There was some cleanup issues during early mount which would trigger
a kernel bug for certain types of failure.  This patch reorganizes the
cleanup to get rid of the bad behavior.

This also merges the 9pnet and 9pnet_fd modules for the purpose of
configuration and initialization.  Keeping the fd transport separate
from the core 9pnet code seemed like a good idea at the time, but in
practice has caused more harm and confusion than good.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Right now when we get an error string from the server that we can't
map we report a cryptic error that actually makes it look like we are
reporting a problem with the client.  This changes the text of the log
message to clarify where the error is coming from.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Some files in the net/9p directory uses "int" for flags. This can
cause hard to find bugs on some architectures. This patch converts the
flags to use "long" instead.

This bug was discovered by doing an allyesconfig make on the -rt kernel
where checks are done to ensure all flags are of size sizeof(long).
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

On error, p9_idpool_create returns an ERR_PTR-encoded errno.
Signed-off-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

Replace semaphores protecting use flags with a mutex.
Signed-off-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

Propagate changes that were made to the parse_options code to the
other parse options pieces present in the other modules.  Looks like
the client parse options was probably corrupting the parse string
and causing problems for others.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The kernel-doc comments of much of the 9p system have been in disarray since
reorganization.  This patch fixes those problems, adds additional documentation
and a template book which collects the 9p information.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Mar 23 09:06:31 opensuse103 kernel: Installing 9P2000 support
Mar 23 09:06:31 opensuse103 kernel: sys_init_module: '9pnet_fd'->init suspiciously returned 1, it should follow 0/-E convention
Mar 23 09:06:31 opensuse103 kernel: sys_init_module: loading module anyway...
Mar 23 09:06:31 opensuse103 kernel: Pid: 5323, comm: modprobe Not tainted 2.6.25-rc6-git7-default #1
Mar 23 09:06:31 opensuse103 kernel:  [<c013c253>] sys_init_module+0x172b/0x17c9
Mar 23 09:06:31 opensuse103 kernel:  [<c0108a6a>] sys_mmap2+0x62/0x77
Mar 23 09:06:31 opensuse103 kernel:  [<c01059c4>] sysenter_past_esp+0x6d/0xa9
Mar 23 09:06:31 opensuse103 kernel:  =======================

Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@opteron.(none)>
Cc: David S. Miller <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <devzero@web.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The variable cb is initialized but never used otherwise.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
type T;
identifier i;
constant C;
@@

(
extern T i;
|
- T i;
  <+... when != i
- i = C;
  ...+>
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Coverity checker spotted that less memory than required was
allocated.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

if (...) BUG(); should be replaced with BUG_ON(...) when the test has no
side-effects to allow a definition of BUG_ON that drops the code completely.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@ disable unlikely @ expression E,f; @@

(
  if (<... f(...) ...>) { BUG(); }
|
- if (unlikely(E)) { BUG(); }
+ BUG_ON(E);
)

@@ expression E,f; @@

(
  if (<... f(...) ...>) { BUG(); }
|
- if (E) { BUG(); }
+ BUG_ON(E);
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ERROR: "p9_printfcall" [net/9p/9pnet_virtio.ko] undefined!
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

This merges the mux.c (including the connection interface) with trans_fd
in preparation for transport API changes.  Ultimately, trans_fd will need
to be rewritten to clean it up and simplify the implementation, but this
reorganization is viewed as the first step.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Request from rusty:
Just cleaning up patches for 2.6.25 merge, and noticed that
net/9p/trans_virtio.c doesn't have a remove function.  This will crash when
removing the module (console doesn't have one because it can't really be
removed).
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

When booting from v9fs, down_interruptible in p9_idpool_get() triggered a BUG
as it was being called with IRQs disabled.  A spinlock seems like the right
thing to be using since the idr functions go out of their way not to sleep.

