See previous commit about p9_read_work() for details.
This fixes a similar race between p9_write_work() and p9_poll_mux()
Signed-off-by: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
At the end of p9_write_work() we want to test if there is still data to send.
This means:
- either the current request still has data to send (wsize != 0)
- or there are requests in the unsent queue
Signed-off-by: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Race scenario between p9_read_work() and p9_poll_mux()
Data arrive, Rworksched is set, p9_read_work() is called.
thread A thread B
p9_read_work()
.
reads data
.
checks if new data ready. No.
.
gets preempted
.
More data arrive, p9_poll_mux() is called. .
.
.
p9_poll_mux() .
.
if (!test_and_set_bit(Rworksched, .
&m->wsched)) { .
schedule_work(&m->rq); .
} .
.
-> does not schedule work because .
Rworksched is set .
.
clear_bit(Rworksched, &m->wsched);
return;
No work has been scheduled, and yet data are waiting.
Currently p9_read_work() checks if there is data to read,
and if not, it clears Rworksched.
I think it should clear Rworksched first, and then check if there is data to read.
Signed-off-by: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reduce object size by deduplicating formats.
Use vsprintf extension %pV.
Rename P9_DPRINTK uses to p9_debug, align arguments.
Add function for _p9_debug and macro to add __func__.
Add missing "\n"s to p9_debug uses.
Remove embedded function names as p9_debug adds it.
Remove P9_EPRINTK macro and convert use to pr_<level>.
Add and use pr_fmt and pr_<level>.
$ size fs/9p/built-in.o*
text data bss dec hex filename
62133 984 16000 79117 1350d fs/9p/built-in.o.new
67342 984 16928 85254 14d06 fs/9p/built-in.o.old
$ size net/9p/built-in.o*
text data bss dec hex filename
88792 4148 22024 114964 1c114 net/9p/built-in.o.new
94072 4148 23232 121452 1da6c net/9p/built-in.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Teach 9p filesystem to work in container with non-default network namespace.
(Note: I also patched the unix domain socket code but don't have a test case
for that. It's the same fix, I just don't have a server for it...)
To test, run diod server (http://code.google.com/p/diod):
diod -n -f -L stderr -l 172.23.255.1:9999 -c /dev/null -e /root
and then mount like so:
mount -t 9p -o port=9999,aname=/root,version=9p2000.L 172.23.255.1 /mnt
A container test environment is described at http://landley.net/lxc
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Now that cmwq can handle high concurrency, it's more efficient to use
work than a dedicated kthread. Convert p9_poll_proc() to a work
function for p9_poll_work and make p9_pollwake() schedule it on each
poll event. The work is sync flushed on module exit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
With cmwq, there's no reason to use a dedicated workqueue in trans_fd.
Drop p9_mux_wq and use system_wq instead. The used work items are
already sync canceled in p9_conn_destroy() and doesn't require further
synchronization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
The function has an unsigned return type, but returns a negative constant
to indicate an error condition. The result of calling the function is
always stored in a variable of type (signed) int, and thus unsigned can be
dropped from the return type.
A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@exists@
identifier f;
constant C;
@@
unsigned f(...)
{ <+...
* return -C;
...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is an off by one bug because strlen() doesn't count the NULL
terminator. We strcpy() addr into a fixed length array of size
UNIX_PATH_MAX later on.
The addr variable is the name of the device being mounted.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.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: Venkateswararao Jujjuri <jvrao@us.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>w
* if we fail in p9_conn_create(), we shouldn't leak references to struct file.
Logics in ->close() doesn't help - ->trans is already gone by the time it's
called.
* sock_create_kern() can fail.
* use of sock_map_fd() is all fscked up; I'd fixed most of that, but the
rest will have to wait for a bit more work in net/socket.c (we still are
violating the basic rule of working with descriptor table: "once the reference
is installed there, don't rely on finding it there again").
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Not including net/atm/
Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the comments -- mostly the improper and/or missing descriptions
of function parameters.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
It is not safe to use match_int without checking the token type returned
by match_token (especially when the token type returned is Opt_err and
args is empty). Fix it.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: Latchesar Ionkov <lucho@ionkov.net>
Impact: Trust in the comment and add '__force' to the cast.
Fix this sparse warning:
net/9p/trans_fd.c:420:34: warning: cast adds address space to expression (<asn:1>)
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes build problem with 9p when building with debug disabled.
Also contains some fixes for warnings which pop up when
CONFIG_NET_9P_DEBUG is disabled.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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>
Simon Derr