Commit graph

5 commits

Author SHA1 Message Date
Chuck Lever
5fd23f7e1d SUNRPC: Address kbuild warning in net/sunrpc/debugfs.c
Cross-compile test on ARCH=mn10300:

In file included from include/linux/list.h:8:0,
                 from include/linux/wait.h:6,
                 from include/linux/fs.h:6,
                 from include/linux/debugfs.h:18,
                 from net/sunrpc/debugfs.c:7:
net/sunrpc/debugfs.c: In function 'fault_disconnect_write':
include/linux/kernel.h:723:17: warning: comparison of distinct pointer
types lacks a cast
    (void) (&_min1 == &_min2);  \
                   ^
>> net/sunrpc/debugfs.c:307:8: note: in expansion of macro 'min'
    len = min(len, sizeof(buffer) - 1);

Fixes: ('SUNRPC: Transport fault injection')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-11 14:01:06 -04:00
Chuck Lever
4a06825839 SUNRPC: Transport fault injection
It has been exceptionally useful to exercise the logic that handles
local immediate errors and RDMA connection loss.  To enable
developers to test this regularly and repeatably, add logic to
simulate connection loss every so often.

Fault injection is disabled by default. It is enabled with

  $ sudo echo xxx > /sys/kernel/debug/sunrpc/inject_fault/disconnect

where "xxx" is a large positive number of transport method calls
before a disconnect. A value of several thousand is usually a good
number that allows reasonable forward progress while still causing a
lot of connection drops.

These hooks are disabled when SUNRPC_DEBUG is turned off.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10 18:37:26 -04:00
Jeff Layton
f9c72d10d6 sunrpc: make debugfs file creation failure non-fatal
We currently have a problem that SELinux policy is being enforced when
creating debugfs files. If a debugfs file is created as a side effect of
doing some syscall, then that creation can fail if the SELinux policy
for that process prevents it.

This seems wrong. We don't do that for files under /proc, for instance,
so Bruce has proposed a patch to fix that.

While discussing that patch however, Greg K.H. stated:

    "No kernel code should care / fail if a debugfs function fails, so
     please fix up the sunrpc code first."

This patch converts all of the sunrpc debugfs setup code to be void
return functins, and the callers to not look for errors from those
functions.

This should allow rpc_clnt and rpc_xprt creation to work, even if the
kernel fails to create debugfs files for some reason.

Symptoms were failing krb5 mounts on systems using gss-proxy and
selinux.

Fixes: 388f0c7767 "sunrpc: add a debugfs rpc_xprt directory..."
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-31 14:15:08 -04:00
Jeff Layton
388f0c7767 sunrpc: add a debugfs rpc_xprt directory with an info file in it
Add a new directory heirarchy under the debugfs sunrpc/ directory:

    sunrpc/
        rpc_xprt/
            <xprt id>/

Within that directory, we can put files that give info about the
xprts. We do have the (minor) problem that there is no succinct,
unique identifier for rpc_xprts. So we generate them synthetically
with a static atomic_t counter.

For now, this directory just holds an "info" file, but we may add
other files to it in the future.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-27 13:14:52 -05:00
Jeff Layton
b4b9d2ccf0 sunrpc: add debugfs file for displaying client rpc_task queue
It's possible to get a dump of the RPC task queue by writing a value to
/proc/sys/sunrpc/rpc_debug. If you write any value to that file, you get
a dump of the RPC client task list into the log buffer. This is a rather
inconvenient interface however, and makes it hard to get immediate info
about the task queue.

Add a new directory hierarchy under debugfs:

    sunrpc/
        rpc_clnt/
            <clientid>/

Within each clientid directory we create a new "tasks" file that will
dump info similar to what shows up in the log buffer, but with a few
small differences -- we avoid printing raw kernel addresses in favor of
symbolic names and the XID is also displayed.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-27 13:14:51 -05:00