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-rw-r--r--Documentation/filesystems/9p.txt129
1 files changed, 95 insertions, 34 deletions
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 43b89c214d2..fec7144e817 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -6,12 +6,28 @@ ABOUT
v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
-This software was originally developed by Ron Minnich <rminnich@lanl.gov>
-and Maya Gokhale <maya@lanl.gov>. Additional development by Greg Watson
+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
+ * VirtFS: A Virtualization Aware File System pass-through
+ http://goo.gl/3WPDg
+
USAGE
=====
@@ -21,17 +37,29 @@ For remote file server:
For Plan 9 From User Space applications (http://swtch.com/plan9)
- mount -t 9p `namespace`/acme /mnt/9 -o proto=unix,uname=$USER
+ mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$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
=======
- proto=name select an alternative transport. Valid options are
+ 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
+ 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
@@ -40,29 +68,48 @@ OPTIONS
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.
+ none = default no cache policy, metadata and data
+ alike are synchronous.
+ loose = no attempts are made at consistency,
+ intended for exclusive, read-only mounts
+ fscache = use FS-Cache for a persistent, read-only
+ cache backend.
+ mmap = minimal cache that is only used for read-write
+ mmap. Northing else is cached, like cache=none
+
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
+ 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 proto=fd
+ rfdno=n the file descriptor for reading with trans=fd
- wfdno=n the file descriptor for writing with proto=fd
+ wfdno=n the file descriptor for writing with trans=fd
- maxdata=n the number of bytes to use for 9p packet payload (msize)
+ msize=n the number of bytes to use for 9p packet payload
port=n port to connect to on the remote server
- noextend force legacy mode (no 9p2000.u semantics)
+ 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
- uid attempt to mount as a particular uid
+ dfltuid attempt to mount as a particular uid
- gid attempt to mount with a particular gid
+ dfltgid attempt to mount with a particular gid
afid security channel - used by Plan 9 authentication protocols
@@ -70,19 +117,41 @@ OPTIONS
This can be used to share devices/named pipes/sockets between
hosts. This functionality will be expanded in later versions.
+ access there are four 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
+ client = ACL based access check on the 9p client
+ side for access validation
+
+ 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
=========
-The Linux version of the 9p server is now maintained under the npfs project
-on sourceforge (http://sourceforge.net/projects/npfs).
+Protocol specifications are maintained on github:
+http://ericvh.github.com/9p-rfc/
+
+9p client and server implementations are listed on
+http://9p.cat-v.org/implementations
+
+A 9p2000.L server is being developed by LLNL and can be found
+at http://code.google.com/p/diod/
There are user and developer mailing lists available through the v9fs project
on sourceforge (http://sourceforge.net/projects/v9fs).
-News and other information is maintained on SWiK (http://swik.net/v9fs).
+News and other information is maintained on a Wiki.
+(http://sf.net/apps/mediawiki/v9fs/index.php).
-Bug reports may be issued through the kernel.org bugzilla
-(http://bugzilla.kernel.org)
+Bug reports are best issued via the mailing list.
For more information on the Plan 9 Operating System check out
http://plan9.bell-labs.com/plan9
@@ -90,11 +159,3 @@ 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 SOURCEFORGE BUG-TRACKER TO REPORT PROBLEMS.
-