GO-FUSE

Go native bindings for the FUSE kernel module.

You should import and usegithub.com/hanwen/go-fuse/fslibrary. It follows the wire protocol closely, but providesconvenient abstractions for building both node and path based filesystems

Older, deprecated APIs are available atgithub.com/hanwen/go-fuse/fuse/pathfsandgithub.com/hanwen/go-fuse/fuse/nodefs.

Comparison with other FUSE libraries

The FUSE library gained a new, cleaned-up API during a rewritecompleted in 2019. Find extensive documentationhere.

Further highlights of this library is

• Comprehensive and up to date protocol support (up to 7.12.28).

• Performance that is competitive with libfuse.

Examples

• example/hello/main.go contains a 60-line "hello world" filesystem

• zipfs/zipfs.go contains a small and simple read-only filesystem forzip and tar files. The corresponding command is in example/zipfs/For example,

  mkdir /tmp/mountpointexample/zipfs/zipfs /tmp/mountpoint file.zip &ls /tmp/mountpointfusermount -u /tmp/mountpoint

• zipfs/multizipfs.go shows how to use in-process mounts tocombine multiple Go-FUSE filesystems into a larger filesystem.

• fuse/loopback.go mounts another piece of the filesystem.Functionally, it is similar to a symlink. A binary to run is inexample/loopback/ . For example

  mkdir /tmp/mountpointexample/loopback/loopback -debug /tmp/mountpoint /some/other/directory &ls /tmp/mountpointfusermount -u /tmp/mountpoint

macOS Support

go-fuse works somewhat on OSX. Known limitations:

• All of the limitations of OSXFUSE, including lack of support forNOTIFY.

• OSX issues STATFS calls continuously (leading to performanceconcerns).

• OSX has trouble with concurrent reads from the FUSE device, leadingto performance concerns.

• Tests are expected to pass; report any failure as a bug!

Credits

• Inspired by Taru Karttunen's package,https://bitbucket.org/taruti/go-extra.

• Originally based on Ivan Krasin'shttps://github.com/krasin/go-fuse-zip

Bugs

Yes, probably. Report them throughhttps://github.com/hanwen/go-fuse/issues

Disclaimer

This is not an official Google product.

Known Problems

Grep source code for TODO. Major topics:

• Missing support forCUSE,BMAP,IOCTL

License

Like Go, this library is distributed under the new BSD license. Seeaccompanying LICENSE file.

Appendix I. Go-FUSE log format

To increase signal/noise ratio Go-FUSE uses abbreviations in its debug logoutput. Here is how to read it:

• iX meansinode X;
• gX meansgeneration X;
• tA andtE means timeout for attributes and directory entry correspondingly;
• [<off> +<size>) means data range from<off> inclusive till<off>+<size> exclusive;
• Xb meansX bytes.

Every line is prefixed with eitherrx <unique> ortx <unique> to denotewhether it was for kernel request, which Go-FUSE received, or reply, whichGo-FUSE sent back to kernel.

Example debug log output:

rx 2: LOOKUP i1 [".wcfs"] 6btx 2:     OK, {i3 g2 tE=1s tA=1s {M040755 SZ=0 L=0 1000:1000 B0*0 i0:3 A 0.000000 M 0.000000 C 0.000000}}rx 3: LOOKUP i3 ["zurl"] 5btx 3:     OK, {i4 g3 tE=1s tA=1s {M0100644 SZ=33 L=1 1000:1000 B0*0 i0:4 A 0.000000 M 0.000000 C 0.000000}}rx 4: OPEN i4 {O_RDONLY,0x8000}tx 4:     38=function not implemented, {Fh 0 }rx 5: READ i4 {Fh 0 [0 +4096)  L 0 RDONLY,0x8000}tx 5:     OK,  33b data "file:///"...rx 6: GETATTR i4 {Fh 0}tx 6:     OK, {tA=1s {M0100644 SZ=33 L=1 1000:1000 B0*0 i0:4 A 0.000000 M 0.000000 C 0.000000}}rx 7: FLUSH i4 {Fh 0}tx 7:     OKrx 8: LOOKUP i1 ["head"] 5btx 8:     OK, {i5 g4 tE=1s tA=1s {M040755 SZ=0 L=0 1000:1000 B0*0 i0:5 A 0.000000 M 0.000000 C 0.000000}}rx 9: LOOKUP i5 ["bigfile"] 8btx 9:     OK, {i6 g5 tE=1s tA=1s {M040755 SZ=0 L=0 1000:1000 B0*0 i0:6 A 0.000000 M 0.000000 C 0.000000}}rx 10: FLUSH i4 {Fh 0}tx 10:     OKrx 11: GETATTR i1 {Fh 0}tx 11:     OK, {tA=1s {M040755 SZ=0 L=1 1000:1000 B0*0 i0:1 A 0.000000 M 0.000000 C 0.000000}}