Instead of creating the new rpc client from a regular server thread,
set a flag, kick off a null call, and allow the null call to do the work
of setting up the client on the callback workqueue.
Use a spinlock to ensure the callback work gets a consistent view of the
callback parameters.
This allows, for example, changing the callback from contexts where
sleeping is not allowed. I hope it will also keep the locking simple as
we add more session and trunking features, by serializing most of the
callback-specific work.
This also closes a small race where the the new cb_ident could be used
with an old connection (or vice-versa).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This will eventually allow us, for example, to kick off null callback
from contexts where we can't sleep.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Make the recall callback code more generic, so that other callbacks
will be able to use it too.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that we have both nfsd4_callback and nfsd4_cb_conn structures, I get
confused if variables of both types are always named cb....
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If a callback is retried at nfsd4_cb_recall_done() due to
some error, the returned rpc reply crashes here:
@@ -514,6 +514,7 @@ decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
u32 dummy;
__be32 *p;
+ BUG_ON(!res);
if (res->cbs_minorversion == 0)
return 0;
[BUG_ON added for demonstration]
This is because the nfsd4_cb_done_sequence() has NULLed out
the task->tk_msg.rpc_resp pointer.
Also eventually the rpc would use the new slot without making
sure it is free by calling nfsd41_cb_setup_sequence().
This problem was introduced by a 4.1 protocol addition patch:
[0421b5c5] nfsd41: Backchannel: Implement cb_recall over NFSv4.1
Which was overlooking the possibility of an RPC callback retries.
For not-4.1 case redoing the _prepare is harmless.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When the rarely-used callback-connection-changing setclientid occurs
simultaneously with a delegation recall, we rerun the recall by
requeueing it on a workqueue. But we also need to take a reference on
the delegation in that case, since the delegation held by the rpc itself
will be released by the rpc_release callback.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
To be used also for the pnfs cb_layoutrecall callback
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd4: fix cb_recall encoding]
"nfsd: nfs4callback encode_stateid helper function" forgot to reserve
more space after return from the new helper.
Reported-by: Michael Groshans <groshans@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If a recall fails for some unexpected reason, instead of ignoring it and
treating it like a success, it's safer to treat it as a failure,
preventing further delgation grants and returning CB_PATH_DOWN.
Also put put switches in a (two me) more logical order, with normal case
first.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Since rpc_call_async() guarantees that the release method will be called
even on failure, this put is wrong.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Note the position in the version array doesn't have to match the actual
rpc version number--to me it seems clearer to maintain the distinction.
Also document choice of rpc callback version number, as discussed in
e.g. http://www.ietf.org/mail-archive/web/nfsv4/current/msg07985.html
and followups.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
nfsd4_set_callback_client must be called under the state lock to atomically
set or unset the callback client and shutting down the previous one.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The rfc allows a client to change the callback parameters, but we didn't
previously implement it.
Teach the callbacks to rerun themselves (by placing themselves on a
workqueue) when they recognize that their rpc task has been killed and
that the callback connection has changed.
Then we can change the callback connection by setting up a new rpc
client, modifying the nfs4 client to point at it, waiting for any work
in progress to complete, and then shutting down the old client.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that the shutdown sequence guarantees callbacks are shut down before
the client is destroyed, we no longer have a use for cl_count.
We'll probably reinstate a reference count on the client some day, but
it will be held by users other than callbacks.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The NFSv4 server's fl_break callback can sleep (dropping the BKL), in
order to allocate a new rpc task to send a recall to the client.
As far as I can tell this doesn't cause any races in the current code,
but the analysis is difficult. Also, the sleep here may complicate the
move away from the BKL.
So, just schedule some work to do the job for us instead. The work will
later also prove useful for restarting a call after the callback
information is changed.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Any null probe rpc will be synchronously destroyed by the
rpc_shutdown_client() in expire_client(), so the rpc task cannot outlast
the nfs4 client. Therefore there's no need for that task to hold a
reference on the client.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Instead of allocating this small structure, just include it in the
delegation.
The nfsd4_callback structure isn't really necessary yet, but we plan to
add to it all the information necessary to perform a callback.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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>
Instead of accessing the lease time directly, some users call
nfs4_lease_time(), and some a macro, NFSD_LEASE_TIME, defined as
nfs4_lease_time(). Neither layer of indirection serves any purpose.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The server's callback client should stop trying to connect to the
client's callback server as soon as it gets ECONNREFUSED.
