Documentation/filesystems/9p.rst

1 .. SPDX-License-Identifier: GPL-2.0
4 v9fs: Plan 9 Resource Sharing for Linux
10 v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
19 the 9p client is available in the form of a USENIX paper:
26 	  http://xcpu.org/papers/xcpu-talk.pdf
30 	  http://xcpu.org/papers/cellfs-talk.pdf
31 	* PROSE I/O: Using 9p to enable Application Partitions
33 	* VirtFS: A Virtualization Aware File System pass-through
41 	mount -t 9p 10.10.1.2 /mnt/9
43 For Plan 9 From User Space applications (http://swtch.com/plan9)::
45 	mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
49 	mount -t 9p -o trans=virtio <mount_tag> /mnt/9
52 mount points. Each 9P export is seen by the client as a virtio device with an
54 seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
86 			0b00000000  all caches disabled, mmap disabled
87 			0b00000001  file caches enabled
88 			0b00000010  meta-data caches enabled
89 			0b00000100  writeback behavior (as opposed to writethrough)
90 			0b00001000  loose caches (no explicit consistency with server)
91 			0b10000000  fscache enabled for persistent caching
97 			none        0b00000000 (no caching)
98 			readahead   0b00000001 (only read-ahead file caching)
99 			mmap        0b00000101 (read-ahead + writeback file cache)
100 			loose       0b00001111 (non-coherent file and meta-data caches)
101 			fscache     0b10001111 (persistent loose cache)
105 		moment, so using other combinations of bit-patterns is not
118 			0x01    display verbose error messages
119 			0x02    developer debug (DEBUG_CURRENT)
120 			0x04    display 9p trace
121 			0x08    display VFS trace
122 			0x10    display Marshalling debug
123 			0x20    display RPC debug
124 			0x40    display transport debug
125 			0x80    display allocation debug
126 			0x100   display protocol message debug
127 			0x200   display Fid debug
128 			0x400   display packet debug
129 			0x800   display fscache tracing debug
136   msize=n	the number of bytes to use for 9p packet payload
140   noextend	force legacy mode (no 9p2000.u or 9p2000.L semantics)
142   version=name	Select 9P protocol version. Valid options are:
145 			9p2000          Legacy mode (same as noextend)
146 			9p2000.u        Use 9P2000.u protocol
147 			9p2000.L        Use 9P2000.L protocol
154   afid		security channel - used by Plan 9 authentication protocols
156   nodevmap	do not map special files - represent them as normal files.
162   ignoreqv	ignore qid.version==0 as a marker to ignore cache
179 				 ACL based access check on the 9p client
184 		/sys/fs/9p/caches. (applies only to cache=fscache)
190 This section aims at describing 9p 'quirks' that can be different
193  - Setting O_NONBLOCK on a file will make client reads return as early
201 http://ericvh.github.com/9p-rfc/
203 9p client and server implementations are listed on
204 http://9p.cat-v.org/implementations
206 A 9p2000.L server is being developed by LLNL and can be found
217 For more information on the Plan 9 Operating System check out
218 http://plan9.bell-labs.com/plan9
220 For information on Plan 9 from User Space (Plan 9 applications and libraries
221 ported to Linux/BSD/OSX/etc) check out https://9fans.github.io/plan9port/