The patch below also addresses a couple of other corner cases in readdir
seen with a large (e.g. 64k) msize.  I'm not sure what people think of
my co-opting of fid->aux here.  I'd be happy to rework if there's a better
way.

When the size of the user supplied buffer passed to readdir is smaller
than the data returned in one go by the 9P read request, v9fs_dir_readdir()
currently discards extra data so that, on the next call, a 9P read
request will be issued with offset < previous offset + bytes returned,
which voilates the constraint described in paragraph 3 of read(5) description.
This patch preseves the leftover data in fid->aux for use in the next call.
Signed-off-by: NJim Garlick <garlick@llnl.gov>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

A looney tunes server sending an invalid error code (which is !IS_ERR_VALUE)
can result in a client oops. So fix it by adding a check and converting unknown
or invalid error codes to -ESERVERFAULT.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Fix the comments -- mostly the improper and/or missing descriptions
of function parameters.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Fix a possible regression with p9_client_stat where it can try to kfree 
an ERR_PTR after an erroneous p9pdu_readf. Also remove an unnecessary data 
buffer increment in p9_client_read.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The default 9p transport module is not chosen unless an option parameter (any)
is passed to mount, which thus returns a ENOPROTOSUPPORT. This fix moves the
check out of parse_opts into p9_client_create.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Currently the 9p code crashes when a operation is interrupted, i.e. for
example when the user presses ^C while reading from a file.

This patch fixes the code that is responsible for interruption and flushing
of 9P operations.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>

p9_client_stat function doesn't return correct value if it fails.
p9_client_stat should return ERR_PTR of the error value when it fails.
Instead, it always returns a value to the allocated p9_wstat struct even
when it is not populated correctly.

This patch makes p9_client_stat to handle failure correctly.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Reviewed-by: NEric Van Hensbergen <ericvh@gmail.com>

The 9P2000 Twstat message requires the size of the stat structure to be
specified. Currently the 9p code writes zero instead of the actual size.
This behavior confuses some of the file servers that check if the size is
correct.

This patch adds a new function that calculcates the stat size and puts the
value in the appropriate place in the 9P message.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Reviewed-by: NEric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Reviewed-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix printk format warnings in net/9p.
Built cleanly on 7 arches.

net/9p/client.c:820: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:820: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:867: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:867: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:932: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:932: warning: format '%llx' expects type 'long long unsigned int', but argument 6 has type 'u64'
net/9p/client.c:982: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:982: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:1025: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:1025: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 7 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 12 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 8 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 13 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 7 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 12 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 8 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 13 has type 'u64'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

If a T or R fcall cannot be allocated, the function returns an error
but neglects to free the wait queue that was successfully allocated.

If it comes through again a second time this wq will be overwritten
with a new allocation and the old allocation will be leaked.

Also, if the client is subsequently closed, the close path will
attempt to clean up these allocations, so set the req fields to
NULL to avoid duplicate free.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

T and R fcall are reused until the client is destroyed. There does
not need to be a special case for Flush
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The client lock must be IRQ safe. Some of the lock acquisition paths
took regular spin locks.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Fix printk format warnings in net/9p.
Built cleanly on 7 arches.

net/9p/client.c:820: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:820: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:867: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:867: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:932: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:932: warning: format '%llx' expects type 'long long unsigned int', but argument 6 has type 'u64'
net/9p/client.c:982: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:982: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:1025: warning: format '%llx' expects type 'long long unsigned int', but argument 4 has type 'u64'
net/9p/client.c:1025: warning: format '%llx' expects type 'long long unsigned int', but argument 5 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 7 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 12 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 8 has type 'u64'
net/9p/client.c:1227: warning: format '%llx' expects type 'long long unsigned int', but argument 13 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 7 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 12 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 8 has type 'u64'
net/9p/client.c:1252: warning: format '%llx' expects type 'long long unsigned int', but argument 13 has type 'u64'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Several sparse warnings were introduced by patches accepted during the merge
window which weren't caught.  This patch fixes those warnings.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The new debug support lacks some of the information that the previous fcprint
code provided -- this patch focuses on better presentation of debug data along
with more helpful debug along error paths.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Now that the new protocol functions are in place, this patch switches
the client code to using the new support code.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

One of the current debug options allows users to get a verbose dump of fcalls.
This isn't really necessary as correctly parsed protocol frames can be printed
as part of the code in the client functions.  The consolidated printfcalls
structure would require new entries to be added for every extension.  This
patch removes the debug print methods and their use.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Alsmot all 9P client wire functions have their own (set of) functions.
Tversion is an exception as its encapsulated into the client_create code.

This patch moves the protocol specifics of this to a function to match the
rest of the code.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Currently reading a directory is implemented in the client code.
This function is not actually a wire operation, but a meta operation 
which calls read operations and processes the results.

This patch moves this functionality to the fs layer and calls component
wire operations instead of constructing their packets.  This provides a 
cleaner separation and will help when we reorganize the client functions
and protocol processing methods.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

There are a couple of methods in the client code which aren't actually
wire operations.  To keep things organized cleaner, these operations are
being moved to the fs layer.

This patch moves the readn meta-function (which executes multiple wire
reads until a buffer is full) to the fs layer.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Currently there are two separate versions of read and write.  One for
dealing with user buffers and the other for dealing with kernel buffers.
There is a tremendous amount of code duplication in the otherwise
identical versions of these functions.  This patch adds an additional
user buffer parameter to read and write and conditionalizes handling of
the buffer on whether the kernel buffer or the user buffer is populated.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This code moves the rpc function to the common client base,
reorganizes the flush code to be more simple and stable, and
makes the necessary adjustments to the underlying transports
to adapt to the new structure.

This reduces the overall amount of code duplication between the
transports and should make adding new transports more straightforward.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Apply the now common p9_req_t structure to the fd transport.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The virtio transport uses a simplified request management system
that I want to use for all transports.  This patch adapts and moves the
exisiting code for managing requests to the client common code.
Later patches will apply these mechanisms to the other transports.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Cleanup files by reordering functions in order to remove need for
unnecessary function prototypes.

There are no code changes here, just functions being moved around and
prototypes being eliminated.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Right now there is a transport module structure which provides per-transport
type functions and data and a transport structure which contains per-instance
public data as well as function pointers to instance specific functions.

This patch moves public transport visible instance data to the client
structure (which in some cases had duplicate data) and consolidates the
functions into the transport module structure.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

9p trans modules aren't refcounted nor were they unregistered
properly.  Fix it.

* Add 9p_trans_module->owner and reference the module on each trans
  instance creation and put it on destruction.

* Protect v9fs_trans_list with a spinlock.  This isn't strictly
  necessary as the list is manipulated only during module loading /
  unloading but it's a good idea to make the API safe.

* Unregister trans modules when the corresponding module is being
  unloaded.

* While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init().
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-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>

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>

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>

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>

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>