Documentation/filesystems/9p.txt

   1                     v9fs: Plan 9 Resource Sharing for Linux
   2                     =======================================
   3
   4 ABOUT
   5 =====
   6
   7 v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
   8
   9 This software was originally developed by Ron Minnich <rminnich@sandia.gov>
  10 and Maya Gokhale.  Additional development by Greg Watson
  11 <gwatson@lanl.gov> and most recently Eric Van Hensbergen
  12 <ericvh@gmail.com>, Latchesar Ionkov <lucho@ionkov.net> and Russ Cox
  13 <rsc@swtch.com>.
  14
  15 The best detailed explanation of the Linux implementation and applications of
  16 the 9p client is available in the form of a USENIX paper:
  17    http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html
  18
  19 Other applications are described in the following papers:
  20         * XCPU & Clustering
  21                 http://xcpu.org/papers/xcpu-talk.pdf
  22         * KVMFS: control file system for KVM
  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
  26         * PROSE I/O: Using 9p to enable Application Partitions
  27                 http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
  28
  29 USAGE
  30 =====
  31
  32 For remote file server:
  33
  34         mount -t 9p 10.10.1.2 /mnt/9
  35
  36 For Plan 9 From User Space applications (http://swtch.com/plan9)
  37
  38         mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
  39
  40 OPTIONS
  41 =======
  42
  43   trans=name    select an alternative transport.  Valid options are
  44                 currently:
  45                         unix    - specifying a named pipe mount point
  46                         tcp     - specifying a normal TCP/IP connection
  47                         fd      - used passed file descriptors for connection
  48                                 (see rfdno and wfdno)
  49                         virtio  - connect to the next virtio channel available
  50                                 (from lguest or KVM with trans_virtio module)
  51                         rdma    - connect to a specified RDMA channel
  52
  53   uname=name    user name to attempt mount as on the remote server.  The
  54                 server may override or ignore this value.  Certain user
  55                 names may require authentication.
  56
  57   aname=name    aname specifies the file tree to access when the server is
  58                 offering several exported file systems.
  59
  60   cache=mode    specifies a caching policy.  By default, no caches are used.
  61                         loose = no attempts are made at consistency,
  62                                 intended for exclusive, read-only mounts
  63                         fscache = use FS-Cache for a persistent, read-only
  64                                 cache backend.
  65
  66   debug=n       specifies debug level.  The debug level is a bitmask.
  67                         0x01  = display verbose error messages
  68                         0x02  = developer debug (DEBUG_CURRENT)
  69                         0x04  = display 9p trace
  70                         0x08  = display VFS trace
  71                         0x10  = display Marshalling debug
  72                         0x20  = display RPC debug
  73                         0x40  = display transport debug
  74                         0x80  = display allocation debug
  75                         0x100 = display protocol message debug
  76                         0x200 = display Fid debug
  77                         0x400 = display packet debug
  78                         0x800 = display fscache tracing debug
  79
  80   rfdno=n       the file descriptor for reading with trans=fd
  81
  82   wfdno=n       the file descriptor for writing with trans=fd
  83
  84   maxdata=n     the number of bytes to use for 9p packet payload (msize)
  85
  86   port=n        port to connect to on the remote server
  87
  88   noextend      force legacy mode (no 9p2000.u semantics)
  89
  90   dfltuid       attempt to mount as a particular uid
  91
  92   dfltgid       attempt to mount with a particular gid
  93
  94   afid          security channel - used by Plan 9 authentication protocols
  95
  96   nodevmap      do not map special files - represent them as normal files.
  97                 This can be used to share devices/named pipes/sockets between
  98                 hosts.  This functionality will be expanded in later versions.
  99
 100   access        there are three access modes.
 101                         user  = if a user tries to access a file on v9fs
 102                                 filesystem for the first time, v9fs sends an
 103                                 attach command (Tattach) for that user.
 104                                 This is the default mode.
 105                         <uid> = allows only user with uid=<uid> to access
 106                                 the files on the mounted filesystem
 107                         any   = v9fs does single attach and performs all
 108                                 operations as one user
 109
 110   cachetag      cache tag to use the specified persistent cache.
 111                 cache tags for existing cache sessions can be listed at
 112                 /sys/fs/9p/caches. (applies only to cache=fscache)
 113
 114 RESOURCES
 115 =========
 116
 117 Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
 118 as the 9p server.  You can start a 9p server under Inferno by issuing the
 119 following command:
 120    ; styxlisten -A tcp!*!564 export '#U*'
 121
 122 The -A specifies an unauthenticated export.  The 564 is the port # (you may
 123 have to choose a higher port number if running as a normal user).  The '#U*'
 124 specifies exporting the root of the Linux name space.  You may specify a
 125 subset of the namespace by extending the path: '#U*'/tmp would just export
 126 /tmp.  For more information, see the Inferno manual pages covering styxlisten
 127 and export.
 128
 129 A Linux version of the 9p server is now maintained under the npfs project
 130 on sourceforge (http://sourceforge.net/projects/npfs).  The currently
 131 maintained version is the single-threaded version of the server (named spfs)
 132 available from the same SVN repository.
 133
 134 There are user and developer mailing lists available through the v9fs project
 135 on sourceforge (http://sourceforge.net/projects/v9fs).
 136
 137 A stand-alone version of the module (which should build for any 2.6 kernel)
 138 is available via (http://github.com/ericvh/9p-sac/tree/master)
 139
 140 News and other information is maintained on SWiK (http://swik.net/v9fs)
 141 and the Wiki (http://sf.net/apps/mediawiki/v9fs/index.php).
 142
 143 Bug reports may be issued through the kernel.org bugzilla
 144 (http://bugzilla.kernel.org)
 145
 146 For more information on the Plan 9 Operating System check out
 147 http://plan9.bell-labs.com/plan9
 148
 149 For information on Plan 9 from User Space (Plan 9 applications and libraries
 150 ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
 151
 152
 153 STATUS
 154 ======
 155
 156 The 2.6 kernel support is working on PPC and x86.
 157
 158 PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
 159