During the reorganization some of the multi-theaded locking assumptions were
accidently relaxed. This patch moves us back towards a more conservative
locking strategy.
Signed-off-by: Eric 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: Eric 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: Eric Van Hensbergen <ericvh@gmail.com>
Post p9_fd_poll() error path which checks m->poll_waddr[i] for PTR_ERR
value has the following problems.
* It's completely unused. Error value is set iff NULL @wait_address
has been specified to p9_pollwait() which is guaranteed not to
happen.
* It dereferences @m after deallocating it (introduced by 571ffeaf and
spotted by Raja R Harinath.
* It returned the wrong value on error. It should return
poll_waddr[i] but it returnes poll_waddr (introduced by 571ffeaf).
* p9_mux_poll_stop() doesn't handle PTR_ERR value. It will try to
operate on the PTR_ERR value as if it's a normal pointer and cause
oops.
As the error path is bogus in the first place, there's no reason to
hold onto it. Kill it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Raja R Harinath <harinath@hurrynot.org>
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: Eric Van Hensbergen <ericvh@gmail.com>
This patch reworks the read_work function to enable it to directly use a passed
in rcall structure. This should help allow us to remove unnecessary copies
in the future.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
The current trans_fd rpc mechanisms use a dynamic callback mechanism which
introduces a lot of complexity which only accomodates a single special case.
This patch removes much of that complexity in favor of a simple exception
mechanism to deal with flushes.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Currently, trans_fd has two structures (p9_req and p9_mux-rpc)
which contain mostly duplicate data.
This patch consolidates these two structures and removes p9_mux_rpc.
Signed-off-by: Eric 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: Eric Van Hensbergen <ericvh@gmail.com>
Now that we are passing client state into the transport modules, remove
duplicate state which is present in transport private structures.
Signed-off-by: Eric 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: Eric Van Hensbergen <ericvh@gmail.com>
trans_fd used pool of upto 100 pollers to monitor the r/w fds. The
approach makes sense in userspace back when the only available
interfaces were poll(2) and select(2). As each event monitor -
trigger - handling iteration took O(n) where `n' is the number of
watched fds, it makes sense to spread them to many pollers such that
the `n' can be divided by the number of pollers. However, this
doesn't make any sense in kernel because persistent edge triggered
event monitoring is how the whole thing is implemented in the kernel
in the first place.
This patch converts trans_fd to use single poller which watches all
the fds instead of the poll of pollers approach. All the fds are
registered for monitoring on creation and only the fds with pending
events are scanned when something happens much like how epoll is
implemented.
This change makes trans_fd fd monitoring more efficient and simpler.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric 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: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Error handling code following a kmalloc should free the allocated data.
The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,l;
position p1,p2;
expression *ptr != NULL;
@@
(
if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S
|
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
)
<... when != x
when != if (...) { <+...x...+> }
x->f = E
...>
(
return \(0\|<+...x...+>\|ptr\);
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
trans_fd leaked p9_mux_wq on module unload. Fix it. While at it,
collapse p9_mux_global_init() into p9_trans_fd_init(). It's easier to
follow this way and the global poll_tasks array is about to removed
anyway.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
p9_fd_poll() is never called with user pointers and f_op->poll()
doesn't expect its arguments to be from userland. There's no need to
set kernel ds before calling f_op->poll() from p9_fd_poll(). Remove
it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* Use kzalloc() to allocate p9_conn and remove 0/NULL initializations.
* Clean up error return paths.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
p9_conn_destroy() first kills all current requests by calling
p9_conn_cancel(), then waits for the request list to be cleared by
waiting on p9_conn->equeue. After that, polling is stopped and the
trans is destroyed. This sequence has a few problems.
* Read and write works were never cancelled and the p9_conn can be
destroyed while the works are running as r/w works remove requests
from the list and dereference the p9_conn from them.
* The list emptiness wait using p9_conn->equeue wouldn't trigger
because p9_conn_cancel() always clears all the lists and the only
way the wait can be triggered is to have another task to issue a
request between the slim window between p9_conn_cancel() and the
wait, which isn't safe under the current implementation with or
without the wait.
This patch fixes the problem by first stopping poll, which can
schedule r/w works, first and cancle r/w works which guarantees that
r/w works are not and will not run from that point and then calling
p9_conn_cancel() and do the rest of destruction.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patch adds support for flag values which are ORed to the type passwd
to socket and socketpair. The additional code is minimal. The flag
values in this implementation can and must match the O_* flags. This
avoids overhead in the conversion.
The internal functions sock_alloc_fd and sock_map_fd get a new parameters
and all callers are changed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>
#define PORT 57392
/* For Linux these must be the same. */
#define SOCK_CLOEXEC O_CLOEXEC
int
main (void)
{
int fd;
fd = socket (PF_INET, SOCK_STREAM, 0);
if (fd == -1)
{
puts ("socket(0) failed");
return 1;
}
int coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if (coe & FD_CLOEXEC)
{
puts ("socket(0) set close-on-exec flag");
return 1;
}
close (fd);
fd = socket (PF_INET, SOCK_STREAM|SOCK_CLOEXEC, 0);
if (fd == -1)
{
puts ("socket(SOCK_CLOEXEC) failed");
return 1;
}
coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if ((coe & FD_CLOEXEC) == 0)
{
puts ("socket(SOCK_CLOEXEC) does not set close-on-exec flag");
return 1;
}
close (fd);
int fds[2];
if (socketpair (PF_UNIX, SOCK_STREAM, 0, fds) == -1)
{
puts ("socketpair(0) failed");
return 1;
}
for (int i = 0; i < 2; ++i)
{
coe = fcntl (fds[i], F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if (coe & FD_CLOEXEC)
{
printf ("socketpair(0) set close-on-exec flag for fds[%d]\n", i);
return 1;
}
close (fds[i]);
}
if (socketpair (PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, fds) == -1)
{
puts ("socketpair(SOCK_CLOEXEC) failed");
return 1;
}
for (int i = 0; i < 2; ++i)
{
coe = fcntl (fds[i], F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if ((coe & FD_CLOEXEC) == 0)
{
printf ("socketpair(SOCK_CLOEXEC) does not set close-on-exec flag for fds[%d]\n", i);
return 1;
}
close (fds[i]);
}
puts ("OK");
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Eric 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: Eric 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: Eric Van Hensbergen <ericvh@gmail.com>
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: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: Eric Van Hensbergen <ericvh@gmail.com>
The list of options that the fd transport accepts is missing end-of-options
marker. This patch adds it.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Acked-by: Eric 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: Eric 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: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Eric Van Hensbergen