github.com/hanwen/go-fuse@v1.0.0/README.md (about) 1 # GO-FUSE 2 3 [![Build Status](https://travis-ci.org/hanwen/go-fuse.svg?branch=master)](https://travis-ci.org/hanwen/go-fuse) 4 [![GoDoc](https://godoc.org/github.com/hanwen/go-fuse?status.svg)](https://godoc.org/github.com/hanwen/go-fuse) 5 6 native bindings for the FUSE kernel module. 7 8 ## Highlights 9 10 * High speed: as fast as libfuse using the gc compiler for single 11 threaded loads. 12 13 * Supports in-process mounting of different FileSystems onto 14 subdirectories of the FUSE mount. 15 16 * Supports 3 interfaces for writing filesystems: 17 - `PathFileSystem`: define filesystems in terms path names. 18 - `NodeFileSystem`: define filesystems in terms of inodes. 19 - `RawFileSystem`: define filesystems in terms of FUSE's raw 20 wire protocol. 21 22 * Both NodeFileSystem and PathFileSystem support manipulation of true 23 hardlinks. 24 25 * Includes two fleshed out examples, zipfs and unionfs. 26 27 28 ## Examples 29 30 * `example/hello/main.go` contains a 60-line "hello world" filesystem 31 32 * `zipfs/zipfs.go` contains a small and simple read-only filesystem for 33 zip and tar files. The corresponding command is in example/zipfs/ 34 For example, 35 36 ```shell 37 mkdir /tmp/mountpoint 38 example/zipfs/zipfs /tmp/mountpoint file.zip & 39 ls /tmp/mountpoint 40 fusermount -u /tmp/mountpoint 41 ```` 42 43 * `zipfs/multizipfs.go` shows how to use in-process mounts to 44 combine multiple Go-FUSE filesystems into a larger filesystem. 45 46 * `fuse/loopback.go` mounts another piece of the filesystem. 47 Functionally, it is similar to a symlink. A binary to run is in 48 example/loopback/ . For example 49 50 ```shell 51 mkdir /tmp/mountpoint 52 example/loopback/loopback -debug /tmp/mountpoint /some/other/directory & 53 ls /tmp/mountpoint 54 fusermount -u /tmp/mountpoint 55 ``` 56 57 * `unionfs/unionfs.go`: implements a union mount using 1 R/W branch, and 58 multiple R/O branches. 59 60 ```shell 61 mkdir -p /tmp/mountpoint /tmp/writable 62 example/unionfs/unionfs /tmp/mountpoint /tmp/writable /usr & 63 ls /tmp/mountpoint 64 ls -l /tmp/mountpoint/bin/vi 65 rm /tmp/mountpoint/bin/vi 66 ls -l /tmp/mountpoint/bin/vi 67 cat /tmp/writable/DELETION/* 68 ``` 69 70 * `union/autounionfs.go`: creates UnionFs mounts automatically based on 71 existence of READONLY symlinks. 72 73 74 Tested on: 75 76 - x86 32bits (Fedora 14). 77 - x86 64bits (Ubuntu Lucid). 78 79 80 ## Benchmarks 81 82 We use threaded stats over a read-only filesystem for benchmarking. 83 Automated code is under benchmark/ directory. A simple C version of 84 the same FS gives a FUSE baseline 85 86 Data points (Go-FUSE version May 2012), 1000 files, high level 87 interface, all kernel caching turned off, median stat time: 88 89 platform libfuse Go-FUSE difference (%) 90 91 Lenovo T60/Fedora16 (1cpu) 349us 355us 2% slower 92 Lenovo T400/Lucid (1cpu) 138us 140us 5% slower 93 Dell T3500/Lucid (1cpu) 72us 76us 5% slower 94 95 On T60, for each file we have 96 - Client side latency is 360us 97 - 106us of this is server side latency (4.5x lookup 23us, 1x getattr 4us) 98 - 16.5us is due to latency measurements. 99 - 3us is due to garbage collection. 100 101 ## macOS Support 102 103 go-fuse works somewhat on OSX. Known limitations: 104 105 * All of the limitations of OSXFUSE, including lack of support for 106 NOTIFY. 107 108 * OSX issues STATFS calls continuously (leading to performance 109 concerns). 110 111 * OSX has trouble with concurrent reads from the FUSE device, leading 112 to performance concerns. 113 114 * Tests are expected to pass; report any failure as a bug! 115 116 ## Credits 117 118 * Inspired by Taru Karttunen's package, https://bitbucket.org/taruti/go-extra. 119 120 * Originally based on Ivan Krasin's https://github.com/krasin/go-fuse-zip 121 122 ## Bugs 123 124 Yes, probably. Report them through 125 https://github.com/hanwen/go-fuse/issues 126 127 ## Disclaimer 128 129 This is not an official Google product. 130 131 ## Known Problems 132 133 Grep source code for TODO. Major topics: 134 135 * Missing support for network FS file locking: `FUSE_GETLK`, `FUSE_SETLK`, 136 `FUSE_SETLKW` 137 138 * Missing support for `FUSE_INTERRUPT`, `CUSE`, `BMAP`, `IOCTL` 139 140 * In the path API, renames are racy; See also: 141 142 http://sourceforge.net/mailarchive/message.php?msg_id=27550667 143 144 Don't use the path API if you care about correctness. 145 146 ## License 147 148 Like Go, this library is distributed under the new BSD license. See 149 accompanying LICENSE file. 150 151 -------- 152 153 ## Appendix I. Go-FUSE log format 154 155 To increase signal/noise ratio Go-FUSE uses abbreviations in its debug log 156 output. Here is how to read it: 157 158 - `iX` means `inode X`; 159 - `gX` means `generation X`; 160 - `tA` and `tE` means timeout for attributes and directory entry correspondingly; 161 - `[<off> +<size>)` means data range from `<off>` inclusive till `<off>+<size>` exclusive; 162 - `Xb` means `X bytes`. 163 164 Every line is prefixed with either `rx <unique>` or `tx <unique>` to denote 165 whether it was for kernel request, which Go-FUSE received, or reply, which 166 Go-FUSE sent back to kernel. 167 168 Example debug log output: 169 170 ``` 171 rx 2: LOOKUP i1 [".wcfs"] 6b 172 tx 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}} 173 rx 3: LOOKUP i3 ["zurl"] 5b 174 tx 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}} 175 rx 4: OPEN i4 {O_RDONLY,0x8000} 176 tx 4: 38=function not implemented, {Fh 0 } 177 rx 5: READ i4 {Fh 0 [0 +4096) L 0 RDONLY,0x8000} 178 tx 5: OK, 33b data "file:///"... 179 rx 6: GETATTR i4 {Fh 0} 180 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}} 181 rx 7: FLUSH i4 {Fh 0} 182 tx 7: OK 183 rx 8: LOOKUP i1 ["head"] 5b 184 tx 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}} 185 rx 9: LOOKUP i5 ["bigfile"] 8b 186 tx 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}} 187 rx 10: FLUSH i4 {Fh 0} 188 tx 10: OK 189 rx 11: GETATTR i1 {Fh 0} 190 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}} 191 ```