libfuse 3.17.1-rc1 Release Notes

Compared to 3.17.1-rc0

• several BSD fixes
• x86 (32bit) build fixes
• nested declarations moved out of the inlined functions to avoid
  build warnings
• signify public key added for future 3.18

libfuse 3.17.1-rc0 Release Notes

First, we apologize for the extended time this release has taken. We wanted to ensure proper ABI compatibility and testing.

Major Changes:

• ABI/API Versioning:
  • API version remains at 3.x as the API is stable
  • SO version increased from 3 to 4 due to ABI issues introduced in 3.11.0 and 3.14.2
  • Restored ABI compatibility to 3.10 (fixing incompatibilities introduced in 3.11 and 3.14.2)
  • Added automated ABI compatibility tests
    Note: Currently tests only verify against previous tag, not 3.10 yet due to too many false positives.
    Further improvements to the ABI testing are planned.
• Version Encoding: The libfuse version is now encoded into programs at compile time using inlined functions in fuse_lowlevel.h and fuse.h
• Switched to posix_spawn for better performance with memory-heavy applications and to prevent RDMA-related issues

New Features:

• Added support for filesystem passthrough read/write when FUSE_PASSTHROUGH capability is enabled
  • New API: fuse_passthrough_open() and fuse_passthrough_close()
  • See example/passthrough_hp.cc for usage
• Added fmask and dmask options to high-level API for separate permission masks for files and directories
• Added signal handling with backtrace printing (fuse_set_fail_signal_handlers())
• Added syslog support for fuse_log() messages
  • New API: fuse_log_enable_syslog() and fuse_log_close_syslog()
• Added thread names to libfuse threads
• Fixed buffer misalignment for FUSE_WRITE

Various minor bugfixes and improvements.

• Readdir kernel cache can be enabled from high-level API.

Future libfuse releases will be signed with signify rather than PGP (rationale). This release is the last to be signed with PGP and contains the signify public key for current (3.15.X) and upcoming (3.16.X) minor release cycle.

• Improved support for some less common systems (32 bit, alternative libcs)

• Unsupported mount options are no longer silently accepted.

• auto_unmount is now compatible with allow_other.

• The extended attribute name passed to the setxattr() handler is no longer truncated at the beginning (bug introduced in 3.13.0).

• As a result of the above, the additional setattr() flags introduced in 3.14 are no longer available for now. They will hopefully be reintroduced in the next release.

• Further improvements of configuration header handling.

• Properly fix the header installation issue. The fix in 3.13.1 resulted in conflicts with other packages.

• Introduce additional setattr() flags (FORCE, KILL_SUID, KILL_SGID, FILE, KILL_PRIV, OPEN, TIMES_SET)

• Fixed an issue that resulted in errors when attempting to compile against installed libfuse headers (because libc symbol versioning support was not detected correctly in this case).

• There is a new low-level API function fuse_session_custom_io that allows to implement a daemon with a custom io. This can be used to create a daemon that can process incoming FUSE requests to other destinations than /dev/fuse.

• A segfault when loading custom FUSE modules has been fixed.

• There is a new fuse_notify_expire_entry function.

• A deadlock when resolving paths in the high-level API has been fixed.

• libfuse can now be build explicitly for C libraries without symbol versioning support.