This patch fixes a simple bug I left behind in my earlier protocol
negotiation patch.

Thanks,
Sripathi.
Signed-off-by: NSripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Removes 'dotu' variable and make everything dependent
on 'proto_version' field.
Signed-off-by: NSripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Add 9P2000.u and 9P2010.L protocol flags to V9FS VFS

This patch adds 9P2000.u and 9P2010.L protocol flags into V9FS VFS side code
and removes the single flag used for 'extended'.
Signed-off-by: NSripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

If match_strdup() fail this function exits without freeing the options string.
Signed-off-by: NVenkateswararao Jujjuri <jvrao@us.ibm.com>
Sigend-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Options pointer is being moved before calling kfree() which seems
to cause problems.  This uses a separate pointer to track and free
original allocation.
Signed-off-by: NVenkateswararao Jujjuri <jvrao@us.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>w

This patch adds a persistent, read-only caching facility for
9p clients using the FS-Cache caching backend.

When the fscache facility is enabled, each inode is associated
with a corresponding vcookie which is an index into the FS-Cache
indexing tree. The FS-Cache indexing tree is indexed at 3 levels:
- session object associated with each mount.
- inode/vcookie
- actual data (pages)

A cache tag is chosen randomly for each session. These tags can
be read off /sys/fs/9p/caches and can be passed as a mount-time
parameter to re-attach to the specified caching session.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

The mount options string is saved in sb->s_options. This patch removes
the redundant duplicating of the mount options. Also, since we are not
displaying anything special in show options, we replace v9fs_show_options
with generic_show_options for now.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Since v9ses->uid is unsigned, it would seem better to use simple_strtoul that
simple_strtol.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r2@
long e;
position p;
@@

e = simple_strtol@p(...)

@@
position p != r2.p;
type T;
T e;
@@

e =
- simple_strtol@p
+ simple_strtoul
  (...)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-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>

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>

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>

fs/9p/v9fs.c (v9fs_parse_options): Handle kstrdup and match_strdup failure. Now that this function can fail, return an int, diagnose other option-parsing failures, and adjust the sole caller: (v9fs_session_init): Handle kstrdup failure. Propagate any new v9fs_parse_options failure "up".
Signed-off-by: NJim Meyering <meyering@redhat.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-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>

match_strcpy() is a somewhat creepy function: the caller needs to make sure
that the destination buffer is big enough, and when he screws up or
forgets, match_strcpy() happily overruns the buffer.

There's exactly one customer: v9fs_parse_options().  I believe it currently
can't overflow its buffer, but that's not exactly obvious.

The source string is a substing of the mount options.  The kernel silently
truncates those to PAGE_SIZE bytes, including the terminating zero.  See
compat_sys_mount() and do_mount().

The destination buffer is obtained from __getname(), which allocates from
name_cachep, which is initialized by vfs_caches_init() for size PATH_MAX.

We're safe as long as PATH_MAX <= PAGE_SIZE.  PATH_MAX is 4096.  As far as
I know, the smallest PAGE_SIZE is also 4096.

Here's a patch that makes the code a bit more obviously correct.  It
doesn't depend on PATH_MAX <= PAGE_SIZE.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Jim Meyering <meyering@redhat.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
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>

v9fs_parse_options function uses strsep which modifies the value of the
v9ses->options field. That modified value is later passed to the function
that creates the transport potentially making the transport creation
function to fail.

This patch creates a copy of v9ses->option field that v9fs_parse_options
function uses instead of the original value.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

This patch fixes a memory leak introduced by
commit ba17674f.

Spotted by the Coverity checker.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
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>

Change the names of 'uid' and 'gid' parameters to the more appropriate
'dfltuid' and 'dfltgid'.  This also sets the default uid/gid to -2
(aka nfsnobody)
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Create more general flags field in the v9fs_session_info struct and move the
'extended' flag as a bit in the flags.
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>

s/9p/v9fs.c: In function 'v9fs_parse_options':
fs/9p/v9fs.c:134: error: 'p9_debug_level' undeclared (first use in this function)
Signed-off-by: NDave Jones <davej@redhat.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

During reorganization, the mount time debug option was removed in favor
of module-load-time parameters.  However, the mount time option is still
a useful for feature during debug and for user-fault isolation when the
module is compiled into the kernel.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

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>

While cacheing is generally frowned upon in the 9p world, it has its
place -- particularly in situations where the remote file system is
exclusive and/or read-only.  The vacfs views of venti content addressable
store are a real-world instance of such a situation.  To facilitate higher
performance for these workloads (and eventually use the fscache patches),
we have enabled a "loose" cache mode which does not attempt to maintain
any form of consistency on the page-cache or dcache.  This results in over
two orders of magnitude performance improvement for cacheable block reads
in the Bonnie benchmark.  The more aggressive use of the dcache also seems
to improve metadata operational performance.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

There is a simple logic error in init_v9fs - the return code checks are
reversed.  This patch fixes the return code and adds some messages to prevent
module initialization from failing silently.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If register_filesystem() fails mux workqueue must be killed.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

There were a number of conflicting naming schemes used in the v9fs project.
The directory was fs/9p, but MAINTAINERS and Documentation referred to
v9fs.  The module name itself was 9p2000, and the file system type was 9P.
This patch attempts to clean that up, changing all references to 9p in
order to match the directory name.  We'll also start using 9p instead of
v9fs as our patch prefix.

There is also a minor consistency cleanup in the options changing the name
option to uname in order to more closely match the Plan 9 options.
Signed-off-by: NEric Van Hensbergevan <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update license boilerplate to specify GPLv2 and remove the (at your option
clause).  This change was agreed to by all the copyright holders (approvals
can be found on v9fs-developer mailing list).
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The code talks about these things called tids, which I eventually figured
out are tags.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

v9fs has been plagued by an over-complicated approach trying to map Linux
dentry semantics to Plan 9 fid semantics.  Our previous approach called for
aggressive flushing of the dcache resulting in several problems (including
wierd cwd behavior when running /bin/pwd).

This patch dramatically simplifies our handling of this fid management.  Fids
will not be clunked as promptly, but the new approach is more functionally
correct.  We now clunk un-open fids only when their dentry ref_count reaches 0
(and d_delete is called).

Another simplification is we no longer seek to match fids to the process-id or
uid of the action initiator.  The uid-matching will need to be revisited when
we fix the security model.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Minor updates to the documentation to bring them into sync with current
websites and available features.  The debug flag was switched back to hex
to match the documentation.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- remove unnecessary -ENOMEM assignments
- return correct value when buf_check_size for second time in a buffer
- handle failures when create_workqueue and kthread_create are called
- use kzalloc instead of kmalloc/memset 0
- v9fs_str_copy and v9fs_str_compare were buggy, were used only in one
  place, correct the logic and move it to the place it is used.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Performance enhancement reducing the number of copies in the data and
stat paths.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

New multiplexer implementation. Decreases the number of kernel threads
required. Better handling when the user process receives a signal.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Data allocated with "__getname()" should always be free'd with "__putname()"
because of the AUDITSYSCALL code.
Signed-off-by: NDavi Arnaut <davi.arnaut@gmail.com>
Cc: <rminnich@lanl.gov>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>