The NFS server's callback client does not call rpc_ping(), but appears
to have it's own "ping" procedure, so it wasn't covered by commit
caabea8a.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The new .h files have paths at the top that are now out of date. While
we're here, just remove all of those from fs/nfsd; they never served any
purpose.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Lots of include/linux/nfsd/* headers are only used by
nfsd module. Move them to the source directory
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that the headers are fixed and carry their own wait, all fs/nfsd/
source files can include a minimal set of headers. and still compile just
fine.
This patch should improve the compilation speed of the nfsd module.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This patch enables the use of the nfsv4.1 backchannel.
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
[initialize rpc_create_args.bc_xprt too]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Implement the cb_sequence callback conforming to draft-ietf-nfsv4-minorversion1
Note: highest slot id and target highest slot id do not have to be 0
as was previously implemented. They can be greater than what the
nfs server sent if the client supports a larger slot table on the
backchannel. At this point we just ignore that.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[Rework the back channel xdr using the shared v4.0 and v4.1 framework.]
Signed-off-by: Andy Adamson <andros@netapp.com>
[fixed indentation]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: fix verification of CB_SEQUENCE highest slot id[
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: Backchannel: Remove old backchannel serialization]
[nfsd41: Backchannel: First callback sequence ID should be 1]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: decode_cb_sequence does not need to actually decode ignored fields]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Follows the model used by the NFS client. Setup the RPC prepare and done
function pointers so that we can populate the sequence information if
minorversion == 1. rpc_run_task() is then invoked directly just like
existing NFS client operations do.
nfsd4_cb_prepare() determines if the sequence information needs to be setup.
If the slot is in use, it adds itself to the wait queue.
nfsd4_cb_done() wakes anyone sleeping on the callback channel wait queue
after our RPC reply has been received. It also sets the task message
result pointer to NULL to clearly indicate we're done using it.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[define and initialize cl_cb_seq_nr here]
[pulled out unused defintion of nfsd4_cb_done]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Follow the model we use in the client. Make the sequence arguments
part of the regular RPC arguments. None of the callbacks that are
soon to be implemented expect results that need to be passed back
to the caller, so we don't define a separate RPC results structure.
For session validation, the cb_sequence decoding will use a pointer
to the sequence arguments that are part of the RPC argument.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[define struct nfsd4_cb_sequence here]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Keep the xprt used for create_session in cl_cb_xprt.
Mark cl_callback.cb_minorversion = 1 and remember
the client provided cl_callback.cb_prog rpc program number.
Use it to probe the callback path.
Use the client's network address to initialize as the
callback's address as expected by the xprt creation
routines.
Define xdr sizes and code nfs4_cb_compound header to be able
to send a null callback rpc.
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[get callback minorversion from fore channel's]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: change bc_sock to bc_xprt]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[pulled definition for cl_cb_xprt]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: set up backchannel's cb_addr]
[moved rpc_create_args init to "nfsd: modify nfsd4.1 backchannel to use new xprt class"]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Callbacks are always made using the machine's identity, so we can use a
single auth_generic credential shared among callbacks to all clients and
let the rpc code take care of the rest.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
On setting up the callback to the client, we attempt to use the same
authentication flavor the client did. We find an rpc cred to use by
calling rpcauth_lookup_credcache(), which assumes that the given
authentication flavor has a credentials cache. However, this is not
required to be true--in particular, auth_null does not use one.
Instead, we should call the auth's lookup_cred() method.
Without this, a client attempting to mount using nfsv4 and auth_null
triggers a null dereference.
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
...rather than as a separate address and port fields. This will be
necessary for implementing callbacks over IPv6. Also, convert
gen_callback to use the standard rpcuaddr2sockaddr routine rather than
its own private one.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Prepare to share backchannel code with NFSv4.1.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Mimic the client and prepare to share the back channel xdr with NFSv4.1.
Bump the number of operations in each encode routine, then backfill the
number of operations.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Move this out of a local variable into the nfs4_delegation object in
preparation for making this an async rpc call (at which point we'll need
any state like this in a common object that's preserved across function
calls).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There's no point in keeping this field around--it's always zero.
(Background: the protocol allows you to tell the client that the file is
about to be truncated, as an optimization to save the client from
writing back dirty pages that will just be discarded. We don't
implement this hint. If we do some day, adding this field back in will
be the least of the work involved.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The nfs4_cb_recall struct is used only in nfs4_delegation, so its
pointer to the containing delegation is unnecessary--we could just use
container_of().
But there's no real reason to have this a separate struct at all--just
move these fields to nfs4_delegation.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
I want to use the name for a struct that actually does represent a
single callback.
(Actually, I've never been sure it helps to a separate struct for the
callback information. Some day maybe those fields could just be dumped
into struct nfs4_client. I don't know.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We don't really need a synchronous rpc, and moving to an asynchronous
rpc allows us to do without this extra kthread.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
