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1 v9fs: Plan 9 Resource Sharing for Linux
2 =======================================
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3
4ABOUT
5=====
6
7v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
8
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9This software was originally developed by Ron Minnich <rminnich@sandia.gov>
10and Maya Gokhale. Additional development by Greg Watson
93fa58cb 11<gwatson@lanl.gov> and most recently Eric Van Hensbergen
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12<ericvh@gmail.com>, Latchesar Ionkov <lucho@ionkov.net> and Russ Cox
13<rsc@swtch.com>.
93fa58cb 14
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15The best detailed explanation of the Linux implementation and applications of
16the 9p client is available in the form of a USENIX paper:
17 http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html
18
19Other applications are described in the following papers:
20 * XCPU & Clustering
f4edeeb3 21 http://xcpu.org/papers/xcpu-talk.pdf
27a2a5ff 22 * KVMFS: control file system for KVM
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23 http://xcpu.org/papers/kvmfs.pdf
24 * CellFS: A New Programming Model for the Cell BE
25 http://xcpu.org/papers/cellfs-talk.pdf
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26 * PROSE I/O: Using 9p to enable Application Partitions
27 http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
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28 * VirtFS: A Virtualization Aware File System pass-through
29 http://goo.gl/3WPDg
27a2a5ff 30
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31USAGE
32=====
33
34For remote file server:
35
ed1f559b 36 mount -t 9p 10.10.1.2 /mnt/9
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37
38For Plan 9 From User Space applications (http://swtch.com/plan9)
39
a80d923e 40 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
93fa58cb 41
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42For server running on QEMU host with virtio transport:
43
44 mount -t 9p -o trans=virtio <mount_tag> /mnt/9
45
46where mount_tag is the tag associated by the server to each of the exported
47mount points. Each 9P export is seen by the client as a virtio device with an
48associated "mount_tag" property. Available mount tags can be
49seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
50
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51OPTIONS
52=======
53
a80d923e 54 trans=name select an alternative transport. Valid options are
93fa58cb 55 currently:
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56 unix - specifying a named pipe mount point
57 tcp - specifying a normal TCP/IP connection
58 fd - used passed file descriptors for connection
93fa58cb 59 (see rfdno and wfdno)
b530cc79 60 virtio - connect to the next virtio channel available
9208d242 61 (from QEMU with trans_virtio module)
f4edeeb3 62 rdma - connect to a specified RDMA channel
93fa58cb 63
ed1f559b 64 uname=name user name to attempt mount as on the remote server. The
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65 server may override or ignore this value. Certain user
66 names may require authentication.
67
68 aname=name aname specifies the file tree to access when the server is
69 offering several exported file systems.
70
01dd2fbf 71 cache=mode specifies a caching policy. By default, no caches are used.
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72 loose = no attempts are made at consistency,
73 intended for exclusive, read-only mounts
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74 fscache = use FS-Cache for a persistent, read-only
75 cache backend.
e03abc0c 76
93fa58cb 77 debug=n specifies debug level. The debug level is a bitmask.
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78 0x01 = display verbose error messages
79 0x02 = developer debug (DEBUG_CURRENT)
80 0x04 = display 9p trace
81 0x08 = display VFS trace
82 0x10 = display Marshalling debug
83 0x20 = display RPC debug
84 0x40 = display transport debug
85 0x80 = display allocation debug
86 0x100 = display protocol message debug
87 0x200 = display Fid debug
88 0x400 = display packet debug
89 0x800 = display fscache tracing debug
93fa58cb 90
a80d923e 91 rfdno=n the file descriptor for reading with trans=fd
93fa58cb 92
a80d923e 93 wfdno=n the file descriptor for writing with trans=fd
93fa58cb 94
14211d02 95 msize=n the number of bytes to use for 9p packet payload
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96
97 port=n port to connect to on the remote server
98
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99 noextend force legacy mode (no 9p2000.u or 9p2000.L semantics)
100
101 version=name Select 9P protocol version. Valid options are:
102 9p2000 - Legacy mode (same as noextend)
103 9p2000.u - Use 9P2000.u protocol
104 9p2000.L - Use 9P2000.L protocol
93fa58cb 105
bd32b82d 106 dfltuid attempt to mount as a particular uid
93fa58cb 107
bd32b82d 108 dfltgid attempt to mount with a particular gid
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109
110 afid security channel - used by Plan 9 authentication protocols
111
112 nodevmap do not map special files - represent them as normal files.
113 This can be used to share devices/named pipes/sockets between
114 hosts. This functionality will be expanded in later versions.
115
76381a42 116 access there are four access modes.
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117 user = if a user tries to access a file on v9fs
118 filesystem for the first time, v9fs sends an
119 attach command (Tattach) for that user.
120 This is the default mode.
121 <uid> = allows only user with uid=<uid> to access
122 the files on the mounted filesystem
123 any = v9fs does single attach and performs all
124 operations as one user
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125 client = ACL based access check on the 9p client
126 side for access validation
ba17674f 127
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128 cachetag cache tag to use the specified persistent cache.
129 cache tags for existing cache sessions can be listed at
130 /sys/fs/9p/caches. (applies only to cache=fscache)
131
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132RESOURCES
133=========
134
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135Protocol specifications are maintained on github:
136http://ericvh.github.com/9p-rfc/
ff76e1df 137
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1389p client and server implementations are listed on
139http://9p.cat-v.org/implementations
ff76e1df 140
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141A 9p2000.L server is being developed by LLNL and can be found
142at http://code.google.com/p/diod/
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143
144There are user and developer mailing lists available through the v9fs project
145on sourceforge (http://sourceforge.net/projects/v9fs).
146
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147News and other information is maintained on a Wiki.
148(http://sf.net/apps/mediawiki/v9fs/index.php).
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149
150Bug reports may be issued through the kernel.org bugzilla
151(http://bugzilla.kernel.org)
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152
153For more information on the Plan 9 Operating System check out
154http://plan9.bell-labs.com/plan9
155
156For information on Plan 9 from User Space (Plan 9 applications and libraries
157ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
158
159
160STATUS
161======
162
163The 2.6 kernel support is working on PPC and x86.
164
ff76e1df 165PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
93fa58cb 166