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>
If we already had a RW open for a file, and get a readonly open, we were
piggybacking on the existing RW open. That's inconsistent with the
downgrade logic which blows away the RW open assuming you'll still have
a readonly open.
Also, make sure there is a readonly or writeonly open available for
locking, again to prevent bad behavior in downgrade cases when any RW
open may be lost.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The vfs doesn't really allow us to "upgrade" a file descriptor from
read-only to read-write, and our attempt to do so in nfs4_upgrade_open
is ugly and incomplete.
Move to a different scheme where we keep multiple opens, shared between
open stateid's, in the nfs4_file struct. Each file will be opened at
most 3 times (for read, write, and read-write), and those opens will be
shared between all clients and openers. On upgrade we will do another
open if necessary instead of attempting to upgrade an existing open.
We keep count of the number of readers and writers so we know when to
close the shared files.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Get a refcount on the client on SEQUENCE,
Release the refcount and renew the client when all respective compounds completed.
Do not expire the client by the laundromat while in use.
If the client was expired via another path, free it when the compounds
complete and the refcount reaches 0.
Note that unhash_client_locked must call list_del_init on cl_lru as
it may be called twice for the same client (once from nfs4_laundromat
and then from expire_client)
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Mark the client as expired under the client_lock so it won't be renewed
when an nfsv4.1 session is done, after it was explicitly expired
during processing of the compound.
Do not renew a client mark as expired (in particular, it is not
on the lru list anymore)
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Currently just initialize the cl_refcount to 1
and decrement in expire_client(), conditionally freeing the
client when the refcount reaches 0.
To be used later by nfsv4.1 compounds to keep the client from
timing out while in use.
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>
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>
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>
