1 .. SPDX-License-Identifier: GPL-2.0
2
3 =======================================
4 v9fs: Plan 9 Resource Sharing for Linux
5 =======================================
6
7 About
8 =====
9
10 v9fs is a Unix implementation of the Plan 9 9p
11
12 This software was originally developed by Ron <
13 and Maya Gokhale. Additional development by G
14 <gwatson@lanl.gov> and most recently Eric Van H
15 <ericvh@gmail.com>, Latchesar Ionkov <lucho@ion
16 <rsc@swtch.com>.
17
18 The best detailed explanation of the Linux imp
19 the 9p client is available in the form of a US
20
21 https://www.usenix.org/events/usenix05/tech
22
23 Other applications are described in the follow
24
25 * XCPU & Clustering
26 http://xcpu.org/papers/xcpu-talk.pdf
27 * KVMFS: control file system for KVM
28 http://xcpu.org/papers/kvmfs.pdf
29 * CellFS: A New Programming Model for
30 http://xcpu.org/papers/cellfs-talk.p
31 * PROSE I/O: Using 9p to enable Applic
32 http://plan9.escet.urjc.es/iwp9/crea
33 * VirtFS: A Virtualization Aware File
34 http://goo.gl/3WPDg
35
36 Usage
37 =====
38
39 For remote file server::
40
41 mount -t 9p 10.10.1.2 /mnt/9
42
43 For Plan 9 From User Space applications (http:
44
45 mount -t 9p `namespace`/acme /mnt/9 -o
46
47 For server running on QEMU host with virtio tr
48
49 mount -t 9p -o trans=virtio <mount_tag
50
51 where mount_tag is the tag associated by the s
52 mount points. Each 9P export is seen by the cl
53 associated "mount_tag" property. Available mou
54 seen by reading /sys/bus/virtio/drivers/9pnet_
55
56 Options
57 =======
58
59 ============= ==============================
60 trans=name select an alternative transpor
61 currently:
62
63 ======== ============
64 unix specifying a
65 tcp specifying a
66 fd used passed
67 (see rfdno a
68 virtio connect to t
69 (from QEMU w
70 rdma connect to a
71 ======== ============
72
73 uname=name user name to attempt mount as
74 server may override or ignore
75 names may require authenticati
76
77 aname=name aname specifies the file tree
78 offering several exported file
79
80 cache=mode specifies a caching policy. B
81 The mode can be specified as a
82 preexisting common 'shortcuts'
83 The bitmask is described below
84
85 ========== ==========
86 0b00000000 all caches
87 0b00000001 file cache
88 0b00000010 meta-data
89 0b00000100 writeback
90 0b00001000 loose cach
91 0b10000000 fscache en
92 ========== ==========
93
94 The current shortcuts and thei
95
96 ========= ==========
97 none 0b00000000
98 readahead 0b00000001
99 mmap 0b00000101
100 loose 0b00001111
101 fscache 0b10001111
102 ========= ==========
103
104 NOTE: only these shortcuts are
105 moment, so using other combina
106 known to work. Work on better
107
108 IMPORTANT: loose caches (and b
109 do not necessarily validate ca
110 words changes on the server ar
111 on the client system. Only us
112 have an exclusive mount and th
113 underneath you.
114
115 debug=n specifies debug level. The de
116
117 ===== ==============
118 0x01 display verbos
119 0x02 developer debu
120 0x04 display 9p tra
121 0x08 display VFS tr
122 0x10 display Marsha
123 0x20 display RPC de
124 0x40 display transp
125 0x80 display alloca
126 0x100 display protoc
127 0x200 display Fid de
128 0x400 display packet
129 0x800 display fscach
130 ===== ==============
131
132 rfdno=n the file descriptor for readin
133
134 wfdno=n the file descriptor for writin
135
136 msize=n the number of bytes to use for
137
138 port=n port to connect to on the remo
139
140 noextend force legacy mode (no 9p2000.u
141
142 version=name Select 9P protocol version. Va
143
144 ======== ======
145 9p2000 Legacy
146 9p2000.u Use 9P
147 9p2000.L Use 9P
148 ======== ======
149
150 dfltuid attempt to mount as a particul
151
152 dfltgid attempt to mount with a partic
153
154 afid security channel - used by Pla
155
156 nodevmap do not map special files - rep
157 This can be used to share devi
158 hosts. This functionality wil
159
160 directio bypass page cache on all read/
161
162 ignoreqv ignore qid.version==0 as a mar
163
164 noxattr do not offer xattr functions o
165
166 access there are four access modes.
167 user
168 if a user trie
169 filesystem for
170 attach command
171 This is the de
172 <uid>
173 allows only us
174 the files on t
175 any
176 v9fs does sing
177 operations as
178 clien
179 ACL based acc
180 side for acce
181
182 cachetag cache tag to use the specified
183 cache tags for existing cache
184 /sys/fs/9p/caches. (applies on
185 ============= ==============================
186
187 Behavior
188 ========
189
190 This section aims at describing 9p 'quirks' th
191 from a local filesystem behaviors.
192
193 - Setting O_NONBLOCK on a file will make clie
194 as the server returns some data instead of
195 buffer with the requested amount of bytes o
196
197 Resources
198 =========
199
200 Protocol specifications are maintained on gith
201 http://ericvh.github.com/9p-rfc/
202
203 9p client and server implementations are liste
204 http://9p.cat-v.org/implementations
205
206 A 9p2000.L server is being developed by LLNL a
207 at http://code.google.com/p/diod/
208
209 There are user and developer mailing lists ava
210 on sourceforge (http://sourceforge.net/project
211
212 News and other information is maintained on a
213 (http://sf.net/apps/mediawiki/v9fs/index.php).
214
215 Bug reports are best issued via the mailing li
216
217 For more information on the Plan 9 Operating S
218 http://plan9.bell-labs.com/plan9
219
220 For information on Plan 9 from User Space (Pla
221 ported to Linux/BSD/OSX/etc) check out https:/
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