lowlevel.h. |
| |
| Version 3.1 (FUSE_MAKE_VERSION(3, 1)) |
| ===================================== |
| |
| New Functions |
| ------------- |
| * ``fuse_lib_help()`` - Print help for generic high-level FUSE options |
| * ``fuse_invalidate_path()`` - Cache invalidation from high-level API |
| |
| Changed Functions |
| ----------------- |
| * ``fuse_new()`` signature changed; applications should call ``fuse_lib_help()`` |
| for --help instead of passing it to fuse_new() |
| |
| Version 3.2 (FUSE_MAKE_VERSION(3, 2)) |
| ===================================== |
| |
| Changed Functions |
| ----------------- |
| * ``fuse_loop_mt()`` and ``fuse_session_loop_mt()`` now take a |
| ``struct fuse_loop_config *`` parameter instead of a *clone_fd* boolean. |
| The struct is public and can be directly initialized. |
| |
| Note: This change was implemented in libfuse release 3.1.1, but the API version |
| that enables it is 32. |
| |
| Version 3.3 (FUSE_MAKE_VERSION(3, 3)) |
| ===================================== |
| |
| New Functions |
| ------------- |
| * ``fuse_open_channel()`` - Open a FUSE file descriptor and set up mount |
| (allows passing open /dev/fuse fd via ``/dev/fd/%u`` mountpoint format) |
| |
| Version 3.4 (FUSE_MAKE_VERSION(3, 4)) |
| ===================================== |
| |
| New Operations |
| -------------- |
| * ``copy_file_range`` - Efficient server-side file copying |
| |
| New Functions |
| ------------- |
| * ``fuse_fs_copy_file_range()`` - High-level API wrapper |
| |
| Version 3.5 (FUSE_MAKE_VERSION(3, 5)) |
| ===================================== |
| |
| Changed Prototypes |
| ------------------ |
| * ``ioctl`` handler: cmd parameter changed from ``int`` to ``unsigned int`` |
| |
| - Use FUSE_USE_VERSION < 35 for old ``int cmd`` prototype |
| - Use FUSE_USE_VERSION >= 35 for new ``unsigned int cmd`` prototype |
| |
| Version 3.7 (FUSE_MAKE_VERSION(3, 7)) |
| ===================================== |
| |
| New Functions |
| ------------- |
| * ``fuse_set_log_func()`` - Install custom log message handler |
| * ``fuse_log()`` - Emit log messages (replaces direct stderr writes) |
| |
| Version 3.8 (FUSE_MAKE_VERSION(3, 8)) |
| ===================================== |
| |
| New Operations |
| -------------- |
| * ``lseek`` - Find next data or hole in sparse files (SEEK_DATA/SEEK_HOLE) |
| |
| New Functions |
| ------------- |
| * ``fuse_fs_lseek()`` - High-level API wrapper |
| * ``fuse_reply_lseek()`` - Low-level reply function |
| |
| Version 3.12 (FUSE_MAKE_VERSION(3, 12)) |
| ======================================= |
| |
| Major Changes |
| ------------- |
| * ``struct fuse_loop_config`` is now **private** (opaque pointer) |
| * Loop configuration must use accessor functions instead of direct struct access |
| * The public struct from version 3.2-3.11 is renamed to ``struct fuse_loop_config_v1`` |
| |
| New Functions |
| ------------- |
| * ``fuse_loop_cfg_create()`` - Create loop configuration |
| * ``fuse_loop_cfg_destroy()`` - Free loop configuration |
| * ``fuse_loop_cfg_set_idle_threads()`` - Set max idle threads |
| * ``fuse_loop_cfg_set_max_threads()`` - Set max total threads |
| * ``fuse_loop_cfg_set_clone_fd()`` - Enable/disable clone_fd |
| * ``fuse_loop_cfg_convert()`` - Convert old config (v1) to new format |
| * ``fuse_lowlevel_notify_expire_entry()`` - Expire dentry without full invalidation |
| |
| Changed Functions |
| ----------------- |
| * ``fuse_session_loop_mt()`` now accepts NULL config pointer |
| * ``fuse_parse_cmdline()`` now accepts ``max_threads`` option |
| |
| Deprecated |
| ---------- |
| * ``max_idle_threads`` parameter (use ``max_threads`` instead) |
| |
| Version 3.17 (FUSE_MAKE_VERSION(3, 17)) |
| ======================================= |
| |
| New Functions |
| ------------- |
| * ``fuse_set_fail_signal_handlers()`` - Handle fatal signals with backtrace |
| * ``fuse_log_enable_syslog()`` - Redirect fuse_log() to syslog |
| * ``fuse_log_close_syslog()`` - Close syslog connection |
| * ``fuse_passthrough_open()`` - Setup passthrough backing file |
| * ``fuse_passthrough_close()`` - Close passthrough connection |
| * ``fuse_session_custom_io()`` - Custom I/O for FUSE daemon (signature extended) |
| |
| New Capabilities |
| ---------------- |
| * ``FUSE_CAP_PASSTHROUGH`` - Enable passthrough read/write to backing file |
| * ``FUSE_CAP_HANDLE_KILLPRIV_V2`` - Support for KILLPRIV_V2 |
| |
| New Mount Options |
| ----------------- |
| * ``fmask`` - umask applied to non-directories (high-level API) |
| * ``dmask`` - umask applied to directories (high-level API) |
| |
| Version 3.17.3 |
| ============== |
| |
| New Functions |
| ------------- |
| * ``fuse_set_feature_flag()`` - Set capability in want_ext field |
| * ``fuse_unset_feature_flag()`` - Unset capability in want_ext field |
| * ``fuse_get_feature_flag()`` - Query capability in want_ext field |
| |
| Note: These replace direct manipulation of conn->want for 64-bit capability support. |
| |
| Version 3.18 (FUSE_MAKE_VERSION(3, 18)) |
| ======================================= |
| |
| New Operations |
| -------------- |
| * ``statx`` - Extended file attributes (struct statx support) |
| |
| New Functions |
| ------------- |
| * ``fuse_fs_statx()`` - High-level API wrapper |
| * ``fuse_reply_statx()`` - Low-level reply function |
| * ``fuse_req_is_uring()`` - Check if request uses fuse-over-io-uring |
| * ``fuse_req_get_payload()`` - Get request payload buffer (io-uring only) |
| * ``fuse_lowlevel_notify_increment_epoch()`` - Increment epoch counter |
| |
| New Features |
| ------------ |
| * fuse-over-io-uring communication support |
| * Request timeouts for hung operation prevention |
| |
| Version 3.19 (FUSE_MAKE_VERSION(3, 19)) |
| ======================================= |
| |
| (Reserved for future use) |
| |
| Migration Notes |
| =============== |
| |
| When upgrading FUSE_USE_VERSION: |
| |
| 1. **3.0 → 3.1**: Handle --help in filesystem code, call fuse_lib_help() |
| 2. **3.1 → 3.2**: Update fuse_loop_mt() calls to use struct fuse_loop_config |
| 3. **< 3.5 → 3.5+**: Change ioctl cmd from int to unsigned int |
| 4. **< 3.12 → 3.12+**: Use fuse_loop_cfg_*() functions instead of direct struct access |
| 5. **< 3.17 → 3.17+**: Use fuse_set_feature_flag() instead of conn->want for new caps |
| |
