mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
9208d24253
This patch adds documentation for new 9P options introduced in 2.6.34. Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
173 lines
6.2 KiB
Text
173 lines
6.2 KiB
Text
v9fs: Plan 9 Resource Sharing for Linux
|
|
=======================================
|
|
|
|
ABOUT
|
|
=====
|
|
|
|
v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
|
|
|
|
This software was originally developed by Ron Minnich <rminnich@sandia.gov>
|
|
and Maya Gokhale. Additional development by Greg Watson
|
|
<gwatson@lanl.gov> and most recently Eric Van Hensbergen
|
|
<ericvh@gmail.com>, Latchesar Ionkov <lucho@ionkov.net> and Russ Cox
|
|
<rsc@swtch.com>.
|
|
|
|
The best detailed explanation of the Linux implementation and applications of
|
|
the 9p client is available in the form of a USENIX paper:
|
|
http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html
|
|
|
|
Other applications are described in the following papers:
|
|
* XCPU & Clustering
|
|
http://xcpu.org/papers/xcpu-talk.pdf
|
|
* KVMFS: control file system for KVM
|
|
http://xcpu.org/papers/kvmfs.pdf
|
|
* CellFS: A New Programming Model for the Cell BE
|
|
http://xcpu.org/papers/cellfs-talk.pdf
|
|
* PROSE I/O: Using 9p to enable Application Partitions
|
|
http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
|
|
|
|
USAGE
|
|
=====
|
|
|
|
For remote file server:
|
|
|
|
mount -t 9p 10.10.1.2 /mnt/9
|
|
|
|
For Plan 9 From User Space applications (http://swtch.com/plan9)
|
|
|
|
mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
|
|
|
|
For server running on QEMU host with virtio transport:
|
|
|
|
mount -t 9p -o trans=virtio <mount_tag> /mnt/9
|
|
|
|
where mount_tag is the tag associated by the server to each of the exported
|
|
mount points. Each 9P export is seen by the client as a virtio device with an
|
|
associated "mount_tag" property. Available mount tags can be
|
|
seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
|
|
|
|
OPTIONS
|
|
=======
|
|
|
|
trans=name select an alternative transport. Valid options are
|
|
currently:
|
|
unix - specifying a named pipe mount point
|
|
tcp - specifying a normal TCP/IP connection
|
|
fd - used passed file descriptors for connection
|
|
(see rfdno and wfdno)
|
|
virtio - connect to the next virtio channel available
|
|
(from QEMU with trans_virtio module)
|
|
rdma - connect to a specified RDMA channel
|
|
|
|
uname=name user name to attempt mount as on the remote server. The
|
|
server may override or ignore this value. Certain user
|
|
names may require authentication.
|
|
|
|
aname=name aname specifies the file tree to access when the server is
|
|
offering several exported file systems.
|
|
|
|
cache=mode specifies a caching policy. By default, no caches are used.
|
|
loose = no attempts are made at consistency,
|
|
intended for exclusive, read-only mounts
|
|
fscache = use FS-Cache for a persistent, read-only
|
|
cache backend.
|
|
|
|
debug=n specifies debug level. The debug level is a bitmask.
|
|
0x01 = display verbose error messages
|
|
0x02 = developer debug (DEBUG_CURRENT)
|
|
0x04 = display 9p trace
|
|
0x08 = display VFS trace
|
|
0x10 = display Marshalling debug
|
|
0x20 = display RPC debug
|
|
0x40 = display transport debug
|
|
0x80 = display allocation debug
|
|
0x100 = display protocol message debug
|
|
0x200 = display Fid debug
|
|
0x400 = display packet debug
|
|
0x800 = display fscache tracing debug
|
|
|
|
rfdno=n the file descriptor for reading with trans=fd
|
|
|
|
wfdno=n the file descriptor for writing with trans=fd
|
|
|
|
maxdata=n the number of bytes to use for 9p packet payload (msize)
|
|
|
|
port=n port to connect to on the remote server
|
|
|
|
noextend force legacy mode (no 9p2000.u or 9p2000.L semantics)
|
|
|
|
version=name Select 9P protocol version. Valid options are:
|
|
9p2000 - Legacy mode (same as noextend)
|
|
9p2000.u - Use 9P2000.u protocol
|
|
9p2000.L - Use 9P2000.L protocol
|
|
|
|
dfltuid attempt to mount as a particular uid
|
|
|
|
dfltgid attempt to mount with a particular gid
|
|
|
|
afid security channel - used by Plan 9 authentication protocols
|
|
|
|
nodevmap do not map special files - represent them as normal files.
|
|
This can be used to share devices/named pipes/sockets between
|
|
hosts. This functionality will be expanded in later versions.
|
|
|
|
access there are three access modes.
|
|
user = if a user tries to access a file on v9fs
|
|
filesystem for the first time, v9fs sends an
|
|
attach command (Tattach) for that user.
|
|
This is the default mode.
|
|
<uid> = allows only user with uid=<uid> to access
|
|
the files on the mounted filesystem
|
|
any = v9fs does single attach and performs all
|
|
operations as one user
|
|
|
|
cachetag cache tag to use the specified persistent cache.
|
|
cache tags for existing cache sessions can be listed at
|
|
/sys/fs/9p/caches. (applies only to cache=fscache)
|
|
|
|
RESOURCES
|
|
=========
|
|
|
|
Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
|
|
as the 9p server. You can start a 9p server under Inferno by issuing the
|
|
following command:
|
|
; styxlisten -A tcp!*!564 export '#U*'
|
|
|
|
The -A specifies an unauthenticated export. The 564 is the port # (you may
|
|
have to choose a higher port number if running as a normal user). The '#U*'
|
|
specifies exporting the root of the Linux name space. You may specify a
|
|
subset of the namespace by extending the path: '#U*'/tmp would just export
|
|
/tmp. For more information, see the Inferno manual pages covering styxlisten
|
|
and export.
|
|
|
|
A Linux version of the 9p server is now maintained under the npfs project
|
|
on sourceforge (http://sourceforge.net/projects/npfs). The currently
|
|
maintained version is the single-threaded version of the server (named spfs)
|
|
available from the same SVN repository.
|
|
|
|
There are user and developer mailing lists available through the v9fs project
|
|
on sourceforge (http://sourceforge.net/projects/v9fs).
|
|
|
|
A stand-alone version of the module (which should build for any 2.6 kernel)
|
|
is available via (http://github.com/ericvh/9p-sac/tree/master)
|
|
|
|
News and other information is maintained on SWiK (http://swik.net/v9fs)
|
|
and the Wiki (http://sf.net/apps/mediawiki/v9fs/index.php).
|
|
|
|
Bug reports may be issued through the kernel.org bugzilla
|
|
(http://bugzilla.kernel.org)
|
|
|
|
For more information on the Plan 9 Operating System check out
|
|
http://plan9.bell-labs.com/plan9
|
|
|
|
For information on Plan 9 from User Space (Plan 9 applications and libraries
|
|
ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
|
|
|
|
|
|
STATUS
|
|
======
|
|
|
|
The 2.6 kernel support is working on PPC and x86.
|
|
|
|
PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
|
|
|