1 v9fs: Plan 9 Resource Sharing for Linux 2 ======================================= 3 4ABOUT 5===== 6 7v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol. 8 9This software was originally developed by Ron Minnich <rminnich@sandia.gov> 10and 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 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 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 * VirtFS: A Virtualization Aware File System pass-through 29 http://goo.gl/3WPDg 30 31USAGE 32===== 33 34For remote file server: 35 36 mount -t 9p 10.10.1.2 /mnt/9 37 38For Plan 9 From User Space applications (http://swtch.com/plan9) 39 40 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER 41 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 51OPTIONS 52======= 53 54 trans=name select an alternative transport. Valid options are 55 currently: 56 unix - specifying a named pipe mount point 57 tcp - specifying a normal TCP/IP connection 58 fd - used passed file descriptors for connection 59 (see rfdno and wfdno) 60 virtio - connect to the next virtio channel available 61 (from QEMU with trans_virtio module) 62 rdma - connect to a specified RDMA channel 63 64 uname=name user name to attempt mount as on the remote server. The 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 71 cache=mode specifies a caching policy. By default, no caches are used. 72 loose = no attempts are made at consistency, 73 intended for exclusive, read-only mounts 74 fscache = use FS-Cache for a persistent, read-only 75 cache backend. 76 77 debug=n specifies debug level. The debug level is a bitmask. 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 90 91 rfdno=n the file descriptor for reading with trans=fd 92 93 wfdno=n the file descriptor for writing with trans=fd 94 95 msize=n the number of bytes to use for 9p packet payload 96 97 port=n port to connect to on the remote server 98 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 105 106 dfltuid attempt to mount as a particular uid 107 108 dfltgid attempt to mount with a particular gid 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. 115 116 access there are four access modes. 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 125 client = ACL based access check on the 9p client 126 side for access validation 127 128 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 132RESOURCES 133========= 134 135Protocol specifications are maintained on github: 136http://ericvh.github.com/9p-rfc/ 137 1389p client and server implementations are listed on 139http://9p.cat-v.org/implementations 140 141A 9p2000.L server is being developed by LLNL and can be found 142at http://code.google.com/p/diod/ 143 144There are user and developer mailing lists available through the v9fs project 145on sourceforge (http://sourceforge.net/projects/v9fs). 146 147News and other information is maintained on a Wiki. 148(http://sf.net/apps/mediawiki/v9fs/index.php). 149 150Bug reports may be issued through the kernel.org bugzilla 151(http://bugzilla.kernel.org) 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 165PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org) 166 167