This patch eliminates the BUG by converting the semaphore to a spinlock.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

This fixes a poorly placed spinlock which could result in a
soft lockup condition.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This replaces the console-based virto client with a block-based
client using a single request queue.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Add a new transport function which allows a cut-thru directly to
the transport instead of processing request through the mux if the
cut-thru exists.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This patch fixes a bug in the copying of 9P
stat information where string references
weren't being updated properly.
Signed-off-by: NMartin Sava <martin.stava@gmail.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Previously we used a type/len pair within the config space, but this
seems overkill.  We now simply define a structure which represents the
layout in the config space: the config space can now only be extended
at the end.

The main driver-visible changes:
1) We indicate what fields are present with an explicit feature bit.
2) Virtqueues are explicitly numbered, and not in the config space.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The list of options that the fd transport accepts is missing end-of-options
marker. This patch adds it.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

v9fs_match_trans function returns arbitrary transport module instead of NULL
when the requested transport is not registered. This patch modifies the
function to return NULL in that case.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds a transport to 9p for communicating between guests and a host
using a virtio based transport.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Most of these fixes were already submitted for old kernel versions, and were
approved, but for some reason they never made it into the releases.

Because this is a consolidation of a couple old missed patches, it touches both
Kconfigs and documentation texts.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

A sysctl method was added to enable and disable debugging levels.  After
further review, it was decided that there are better approaches to doing this
and the sysctl methodology isn't really desirable.  This patch removes the
sysctl code from 9p.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
  

This patch moves transport dynamic registration and matching to the net
module to prevent a bad Kconfig dependency between the net and fs 9p modules.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.

Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.

This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):

- attach-per-user (access=user) (default mode for 9P2000.u)
 If a user tries to access a file served by v9fs for the first time, v9fs
 sends an attach command to the server (Tattach) specifying the user. If
 the attach succeeds, the user can access the v9fs tree.
 As there is no uname->uid (string->integer) mapping yet, this mode works
 only with the 9P2000.u dialect.

- allow only one user to access the tree (access=<uid>)
 Only the user with uid can access the v9fs tree. Other users that attempt
 to access it will get EPERM error.

- do all operations as a single user (access=any) (default for 9P2000)
 V9fs does a single attach and all operations are done as a single user.
 If this mode is selected, the v9fs behavior is identical with the current
 one.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules.  This should also allow kernel
configuration of transports without ifdef-hell.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

When buf_check_overflow() returns != 0 we will hit kfree(ERR_PTR(err))
and it will not be happy about it.
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

On 7/22/07, Adrian Bunk <bunk@stusta.de> wrote:
     The Coverity checker spotted the following use-after-free
     in net/9p/mux.c:

     <--  snip  -->

     ...
     struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
                                         unsigned char *extended)
     {
     ...
             if (!m->tagpool) {
                     kfree(m);
                     return ERR_PTR(PTR_ERR(m->tagpool));
             }
     ...

     <--  snip  -->

Also spotted was a leak of the same structure further down in the function.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

When buf_check_overflow() returns != 0 we will hit kfree(ERR_PTR(err)) and
it will not be happy about it.
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The recent 9p commit: bd238fb4 that
supposedly only moved files also introduced a new 9p sysctl interface
that did not properly register it's sysctl binary numbers.

And since it was only for debugging clearly did not need a binary fast
path in any case.  So this patch just remove the binary numbers.

See Documentation/sysctl/ctl_unnumbered.txt for more details.

While I was at it I cleaned up the sysctl initializers a little as
well so there is less to read.

Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

umounting partitions after heavy activity would sometimes trigger a
segmentation violation.  This fix appears to remove that problem.
Fix originally provided by Latchesar Ionkov.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

If trans->write returns 0, p9_write_work goes through the error path, but
sets the error code to zero.

This patch sets the error code to EREMOTEIO if trans->write returns zero
value.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>

Change module name of net/9p module from 9p.ko to 9pnet.ko. fs/9p module
already uses 9p.ko name.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>

This patchset moves non-filesystem interfaces of v9fs from fs/9p to net/9p.
It moves the transport, packet marshalling and connection layers to net/9p
leaving only the VFS related files in fs/9p.  This work is being done in
preparation for in-kernel 9p servers as well as alternate 9p clients (other
than VFS).
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>